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Some aspects of the neurology of the cervical spine
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S O M E A S P E C T S OF THE N E U R O L O G Y OF T H E CERVICAL SPINE* BY SIR RUSSELL BRAIN, Bt., D.M., LL.D., D.C.L., P.R.C.P., Hon.
F.F.R.
I GREATLY appreciate the honour of giving the first Crookshank Lecture. It is a privilege to be allowed to share thus in the first commemoration of Mrs. Crookshank, that gracious lady who during her lifetime gave such generous help to institutions connected with medicine. It is an additional pleasure that this lecture should have been founded by her son, Viscount Crookshank of Gainsborough, a former Minister of Health, a distinguished parliamentarian, and himself a friend to medicine and of many doctors. It is also a responsibility for one who, though privileged to be an honorary Fellow, is not a radiologist, to deliver this important lecture to this Faculty. However, I have chosen a subject which seems to me to illustrate particularly well the value of the close co-operation between the radiologist and the clinician, which is such an important factor in the progress of medicine at the present time, and one of my aims is to point out that, when the neurologist has to deal with a difficult diagnostic problem involving the spinal cord at the cervical level, the radiologist may be able to supply the vital clue which makes the correct diagnosis possible.
CONGENITAL ABNORMALITIES My interest in the neurology of the cervical spine began about ten years ago when I first began to realize the neurological importance of the intervertebral disk in this region. I soon became aware that there were other disorders of the spinal cord at the cervical level which needed to be differentiated from the cervical myelopathy associated with intervertebral disk protrusion, and that radiology might play an essential part in the diagnosis. Prominent among such conditions are those associated with congenital abnormalities of the cervical spine. This subject has recently been reviewed by Garcin and Oeconomos (i953) , and I shall not now attempt to give a comprehensive account of it. What I have to say throughout this lecture will be based primarily upon my own clinical experience. Congenital abnormalities of the cervical spine are the result of developmental errors. In order to understand them, therefore, it is necessary to begin with a short review of the embryology of this region and it is necessary to take into account the development of the occipital bone also. According to List (1941) the occiput is formed from four sclerotomes. The first cervical vertebra is derived from two sclerotomes--the posterior part of the fourth occipital and the first cervical, but the second cervical vertebra is derived from three. The tip of the odontoid process comes from the fourth occipital sclerotome, the bulk of it from the first cervical sclerotome, of which it would otherwise form the mass of the body, and the base, like the rest of the axis, comes from the second cervical sclerotome. Most of the congenital abnormalities of the occiput and cervical spine are the result either of defective fusion of bones which should be united, or defective differentiation of bones which should be separated. Examples of both will be given later. The congenital abnormalities may be classified as follows : - i. Basilar impression. 2. Occurrence of an occipital vertebra. 3. Occipito-atlantal fusion : assimilation or occipitalization of the atlas. 4. Deformities of the foramen magnum. 5. Malformations of the axis : especially those leading to atlanto-axial dislocation. 6. Cervical spina bifida. 7. The Klippel-Feil syndrome. 8. Miscellaneous abnormalities, including cervical ribs. * The first Crookshank lecture.
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Three points emerge from a study of the literature and of individual cases. Whereas some of these congenital abnormalities occur in isolation, they tend to be multiple. Secondly, in considering the neurological syndromes with which they may be associated it is necessary to distinguish those which are the effects of the congenital bony abnormalities upon the nervous system from congenital abnormalities of the nervous system itself, which are the results of the same tendency to developmental error which produced the bony abnormalities, e.g., the Arnold-Chiari malformation, syringomyelia, hydromyelia, and myelodysplasia. The position is further complicated by the fact that a bony
Fig. 88.--Myelogram in a case of cervical spins bifida with Arnold-Chiari malformation and syringomyelia.
T h e myodil
entered the fourth ventricle which extends to the level of the body of the second cervical vertebra.
abnormality may compress a congenital neurological abnormality. Finally, there is no constant correlation between one type of bony abnormality and one type of neurological abnormality. These facts make the classification of these conditions difficult, since individual patients could often be placed in more than one category. I have decided to classify the cases I am to refer to in relation to what seems their most significant radiological abnormality. Oecipitalization of the Atlas.--Occipitalization of the atlas was the commonest congenital abnormality observed by McRae (1953) in his study of the occipitocervical region. He found that neurological symptoms occurred if the anteroposterior diameter of the spinal cord was 19 mm. or less, or if, as a result of the laxity of the transverse ligament, the odontoid moved backwards and forwards more than 3 mm. on flexion and extension of the head. The signs of compression of the medullospinal junction include nystagmus, hypoglossal palsy, analgesia and thermo-an~esthesia over the cutaneous distribution of the ophthalmic divisions of the trigeminal nerves, and bilateral pyramidal signs, with impairment of superficial and deep sensibility to a variable extent in the limbs. In my own series occipitalization of the atlas has occurred in association with other abnormalities but does not appear to have been responsible for symptoms in itself.
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B a s i l a r Impression.--Basilar impression may be the result either of a congenital abnormality --primary basilar impression, or of a variety of bone diseases, including Paget's osteitis, osteomalacia, rickets, osteofibrosis cystica, hyperparathyroidism, renal rickets, some lipidoses, and some cranioskeletal dysplasias--secondary basilar impression. The primary variety may be familial. I shall not discuss basilar impression in any detail, since it is not in itself an abnormality of the cervical spine. Bull, Nixon, and Pratt (I955) have discussed its radiological criteria. Chamberlain (I939) stated that in normal subjects " all parts of the atlas and axis lie caudad of the base line " drawn
Fig. 89.--Cervical spina bifida with occipitalizafion of the atlas and fusion of the laminae of the first and second cervical vertebrae and the right half of C.3.
