Deutsche EEG-gesellschaft (The German EEG society)

SOCIETY PROCEEDINGS DEUTSCHE EEG-GESELLSCHAFT (The German EEG Society) 19 22nd of S e p t e m b e r , 1956, Berlin, G e r m a n y

Secretary : H. G A E N S H I R T Moorenstr. 5, Diisseldorf, Germany 1.

T h e differential diagnostic delimitation of epilepsy in the electroencephalogram. ~ R. HESS, Zurich. E p i l e p s y is d e f i n e d as a s t a t e c h a r a c t e r i z e d by h y p e r s y n e h r o n o u s p o t e n t i a l v a r i a t i o n s which produce the a t t a c k . T h e s e m a n i f e s t themselves in t h e E E G by h i g h a m p l i t u d e , h i g h f r e q u e n c y s h o r t t r a n s i e n t s , by r h y t h m i c i t y a n d p a r o x y s m a l occurrence. These c l m n g e s can be g e n e r a l i z e d or focal. A m o n g the generalized d i s t u r b a n c e s the m o r p h o l o g y allows to draw c e r t a i n conclusion on a s t a t i s t i c a l b a s i s : the spike a n d wave d i s c h a r g e s express a h i g h p r o b a b i l i t y for the presence of " a b s e n c e s " . F u r t h e r n m r e , the m a j o r i t y of these cases are n o t related to a dem o n s t r a b l e o r g a n i c cause a n d one h a s to reckon with a h e r e d i t a r y f a c t o r . The m o r e the spike a n d wave complexes d i f f e r f r o m t h e ideal f o r m described by .lasper a n d Droogleever-]~ortuyn the less c e r t a i n these correlations become. A p a t t e r n a l n m s t as c h a r a c t e r istic is seen in t h e f o r m of "hypsarrhythmia" described b y Gibbs. T h i s is a d i s t u r b a n c e which is m o s t f r e q u e n t l y seen in convulsive disorders of inf a n c y w i t h a b a d p r o g n o s i s . Otherwise a n y generalized d i s t u r b a n c e s u g g e s t s t h a t t h e origin of the seizures is m o s t likely n o t related to a focal process in one of t h e cerebral h e m i s p h e r e s . Such focal lesions, however, are s u g g e s t e d b y focal E E G c h a n g e s t h o u g h the correlation here is n o t always certain. I n general, an epileptogenie f o c u s r e m a i n i n g c o n s t a n t over a longer period of t i m e r e p r e s e n t s a good i n d i c a t i o n for a c i r c u m s c r i b e d o r g a n i c lesion w i t h d i s t u r b e d f u n c tion at i t s border zone. T h e wave f o r m of the focal d i s t u r b a n c e s allows only to draw u n c e r t a i n conclusions. A n i m p o r t a n t correlation exists b e t w e e n the E E G p a t t e r n a n d the p a t i e n t ' s age. I n i n f a n t s tho h y t ) e r s y n c h r o n o u s p o t e n t i a l s arc u s u a l l y c o n t i n u o u s a n d generalized, in older children i n t e r m i t t e n t a n d f i n a l l y t y p i c a l l y p a r o x y s m a l . I n a d u l t s foe'd lesions are t h e m o s t f r e q u e n t ones. Its children focal lesions a c c o u n t for a b o u t h a l f of the cases b u t seem to have some p r e f e r e n t i a l localizations a c c o r d i n g to the ,~ge of the p a t i e n t . 2.

T h e diagnostic significance of the EEG in cerebral tumours w i t h o u t papilloedema. - - KRENKEL, C o l o g n e . T h e a u t h o r r e p o r t s the E E G f i n d i n g s in 95 cerebral t u m o u r s w i t h o u t papilloedema. I n 80 cases (84 per cent) c i r c u m s c r i b e d d i s t u r b a n c e s u s u a l l y in the f o r m of delta or t h e t a w a v e s were recorded. I n 7 p a t i e n t s only a l a t e r a l i z i n g d i a g n o s i s was possible. Two g l i o n m s only showed generalized c h a n g e s and in 6 c'tses the E E G w a s completely n o r m a l (1 meningioma, 4 elfidermoid cysts, 1 osteo-lipo-fibro-chron-

d r o m a ) . W h e n c o m p a r e d with m e t h o d s u s i n g radioopaque c o n t r a s t s t h e E E G o f t e n shows in early cases a h i g h e r incidence of positive f i n d i n g s . F r o m t h e diff e r e n t i a l d i a g n o s t i c p o i n t of view the d i f f e r e n t i a t i o n t o w a r d s c i r c u l a t o r y d i s t u r b a n c e s is o f t e n n o t possible in a single e x a m i n a t i o n . However, w i t h followu p studies tile d i f f e r e n t i a l d i a g n o s t i c p r o b l e m is alm o s t always possible to solve. Since the b e n i g n cerebral t u m o u r s produce seizures in 80 per cent of t h e cases r e p e a t e d E E G e x a m i n a t i o n s in epileptics a t s h o r t i n t e r v a l s are i n d i c a t e d in order not to overlook t h e o p p o r t u n e m o m e n t for a n operative procedure. 3.

Traumatic epilepsy in children and adolescents and their relation to epilepsy. ~ R. W . M~YERMICKELEIT and E. SCHNEIDER, Freiburg/Br.

Epilepsies a f t e r head i n j u r i e s in childhood ( b i r t h i n j u r i e s excluded) are elinically a n d eleetrographically d i f f e r e n t f r o m the p o s t - t r a u m a t i c epilepsies in adults. A n a t t e m p t to a n s w e r the q u e s t i o n w h e t h e r t h e childhood t r a u m a t i c epilepsies can be l e g i t i m a t e l y incorp o r a t e d w i t h i n t h e g r o u p of residual epilepsies of o t h e r etiology, 65 epilepsies h a v i n g occurred a f t e r c o n f i r m e d t r a u m a t i c cerebral lesions, were c o m p a r e d in m a t c h e d age g r o u p s with 41 residual epilepsies havi n g occurred a f t e r e n c e p h a l i t i d e s a n d m c n i n g i t i d e s . F i f t y - e i g h t closed a n d 7 open h e a d a n d cerebral t r a u m a s occurred at the a g e s of 7 m o u t h s to 14 years. T w e n t y - s i x encephalitides a n d 15 m e n i n g i t i d e s occurred at the ages between 2 m o n t h s a n d 14 years. A t the t i m e of the f i r s t E E G e x a m i n a t i o n , the two g r o u p s of t r a u m a t i c a n d i n f l a m m a t o r y residual epilepsies were at a b o u t the s a m e age level; one q u a r t e r were a d u l t s a n d three q u a r t e r s children a n d adolescents. Clinically, t h e two g r o u p s of epilepsy due to t r a u m a a n d to i n f l a n n n a t o r v cerebral lesions are not characteristically d i f f e r e n t : in each g r o u p in a b o u t 40 per cent of tile cases neurological f i n d i n g s were p r e s e n t a n d in 60 per cent of t h e eases m e n t a l c h a n g e s were f o u n d . A b o u t 50 per cent of the eases showed focal seizures. I n t h e E E G the p o s t - t r a u m a t i c epilepsies of elfildhood showed s o m e w h a t more f r e q u e n t l y g e n e r a l i z e d c h a n g e s and epileptic p o t e n t i a l s t h a n t h e residual epilepsies a f t e r i n f l a m m a t o r y cerebral lesions. Otherwise, t h e f i n d i n g s were very s i m i l a r ; in both g r o u p s a b o u t h a l f of the cases showed focal c h a n g e s a n d one t h i r d spike a n d wave v a r i a n t f o r m s in a focal or bilateral d i s t r i b u t i o n . T h r e e c o n f i r m e d postt r a u m a t i c epilepsies of childhood showed 3 per sec. b i l a t e r a l l y s y m m e t r i c a l spike a n d wave d i s c h a r g e s w i t h clinical "absences". I n tile whole cases m.tterial "absences" ( f o u n d in a b o u t o n e - f i f t h of the cases) were only f o u n d in c o m b i n a t i o n with other t y p e s of a t t a c k s . The y o u n g e r the child was when the cerebral

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lesion occurred the more frequent were focal seizures, focal changes and epileptic potentials in the E E G . F r o m this investigation it can be concluded that the age at which the cerebral lesion occurs is a more important factor than the etiology in deciding which type of childhood epilepsy will occur. I t seems therefore j u s t i f i a b l e to consider childhood p o s t - t r a u n m t i c epilepsies as a sub-group of the residual epilepsies.

4.

Concerning the problem of psychomotor epilepsy in childhood. ~ Niedermeyer, Innsbruck.

Forty-seven children with psychomotor epilepsy were investigated, 22 of whom were hospitalized the others were out patients. I n all cases E E G f i n d i n g s are available. I n 34 children the epilepsy was of a purely psychomotor type, iu 13 there was a combination w i t h g r a n d real. The cause of the seizures was usually u n d e t e r m i n e d and a positive history for heredity was f o u n d in only 5 cases. The neurological f i n d i n g s were most often normal. The pneumoencephalographie f i n d i n g s also were p r e d o m i n a n t l y normal. The intellectual capacities were greatly dist u r b e d in only 5 cases and in 7 cases intelligence was s u r p r i s i n g l y good. Tile electroencephalogram was only n o r m a l in 2 children. I n 7 cases there was an unspecific dysrhythmia and in 38 eases specific epileptogenic changes were recorded. A m o n g those, 14 children showed diffuse, 3 eentreneephalic epileptic changes and in 21 eases the changes were of a focal nature. I n these cases the focus was 18 times f o u n d in the temporal lobe and a m o n g those a g a i n 10 eases showed m a r k e d unilateral E E G changes. This d e m o n s t r a t e s how intimately the patho-physiology of p s y c h o m o t o r epilepsy is related to the t e m p o r a l lobe. The mesial arehicortieal s t r u c t u r e s belonging to the rhineneephalon and which to-day are so much investigated f r o m a neurophysiologieal point of view seem to play the m a j o r role in this seizure form. I t is necessary to distinguish as d e a r l y as possible between psychomotor epilepsy and petit real since this is also i m p o r t a n t f r o m tile therapeutic point of view. Only the true petit real is improved hy Oxazolidindion-therapy. The prognosis of psychomotor epilepsy is not as often assumed, generally had.

5.

