O72 Motor and somatosensory evoked potentials in patients with focal lesions of the spinal cord

Neurophysiol Clin (1990)

25s

20, S, 2 5 s - 2 7 s

© Elsevier, Paris

Communications orales

Oral communications

SESSION 9 Exploration 41ectrophysiologique du contr61e moteur

Electrophysiological testing of motor control

O71 FUNCTIONAL COMPONENTSOF SLOW BRAIN POTENTIALS DURING VISUO-MANUAL TRACKING A. Hufschmidt, T. Winker, C. H. LUcking Neurologische U n i v e r s i t g t s k l i n i k , D-7800 Freiburg, Hansastr. 9

072 /~D S C m ~ T Q ~ 0 F ~

M.D., C I ~

EVOKe3 POI~h~IALS IN P A ~

P., I~SIATO M.T., ~

F., LAVARONI F., I ~ D I

G.

a~d ROS~INI P.M. Clin. ~urol. 11 University of Rcme '~c~ V e r ~ " .

Cortical n e g a t i v i t y accompanying visuo-manual tracking is poorly l o c a l i z e d , spreading over almost the e n t i r e cortex. In the present work, i t was attempted to i d e n t i f y single components o f the slow p o t e n t i a l by t h e i r r e l a t i o n to individual stages of sensorimotor processing. This was done by presentation o f two or three d i f f e r e n t tasks in a l t e r n a t e t r i a l s (movements without visual c o n t r o l , visual stimulation o f one/both h e m i - f i e ] d ( s ) w i t h / w i t h o u t movement). As a r e s u l t , i t was found that e l e c t r i c a l c o r r e l a t e s of visual perception as well as of pure motor output c o n t r i bute l i t t l e to the o v e r a l l p o t e n t i a l amplitude compared to the e f f e c t s o f visuomotor i n t e g r a t i o n and directed visual attention. For the l a t t e r two components, a r i g h t p a r i e t a l dominance was found. In a second series of experiments, a d i f f e r e n t i a t i o n between these two stages was endeavoured.

WI]~ YDCAL LESICNS OF

Roma - Italy -

A comparative ~ of Nbto~ Ev~ed P o ~ t j a ] ~ ( B ) and ~ otr~ nn 16 p ~ i ~ " l t s witah spastic l ~ m r ~ i s (8) and N i s

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(8) due focal extr-amedu]Ja~ (9 h~mat~d d i ~ , 3 m~iz~,ms, 1 radiculm." haematcrams) and ~¢cra,mdullm~ om'd ]~ions (3 hammtmms). ~ to m~netic brain ~ d m . t l a t i m ~ r e r e c ~ * l ~ from p r c ~ m a l N d i s t a l limb muscles and from addcmir~ masclas. As MEP N m c ~ m i i t i e s ~ ~l~sidered ~ne fol l ~ r i n g : 1) N N l d f~" I~P e l i c i g a t i o n ; 2) i N c r a v a t con~c~ion time and 3) almm~t r e ~ p c ~ . S i g n i f i c a n ~ fhr~shold N t f w mdd0mJna] and foot ~ elicJfatioo ~ foh~d in all patimts ~Jth ak~sc~lum~ cord lesi~ws and in 7 out of 8 p~ci~-~s ~Jda cervical oc~dq~ior~. P m o l o r ~ scalp %o cervical c¢~d cc'r and scalp to lumb~- ccrd OCT ~ r e observed in 5 limbs and 8 icier limbs. /Ibsemt MI~s from lo~er limb ~ n g s were found in 3 patients with lumbar lesions (6 limbs) and in 2 patients (4 limbsl witin c e r v i c a l l ~ i c r ~ . ~ intervals ~ delioJd-d~m%~', i n n ml and a d d o m i n a l - p ~ muscle~ considered with ~ i d and our values permitted fn localize the leve/ of altered pr~pas~ion in ~ m e n t with the. n e ~ x ~ o l o ~ i c a l f'mdir~s (~C and ~I). SEPs to medi~, and p e r ~ i .erv~S ~e l~ss affected d~an M~s. Absent scalp responses to a fotmd in 2 patJe~Its Al~on of tile cervical cord %0 scalp (L'r ~s encomte~ in 3 patients (5 ~ ligl~), of hhe lumbar onrd to scalp (lYr in 7 patients (I0 lo~er limbs). ~hese t2pe o f netn~tinysiologic ~ aklo~d a faidnful ~ of ~e level and of the ~ of spinal cc~d functional dsmm~e, i ~ out to be. perticulz~ly t ~ e f u l i n the proNqc~ic eskimm~ as ,,~ll ~ f ~ the i n d i c a t i o n of a possible ~cal

l~eaimant.