from the dorsal margin of the hard palate to the dorsal lip of the, foramen magnum. McGregor (i948) introduced a modifl~cation of Chamberlain's line, namely, the line drawn from the upper surface of the posterior edge of the hard palate to the most caudal point of the occipital curve in the true lateral X-ray ". Bull and his collaborators have introduced a new radiological measurement, which they find more satisfactory, namely, the angle between the plane of the hard palate and the plane of the atlas vertebra, which should not be more than io-z3 °. Using this criterion they have been able to demonstrate the abnormality in I I out of 39 relatives of 20 patients who exhibited primary basilar impression. Fischgold's line is also used in the diagnosis of basilar impression. It is the line drawn between the tips of the mastoid processes in the anteroposterior view or in a tomograph and normally passes between I-2 mm. above or below the tip of the odontoid process. Symptoms were present in io and neurological signs in 8 of McRae's 2I patients with basilar impression. Symptoms of the basilar impression itself may be predominantly ponto-bulbocerebellar or those of a lesion of the upper cervical level of the spinal cord. The former may closely simulate a cerebellar tumour, the latter syringomyelia or disseminated sclerosis. Any of the other congenital abnormalities already mentioned may or may not be associated with primary basilar impression. We need not now further consider malformations of the foramen magnum or the rare occipital vertebra.
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Cervical Spina B i f i d a . - - T h e following three cases illustrate the which cervical spina bifida m a y be associated. Case i.--Female, aged 3o. Several years before, weakness of right arm child ; gradually improved after io months ; diagnosed disseminated sclerosis. months, recurrence of weakness in right arm and leg. Cranial nerves normal.
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v a r i e d clinical pictures w i t h and leg followed birth of third Recovery incomplete. Eleven Slight wasting and weakness of
Fig. 9o.--Same patient as Fig. 89. Myelogram showing obstruction at the level of C.2-3 intervertebral disk.
right upper limb with analgesia and thermo-an~esthesia over area from cervical 4 to dorsal 2 dermatomes inclusive. Spastic weakness of both lower limbs. Tendon-jerks exaggerated, especially on the right side. Both plantar reflexes extensor. Radiographs showed cervical spina bifida C.2, 3, and 4. In cisternal myelography myodil entered 4th ventricle which extended as low as C.2 (Fig. 88). Operation by Mr. Crawford showed ArnoldChiari malformation associated with syringomyelia. A n u m b e r of recent papers have a d d e d to our knowledge of the A r n o l d - C h i a r i malformation. Garcin and O e c o n o m o s p o i n t out that it occurs chiefly in three c i r c u m s t a n c e s : (i) Usually in infancy associated with spina bifida and a m y e l o m e n i n g o c e l e . T h e s e patients often have h y d r o cephalus. (2) It m a y be associated with p r i m a r y basilar impression. (3) I t m a y be apparently the sole, or practically the sole, abnormality. W h e n the A r n o l d - C h i a r i m a l f o r m a t i o n does not give rise to s y m p t o m s until m i d d l e life its diagnosis m a y be e x t r e m e l y difficult. Its association w i t h cervical spina bifida as the sole radiological a b n o r m a l i t y should therefore be b o r n e in mind. I n the n e x t case cervical spina bifida was associated w i t h an unusual p r e s e n t i n g s y m p t o m . Case 2.--Male, aged 18. Born with torticollis treated by operation on right sternomastoid. When I4, while wrestling with a friend, jerked his head backwards and to right and was immediately paralysed from neck down, for I5 minutes. Minor attacks also occurred and he was paralysed for 2 hours after a fall while skating. Can provoke the attacks voluntarily. Head slightly inclined to right. No abnormality in central nervous system. Extension of neck to just beyond vertical limited by tingling. Various manceuvres of neck caused an audible and
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palpable click. Radiographs of neck showed a congenital fusion of C.I, 2, and 3 where the neural arches were bifid (Fig. 89), with some minor congenital abnormalities. Myelography showed an obstruction opposite the C.2-3 disk when the medium flowed from above and opposite C.3-4 disk when it flowed from below (Fig. 9o). Operation by Mr. Northfield and Mr. Osmond-Clarke showed various abnormalities, of which the chief was a large mass of bone occupying the normal position of the posterior arch of the atlas, the laminae and process of C.2, and the left lamina of C.3. This mass appeared fused to the occiput. T h e right lamina of C.3 was loose,
Fig. 9I.--Cervical spina bifida in a patient with a progressive lesion of the cervical spinal cord. and was removed. T h e patient did well until, two years after his operation, he was involved in a motor accident. He was thrown forwards and his head thrown back and he became quadriplegic, but he has partially recovered from this. I n t h e t h i r d case radiological d e m o n s t r a t i o n o f a cervical s p i n a bifida e s t a b l i s h e d a c o n g e n i t a l o r i g i n for t h e c o n d i t i o n a n d m a d e it p o s s i b l e to e x c l u d e d i s s e m i n a t e d sclerosis, w h i c h h a d b e e n a p r e v i o u s diagnosis.
Case 3.--Female, aged 35. T e n years previously noticed dragging of the right leg. Gradually increasing weakness of right leg, then left leg, then arms. T h e r e was a history of a fall many years previously. T h e clinical picture was a moderate spastic quadriplegia with normal cranial nerves, including a normal jaw-jerk and slight relative analgesia below C.5 on both sides. Radiographs showed cervical spina bifida at the level of C.z (Fig. 9I). No further investigations were possible. T h e s e cases i l l u s t r a t e t h e v a l u e of m y e l o g r a p h y w i t h a n o p a q u e m e d i u m , b u t i n s u i t a b l e cases m y e l o g r a p h y w i t h air o r gas m a y give as m u c h , or e v e n m o r e , i n f o r m a t i o n . The Klippd-Feil Abnormality.--The K l i p p e l - F e i l a b n o r m a l i t y is n o t u n c o m m o n l y associated w i t h t h e S p r e n g e l s h o u l d e r . I n o n e s u c h case t h e r e was w a s t i n g of t h e m u s c l e s o f t h e s h o u l d e r - g i r d l e o n o n e side, a n d o n t h i s a c c o u n t t h e p a t i e n t was s e n t for i n v e s t i g a t i o n w i t h a t e n t a t i v e diagnosis of poliomyelitis.