Follow-up and EEG studies in pyknoepilepsy. G. PAAI., Freiburg/Br. A m o n g 90 children and juveniles with repeated

frequent small attacks in whom at same time during the period f r o m 1938 until 1950 a petit real p a t t e r n was recorded in the E E G , 43 had a syndrome of pure pyknoepilepsy w i t h o u t g r a n d mal attacks and 47 already s u f f e r e d f r o m generalized seizures. The 43 patients with pyknoepilepsy (24 girls, 19 boys) were followed-up and re-examined 6 years later at the earliest and 17 years later at the ~latcst. Free'teen of these patie*~ts had become seizure free, 12 now had generalized a t t a c k s and 12 still had u n c h a n g e d m i n o r attacks. W i t h five p a t i e n t s contact could not be renewed. The p a t i e n t s in w h o m m a j o r seizures had appeared were p r e d o m i n a n t l y male (8 nmle and 4 fem a l e ) , the g r o u p of the unchanged petit real eases (9 females and 3 males) and those having beeome seizures free (9 females and 5 males) were p r e d o m i n a n t l y female. Generalized attacks a p p e a r e d at the earliest 3 at the latest 10 years a f t e r the b e g i n n i n g of the disease whereas freedom f r o m seizure occurred at the earliest 3 and at the latest 17 years a f t e r the beg i n n i n g of the disease. Changes in the generative sys-

tem (puberty, menarche, p r e g n a n c y ) produced some changes in tile clinical picture in nmst of the eases. I n some this was represented hy arrest of seizures in others by the onset of m a j o r attacks. Still others showed d u r i n g m e n s t r u a t i o n a el(mr increase of seizure incidence. The clinical p a t t e r n gave no clues allowing to make a clear prognosis. It seems, however, t h a t late onset of the disease, a demonstrable organic cerebral damage, a tendency to frequent attacks early in the m o r n i n g or personality changes, indie'~te an u n f a v o r able course of the disease. Tile presence of hereditary factors does not exclude "2 favorable course. The f o r m of the petit nml discharges in the EEG did not allow any prognostic conclusions, since tim same patterns were f o u n d when later freedom of seizures occurred as well as in tile catses which showed transition to g r a n d real. However, it seems t h a t a great frequency o f occurrence / l n d s p o n t / / l l e o u s o c c u r r e n c e o f petit real attacks is rather a prognostic'flly favorable sign. I l l eases where later m a j o r attacks occurred a minor a t t a c k couhl often only be ohtaincd with hyperventilation and in almost "ill eases which meanwhile became free from attacks, such minor discharges were already seen spontaneously at rest. Signs pointing to a r a t h e r unfavorat)le course are isolated spikes, const-tnt focal changes and severe generalized E E G disturlmnees. In 5 l)'ltients free of seizures clinically and in which an E E G follow-up study could be obtained, 2 had a normal EEG, 3 showed some isolated waves with a steep wave front among which was a p a t i e n t who had 1)een seizure free for 17 years, whereas another p a t i e n t who had been seizure free for 5 years showed g r o u p s of atypical epilei)togenie l,Otin'rials.

6.

Focal changes and EEG in petit real epilepsy. A. CALD~RON and G. PAAI., Freiburg/Br.

I n 144 p a t i e n t s with typical petit real and 3 per see. spike and wave discharges in the EEG, 65 per cent showed no focal changes, 21 per cent showed changes suggestive of a focal almormality of s h i f t i n g feel and 14 per cent showed c o n s t a n t circumscribed E E G feel. E i g h t y - t w o l)atients had m a j o r and m i n o r qttacks and 62 only minor attacks. Temporql lobe ;tnd aacksonian epilepsies were excluded in this study. A m o n g 50 tmtients with focal changes in the E E G 30 had n d n o r and m a j o r attaeks ~lnd 20 onl,v nlin0r attacks. The age of onset of the disease in the patients with m a j o r and minor attacks wits definitely higher t h a n in those with only nfinor seizures. In 26 patients an exogenous cause w'ls detectable but in 24 there was no such indication. When c o m p a r i n g the E E G with the clinical and X-ray f i n d i n g s there was a good correlation. The minor attacks were ahvays corrchtted in tlle E E G with typic:fi 3 per sec. tlarox ysm-tl discharges which only in l(! cases showed an inconstant

f o c a l OllSet 02' ill l ~ (qlses "1 l n o r e e(~llStHllt

asymmetry. Besides the 3 per sec. discharges there were also 2 per see. variants, seen 14 times during the n|inor attacks in younger p a t i e n t s below 1[) years, and 7 times in an isolated focal distribution in diff e r e n t age groups. Focal changes were only found in between the attacks mostly ill the form of steep waves, isolated spikes or typical o," m|ilateral p a r o x y s m a l waves and their variants. Only 16 had delta feel and focal dysrhythmias. Ten feel were found occipital and 10 in oecipito-t)arietal regions, 2 in parietal a.reus, 2 in t e m p o r a l regions, 5 in temlloral /)asal regions, 4 in precm|tral areas and 2 in f r o n t a l regions. F i f t e e n l)atients showed ,lysrhythn|ias over m|e heat-

SOCIETY PROCEEDINGS isphere w i t h o u t c i r c u m s c r i b e d focus. T h e relatively f r e q u e n t occurrence of focal changes in the E E G (35 per cent of all cases of p e t i t real) a n d of e x o g e n o u s cerebral d a m a g e in those focal eases (52 per cent) is in c o n t r a d i c t i o n to the view t h a t bilateral 3 per sec. spike a n d wave d i s c h a r g e s are s i g n s of i d i o p a t h i c epilepsy. I t is m o r e likely t h a t t h e E E G f o r m of p e t i t real is a reaction of the i n f a n t i l e c e r e b r u m to a n y epileptogenie i r r i t a t i o n s which c a n act on v a r i o u s places within tile brain.

7.

The significance of electroencephalography for the treatment of epilepsy. - - Landolt, Zurich. S t a r t i n g f r o m the "~ssumi)tion t h a t in princilde in t r e a t i n g epileptic p a t i e n t s the n o r m a l i z a t i o n of the E E G is a desirable goal, the npi>lieation of this m e t h o d a n d its u s e f u l n e s s in relation to t h i s goal are reviewed, always q s s u m i n g t h a t a pathological E E G is the s t a r t i n g p o i n t of such a n i n v e s t i g a t i o n . One of the premises under which such a s t u d y h a s to be carried out is a p r o f o m t d knowledge of the E E G in h e a l t h y persons, in which n o r m a l l y some a s y m m e t r i e s a n d focal c h a n g e s m a y be found. E q u a l l y i m p o r t a n t is a d e q u a t e knowledge of those E E G c h a n g e s which are not necessa.rily in relation with the disease, such as for i n s t a n c e , m a t u r a t i o n a l d i s t u r b a n c e s a n d ret a r d a t i o n s . There are t y p e s of waves which are not a p t to be i n f l u e n c e d I)y anti-convulsive medic:~tions a n d an a t t e m p t to do so could lead to a d n f i n i s t r a t i o n of anti-convulsive m e d i c a t i o n in too h i g h a n d w r o n g (losages. The correlation betwe-,n the imi)rovemcnt of the convulsive disorder and of t h e E E G c h a n g e s is in general s a t i s f a c t o r y . T h e r e f o r e especiqlly in p a t i e n t s with a rare incidence of a t t a c k s a n d f r e q u e n t occurrence of a b n o r m a l waves, this m e t h o d r e p r e s e n t s a useful indication for the p h y s i c i q n a n d for the p a t i e n t to e v a l u a t e the e f f e c t of t r e a t m e n t . l~ess c o n s i s t e n t is the correlation between the E E G a n d the episodic p h e n o m e n a of epilepsy such as twilight s t a t e s psychotic episodes a n d c h a n g e s in mood in which the e l e c t r o g r a p h i e p a t t e r n can beeeme nearly n o r m a l in certain cases even d u r i n g exacerbation of t h e clinical syml)tOlnS. Only rarely is the correlation simple ",ml direct for the chronic m e n t a l qn(l neurological c h a n g e s in epilepsy. A n o r m a l E E G with a c o n t i n u e d s t a t e of defect ( d e f i c a t o r y s y n d r o m e ) can l>e the expression of a 1)rimary or secondary loss of s u b s t a n c e a n d thus, cxcei)t for m a t u r a t i o n a l 1)recesses in ehihlren, no f u r t h e r inli)rovement can be expected. On the other h a n d a pathological E E G :allows to expect t h e presence of an, at least p a r t i a l l y reversible, d y s f u n c t i o n p r o d u c i n g the eleetrographic d i s t u r b a n c e . The more detailed knowledge of epileptogenie patt e r n s and the increase of the n u m b e r of anti-~.onvulsive d r u g s give rise to the hope t h a t these d r u g s could be especially suited for special f o r m s of t h e disease. T h u s , generM rules for the a d m i n i s t r a t i o n of these d r u g s were estat)lished t h o u g h in m a n y cases one is still forced to rely on empirical m e t h o d s neeess i t a t i ~ g e x p e r i m e n t a l trials in order to f i n d ()lit which are the optimal conll)inations qnd dosages of the d r u g s to be used. T h e recognition, m a i n t e n a n c e a n d restoration of the i n d i v i d u a l psycho-physiological b a l ' m c e ( f o r i n s t a n c e E E G and p s y c h e ) is o f t e n very i m p e l taut. In no ease is one entitled to ex('lude a b r a i n runlet or a d e s t r u c t i v e lesion w h e n the E E G p a t t e r n becomes nornml.

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8.

The importance of the EEG for the operative indication in symptomatic epilepsies, m YON W . G6TZr, Berlin. On tile b a s i s of a statistical analysis c o m p u t e d f r o m f i n d i n g s p u b l i s h e d in t h e l i t e r a t u r e a n d on the basis of own o b s e r v a t i o n s it was d e m o n s t r a t e d t h a t a f t e r excision of m e n i n g o - c e r e b r a l scars in focal epilepsies a considerable p a r a l l e l i s m exists 1)etween the p e r s i s t a n c e of e p i l e p t i f o r m d i s t u r b a n c e s a n d t h e rea p p e a r a n c e of seizures. Cases which r e m a i n e d seizure free over ye'~rs u s u a l l y were also free of epileptogenie c h a n g e s in the post-operative records. A n a l m o s t 100 per cent correlation between post-operative f r e e d o m f r o m seizures a n d i m p r o v e m e n t in t h e E E G wits f o u n d in cases with h e m i s p h c r e c t o m i e s . I n focal epilepsies cases w i t h loeallzed spikes showed :t more f a v o r a l d e p r o g n o s i s t h a n those with localized slow waves. Generalized occurrence of slow disturl)ances i m p a i r e d the post-operative prognosis. I n t e m p o r a l lobe epilepsies the operative success is imp a i r e d as soon as there arc b i l a t e r a l epileptogenie feel in the E E G . I t h a s been p o i n t e d out t h a t eorticog r a p h y , which showed in 80 per cent of the eases localized epileptogenic c h a n g e s , is of g r e a t i m p o r t a n c e in s y m p t o m a t i c elfilepsies in order to delineate the localization of the focus. Especially in the residual epilepsies, in which clinical s i g n s for foc'd loe:flization were al)sent, a c o n s t a n t E E G a n d eortieographic localization c a n give tile only indictttion for a n operqtive procedure. E v e n a f t e r a n open cerebral t r a u m a which lies back m a n y y e a r s the e l e c t r o e n e e p h a l o g r a p h i e inv e s t i g a t i o n is t h e only m e t h o d which gives qn indication for c h a n g e s in t h e f u n c t i o n a l s t a t e in t h e vicinity of the scar, as t h e y s o m e t i m e s occur in the course of encephalitic processes. O f t e n in these cqses with large s c a r r i n g p a r t i ' d removals can be carried out successfully. The E E G criteria considered n e c e s s a r y to j u s t i f y o p e r a t i o n qre as follows: (1) the clinical localization a n d the localization of the E E G focus m u s t coincide; (2) when the clinical f i n d i n g s arc n e g a t i v e the E E G localization h a s to be controlled by repeate
Excitation and excitability. - - E. SCHi)TZ and H. CASPERS, Miinster. The f u n c t i o n a l organizatioi1 of t h e c e n t r a l n e r v o u s s y s t e m disposes of w/rious physiological m e c h a n i s m s of r e g u l a t i o n which p r e v e n t s y n c h r o n i z e d m a s s disc h a r g e s even when there is a n m s s i v e synchronized e x c i t a t o r y i n p u t as for i n s t a n c e d u r i n g arousal. One of these m e c h a n i s m s is r e p r e s e n t e d by the c o n t i n u o u s oscillqtions of t h e c e n t r a l e x c i t a t o r y s t a t e which follow the rhythn~ of the s p o n t a n e o u s p o t e n t i a l oscillations. Besides this, the n m n n e r in which tile c e n t r a l uervous