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Case 4 - - M a l e , aged i I. A t t h e age of 6 h e was noticed to have a p r o t r u d i n g s h o u l d e r - b l a d e . T h e right scapula was h i g h e r t h a n the left, a n d t h e right trapezius, r h o m b o i d s , a n d levator anguli scapulae were wasted a n d weak. Radiographs s h o w e d assimilation of t h e atlas a n d fusion of t h e bodies of C.z, 3, a n d 4 (Fig. 92).
Sometimes a half-vertebra may be present on one side and not on the other, giving rise to cervical scoliosis or torticollis. T h e following case is an instance of this. Case 5 . - - M a l e , aged 26, h a d always been smaller on t h e left side of his b o d y t h a n on t h e right. H e h a d a cervicodorsal scoliosis c o n v e x to t h e left. T h e r e was no evidence of organic disease of t h e central n e r v o u s
Fig. 9z.--Occipitalization of the atlas and fusion of C.2 and C.3. system, b u t he h a d hysterical t r e m o r a n d weakness of t h e left u p p e r a n d lower limbs. R a d i o g r a p h s s h o w e d fusion of the bodies of C.2 a n d 3, C.5 a n d 6, a n d C.7 a n d D . I with separated f r a g m e n t s , one of w h i c h appeared to be an additional h a l f - b o d y c a u s i n g t h e scoliosis (Fig. 93).
Other associated abnormalities include cervical ribs. One patient had a Klippel-Feil syndrome and bilateral cervical ribs, together with the characteristic spatulate expansion of seventh cervical spinous process (Figs. 94, 95). This patient's radiographs illustrate the common association of the Klippel-Feil abnormality with cervical spondylosis, which is no doubt to be explained by the undue stress upon adjacent intervertebral disks caused by the lack of mobility in the fused vertebra. This patient attended hospital on account of pain, tingling, numbness, and weakness in the right hand. In spite of all these abnormalities in the neck the symptoms proved to be due to compression of the median nerve in the carpal tunnel, and were cured by operation on that. Lesions involving the Odontold P r o e e s s . - - L e s i o n s involving the odontoid process are not uncommon, are of considerable clinical interest, and sometimes pass unrecognized. According to one classification the term dislocation of the atlas is used when the transverse ligament is torn and fracture-dislocation when the odontoid process is fractured at the base. It is perhaps more convenient to use the term atlanto-axial dislocation to cover all displacements of one bone on the other, whatever the cause. The following varieties may then be recognized. I. Dislocation secondary to the spread of infection to the atlanto-axial articulation : This, though rare to-day, was well recognized by the clinicians of fifty years or more ago. It was most frequently
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encountered in children as the result of tonsillitis, retropharyngeal abscess, acute mastoiditis and osteomyelitis of the occiput, tuberculous cervical adenitis, and tuberculous caries. Charcot (i88i) alludes to " the terrible accident which somewhat frequently happens in Pott's disease of the cervical region ", i.e., rupture of the transverse ligament resulting in sudden death. T h e symptoms in non-fatal cases may include headache and vomiting, hypoglossal paralysis, sensory loss over the ophthalmic division of the trigeminal nerve to pain, heat, and cold, motor
Fig. 93.--Klippel-Feil abnormality with asymmetry leading to cervical scoliosis.
weakness and spasticity in the limbs with impairment of superficial and deep sensibility. The head is likely to be tilted, with pain in the neck, especially on any attempt to move it. D u r i n g the war I saw a young soldier in whom this lesion had followed an acute retropharyngeal infection. His only symptom was bilateral paralysis of the tongue. More recently I saw another case. Case 6.--Female, aged 7- (A patient of Mr. Osmond-Clarke and Mr. Northfield.) A few days after an illness characterized by high fever, a septic throat, and a lump in the side of the neck, her head was noticed to be on one side. Head was held in torticollis with chin to right and occiput to left. Central nervous system normal. Radiographs showed atlanto-axial dislocation with destruction of the left lateral mass of the atlas (Fig. 96). She was treated with head traction and a minerva plaster, and later a plaster collar, with excellent result. W h e n the transverse ligament has been softened by disease the dislocation may be provoked by a normal movement of the head. I n the following case, however, there was evidence that both infection and trauma played a part. Case 7.--A male, aged 44, suffered 5 years previously from an attack of meningitis which followed a boil on the neck. He made a good recovery with chemotherapy, and was free from symptoms except for neck stiffness until he fell and hit the back of the head, after which he developed severe pain in the neck accompanied by
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Fig. 94.--Klippel-Feil abnormality. Note the abnormal spinous processes.
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Fig. 95.--Same patient as Fig. 94 showing bilateral cervical ribs and abnormal spinous processes.
Fig. 96,--Atlanto-axial dislocation associated with osteomyelitis of the lateral mass of the atlas (tomogram).
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occipital headaches, both made worse by coughing. On examination he exhibited nystagmus, analgesia over the ophthalmic division of the trigeminal nerve on both sides, weakness and cutaneous sensory loss in both upper limbs with general exaggeration of the tendon reflexes and bilateral extensor plantar reflexes. His cerebrospinal fluid contained i6o rag. of protein and there was little rise of pressure on jugular compression. Radiographs showed an atlanto-axial dislocation (Fig. 97). He was treated at first with a plaster collar, but subsequently required operation--cervical laminectomy and occipito-cervical fusion by Mr. Northfield and Mr. Osmond-Clarke.
Fig. 9 7 . - - T o m o g r a m of atlanto-axial dislocation due to t r a u m a following meningitis,
Fig. 98.--Atlanto-axiat dislocation following ? congenital failure of fusion of odontoid and leading to myelopathy of late onset.
2. Traumatic atlanto-axial dislocation clue to rupture of the transverse ligament : T h i s condition calls for no special comment.
3. Atlanto-axial dislocation due to interruption of the odontoid process : T h e pathogenesis of this condition has recently been reviewed by Bachs, Barraquer-Bordas, Barraquer-Ferr4, Canadell, and Modolell (i955). T h e y recognize that the interruption of the odontoid process may be due to one of four causes : - i. Simple fracture of the odontoid. ii. Apophysiolysis. Since the odontoid does not unite to the body of the axis until the age of 3 years, trauma occurring before that age may result in separation of the odontoid through apophysiolysis. iii. Congenital absence of the odontoid process. iv. Failure of union of the odontoid with the rest of the axis. I n any of these four conditions atlanto-axial dislocation may occur after trauma. T o this must be added another cause. v. A b n o r m a l laxity of the transverse ligament in association with assimilation of the atlas (List, I94I ; McRae, I953). Bachs and others point out the distinguishing features of simple atlanto-axial dislocation and atlanto-axial dislocation following interruption of the odontoid process. I n the former there is slipping, usually moderate, between the atlas and the axis in two parallel planes, and when the head
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is flexed the abnormal mobility is reduced to a minimum. W h e n the odontoid process is separated, however, the skull and the atlas together show what they describe as an intense abnormal ' patellar ' mobility on the convex surface of the axis body. W h e n the head is flexed, the dislocation between the atlas and the axis is more severe than that occurring in simple atlanto-axial dislocation. Moreover the dislocation does not follow two parallel planes, because the atlas slips forwards and downwards, so that its plane makes with the plane of the axis a progressive angle open upwards and backwards. Another radiological diagnostic point, of course, is that when the transverse ligament is ruptured the odontoid process moves laterally together with the axis, whereas when the odontoid itself is fractured it is fixed to the atlas by the transverse ligament and therefore follows the displacements of the atlas. McRae (1953) measured the amount of slipping of the atlas on the axis. I n three cases of simple atlanto-axial dislocation the slipping was slight, up to 4 mm., but when the odontoid process was separated the slipping measured 5-25 mm., with an average of 14 mm. in the patients with symptoms and i o mm. in those without.
Late Myelopathy after Atlanto-axial Dislocation.--Several authors have recently drawn attention to the occurrence of symptoms resulting from atlanto-axial dislocation many years after the trauma which is likely to have been responsible for it (Salvini and Pelliccioli, 1955; Paillas, Legre, Pellegrin, and Bonnal, 1955; Bachs, BarraquerBordas, Barraquer-Ferr6, Canadell, and Modolell, 1955). Not infrequently head injury has occurred during childhood or adolescence. T h e onset of neurological symptoms was in one case delayed eig. 99.--Atlanto-axialdislocationdue to secondarycarcinoma for 44 years. By the time the patient comes under of atlas. observation there may be no way of deciding whether the initial lesion was a fracture of the odontoid or whether the injury caused trouble only because there was a pre-existing congenital abnormality, such as a failure of the odontoid to unite with the body of the axis. I n some cases, however, there is clear radiographic evidence of a congenital abnormality in the occipito-atlantal region and then the myelopathy may be presumed to be the delayed effect of this congenital abnormality upon the junction of the medulla and the spinal cord. Bachs and his fellow workers draw attention to the occurrence of subluxation of the odontoid owing to laxity of the transverse ligament as a result of which flexion of the head m a y produce repeated pressure by the odontoid upon the spinal cord. The following patient of m y own illustrates some of these points. Case 8.--Female, aged 56. For about a year had noticed increasing weakness and stiffness of the legs and later the arms. She denied injury. Her cranial nerves were normal except for nystagmus. She had a severe spastic quadriplegia with loss of postural sensibility in the right hand and both feet. Both plantar reflexes were extensor. Her cerebrospinal fluid was normal in both composition and dynamics. Radiographs showed that the skull, atlas, and odontoid had turned forwards on the axis, with arthritic changes between atlas and axis (Fig. 98). She was treated with head traction and a plaster collar.
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NEOPLASMS OF THE CERVICAL SPINE C a r c i n o m a t o u s I n v o l v e m e n t o f the A t l a s . - - T h i s rare o c c u r r e n c e is i l l u s t r a t e d b y the f o l l o w i n g case : -
Case 9.--Male, aged 53. One year previously suddenly noticed stiffness of the neck and that his head was twisted to one side. Pain and stiffness of the neck increased : 2 weeks previously developed double vision.
Fig. Ioo.--Enlargement of intravertebral foramen between C.3 and C.4 due to neurofibroma (dumb-bell tumour),
Fig. IOI.--Invasion of cervical spine by secondary carcinoma of prostate.
Head flexed to left : lateral flexion and rotation to left very limited and painful. Left external rectus palsy with slight weakness of left half of soft palate, left sternomastoid and left half of tongue. Radiographs showed extensive destruction of bone of skull on left side and of left half of anterior arch of atlas, due to metastatic carcinoma (Fig. 99). There was also a metastasis in the right 6th rib. No primary was found. N e o p l a s m s of t h e cervical s p i n e are rare. Fig. I 0 0 s h o w s e n l a r g e m e n t of a n i n t e r v e r t e b r a l f o r a m e n b y a n e u r o f i b r o m a . Fig. i o i is a n e x a m p l e of s e c o n d a r y c a r c i n o m a f r o m t h e p r o s t a t e .