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system deals with incoming stimuli plays an import a n t role in the prevention of development of seizure discharges. Each stimulus produces activating effects, but besides this, also inhibitory phenomena. These are partially structurally determined (e.g., on- and offelements) and partially are dependent upon dynamic factors such as the activity of the stimulated subs t r a t m n before the stimulation took place "tnd the parameters of stimulation used. Owing to a tenq)oral and spatial dispersal of the facilitatory and inhibitory processes, considerable shifts in the balance of excitation are prevented ( J u n g and coll.). In the cortex the tendency to synchronization of excitation is not only i n f h e n c e d within a large degree by loe,ll regulatory mechanisms but also by the state of activity of the unspecific projection mechanisms of the br.fin stem reticular formation. According to results obtained by direct threshold measurement (Caspers) the convulsive excitability of the cortex diminishes by about 20-30 per cent below the average level during wakefulness when the reticular excitatory state is enhanced by direct, peripheral or cortical stimul'ttion. Conversely this cortical convulsive excitability increases by about the same amount above the initial value, when the activity of the unspecific I)rojection system is inhibited by spontaneous or electrically induced sleep, light anaesthesia or after often repeated central or peripheral stimulations. These results suggest t h a t the development of convulsive activity can only in rare cases, if in any, be related to the disturbance of a single inhibitory factor at the site where the convulsive activity develops. 10. C o n d i t i o n s for the d e v e l o p m e n t of seizure activity in e x p e r i m e n t a l e p i l e p s y . ~ R. JUNO, Freiburg/Br. The author discusses the development of local seizure activity in the iso-cortex in response to electrical stimulation and strychnization. The experiments were based upon recordings from single, neuroues and of the surface activity recorded with conventional electrodes. Development of epileptic convulsive activity presupposes disturbances of the normal regulation of cerebral activation and ef b r a k i n g mechanisms. On tlle basis of microeleetrode records taken in regions of the cortex with a f f e r e n t input, three physiological anti-convulsive b r a k i n g mechanisms of neurones can be differentiated, which in the nornml brain, prevent the development of the convulsive activity: (1) stabilizing activity of the A-neurones which are not influenced by a f f e r e n t stimuli; (2) the balance of excitation and inhibition in the activity of the neurones influenced by a f f e r e n t stimuli - (a) simultaneous and reciprocal excitation and inhibition of several antagonistic neurones, (b) consecutive pre- or post-excitatory inhibition of the same neurone - - (3) inhibition of over-excitation characterized by diminution of the living freqnency of the neurones in response to high frequency a f f e r e n t stinmlation. A f t e r electrical stimulation f u n d a m e n t a l l y different reactions to low and high frequency excitation are noticed: single stimuli or low frequency stimuli below a repetition rate of 8 c/see, produce constant inhibitory pauses with secondary activation but no epileptiform discharges. W i t h higher frequency stimulations f r o m 10-100 c/see, the neurones become able to discharge also during the inhibitory pause and are apt to precipitate in every normal brain an epileptiform discharge, provided t h a t the duration and i n t e n s i t y of the stimulation is of sufficient magnitude. Before the convulsive stage the microrhythms show a

prolongation of tile primary wave and tile single neurones show repetitive discharges without prolonged inhibitory pauses. A f t e r strychnine administration there is a similar prolongation of the primary wave with enhancement of the secondary waves and the single cells show the transition from a single or twin discharge to repetitive discharges. It is postulated t h a t the single electrieal stimuhls produces a short-lived sumnmtive faeilitatiol~ and a more prolonged inhibition. It is also assumed t h a t the inhibitory mechanism f a t i g u e s with rapidly repetitive stimuli and is paralyzed by strychnine. 1 1. T h e spread of epileptic e x c i t a t i o n . ~ E. MOLLea, Dortmund. The spread of the after discharges outlasting the application of chemical or electrical stimuli, which are considere
SOCIETY

PROCEEDINGS

P e n n e s ) . Tile cause for the increase of circulation is increase in CO._, tension, f o r m a t i o n of lactic acid a n d p e r h a p s liberation of aeetyleholine. The diminution of glucose and the h i g h e n e r g y p h o s p h a t e s as well as t h e a c c u m u l a t i o n of a n o r g a n i e p h o s p h a t e and of lactic acid d u r i n g the a t t a c k i n d i c a t e a n increase of liberation of e n e r g y a n d of a n a e r o b i c glyeolosis. Tile cerebral circulation i n c r e a s e s d u r i n g thc epileptic a t t a c k b y a b o u t 60 per cent .lad the o x y g e n u p t a k e of the b r a i n i n c r e a s e s by a b o u t 100 p e r cent ( K e t y a n d co-workers). T h e o u t p u t of electrical p o t e n t i a l s as m e a s u r e d f r o m scalp records i n c r e a s e s by a b o u t 12 t i m e s d u r i n g the electro-convulsive seizures (MeyerMickeleit) a n d w h e n recorded directly f r o m tile surface of the b r a i n the increase is a b o u t 50 t i m e s the r e s t i n g value ( J u n g ) . The o u t p u t of electrical potentials is n o t p r o p o r t i o n a l to the aerobic e n e r g y production because it is d e p e n d e n t also u p o n the degree of s y n c h r o n i z a t i o n a n d because the a n a e r o b i c e n e r g y p r o d u c t i o n c a n n o t be calculated f r o m the o x y g e n u p t a k e . I f t h e doubled o x y g e n u p t a k e of t h e b r a i n d u r i n g t h e seizure is used in K r o g ' s f o r m u l a a n d apl)lied to a s t a n d n l ' d tissue cylinder of cerebral cortex a n d if f m ' t h e r m o r e one considers, w h e n doing so, t h a t t h e o x y g e n reserve (Opitz a n d Schneider) of the brain is e x h a u s t e d due to tile almoen a n d tile i n c r e a s e d o x y g e n c o n s u m p t i o n by the c o n v u l s i n g m u s c u l a t u r e d u r i n g the g e n e r a l i z e d epileptic a t t a c k , one can comp u t e t h a t t h e o x y g e n t e n s i o n in the cerebral tissue d u r i n g a g e n e r a l i z e d seizure is locally d i m i n i s h e d belmv 19 m m IIg. Despite tile increase of circulation the e e r e b r u m d u r i n g a n a t t a c k becomes deficient in oxygen. T h u s t h e conditions are f u l f i l l e d for t h e d e v e h l p m e u t of a n a t o m i c a l l y detectable lesious of t h e tissue. E x p e r i m e n t a l i n v e s t i g a t i o n s proved t h a t strychnine d i s c h a r g e s a n d electro-convulsive seizures can 1)e s h o r t e n e d by lack of o x y g e n a n d cait be p r o l o n g e d considerably b y s u p l d y i n g o x y g e n ( K o r n m i i l l e r a n d Noell; Gellhorn a n d I I y n m u s ; R u f ) . W i t h complete a r r e s t of circulation (occlusion of t h e a o r t a or pulm o n g r y a r t e r y ) a n d a f t e r d i s a p p e a r a n c e of tile cluetrical s p o n t a n e o u s a c t i v i t y the b r a i n can still be illdueed to produce convulsive a c t i v i t y b y apt)lying "t d i f f u s e electricgl s t i m u l u s ( G i i n s h i r t ) . T h e b r a i n is still t h e r e f o r e lille t'* convulse even w i t h o u t oxygen. L a c k of o x y g e n in the b r a i n can p r e c i p i t a t e seizures bec:mse the n e r v o u s tissue becomes h y p e r e x c i t a b l e by the deI)olarization i n d u c e d by the h y p o x b t ( L o r e u t e de N 5 ) . A n o x i a produces inhibition of convulsive a c t i v i t y boo'rose of lack of e n e r g y and because the tissue becomes unexeitallle. T h e degree of the hyl,oxia ,nml the i n t e n s i t y of the p a t h o l o g i c a l s t i m u l u s t o g e t h e r with regional d i f f e r e n c e s in t h e s u s c e p t i b i l i t y to l:,ck of o x y g e n ( h i g h a l t i t u d e convulsions) d e t e r m i n e w h e t h e r a n d w h e n h,cl~ of o x y g e n will produce convulsions. 13. C h r o n i c

focal e p i l e p s y in a n i m a l

experiments.

STEINMANN, C o l o g n e . I n e x p e r i m e n t a l rese:,reh of epilepsy the s t a n d a r d procedure to p r o d u c e chronic cpilcptogenic p h e n o m e n a is the K o p e l o f f m e t h o d . D e p e n d i n g upon tile species of :,uimnls used, 0.0547.1 co. of alulnin't c r e a m applied to the e(>rtex or to subcortical uuclei are n e c e s s a r y to produce m a n i f e s t seizure p h e n o m e n a which occur fl)r tile f i r s t t i m e a f t e r a l a t e n t period of several weeks to several m o n t h s . M o s t studied, so f a r , were the convulsive m a n i f e s t a t i o n s p r o d u c e d b y such lesions in t h e sensory m o t o r region of tile cortex, as well as in the t e m p o r a l cortex a n d in c e r t a i n sub-cortical :~,'e'~s. The i)(?lutviour d i s t u r b a n c e s in t e m p o r a l a n d occipital

353

epileptogenie lesions described in the literature were b r i e f l y s u m m a r i z e d t)y t h e author. More closely described was the course of the tdllelectrical c h a n g e s in the region of the lesion, in the r e m a i n d e r of the cortex a n d in certain sub-cortical are:is. Especially the v a r i a b i l i t y of the t e m p o r a l loci wns a n a l y z e d closely because of their g r e a t i m p o r t a n c e f o r clinical problems. W i t h tile :lid of several exl)eriments with removals which were checked on model e x p e r i m e n t s thc possibilities a n d l i m i t a t i o n s of a successful surgical t h e r a p y we,'e finally discussed. 14. S y n c h r o n i z a t i o n p h e n o m e n a of n e i g h b o u r i n g intracerebral n e r v e ceils. - - R. YON BAUMGARTEN a n d K. P. SCltAEFER, G 6 t t i n g e n . The action p o t e n t i a l s of n e i g h b o u r i n g nerve cells in file cortex a n d in a n o t h e r series of e x p e r i m e n t s in the r e t i c u l a r f o r m a t i o n of the lower b r a i n s t e m in t h e cat were s t u d i e d with extracellu/.~r micro-electrodes. T h e electrical p h e n o m e u a were displayed on the cathode r a y oscilloscope a n d photogr:lphed at a h i g h f i l m speed. W i t h this m e t h o d the following t e m p o r ' d relat i o n s h i p s between single d i s c h a r g e s of n e i g h b o u r i n g g a n g l i o n i c cells were f ( m n d : (1) Loose coupling, i.e. not always c o n s t a n t I)ut s t a t i s t i c a l l y v a l i d a t e d relationship of f i r i n g of two or several units. (2) R i g i d coupling, i.e. c o n s t a n t s y n c h r o n i z a t i o n of two or severM units. (3) W h e n t h e f i r i n g f r e q u e n c y is forced to increase due to electrical or p h a r m a c o h l g i c a l influences, there are c o n t i n u o u s t r a n s i t i o n s f r o m loose to rigid coupling. (4) A c c o r d i n g to the rules of relative coordination developed b y von Holst, it is tile u n i t w i t h h i g h e r d i s c h a r g e f r e q u e n c y which exists a " m : ~ g a e t i z i n g e f f e c t " Ul)On the less f r e q u e n t l y d i s c h a r g i n g ullit a n d t h e r e f o r e d e t e r m i n e s its t i m i n g of discharge. (5) The t h u s s y n c h r o n i z e d u u i t can, a c c o r d i n g to its own p r o p e n s i t y to d i s c h a r g e fire within its a s s i g n e d d i s c h a r g i n g period either i m m e d i ' l t e l y before or i m m e d i a t e l y a f t c r t h e s y n c h r o n i z i n g unit. Tile lust f i n d i n g t o g e t h e r with other observ'/tions d e m o n s t r a t e clearly t h a t w i t h i n a period of at least 30 msec. before and a f t e r tile d i s c h a r g e of a r.~ t h m i e a l unit, the p r o p e n s i t y to d i s c h a r g e i n c r e a s e s ill ils extracellular e n v i r o m n e n t in all a r e a which includes tlmt occupied b y neighl)onring ceils. These rll?'thmical v a r i a t i o n s of the loe:~l conditions f u v o a r i u g (liscllarKe of nerve cells "let i n d e p e n d e n t l y f r o m the nun-syn:,i)tic time relations and c ' m be consi(lered as l:~te et'f~,cts of a p r e c e d i n g d i s c h a r g e or as e f f e c t s excrt,,d 1,v :l t h i r d element a c t i u g as "~ p a c e m m k e r . E x t r a c e l h d a r s y n c h r o n i z i n g I)hc,nome,m f a v o u r tile h y p o t h e s i s of von Ger'urd a n d lAbet gml P, remer and other a u t h o r s a c c o r d i n g to which in epileptic convulsive a c t i v i t y o n e Ires to reckon with nl)w~y,u,l)tic ~ e p h g p t i e ~' sllread of convulsive activity besides the proprog:,tion m e d i n t e d t)y n e r v o u s p~,thw:~ys. 15. C o n v u l s i v e discharges of single cortical neurones. ~ O. CREUTZFELDT, F r e i b u r g / B r . M i e r o e l e c t r o d e records of couvulsive ,lisulmrges of sil~gle cortical lleurones were demoustr:~ted t o g e t h e r with " n m e r o - r e e o r d s " of tile EE(I. The (.onvulsive disch'~rges were p r e c i p i t a t e d by electric;ll s t i m u l a t i o u s at 10-50 c/see, al)plied to the cortical surf;we close to tile lnicro electrode. O f t e n the convulsive ,lisclmrge of single n e u r o n e s s t a r t only 10()-500 nts,.c. :tt'ter th(, end of s t i m u l a t i o n a n d only with long dur:,tions of these s t i m u l a t i o n s were seen to s t a r t :dre;tdy d u r i n g

354

DEUTSCHE

EEG-GESELLSCHAFT

s t i n m l a t i o n . I n convulsive d i s c h a r g e s of a tonie-clonie one observes f i r s t t h a t all n e u r o n e s s h o w s i m u l t a n e o u s c o n t i n u o u s a c t i v i t y with d i s c h a r g e s between 10-50 e/see, rarely with h i g h e r f r e q u e n c y dise h a r g e s u p to 300 e/see, which are n o t co-ordinated with each other. I n t h e E E G one observes f i r s t only s m ' d l waves w i t h a f r e q u e n c y of 10-50 e/see, a n d later l a r g e r convulsive potentials. A f t e r the tonic s t a g e t h e r e is in c e r t a i n eases a s t a g e of " c l o c k w o r k " activity, c h a r a c t e r i z e d in the E E G by very r e g u l a r epileptogenie p o t e n t i a l s a t 10 e/see. The single n e u r o n e s show u n i t a r y d i s c h a r g e s synchronized with tile E E G which occur singly or in short b u r s t s of 2-5 d i s c h a r g e s . I n t h e following clonie s t a g e the E E G shows either single l a r g e epileptogenie p o t e n t i a l s or short b u r s t s of p o t e n t i a l s with i n c r e a s i n g intervals. T h e single cell d i s c h a r g e s a p p e a r s y n c h r o n o u s l y with these E E G p o t e n t i a l s in h i g h f r e q u e n c y b u r s t s with (lischarge f r e q u e n c i e s r a n g i n g f r o m 50-300 e/see, a n d even r e a c h i n g s o m e t i m e s 700 c/see. The d u r a t i o n of these b u r s t s is d i f f e r e n t w i t h d i f f e r e n t n e u r o n e s a n d t h e y m a y consist of 2-20 discharges. T o w a r d s the end of the convulsive period tile f r e q u e n c y of the b u r s t s am of their single d i s c h a r g e s diminishes. A f t e r the p : m l x y s m there is quiescence for at least 10-20 see. V n t i l t/ n o r m a l d i s c h a r g i n g rhythn~ of the single neur(mes is r e s u m e d at least 1 rain. elapses. T h e r e are numerous deviations from this "typical" course of convulsive events as i l l u s t r a t e d by the a u t h o r with several examl)les. Two m e c h a n i s m s of altered n e u r o n a l :~ctivity d u r i n g the cortical convulsive a t t a c k have to he considered: (1) "t p a t h o l o g i c a l increase of activity of the single neurone, a n d (2) a t e n d e n c y to :lbnormal s y n c h r o n i z a t i o n . The e n h a n c e m e n t of activity of the single elements is p r e p o n d e r : / n t d u r i n g the tonic st:lee :rod t h e r e f o r e the single n e u r o n e s d i s c h a r g e in an u n c o o r d i n a t e d way d u r i n g t h i s phase. On the other hand in the clonie s t a g e s y n c h r o n i z a t i o n with grouping of d i s c h a r g e s p r e d o m i n a t e s .

se(tuellee

16. Investigations concerning cerebral metabolism during electroencephalographic convulsive activity and in petit real attacks. ~ HEYCK, Zurich. In 2 fenmle p a t i e n t s with epilepsy a n d easily induced g e n e r a l i z e d convulsive a c t i v i t y in the E E G it was possible to d e t e r m i n e the cerebral a f t e r | o - v e n o u s o x y g e n d i f f e r e n c e w i t h t h e m e t h o d of t I a l d a n e cont i n u o u s l y before a n d a f t e r the a t t a c k s . Tile f i r s t p a t i e n t showed, with little Cardiazol, multiple spike a n d wave p a t t e r n s w i t h o u t clinical m a n i f e s t a t i o n s of :l d u r a t i o n of more t h a n 10 rain. Tile second p a t i e n t a f t e r stroboscopic s t i m u l ' l t i o n w i t h o u t a n y use of d r u g s or hyt)erventilation showed d u r i n g 5 nfin. alm o s t u n i n t e r r u p t e d b y clinical " a b s e n c e s " with associated typical 31~ e/see, spike a n d wave discharges. In both l i n t | e a t s t h e r e s t i n g electroeneel)halogram u n t i l the b e g i n n i n g of the t/rovoeation of these p h e n o m e n a was entirely normal. T h e f i r s t case showed a small inereqse of a f t e r | o - v e n o u s o x y g e n d i f f e r e n c e which w a s within n o r m a l limits a n d in t e m p o r a l relationship with the a p p l i c a t i o n of t h e Cardiazol. I n t h e second c:lse, a very m i n u t e increase of the arteriovenous d i f f e r e n c e receded, a l r e a d y d u r i n g t h e a t t a c k , to the pre-seizure level. T h i s i n d i c a t e s t h a t t h e r e was only a snmÂl increase of cerebral m e t a b o l i s m which was in no q u a n t i t a t i v e r e l a t i o n s h i p w i t h t h e increase of electrical a c t i v i t y as me,lsured in t h e E E G . Cerebral a n o x e m i a s a n d t h e i r sequelae in epilepsy are t h e r e f o r e unlikely to be related to an increase in a c t i v i t y of cerel)ral n e u r o n e s as s u g g e s t e d by the

E E G a n d as a s s u m e d by J u n g a n d others, b u t t h e y are a p p a r e n t l y related to those circulatory disturbanees whieh only occur with tonic-clonie seizuros (Seholz). T h e h y p e r s y n c h r o n y is no m e a s u r e for the increase in cerebral m e t a b o l i s m . The a u t h o r demons t r a t e s tile E E G reeords, the data of the measurem e n t s of tile arterio-venous d i f f e r e n c e s aml their t e m p o r a l relationships. 17. "Expansive"

psychoses in epilepsy changes. - - FAUST, Fro|burg.

with E E G

( A b s t r a c t not s u b m i t t e d . )

18. Investigations of free amino acids and peptides with high voltage electrophoreses with special consideration of epilepsy. ~ HEMMER, Freiburg. W i t h the aid of high voltage eleetrophoresis m o d i f i e d f o r t h e clinical use by t t e i h n e y e r and Clottell it is possible to investig'/te the s u b s t a n e e s responsible for the n o n - p r o t e i n n i t r o g e n ill the blood, especially the free anfino acids a n d the pepti
19. T h e importance of the value of background cerebral activity related to vegetative tonus for the cortical EEG. ~ H. HIemus, Berlin. Ill s t i m u l a t i o n e x p e r i m e n t s with s t r y c h n i n e perf o r m e d on the cerebral cortex of t h e rabbit, ,lanzen ~md co-workers showed a topical (lifferent:ltion of eortieal epileptogenie p o t e n t i a l s in the eleetrocorticogr:ml. W i t h this e x p e r i m e n t a l technique it is i)ossible to d e m o n s t r , te n o t only a r e l a t i o n s h i p of the eharacter|sties of the convulsive activity d e p e n d e n t upon the locus of s t i m u l a t i o n , b u t "dso (lependeut upon the f r e q u e n c y of the b a c k g r o u n d r h y t h m s . \Vith interm e d i a t e f r e q u e n c i e s g r o u p s (if convulsive singh~ diselmrges at the locus of s t i m u l a t i o n occur for i n s t a n c e in a p r e e e n t r a l s t r y c h n i n e focus. With increase of tla, frequency, the mmfller of single convulsive d i s e h a r g e s belonging to "l p a r t i c u l a r groull increases anti tln, n u m b e r of these convulsive single d i s c h a r g e s per unit of time r a t h e r decreases because th(. i n t e r w d s lie tween the g r o u p s of single eonvulsive d i s c h a r g e s be eonm more prolonged. W i t h p r o n o u n c e d iucre:~se of b a c k g r o m l d f r e q u e n c y isolate(l eleetro-eouvulsive, dis c h a r g e s m a y occur. I f b a c k g r o u n d frequency goes below n o r m a l r a n g e , the gr/laps m a d e Ull ef single convulsive (liseharges d i s i n t e g r a t e t o g e t h e r with a eonconlit;lllt illcI'efise o f t h e llUIll~)or Of" s i n g l e c ( m v u I s i \ ' ~