CERVICAL S P O N D Y L O S I S T h e p r i n c i p a l n e u r o l o g i c a l m a n i f e s t a t i o n s of cervical s p o n d y l o s i s are n o w well d e f i n e d a n d I do n o t p r o p o s e to deal w i t h t h e m p r i m a r i l y h e r e . I t h i n k it w o u l d b e m o r e useful to discuss t h e i n t e r p r e t a t i o n of t h e radiological a p p e a r a n c e s i n r e l a t i o n to t h e clinical p i c t u r e a n d to t h e i r p a t h o logical basis. Fig. i 0 2 s h o w s a sagittal s e c t i o n t h r o u g h t h e cervical s p i n e i n a case of cervical spondylosis. T h e p o i n t to w h i c h I w o u l d d r a w a t t e n t i o n is t h a t a l t h o u g h a n u m b e r of i n t e r v e r t e b r a l disks s h o w d e g e n e r a t i o n , n o t all d e g e n e r a t e d disks are t h e site of o s t e o p h y t e s . S i n c e it is t h e o s t e o p h y t e s w h i c h
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are the chief cause of symptoms, it follows that disk degeneration in itself, as shown radiologicaUy, is not necessarily a cause of symptoms. Fig. Io 3 shows the myelogram of a patient with obvious disk degeneration, as indicated by narrowing of the intervertebral disk spaces, yet with no evidence of projection into the spinal canal at that level.
Fig. Io2.--Sagittal section of cervical spine in cervical spondylosis (kindly lent by Dr. Marcia Wilkinson).
Returning to the sagittal section you will note that where a posterior osteophyte has been formed there is a noticeable sclerosis of the posterior and inferior part of the bodies of the adjacent vertebrze. It follows that in radiographs of the neck of a patient suspected of symptoms due to cervical spondylosis the point to which attention should be directed is not only, or even chiefly, narrowing of the intervertebral disk spaces, but the presence or absence of an opacity projecting into the spinal canal from the posterior end of the disk space, and associated with sclerosis of the adjacent portions of the bodies of the vertebrae. The osteophyte is usually easy to distinguish, but may show up better when less penetration is used. Can we then dispense with myelography in many cases ? When posterior osteophytes are readily recognizable, and correspond in position to the level of the symptoms, it will often be unnecessary to do a myelogram. But it is important to remember that some osteophytes show up very little, or appear on plain radiographs to be much smaller than in fact they are. In such cases only a myelogram will give a reliable account of the size of the protrusion. In Fig. 104 the plain lateral view of the cervical spine shows how little disk narrowing there may be in spite of the presence of large posterior osteophytes and how little evidence the plain radiograph may give of the size of the osteophytes as shown in the myelogram.
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Another common point of difficulty is what appears to be a lack of correlation between the level of the disk protrusion and the upper level of the spinal cord lesion. It is quite common to find that motor, reflex, and sensory functions of the spinal cord are disturbed up to a segment or two higher than that which should be compressed by the highest disk protrusion. The explanation of
Fig. io3.--Normal myelogram in cervical spondylosis.
Fig. io4.--Cervieal spondylosis. Plain radiograph and myelogram showing posterior osteophytes.
this is that the production of pathological changes in the spinal cord in cervical spondylosis is a complex matter, into which enter a number of factors, of which the direct pressure of the protruding intervertebral disk is only one. As the result of tension, traction, and interference with blood-supply the cervical myelopathy is more extensive than the area directly compressed. The same is true of radicular symptoms. Here again a number of factors come into play. Fig. lO5 illustrates the three common sites of intervertebral disk protrusion. A central protrusion, if large enough, will compress the spinal cord. A posterolateral protrusion will sometimes compress the spinal cord, but may compress the spinal roots within the spinal canal against the corresponding lamina. An intraforaminal protrusion will compress the spinal roots within the intervertebral foramen. There is one point in connexion with spinal root pressure which is liable to be overlooked. As one moves down the cervical cord one finds that the spinal roots run more and more obliquely to reach the intervertebral foramina. This, of course, is true throughout the spinal canal, and is due to the fact that the spinal cord is shorter than the spinal column. The result of this is that a spinal root from any segment of the cervical enlargement may be compressed at more than one level of the spine, either by a posterolateral protrusion of the intervertebral disk at the level at which it leaves the spinal cord, or, usually at one vertebra lower, by an intraforaminal protrusion into the foramen through which it leaves the spinal canal. There is yet another factor. Frykholm (1951) has pointed out that cervical spondylosis, by narrowing intervertebral disks, shortens the cervical spine. As the spinal cord remains the same length, shortening the spine must affect the position of the spinal roots within the intervertebral
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foramina, particularly in the case of the lower cervical vertebrae. As a result the spinal roots may be compressed against the lower border of intervertebral foramina which are themselves normal in that they are neither narrowed nor the site of osteophytes. Here, then, we have some of the explanations of apparent discrepancies between the level of a root lesion and the radiographic changes in the neck, and also of the common observation that a patient may appear to have multiple roots involved - - a typical picture of what used to be called ' brachial neuritis ' - - a n d yet the radiographic changes may
Fig. ~os.--Common sites of protrusion of intervertebral disks in cervical spondylosis (Frykholm).
Fig. Io6.--Barium swallow showing deformity of oesophagus caused by anterior osteophytes in cervical spondylosis.
appear to be limited to one intervertebral disk and the corresponding foramina. I suspect that there be yet another causal factor here. In the presence of even a limited amount of cervical spondylosis, if it is sufficient to tether the spinal roots within the foramina, it disturbs the normal reactions of the nerve-roots of the brachial plexus to comparatively slight everyday stresses and strains. Such patients may, therefore, very easily, as the result of perhaps unnoticed strains or postural stresses, develop the clinical picture of multiradicular brachial-root irritation. While limitation of both active and passive movement of the neck is the common result of cervical spondylosis, abnormal mobility is not rare. Slipping of the body of one vertebra upon another at the site of a degenerated disk on flexion and extension of the spine is a potent cause of increasing the damage.