diseh'lrges per u n i t of time. W i t h I'Vell more pronounced decrease of b a e k g r o t m d frellUeney tile single c o n v u l s i v e d i s c h a r g e s b e e o l n e lllore alld nl(lro r a r e m,til they f i n a l l y d i s a p p e a r ('omi/letely. In these e x p e r i m e n t s it was seen t h a t it is irrelevant w h e t h e r the c h a n g e s in l/aekground f r e q u e n c y :ire of Slmlltaneons origin or artifiei:llly produced, e.g. I)y drugs. Since the c h a n g e s ill t)ackgr
SOCIETY PROCEEDINGS 20. E n d o g e n o u s epilepsy of the rat and its response to anticonvulsive medication. ~ QUADBECK, Heidelberg. In n u m e r o u s r a t s t r a i n s one can ol)serve a high incidence of epileptic seizures. T h e s e occur spontaneously a n d are especially easily p r e c i p i t a t e d by a u d i t o r y stinmli. T h e r e is a h e r e d i t a r y disposition for these convulsions a n d it is t h e r e f o r e possible to breed rats with a h i g h incidence of seizures. I n the course of two years, the ineidenee of seizures in a s t r a i n couhl 1,e i n c r e a s e d by i n b r e e d i n g f r o m 52 per cent to 5(; per cent. Besides t h e h e r e d i t a r y f a c t o r t h e propensity to convulsions of t h e single a n i m a l is influenced by several e x t e r n a l f a c t o r s such as n u t r i t i o n , the w e a t h e r a n d there is also a cycle of v a r i a t i o n d u r i n g a 24 hour period. The convulsions can be sui)pressed for prolm~ged periods of time b y the use of anti-convulsiw~ d r u g s . A single a d m i n i s t r a t i o n of 200 rag. s u b s t a n c e / k g , body w e i g h t g i v e n by m o u t h proteets 50 per cent of the e x p e r i m e n t a l a l d m a l s even with i n t e n s e a u d i t o r y provocation. W i t h Zentropil protection l a s t s for 24 hours, w i t h M e s a n t o i n f o r 27 hours, with Mylei)sin for 44 hours, w i t h p-BromNirvanol ( H e y d e n S127) f o r 94 h o u r s with P h e n u r o n e 9 h o u r s a n d with Tridionc one hour. T h e r e is therefore a consideralde correlation between t h e anticonvulsive a c t i v i t y in the r a t a n d the e f f i c i e n c y to (.ontrol g r a n d real seizures ll) re'in. Since t h e r e is no such p a r a l l e l i s m for electroeonwflsive seizures as well as for the chemically i n d u c e d a t t a c k s , it is probable t h a t the s p o n t a n e o u s el)ilepsy of the r a t p e r h a p s is more (.h)sely related to g r a n d nml epilet)sy in n m n t h a n those f o r m s . I t is t h e r e f o r e considered t h a t such rats are good s u b j e c t s for model studies on epilepsy. ( Film ) 21. Excitatory pattern in pre-central loci. - - K. SCHMALBACFI, C o l o g n e . The a u t h o r r e p o r t s on e x p e r i m e n t s carried out on 23 cats with chronic ei)ileptogenic loci a c c o r d i n g to the m e t h o d of K o p e l o f f a n d on 10 eats with focal d i s c h a r g e s p r o d u c e d by electrical s t i m u l a t i o n or s t r y c h n i n e :q)plieation. All these loci ~ e r e locqted in the m o t o r cortex. The r e c o r d i n g s f r o m the cortex and d e p t h r e c o r d i n g s o b t a i n e d with needles i m p l a n t e d in sub-cortical s t r u c t u r e s showed typical e x c i t a t o r y patt(,rns in d i f f e r e n t s t a g e s of d e v e l o p m e n t of t h e epilepsy, the m o t o r m a n i f e s t a t i o n s of w h i c h o f t e n showed the p i c t u r e of epilepsia p a r t i a l i s c o n t i n u a . T h e acute e x p e r i m e n t s which were p e r f o r m e d with the same r e c o r d i n g t e c h n i q u e shed l i g h t u p o n ,'t comi)letely d i f f e r e n t asI)ect of epilepsy since iu this f o r m the c o u n t e r - r e g u l a t i o n s typical for chronic processes are :d)sent. P a t t e r n s with t y p i c a l f o r m a t i o n s of s h a r p waves in the region of the f o c u s were seen in reeords t'tken f r m n the bone a n d the lability of the s i t u a t i o n in the 1)rain b e f o r e the o u t b r e a k of a n a t t a c k w a s d e m o n s t r a t e d . The a u t h o r d e m o n s t r a t e s w i t h diff e r e n t d e p t h r e c o r d i n g s sub-cortietd d i s c h a r g e s in rostral p a r t s of the b r a i n which o f t e n show a m u c h more i n t e n s e convulsive a c t i v i t y a n d m a y or m a y n o t be s y n c h r o n o u s with the cortical diseharges. I n t h e s e vases there is no p a r t i c i p a t i o n of the a m y g d a l o i d nucleus in the convulsive activity. The a u t h o r also c a u t i o u s a g a i n s t the o v e r r a t i n g of t h e p h e n o m e n a ,terived f r o m i n s p e c t i o n of the a c t u a l record. 22. C h l o r p r o m a z i n e sleep as an e l e c t r o e n c e p h a l o . graphic activation method. - - D. BENTE and T. ITm, Erlangen.

355

Previous eleetroeneephalographic investigations have s u g g e s t e d t h a t ehlort)romazine (Megaphen, Bayer) fosters dysrhythmie activity and activates d i s c h a r g e s of epileptogenie potentials. C h l o r p r o m a z i n e sleep was, therefore, used as a d i a g n o s t i c provocation method. Sleep induced by ehlorpromazine is w~ry similar to physiological sleep. However, the particular e f f e c t of t h e d r u g is still clearly recognizable by the t e n d e n c y to r a p i d i n c r e a s e s in a m p l i t u d e , slowing of the r h y t h m s a n d s y n c h r o n i z a t i o n of g r o u p e d discharges. T h e s e peculiarities are already seen before the p a t i e n t goes to sleep a n d are still recognizable d u r i n g sleep. C h l o r p r o m a z i n e exerts its a c t i v a t i n g effect especially u p o n m i h l d y s r h y t h n f i a s , m i n o r s h a r p waves a n d sequences similar to convulsive activity. T h e s e p h e n o m e n a are a c c e n t u a t e d in direction of a inore unequivocal epileptogenic m a n i f e s t a t i o n . The a d w n l t a g e of chlorpronmzine a c t i v a t i o n is due to the f a c t t h a t r e l a x a t i o n a n d slee I) eqn he o h t a i n e d in 86 per cent of the cases with a l m o s t none of the disturbl u g p l m r m a c o l o g i e a l side e f f e e t s as seen with barb i t u r a t e s . F o r the a c t i v a t i o n of circumsei'ibed cortical loci this m e t h o d is however s u r p a s s e d by other aetivation procedures. For the E E G d i a g n o s i s in ehihlren chlorpromazine a d m i n i s t r a t i o n is a good p r e I m r a t o r y m e a s u r e and easy to h.m(lle. 23. Activation by M e g a p h e n and Cardiazol. - E. W . FONFGELD, Marburg. B a s e d on t)revious i n v e s t i g a t i o n s (published in the Arch. P s y c h i a t r . Zlsehn Neuro]., vol. 194) the p r e s e n t one was carried out. T h e m e t h o d consisted of m i x i n g 2 ec. equal to 50 mg. M e g a p h e n with 100 co. equal to 300 rag. of Cardiazol ( a c c o r d i n g to the body weight of the p a t i e n t ) with 15 ce. of an isotonic blood salt solution ( J o n o s t e r i l ) . The i n j e c t i o n w~ls slow at a rate of 1-2 co. per rain. As soon as reeognizable c h a n g e s appea.red in the E E G the injection was discontinued. I m m e d i a t e l y a f t e r w a r d s a short l)eriod of hyi)erventih~tion was induced. T h e a n x i o u s excitation which usually seizes the p a t i e n t with ('ardiazol injection alone does n o t occur due to t h e q a i e t e u i n g e f f e c t of M e g a p h e n . B o t h d r u g s t o g e t h e r exert, as h a s a h ' e a d y been shown, q s u n m m t i v e aetiw~.ting e f f e c t upon the E E G . A n m n g the 17 p a t i e n t s rel)orted in this series 9 times a more precise E E G d i a g n o s i s w a s possible. F o u r cases s u f f e r e d f r o m i d i o p a t h i c epilepsy, .l froul focal epilet)sy and once a t h e t a wave focus was observed. E v e n d u r i n g c o n t i n u e d anti-epileptic medication an activ'ttion procedure is s o m e t i m e s i n d i c a t e d in c e r t a i n cases. W i t h focal lesions w i t h o u t an increased t e n d e n c y f o r seizures the m e t h o d is also useful in g i v i n g m o r e precise i n f o r m q t i o n s . 24. T h e h y p n o t i c and sedative drug N-PhthalylGlutaminic.acidimid as a useful activator in electroencephalography. - - A. WALKENUOaST, Bocbum-Langendreer. The a u t h o r p o i n t s out to the l a r g e n u m b e r of a e t i w ) t i n g p r o e e d u r e s in e l e c t r o e n c c p h a l o g r a p h y and to t h e l i m i t a t i o n s of each single m e t h o d . With sleep a c t i v a t i o n t h e choiee of the d r u g used for a c t i v a t i o n was discussed. I t was t h o u g h t t h a t C o n t e r g a n , a g l u t a m i n i e acid derivative with a closed r i n g s t r u c t u r e s i m i l a r to piperidine, w a s very u s e f u l since it is c h a r a c t e r i z e d toxicologically by a r e m a r k a b l e lack of toxicity a n d singe p h a r m a c o l o g i c a l l y it exerts "t p r o n o u n c e d c e n t r a l sedative a n d h y p n o t i c e f f e c t which develops r a p i d l y a n d w i t h o u t an initial e x c i t a t o r y

35(;

DEUTSCHE

E:EG-GESELLSCHAFT

singe. Quite in contrast to barbiturates it does not show a narcotic effect and produces in the E E G of benlthy persons all activation of the alpha rhythm. W i t h a dosage of 200 rag. given by m o u t h and with au averag e d u r a t i o n of action of 11/2 hours it w a s possible to obtain positive activating effects in 72 out of q9 cqses with epilepsy and in 24 out of 26 cases with cerebral tumours showing "~ n o r m a l resting electroenceph'flogranL A comparison was carried out with the effects obtained in epileptics "ffter administration of N-Methyl-eyelohexenylmethylbarbiturates qt a close of 250 rag. given by m o u t h and with the iuw~stigations carried out under exactly the snme conditions. Only 23 out of 99 cases showed a positive activating effect. I n epilepsies an increase of the l)~sitivc effects of activation with increasing feeling of f n t i g u e was noted b u t this was not observed in p a t i e n t s with cerebral tumours. The testing of the a d m i n i s t r a t i o n of higher doses ill epilepsies is discussed ns well as the activity of Contergan as n useful activator ill t r n u m a t i s m s , vascular i)rocesses and in other cerebral diseases. :Z5. Clinical a n d e x p e r i m e n t a l E E G i n v e s t i g a t i o n in epileptics a n d h e a l t h y i n d i v i d u a l s w i t h P r e l u d i n ( 2 - p h e n y l - 3 - m e t h y l - t e : r a h y d r o - 1, 4 . o x a c i n h y d r o c h l o r i d e ) . - - BOCnNIK a n d SPIEGrLBrRG, Hamburg. This an,lleptic nnd f a t i g u e inhibiting ox'~zine con> pound exerts, besides this effect q ndld eentr'd circulatory influence. T r a n s i e n t increases hi blood sugar concentration are only observed with intr.lvenous a d m i n i s t r a t i o n . Clinically P r e l u d i n has been of use ill cases with a p a t h y w i t h o u t internal restlessness and as an active ther:/peutic a g e n t in endogenous, reactive, l)syehopathie qnd organic cerebral diseases as well as in states of exhaustion ( S p i e g e l b e r g ) . Preludin became b e t t e r kuown as a drug able to inhibit the appetite, l ) u r i n g the phase of recovery from disease, however, the stimulation by this drug nlso produces an ilwrease in body weight. I n its action Prelndin has t'a 1)e el:~ssified qs somewhere between c a f f e i n and the a m p h e t a m i n e s and this has been corr o b o r a t e d by physiological and psychological illve~tigalions. ~:Iagoun and co-workers observed in :minml e x p e r i m e n t a t i o n s t h a t P r e l u d i n produced a l r a n s i e n t inhibition ef cortical strychnine spikes. I n order to investigate w h e t h e r this "ergotropic" d r u g ,~dministered ill epileptics would be capable of i m p r o v i n g their slowing and a p a t h y without nny d a n g e r of prodneing seizures~ the d r u g wns administered in 22 eases ill large intravenous doses r a n g i n g f r o m 50-300 rag, with simultaneous E E G control. I n e;tses in w h o m there w:ts a certain incidence of gross mental eh'tnges the tendency to seizure activity as measured by the E E G was not changed in 16 cases. I n 3 cases there was improventent and ill nnother 3 an i m p a i r m e n t , one with occurrence ef a gem,ralized seizure. I t is u n k n o w n to w h a t extent in these instances incidet~tnl changes of activity t o n y have played a I'o~(!. l)iminution of a t,eu(lency for seizures l)recil,itated tly exh:lustion by P r e l a d i n can be obtained since this d r u g nets a g a i n s t the fatigue. This is very remarkql)h, f r o m n therapeutic point of view. I n 3 nareolepsies, in 5 cerebral diseases of vh'al origin, in 5 general :umesthesias induced by E v i p a n as well as in an experimental alcoholic intoxication there was a disnppe~rnnee of f a t i g u e b u t no changes in the E E G attributnl)le to Preludin,

I n one psychopath and 3 epileptics 2 periods of a b n o r m a l behaviour without E E G chnnges were observed which developed oil a lmekgrmmd of vegetative affeetive decompensation due to the Preludin. I n a control g r o u p of 14 individuals w i t h o u t any cerebral disease there were despite a r a t h e r nmrked influence on tile mental state no gross EEG eh'mges. As in other g r o u p s f a t i g u e was inhil)ited :ln(l the electroeneephalogran~ sonletimes beeaine r e g u l a r and beta•alpha activity was occasionally activated similnr to w h a t lms been described by Colombati and Canerstrari. I n therapeutic oral doses of 25-51) rag. no activation of seizures was observed in epileptics. There is a eertnin cantion to be exerted in 1)sychop:/ths inclined to become drug addicts. 2 6 . C o n c e r n i n g the p r o b l e m of C a r d i a z o l t h r e s h o l d . HANS KELLER, M u n i c h . The a u t h o r reports first on the findings in 100 cases observed at the deimrtment of n e u r o s u r g e r y at lschl qnd at the university neurological clinir of Munich, in whom fraetionnted (*ardinzel and bnrbitu rate activ'ltion ineasured ill m g / k g , bodv weight were carried out. h i p a t i e n t s showing previo'{lsly a normal E E G and in cases in which t)athologicnl disturbances were suspected on clinical g r o u n d s or were clearh' demonstrated, 26 n o r m a l ]'~E(3s were recorded, 2'1 border line t r a c i n g s were obtained, and 53 :lbnormnl records observed. An tmspecifie and "l specific C a r diazol threshold was distinguished. Specific changes w e r e n l o s t f r e q u e n t l y soun i a ceret)r:ll s e i z l l r e s a l l d ill t t l n l o t l r s u l a c h l n o r e r a r e l y ill (!erel)r:ll d i s l a r l l l l l i t ' e s of t r ' m n m t i e or other origin and ahnost never in attacks off non-e-pilei)tie origin. The average values ef the threshohls and the activatim~ in ronvulsiw, disorders of various origins suggested a ct!rt:till trl,lld: the highest threshohls were f o u n d ill i)sychogeni(, and nol>epileptie convu]sive disorders, relatively high vahlos were found ill post-trnunmtic epiieps.(; some what lower ones in s y m p t o m a t i c epilepsy, still lower vnlaes in epilepsies consecutive to cerebr:ll (hlmagv h:,ving occurred in early childhood amI the lowesl threshohls in idiopathic epilepsy. F u r t h e n m ) r e it was attempted to "tnswer the question whether any con chlsions couhl be d r a w n concerning the incidence of seizures frenl the measured level of the Cardiqz(d threshohl. S u r p r i s i n g l y enough it w , s f o u n d t h a t the highest Cardiazol threshoh[ was f o u u d in cases showlllg" 311 lllCidellCe of 0-4 seiz/iPes :t nlgtlth, ~vhel'ei[s ill p a t i e n t s lmving only one or two seizui'es every ~; Inontlls, filial i n grit)SO having very f r e q u e n t s e i z u r e s , 2 a week or even nlore, the threshohl was fouml to I)e low. Sillce these dat:~ were obt:fined in a rath,.t limited mmlber of cases c o n f i r m a t i o n with re stud vin~ of a larger g r o u p of p : l t i e n l s is :/dvis:l[)Ie.

2 7 . I n f l u e n c e u p o n e p i l e p t o g e n i c activities e x e r t e d by s u b s t a n c e s acting u p o n Blood vessels. - - J. KuoLt~, Munich. Tim a u t h o r eqrried out elinic:d and e x p e r i m e n h d investigations on the time course of EEG eh.mg'es in epih'l)tics occurring a f t e r injecthms of drugs known to 1to Qctive ()ll 1)loo(l vessels. Pal,averhl (0.05 g. in 1(i co. of isotonic snliue injected over :l period of 5 nlin.} n114 I{v,lergin (0.3/10 ec. over 5 rain.') 1)reduced nn netixa'tion :is evidenced by blcrease in aulplitude, decrease in frequency, n u m b e r of lmthologieM diselmrges, dur:ttion of l)aroxysnml discharges and incre;ise Of' the delta index. The l)ulse frequency and blood pressurv llstl:llly

SOCIETY PROCEEDINGS

decreased s o m e w h a t d u r i n g this time. I n c o n t r a s t to t h i s blockades of the s t e l l a t e - g a n g l i o n on one side, w i t h 10-20 ee. of Xovocain at a dose of 10 ce. g i v e n i n t r a v e n o u s l y over a period of 5 min. or at a dose of 20-50 co. g i v e n s u b c u t a n e o u s l y a n d i n t r a m u s c u l a r l y , b e t a n i e o t i n i e acid d e r i v a t i v e s (Ronicol, Dilatol) a n d E u p h y l l i n (0.24/10 co. over 5 rain.) all produced, t h o u g h w i t h c e r t a i n d i f f e r e n c e s in the time course a d i m i n u t i o n of t h e a m p l i t u d e with increase of t h e frequency, d i n l i n u t i o n of focal d i s c h a r g e s a n d shorteni n g of the p a r o x y s m a l d i s c h a r g e s . T h e v a l i d i t y of these f i n d i n g s was checked with control i n v e s t i g a t i o u s w h e n venous p u n c t u r e s for w i t h d r a w a l of blood were carried o u t a n d in other controls where d r u g s of a n entirely d i f f e r e n t t y p e of action were injected. C o n t r a d i c t i o n s with the e x p e r i m e n t a l , clinical a n d p h a r m a c o l o g i c a l f i n d i n g s of other a u t h o r s were found. T h e a u t h o r discussed the following a s p e c t s of the problem : ( l ) The complex a c t i v i t y of v a s o - m o t o r c h a n g e s with s u b s e q n e n t m e t a b o l i c reactions. (2) I n a g r e e m e n t with other a u t h o r s the opinion is e x p r e s s e d t h a t v a s c u l a r s p a s m s c a n n o t be considered as p r i m a r i l y involved in t h e g e n e s i s of epileptic a t t a c k s . 28. T h e u s e of P y r l f e r as a n a c t i v a t i o n m e t h o d . H . E. KEtmER, J u n . , M i i n s t e r .

I t w a s a t t e m p t e d to activate the electrical activity of t h e cerebral cortex in epilepsies a n d o t h e r cerebral diseases by P y r i f e r h y p e r t h e r m i a . T h e pro~ cedures consisted in g i v i n g to p a t i e n t s which previously showed a n e g a t i v e or u n c h a r a c t e r i s t i c E E G an i n j e c t i o n of 50 u n i t s of P y r i f e r ( s t r e n g t h 1). A b o u t 24 h o u r s l a t e r an E E G w a s recorded. W i t h this m e t h o d of provocation~ more or less pron(mneed d y s r h y t h m i c d i s t u r b a n c e s , d i m i n i s h e d frequencies a n d i n c r e a s e d a m p l i t u d e of d i s c h a r g e s were o b t a i n e d in 9 epileptics. These c h a n g e s i n c r e a s e d u n d e r h y p e r v e n t i l a t i o n . Clear f o c a l c h a n g e s w h e n previously only g e n e r a l i z e d d i s t u r b a n c e s or n o r m a l activity were p r e s e n t were observed in 5 cases. Tbe ]oc'dization of these e l e c t r o e n c e p h a l o g r a p h i c loci were a h n o s t all h t e r a l i z e d on the s a m e side on which t h e p n e u m o e n c e p h a l o g r a n l h a d i n d i c a t e d t h e location of the h,sion. In 6 p a t i e n t s w i t h o u t cerebral disease such pathologic:d E E G c h a n g e s a f t e r P y r i f e r actiw~tion were n o t f o u n d . T h i s t y p e of a c t i v a t i o n w a s n o t successful in 3 epileptics, 2 of which h a d cortical a n d one questionable p s y c h o - m o t o r a t t a c k s . I n other patients w i t h o u t a t t a c k s , in w h o m t h e p n e u m o - e n c e p h a h ) g r a m showed some residual cerebral d a m a g e t h i s type of a c t i v a t i o n p r o d u c e d a m i l d g e n e r a l i z e d dysr h v t h m i a w i t h o u t focal signs, b u t w i t h a b s e n t .alpha ac}ivity. T h e a e t i w t t i o n of the E E G does n o t occur a t t h e peak of the f e v e r b u t a f t e r t h e decline of t h e hypert h e r n d a , i.e. in the period of c o u n t e r r e g u l a t i o n . i t is known t h a t due to the increase of t h e blood glolmlins in i n f l a m m a t o r y diseases t h e t e n d e n c y to seizures in epileptics is diminished. F r i s e h , however, f o u n d t h a t a f t e r a b o u t of fever t h e r e is always a c o u n t e r reaction with a period of i n c r e a s e d f r e q u e n c y and i n c r e a s e d severity of a t t a c k s . P y r i f e r i n j e c t i o n is well s u i t e d for t h e E E G activation, because it exerts a s t i n m l a t i n g e f f e c t upon a h n o s t all c e n t r a l r e g u l a t o r y m e c h a n i s m s a n d because the e f f e c t i v e c o u n t e r - r e g u l a t i o n following i t s a d m i n i s t r a t i o n is a physiological process which is m o s t likely r e l a t e d to t h e processes which p r e c i p i t a t e the s p o n t a n e o u s a t t a c k s in epileptics.