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Among the curiosities of cervical spondylosis may be mentioned pressure upon the eesophagus by large anterior osteophytes. Fig. lO6 illustrates this. The disk protrusion was discovered in the course of a barium swallow and it was then realized that the pains in the arms of which the patient had complained were due to cervical spondylosis. Whether oesophageal symptoms can be produced by cervical spondylosis, either as the result of the pressure of osteophytes or as the result of interference with the innervation, is a point which we are at present investigating. Another point which
Fig. IO7.--Paget's osteitis of cervical spine : a case in which quadriplegia followed a blow on the head.
would repay investigation is the importance of changes in the occipito-atlantal and atlanto-axial joints as a cause of symptoms, particularly headache. T h e Effect o f T r a u m a u p o n C e r v i c a l Spondylosis. Attention has recently been drawn to the effect of trauma to the head and neck upon patients suffering from cervical spondylosis. In such patients a blow on the head, particularly one producing forcible extension of the neck, or even hyperextension in the course of an anesthetic or operation (Symonds, I953), may cause severe and largely irreparable damage to the cervical spinal cord. This is the result of the complex factors which limit movement and tend to impair the blood-supply of the cervical spinal cord in spondylosis. It is well established that this type of traumatic myelopathy may, and usually does, occur in the absence of any gross change produced by the injury in the ligaments or bones of the spine. Less attention has been directed to the similar damage to the cervical nerve-roots which may be produced in the same way. This may be unilateral or bilateral and may, or may not, be associated with damage to the spinal cord. Fig. IO7 shows that the same thing may happen when the cervical spine is the site of a lesion other than spondylosis. Case i o . - - A n elderly m a n s l i p p e d w h i l e w a l k i n g d o w n s t a i r s and s t r u c k his head against the wall. H e fell d o w n a n d f o u n d t h a t he was u n a b l e to get up again. H e was f o u n d to h a v e m o d e r a t e q u a d r i p l e g i a from w h i c h he m a d e a partial recovery, so t h a t he b e c a m e able to walk. R a d i o g r a p h s of his cervical spine s h o w e d the c h a n g e s of P a g e t ' s osteitis.
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ARTHROPATHIES
T h i s case leads n a t u r a l l y to t h e c o n s i d e r a t i o n of b o n y c h a n g e s i n t h e cervical s p i n e w h i c h m a y closely s i m u l a t e cervical s p o n d y t o s i s a n d w h i c h t h e r e f o r e e n t e r i n t o its differential diagnosis. T h e s e are the cervical a r t h r o p a t h i e s , a n d as i n t h e s e cases t h e b o n y c h a n g e s are always associated w i t h evidence of a lesion of t h e cervical s p i n a l cord, t h e y m a y give rise to a c o n s i d e r a b l e difficulty.
Case i i . - - F e m a l e , aged 53. W h e n she was about a6 she noticed that the left foot began to twist. In her early thirties she noticed numbness and pains in the hands, and that she would burn the right hand without
Fig. io8.--Cervical arthropathy in syringomyelia radiographed in 1947.
A larninectomy had previously been carried out.
Fig. IO9.--$ame patient as in Fig. lO8.
Radiograph taken in
1953.
knowing it. Weakness developed in the upper limbs, where she said the left was weaker and the right the more numb. She also complained of numbness of the right leg and of pains in the head and neck. When she was 33 she had a laminectomy done, after which it was stated that there was some doubt whether she had a lesion of an intervertebral disk or syringomyetia. On examination her fundi and cranial nerves were normal. There was no wasting of the right upper limb, but the left upper limb showed wasting mainly in the muscles innervated from the 7th and 8th cervical and ist dorsal spinal segments with corresponding weakness, and there was also slight weakness of movements at the shoulder and elbow. T h e lower limbs were the site of spastic weakness which was more pronounced on the left side than on the right. T h e tendon reflexes in the upper limbs were brisker on the right side than on the left : in the lower limbs on the left side than on the right. There was left ankle clonus and both plantar reflexes were extensor. Relative analgesia and thermo-an~esthesia were present over both upper limbs below the 5th cervical dermatome, the right half of the trunk, and the right lower limb. There was loss of postural sensibility in the left fingers and toes. T h e r e was thickening of the articular margins of the interphalangeal joints of the right hand. T h e r a d i o g r a p h s are of i n t e r e s t as s h o w i n g a p r o g r e s s i v e c h a n g e . T h e lateral view of t h e cervical s p i n e i n 1947 (Fig. 108) s h o w s gross c h a n g e s i n v o l v i n g C.4, 5, 6, a n d 7 a n d D . I . T h e r e are 6
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osteoporosis and diminution of the intervertebral disk spaces, particularly that between C. 5 and 6, which has almost disappeared. There are also large anterior and posterior osteophytes, and there are suggestions of hyperostosis in the region of the atlanto-axial articulation. A further radiograph taken in 1953 (Fig. lO9) shows that all these changes are further advanced. T h e osteoporosis is
Fig. I Io.--Arthropathyof interphalangealjoints, predominantlyin right hand, in same patient as Figs. io8 and Io9.
greater, and the bodies of C.4, 5, and 6 are now fused together. T h e changes at the atlanto-axial articulation are also more pronounced. Radiographs of the hands (Fig. i I o) show trophic changes in the interphalangeal joints on the right side. This is a case of syringomyelia with secondary arthropathy of the cervical spine which was severe enough at an early stage to give rise to difficulty in diagnosis. T h e disappearance of intervertebral disk space may suggest the Klippel-Feil syndrome, b u t in this case the bodies of the vertebrae have not the characteristic narrow anteroposterior diameter of the Klippel-Feil vertebrre, and by comparing the two radiographs at an interval of six years we can see the intervertebral disk in process of disappearing. T h e bony changes of a cervical arthropathy may be in themselves severe enough to add to the neurological symptoms by compressing the spinal cord and nerve-roots. T h e other principal disorder in which cervical arthropathy can occur is, of course, tabes. The following case illustrates this : Case I2.--A man known to be suffering from tabes of long standing, who had had what was felt to be adequate treatment, complained of severe pains and increasing weakness of the upper limbs. These were the site of muscular wasting and weakness, together with both superficial and deep sensory loss, of a degree quite unusual in tabes. Radiography of the cervical spine showed that he had the gross bony changes of a cervical arthropathy (Fig. 11 i).