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29. Photic stimulation. ~

SCHAPER. Tile a u t h o r r e p o r t s on its experience w i t h photic s t i m u l a t i o n in 2000 ehihlren a n d adults. Tile cortical r e s p o n s e s u p o n i l l u m i n a t i o n of the r e t i n a are c h s s i fled into n o n - p a r o x y s m a l a n d p a r o x y s m a l reactions. T h e m o s t i m p o r t a n t n o n - p a r o x y s m a l reaction is t h e simple h a r m o n i c s y n c h r o n i z a t i o n c h a r a c t e r i z e d by t h e 1:1 r e l a t i o n s h i p between f r e q u e n c y of the photic f l a s h e s a n d occipital responses. T h i s response is discussed in detail a n d its dependence upon age pointed out. S h o r t reference is m a d e to the s u b - h a r m o n i c a n d m u l t i p l e h a r m o n i c responses, as well as to the criteria of tile pathologically s i g n i f i c a n t a s y m m e t r i e s of the response. T h e p a r o x y s m a l r e a c t i o n s are divided into 3 g r o u p s : (1) photic sensitivity, (2) photo-convulsive response, (3) photo-myoclonic response. 11, the l a t t e r a c c o r d i n g to clinical a n d e l e c t r o e n e e p h a l o g r a p h i c crit e r i a 4 s u b - g r o u p s can be observed. F i n d i l l g s : in 375 chihlren a n d a d u l t s w i t h o u t convulsive disorders "rod w i t h o u t n e u r o p s y e h i a t r i c s y m p t o m s , p a r o x y s m a l reactions were a c t i v a t e d in 3 per cent. h i convulsive p a t i e n t s the n u m b e r of f i n d i n g s of d i a g n o s t i c signif i c a n c e a f t e r n o r m a l bret:~thing qnd h y p e r v e n t i l a t i o n were i n c r e a s e d b y 10-25 per cent. In neuropsychiatric syndromes and psychosomatic diseases such as in neurosis, v o m i t i n g , f a i n t i n g , headaches, u m b i l i c a l colics, p u b e r t a r y anorexia, a s t h m a a n d others, p a r o x y s m a l r e a c t i o n s were a c t i v a t e d in 15-30 per cent of t h e cases. 30. Photlc stimulation. ~

LElSCtlNEa. The a u t h o r p o i n t s out t h a t of the p h a r m a c o l o g i c a l a c t i v a t i o n m e t h o d s in E E G practice have only "~ relative vMue. The r e s u l t s of photie s t i m u l a t i o n in 100 p a t i e n t s with o r g a n i c b r a i n d a m a g e f r o m the ' ' R h e i n i s c h e L a n d e s k l i n i k ffir H i r n v e r l e t z t e ' ' in B o n n are reported. I n all these p a t i e n t s the r e s t i n g E E G was f i r s t recorded t h e n the E E G d u r i n g a 5 rain. period of h y p e r v e n t i l a t i o n a n d a f t e r this photic s t i m u l a t i o n f o r 5-10 min. w a s carried out with tile "Strobotest" a p p a r a t u s of Sehwarzer. ~ i r s t single f l a s h e s of a f r e q u e n c y of 2-30 e/see, with a c o n s t a n t c h a n g e in f r e q u e n c y were applied. H e r e a f t e r twin f l a s h e s were p r e s e n t e d w i t h i n t e r v a l s between the single f l a s h e s v a r y i n g between 30-I70 reset. The twin f l a s h e s were s e p a r a t e d by i n t e r v a l s of 25-500 msec. I n the 100 p a t i e n t s i n v e s t i g a t e d 36 cases showed a d d i t i o n a l c h a n g e s in t h e E E G when c o m p a r e d with the record t a k e n at t h e r e s t i n g st'tte a n d d u r i n g h y p e r v e n t i l a t i o n . However, in only 22 i n s t a n c e s these c h a n g e s were of a p a t h o l o g i c a l l y s i g n i f i c a n t character. M o s t of these c h a n g e s consisted of waves in t h e t h e t a f r e q u e n c y b a n d or rarely in t h e delta f r e q u e n c y band. Only in a few cases convulsive p o t e n t i a l s or focal d y s r h y t h m i a s were encountered. Only in 4 p a t i e n t s photic s t i m u l a t i o n alone was qble to d e m o n s t r a t e a pqthologieal E E G change. I n 18 cases t h e r e was merely an a c c e n t u a t i o n of a previously detected pathological f i n d i n g . Localized d i s t u r b a n c e s were encountered in 13 cases. I t a p p e a r e d t h a t twil~ flashes were more p o t e n t t h a n single flashes. 3 1. P r o d r o m a I s y m p t o m s as a n a c t i v a t i n g f a c t o r for t h e EEG in e p i l e p s y . ~ K. PATEmKY.

I n a c e r t a i n n u m b e r of epileptic p a t i e n t s the E E G at rest a n d d u r i n g h y p e r v e n t i l a t i o n a n d with t h e u s u a l a c t i v a t i o n p r o c e d u r e s r e m a i n s normal. A detailed s t u d y of t h e history, however, shows t h a t such

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I)EUTSCHE EEG-GESELLSCHAFT

1)atients o f t e n c o m p l a i n of d i s t u r b a n c e s between t h e i r attacks and especially in the p r o d r o m a l p h a s e and d u r i n g the a u r a which can be e x p l a i n e d by the m e c h a n i s m which P o t z l described as " E r r e g u n g s fang" [ = c a p t u r i n g of e x c i t a t i o n ] . Such p a t i e n t s o f t e n give the history, t h a t t h e y s u f f e r f r o m periods ef obsessional r e p e a t e d m e m o r i e s o f t e n with a c o n t e n t d e s c r i b i n g t h e s i t u a t i o n in which the f i r s t a t t a c k occurred or related to the o r i g i n a l t r a u m a which c a u s e d t h e epilepsy. The relatives of such p a t i e n t s o f t e n notice periods in which the p a t i e n t s show nervous t e n s i o n w i t h o u t a n y a p p a r e n t cause a n d veget a t i v e d i s t u r b a n c e s which o f t e n are followed by an a t t a c k . T h e s e p a t i e n t s were a s k e d to come for an E E G e x m n i n a t i o n at a t i m e w h e n t h e y experienced these prodromal signs. In the m a j o r i t y of eases the E E G was f o u n d to be a b n o r m a l d u r i n g this period. I t is t h e r e f o r e possible to c a r r y out E E G e x a m i n a t i o n s in these p a t i e n t s at a period which is m o s t o p p o r t u n e morn,rot for f i n d i n g a b n o r m a l i t i e s a n d t h i s procedure can 1)c e q u a t e d to the e f f i c i e n c y of the a c t i v a t i n g procedure.

32. The EEG in poriomanics. ~ W I S S F E L D , Frankfurt/Main. The e l e c t r o e n c e p h a l o g r a m s in 50 i)oriontanies were n o r m a l in 26 a n d a b n o r m a l in 24 eases. Besides generalized d i s t u r b a n c e s with d y s r h y t h n f i a s a n d slowing of the r h y t h m s , localized focal c h a n g e s were f o u n d in 2 cases a n d in 10 cases e p i l e p t i f o r m disturl)anees were b r o u g h t out by hyl,erventilation. The m a j o r i t y of poriomanies are represented by epileptoid tlsy ehot)aths (16) a n d p a t i e n t s w i t h o r g a n i c b r a i n (lqmagc (11). More rarely one f i n d s oligophrenia (7), n e u r o t i c conflicts (7), e n v i r o n m e n t a l f a c t o r s (6) a n d u n s t e a d i n e s s of e h q r a c t e r (3) as t h e cause for the p o r i o m a n i e u r g e to r u n away. M o s t of the E E G c h a n g e s are seen in epileptoid p s y c h o p a t h s a n d in the p a t i e n t s s u f f e r i n g f r m n o r g a n i c b r a i n d a m a g e , whereas the other g r o u p s u s u a l l y showed a n o r m a l E E G . On t h e b a s i s of the clinical a n d electroencepha l o g r a p h i c f i n d i n g s one can a s s u m e t h a t a b o u t h a l f of tile p o r i o m a n i c s show evidence for cerebral pathology. On the other h a n d t h e r e are t ' m s i t o r y conditions between a n o r g a n i c a l l y d e t e r m i n e d cause to those which are of q irately psychological n a t u r e . 33. Latent epilepsy in the EEG of children and adolescents presenting behavior problems. EIDrN, Munich. More t h a n 50 per cent of a b n o r m a l E E G s were olltained in 500 children a n d adolescents which were psychologically a b n o r m a l a n d p r e s e n t e d a behavior problem. I n none of these there w a s a n y i n d i c a t i o n for a convulsive disorder f r o m t h e i r history. Quite f r e q u e n t l y E E G s i g n s of residual epilepsy ( a b o u t 50 per cent of the cases) were f o u n d a n d in 2 / 3 of tile cases these involved the l e f t h e m i s p h e r e with s i g n s of focal convulsive d i s c h a r g e s which were m o s t l y f o u n d in the t e m p o r a l region. " L a t e n t e p i l e p s y " was f o u n d with d e a r l y d e f i n e d convulsive p o t e n t i a l s mostly of the t y p e e n c o u n t e r e d in t e m p o r a l lobe epilepsy. Borderline f i n d i n g s described as ~ ' i n c r e a s e d excitability of the c e n t r a l n e r v o u s s y s t e m " m a n i f e s t e d t h e n > selves in the f o r m of b u r s t s a n d s y n c h r o n i z e d disc h a r g e s occasionally of a p a r o x y s m a l c h a r a c t e r with steep 3-6 e/see, slow w a v e s a n d some s h a r p w a v e s which, however, did not a s s u m e the f o r m of t y p i c a l e p i l c p t i f o r m i)otcntials.

B e s i d e s h y p e r v e n t i l a t i o n q good a c t i v a t i o n proeedure in children was to take the record in the fasting state. T h u s quite f r e q u e n t l y epileptogenic p o t e n t i a l s became more p r o m i n e n t a n d the E E G diagnosis couhl be c o n f i r m e d . Follow-up s t u d i e s with E E G control records in these psychologically a h n o r m f d children al.1 adolesc e n t s s h o w i n g a b n o r m a l E E G s are considered as nec e s s a r y in order to arrive at "1 more clearly defined concept of the e l e c t r o e n c e p h a l o g r a p h i c (not clillical~ concept of ' ' l a t e n t epilepsy ' '.