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There is a natural tendency when patients known to be suffering from tabes complain of severe radicular symptoms to attribute these to the tabes itself. I t should be borne in mind, however, that they may be the result of a severe arthropathy of the spine, which may cause radicular symptoms by compressing the intervertebral foramina, or even spinal cord symptoms by compressing the cord itself. These changes may occur at any level from the cervical to the lumbar region.
Fig. iii.--CervicaI arthropathy in tabes.
In conclusion let me r e m i n d you that much of what I have been discussing this afternoon was unknown ten years ago, and it is owing to radiology that we know it now. I should like to end, therefore, by paying a tribute to m y radiological colleagues at the L o n d o n Hospital, Dr. Jupe, Dr. Rae, and Dr. Murray, and to my past and present colleagues at the Maida Vale Hospital, Dr. Bull, Dr. Sutton, and Dr. du Boulay. T h e pictures you have seen are all their work. I am only the guide to the gallery. REFERENCES BACHS, A., BARRAQUER-BORDAS,L., BARRAQUER-FERRf~,L., CANADELL, J. M., and MODOLELL, A. (I955) , Brain,
78, 537BULL, J. W. D., NIXON, W. L. B., and PRATT, R. T. C. (I955), Ibid., 78, 229. CHAMBERLAIN,W. E. (I939) , YaleJ. Biol. Med., II, 487 . CHARCOT,J. M. (I88I), Lectures on the Diseases of the Nervous System, 121. Second series. London : Sydenham Society. FRYKHOLM,R. (I95I), Acta chir. scand., IOI, 457. GARClN, R., and OECONOMOS,D. (I953), Les Aspects Neurologiques des Malformations Congdnitales de la Charni~re Craniorachidienne. Paris : Masson. LIST, C. F. (i94i), Arch. Neurol. Psychiat., Chicago, 45, 577. MCGREGOR, M. (i948), Brit. J. Radiol., 21, 171. MCRAE, D. L. (I953), Acta. radiol., Stockh., 4o, 335. PAILLAS,J. E., LEQI~, J., PELLEGRIN,J., and BONNAL,J. (1955), Neurochirurgie, I, 76. SALVINI,L., and PELLICClOLI,V. (I955), Rev. Neurol., 92, 122. SYMONDS,C. P. (I953), Lancet, I, 451.
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S O M E A S P E C T S OF THE N E U R O L O G Y OF T H E CERVICAL SPINE* BY SIR RUSSELL BRAIN, Bt., D.M., LL.D., D.C.L., P.R.C.P., Hon.
F.F.R.
I GREATLY appreciate the honour of giving the first Crookshank Lecture. It is a privilege to be allowed to share thus in the first commemoration of Mrs. Crookshank, that gracious lady who during her lifetime gave such generous help to institutions connected with medicine. It is an additional pleasure that this lecture should have been founded by her son, Viscount Crookshank of Gainsborough, a former Minister of Health, a distinguished parliamentarian, and himself a friend to medicine and of many doctors. It is also a responsibility for one who, though privileged to be an honorary Fellow, is not a radiologist, to deliver this important lecture to this Faculty. However, I have chosen a subject which seems to me to illustrate particularly well the value of the close co-operation between the radiologist and the clinician, which is such an important factor in the progress of medicine at the present time, and one of my aims is to point out that, when the neurologist has to deal with a difficult diagnostic problem involving the spinal cord at the cervical level, the radiologist may be able to supply the vital clue which makes the correct diagnosis possible.
CONGENITAL ABNORMALITIES My interest in the neurology of the cervical spine began about ten years ago when I first began to realize the neurological importance of the intervertebral disk in this region. I soon became aware that there were other disorders of the spinal cord at the cervical level which needed to be differentiated from the cervical myelopathy associated with intervertebral disk protrusion, and that radiology might play an essential part in the diagnosis. Prominent among such conditions are those associated with congenital abnormalities of the cervical spine. This subject has recently been reviewed by Garcin and Oeconomos (i953) , and I shall not now attempt to give a comprehensive account of it. What I have to say throughout this lecture will be based primarily upon my own clinical experience. Congenital abnormalities of the cervical spine are the result of developmental errors. In order to understand them, therefore, it is necessary to begin with a short review of the embryology of this region and it is necessary to take into account the development of the occipital bone also. According to List (1941) the occiput is formed from four sclerotomes. The first cervical vertebra is derived from two sclerotomes--the posterior part of the fourth occipital and the first cervical, but the second cervical vertebra is derived from three. The tip of the odontoid process comes from the fourth occipital sclerotome, the bulk of it from the first cervical sclerotome, of which it would otherwise form the mass of the body, and the base, like the rest of the axis, comes from the second cervical sclerotome. Most of the congenital abnormalities of the occiput and cervical spine are the result either of defective fusion of bones which should be united, or defective differentiation of bones which should be separated. Examples of both will be given later. The congenital abnormalities may be classified as follows : - i. Basilar impression. 2. Occurrence of an occipital vertebra. 3. Occipito-atlantal fusion : assimilation or occipitalization of the atlas. 4. Deformities of the foramen magnum. 5. Malformations of the axis : especially those leading to atlanto-axial dislocation. 6. Cervical spina bifida. 7. The Klippel-Feil syndrome. 8. Miscellaneous abnormalities, including cervical ribs. * The first Crookshank lecture.