34. U n e x p e c t e d epileptogenic findings in several conditions with disturbed mood. ~ BOCHNIK, Hamburg. ] r r i t q h l e , depressive a n d m a n i f o r m chauges Of mood w i t h o u t a n y alteration of consciousness as setm in some epileptics were considered by the classical p s y c h i a t r y , on the basis of genetic a n d s y m p t o m a t o logical a r g u m e n t s , as due to c o m b i n a t i o n of el)ilepsv with cyclothymia, s c h i z o p h r e n i a or p s y c h o p a t h i c p e r sonqlity changes. E E G i n v e s t i g a t i o n s ill relatives ot elfileptics , p s y c h o p a t h s , m i g r a i n e p a t i e n t s a n d il, children with behavior d i s t u r b a n c e s , umbilical colics. etc., showed t h a t epileptogenic d i s t u r b a n c e s are oftel~ e n c o u n t e r e d besides more c o m m o n f u n c t i o n a l c h n n g e s of a d i f f e r e n t character. T h e a u t h o r r e p o r t s on tlw r e l a t i o n s h i p s between c h a n g e s in mood a n d electro g r a p h i c d i s t u r b ' r a c e s in tile E E G which arc not well known a n d which are d e m o n s t r q t e d with a few clinical examples. T h e clinical p i c t u r e ill these p a t i e n t s o f t e n show a t y p i c a l s y m p t o m s a n d complex changes. Tlw f r e q u e n t d i a g n o s t i c question, w h e t h e r this is "l cas4, of epilepsy or not, when Imroxysnml c h a n g e s are recorded in the electroenceph.flogram, is an u n f r u i t f u l a p p r o a c h to the problem. I t is more i m p o r t a n t t,, e v a h t a t e the i m p o r t a n c e of the eleetrogr:q)hic dist u r b a n c e in relation to the single case to be studied. Such electrographic d i s t u r b a n c e s can be very relevant or only indicate tile presence of an a d d i t i o n a l m o d i f y i n g factor, or it can he w i t h o u t a n y importalu, e at all. Tile cerebral d i s t u r b a n c e s u n d e r l y i n g these elm, trogr'q)hic c h a n g e s m a y determine or f a v o r ntental disturlmm!es such as lack of inhibition, irrit:dfility, co'trseness of eharactcr, c h a n g e s of a f f e c t i v i t y and of m e n t a l a n d m o t o r speed, as well as vegetativ,. e h ' m g e s a n d their p a r o x y s m a l m a n i f e s t a t i ( m s . These c h a n g e s can he qssociated with clinical s y n d r o m e s ll(,t necessnrily of a n epileptogenic n a t u r e . The establishm e n t of an a b n o r m a l E E G is also v'tlnable as air ancillary f i n d i n g since the i n s t i t u t i o n of anti-coltwllsive t h e r a p y is s o m e t i m e s h e l p f u l in the cases in view of t h e possibility to i n t e r r u p t a vicious circh.. F u r t h e r m o r e , the electroenceph'flogram is h e l p f u l in a m h i g u o u s s y n d r o m e s where it is i m p o r t a n t to dist i n g u i s h b e t w e e n p r i m a r i l y organic or p r i m a r i l y psy ehogenie d i s t u r b a n c e s . T h e pathological E E G c h a n g e s in the f o r m of d i f f u s e c h a n g e s , focal d i s t u r b a n c e s , p a r o x y s m a l d y s r h y t h m i a s a n d convulsive discharges are e n c o u n t e r e d in certain p a t i e n t s with very mttrkedlv a t m o r m a l p e r s o n a l i t y a n d in I)aroxysnud and exogenous d i s t u r b a n c e s in p a t i e n t s s u f f e r i l l g f r o m endogenous psyehosis. Etiologic'd/y, these d i s t u r b a n c e s are often related to early chihlhood cerebral t r a u m a s a n d to h e r e d i t a r y f o r m s of d y s r h y t h m i q . Speci'al m e n t i o n was m a d e l,y the a u t h o r of lmt i e n t s with long s t a n d i n g depressive s y n d r o m e s and m a r k e d epileptogenie E E G c h a n g e s w i t h o u t a n y clear h i s t o r y of elfileptie a t t a c k s . T h e s e p a t i e n t s are somet i m e s i m p r o v e d with anticonvulsive medication.

SOCIETY PROCEEDINGS 35. EEG in febrile convulsions. ~ SCHAPER. I n v e s t i g a t i o n s in children with febrile eonvulsim~s show t h ' / t one out of 3 children later developed conw d s i o n s even w i t h o u t fever. I n p a t i e n t s who were free of seizures for t e n years, 40 per cent showed epileptogenic p o t e n t i a l s in response to photic stimulation a n d t h e r e f o r e h a d to be considered as still potentiMly epileptic. F r o m a practical p o i n t of view the conclusion is w a r r a n t e d t h a t p r o g n o s i s in febrile convulsions is r a t h e r serious. I t is i n d i c a t e d to prescribe anti-convulsive m e d i c a t i o n for n long period of time a f t e r the f i r s t febrile convulsion a n d to prescribe "m lulti-1)yretic d r u g as well, which t h e p a t i e n t is ordered to take as soon as the f i r s t s i g n s of i n t e r c u r r e n t i n f e c t i o n s m a n i f e s t themselves. 36. Electroencephalographic and clinical observations concerning the therapeutic effect of Diamox (Azetazolamid) in epilepsy and in conditions with increased intra-cranial pressure. K. PATHSKY and H. PETSCHE, Vienna. 1)iamox is a p o t e n t i n h i b i t o r of e a r b o a n h y ( l r a s e a n d produces alkalinization of the urine, slight acidosis of the blood, increase in C Q c o n t e n t of t h e tissm.s a n d excretion of w a t e r r e t a i n e d in oedemas. I ) i a n m x was f i r s t used as a d e h y d r a t i n g d r u g in order to arrive "It a b e t t e r localizing d i a g n o s i s in focal eerel)ral lesions a t t e n d e d by m a r k e d increase of int r a c r a n i a l pressure. P a t h o l o g i c a l c h a n g e s in the E E G , however, showed i m p r o v e m e n t u n d e r D i a m o x , even when no oedeina was responsible for the initial pathological c h a n g e s in the e l e c t r o e n c e p h a l o g r a m . W i t h l ) i a m o x the d m ' a t i o n a n d numl)er of the lIaroxysmal d i s c h a r g e s ( p a r o x y s m a l delta, spike a n d wave complexes of a n y f o r m , p a r o x y s m a l d y s r h y t h m i a s ) d i m i n i s h e s a n d d y s r h y t h m i e E E G p a t t e r n s become more normal. T h e r e is a n increase in the aml)litude a n d the r e g u l a r i t y of the a l p h a r h y t h m . T h e a c t i v i t y of the focus itself is n o t i n f l u e n c e d , b u t fecal c h a n g e s become more a p p a r e n t because of the d i m i n u t i o n of tile d i f f u s e d i s t u r b a n c e s . On tile basis of these experiences I)iamox was given a t h e r a p e u t i c t r i a l in cases of epileptic s t a t u s a n d in conditions a s s o c i a t e d with raised i n t r a e r a n i a l p r e s s u r e (52 1)a) t e n t s ) . In epilepsies the ther./peutic e f f e c t w a s best, as could be expected, w h e n g e n e r a l i z e d p a r o x y s n m l c h t m g e s were present. I n epileptic s t a t u s a n d iu conditions a s s o c i a t e d with i n c r e a s e d i n t r a c r a n i a l pressure D i n m o x was especially h e l p f u l since it exerts a two-fold e f f e c t , f i r s t d e h y d r a t i n g the tissues and secondly d i m i n i s h i n g the excitability. 37. Electroencephalographic studies concerning the action of LSD 25. - - D. BENTE, T. ITIL and E. E. S c u m o . In view of till" f a c t t h a t p h a r m a c o - p s y c h i a t r i c forlnS of t r e a t m e n t as well as the classical t r e a t m e n t

35!1

with i n s u l i n coma a n d electro-schock result in the slowing of t h e s p o n t a n e o u s cerebral rhyttmls, tile e f f e c t of t h e hallucinogenic d r u g I,ysergie acid diat h y l a m i d ( L S D 25 " S a n d o z ' ') upon s y n d r o m e s ch'lracterized by slowing in the e l e c t r o e n c e p h a l o g r a m w a s studied. The d r u g was given "It a close of 20-150

garama. P r e m e d i c a t i o n with L S D 25 inidbits the developm e n t of slow waves raider the i n f l u e n c e of E v i p a n a n d Pent-,~thal. Slowing of cerel)ral r h y t h m s due to ehlorprom'~zine is also i n h i b i t e d by LSD pre medication. I n akinctic-al)ulie s y n d r o m e s produced by combined R e s e r p i n - c h l o r p r o m a z i n e m e d i c a t i o n and associated with slowing of the b a c k g r o u n d r h y t h m s in the E E G as well as in similar E E G l)ictures due to repe',ted electro-shock t r e a t m e n t s , LS]) 25 produces an increase in acceleration of the cerebral r h y t h m s with eonco m i t a n t r e d u c t i o n of the a m p l i t u d e a n d fin,ally induce.~ periods of f l a t a c t i v i t y with beta rh.ythms. An i m p r e s s i v e e f f e e t of LSI) 2,3 l a s t i n g for several h o u r s can also lie ebserved in severe g e n e r a l dist u r b a n c e s e n c o u n t e r e d in epileptic i)atients. Ilere also there is a progressive accelleration a n d d i m i n u t i o n of a m p l i t u d e of tile lirain r h y t h m s . I n i t i a l l y there is o f t e n a n a p p e a r a n c e of s y n c h r o n i z e d rqpid r h y t h m s o c c u r r i n g in 1)ursts. Clinically, one ot/serves in these eases o f t e n a t r a n s i e n t sleepiness. W h e n l)arox.'y'smal slow waves are p r e s e n t L S D 25 inhil)its the slow c o m p o n e n t s a n d produces a n increase in sI/ike activity a n d t h e r e f o r e can p r e c i p i t a t e an attack. LSD 25 t h e r e f o r e n o t only i n f l u e n c e s psychical f u n c t i o n , b u t also exerts a ulnrked e f f e c t upolt cortical electrical activity. I n view of the a n t a g o n i s t i c e f f e c t produced by I~SD to t h a t produced by t h e new neuroleptic d r u g s i n t e r e s t i n g ./l)proaches to i)harnmeo-psychi:ttri~' p r o b l e m s cau lie developed.

38. Clinical diagnosis and the incidence of positive clinical findings in electroencephalograms showing pathological changes. - - BEHREND, Hamburg. The p r o b l e m of correlation of E E G ch'~nges with neurological s y n d r o m e s h a s been often discussed. D i v e r g e n t views which have o f t e n l)een expressed are p a r t l y due to the diversity of t h e i m t i e n t m a t e r i a l s t u d i e d in p s y c h i a t r i c neurologicM a n d n e u r o s u r g i c a l clinics. I n t h e period fronl the / s t of J a n u a r y 1951 to October 31st, 1965, 7449 E E G s were t a k e n qt our clinic on a t o t a l n u m b e r of 6111 p,ltients; 4592 f i n a l d i a g n o s e s were made. The m a t e r i a l on which these f i g u r e s were el)rained consisted of o u t - p a t i e n t s a n d neurological "rod n e u r o s u r g i c a l in-f)atients. These f i g u r e s c o n c e r n i n g the incidence of positive d i a g n o s i s in a l m o r m a l E E G s in a p a t i e n t m a t e r i a l ilmlu(ling a m u l t i t u d e of d i f f e r e n t clinicM di'/gnoses m a y a p p e a r surI)rising. T h e y are, however, in accord with wlmt a clinician expects f r o m the E E G . The puri)ose of this s t u d y was to express this s u b j e c t i v e experience in quantitative terms.