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Three points emerge from a study of the literature and of individual cases. Whereas some of these congenital abnormalities occur in isolation, they tend to be multiple. Secondly, in considering the neurological syndromes with which they may be associated it is necessary to distinguish those which are the effects of the congenital bony abnormalities upon the nervous system from congenital abnormalities of the nervous system itself, which are the results of the same tendency to developmental error which produced the bony abnormalities, e.g., the Arnold-Chiari malformation, syringomyelia, hydromyelia, and myelodysplasia. The position is further complicated by the fact that a bony
Fig. 88.--Myelogram in a case of cervical spins bifida with Arnold-Chiari malformation and syringomyelia.
T h e myodil
entered the fourth ventricle which extends to the level of the body of the second cervical vertebra.
abnormality may compress a congenital neurological abnormality. Finally, there is no constant correlation between one type of bony abnormality and one type of neurological abnormality. These facts make the classification of these conditions difficult, since individual patients could often be placed in more than one category. I have decided to classify the cases I am to refer to in relation to what seems their most significant radiological abnormality. Oecipitalization of the Atlas.--Occipitalization of the atlas was the commonest congenital abnormality observed by McRae (1953) in his study of the occipitocervical region. He found that neurological symptoms occurred if the anteroposterior diameter of the spinal cord was 19 mm. or less, or if, as a result of the laxity of the transverse ligament, the odontoid moved backwards and forwards more than 3 mm. on flexion and extension of the head. The signs of compression of the medullospinal junction include nystagmus, hypoglossal palsy, analgesia and thermo-an~esthesia over the cutaneous distribution of the ophthalmic divisions of the trigeminal nerves, and bilateral pyramidal signs, with impairment of superficial and deep sensibility to a variable extent in the limbs. In my own series occipitalization of the atlas has occurred in association with other abnormalities but does not appear to have been responsible for symptoms in itself.
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B a s i l a r Impression.--Basilar impression may be the result either of a congenital abnormality --primary basilar impression, or of a variety of bone diseases, including Paget's osteitis, osteomalacia, rickets, osteofibrosis cystica, hyperparathyroidism, renal rickets, some lipidoses, and some cranioskeletal dysplasias--secondary basilar impression. The primary variety may be familial. I shall not discuss basilar impression in any detail, since it is not in itself an abnormality of the cervical spine. Bull, Nixon, and Pratt (I955) have discussed its radiological criteria. Chamberlain (I939) stated that in normal subjects " all parts of the atlas and axis lie caudad of the base line " drawn
Fig. 89.--Cervical spina bifida with occipitalizafion of the atlas and fusion of the laminae of the first and second cervical vertebrae and the right half of C.3.
from the dorsal margin of the hard palate to the dorsal lip of the, foramen magnum. McGregor (i948) introduced a modifl~cation of Chamberlain's line, namely, the line drawn from the upper surface of the posterior edge of the hard palate to the most caudal point of the occipital curve in the true lateral X-ray ". Bull and his collaborators have introduced a new radiological measurement, which they find more satisfactory, namely, the angle between the plane of the hard palate and the plane of the atlas vertebra, which should not be more than io-z3 °. Using this criterion they have been able to demonstrate the abnormality in I I out of 39 relatives of 20 patients who exhibited primary basilar impression. Fischgold's line is also used in the diagnosis of basilar impression. It is the line drawn between the tips of the mastoid processes in the anteroposterior view or in a tomograph and normally passes between I-2 mm. above or below the tip of the odontoid process. Symptoms were present in io and neurological signs in 8 of McRae's 2I patients with basilar impression. Symptoms of the basilar impression itself may be predominantly ponto-bulbocerebellar or those of a lesion of the upper cervical level of the spinal cord. The former may closely simulate a cerebellar tumour, the latter syringomyelia or disseminated sclerosis. Any of the other congenital abnormalities already mentioned may or may not be associated with primary basilar impression. We need not now further consider malformations of the foramen magnum or the rare occipital vertebra.
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Cervical Spina B i f i d a . - - T h e following three cases illustrate the which cervical spina bifida m a y be associated. Case i.--Female, aged 3o. Several years before, weakness of right arm child ; gradually improved after io months ; diagnosed disseminated sclerosis. months, recurrence of weakness in right arm and leg. Cranial nerves normal.
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v a r i e d clinical pictures w i t h and leg followed birth of third Recovery incomplete. Eleven Slight wasting and weakness of
Fig. 9o.--Same patient as Fig. 89. Myelogram showing obstruction at the level of C.2-3 intervertebral disk.
right upper limb with analgesia and thermo-an~esthesia over area from cervical 4 to dorsal 2 dermatomes inclusive. Spastic weakness of both lower limbs. Tendon-jerks exaggerated, especially on the right side. Both plantar reflexes extensor. Radiographs showed cervical spina bifida C.2, 3, and 4. In cisternal myelography myodil entered 4th ventricle which extended as low as C.2 (Fig. 88). Operation by Mr. Crawford showed ArnoldChiari malformation associated with syringomyelia. A n u m b e r of recent papers have a d d e d to our knowledge of the A r n o l d - C h i a r i malformation. Garcin and O e c o n o m o s p o i n t out that it occurs chiefly in three c i r c u m s t a n c e s : (i) Usually in infancy associated with spina bifida and a m y e l o m e n i n g o c e l e . T h e s e patients often have h y d r o cephalus. (2) It m a y be associated with p r i m a r y basilar impression. (3) I t m a y be apparently the sole, or practically the sole, abnormality. W h e n the A r n o l d - C h i a r i m a l f o r m a t i o n does not give rise to s y m p t o m s until m i d d l e life its diagnosis m a y be e x t r e m e l y difficult. Its association w i t h cervical spina bifida as the sole radiological a b n o r m a l i t y should therefore be b o r n e in mind. I n the n e x t case cervical spina bifida was associated w i t h an unusual p r e s e n t i n g s y m p t o m . Case 2.--Male, aged 18. Born with torticollis treated by operation on right sternomastoid. When I4, while wrestling with a friend, jerked his head backwards and to right and was immediately paralysed from neck down, for I5 minutes. Minor attacks also occurred and he was paralysed for 2 hours after a fall while skating. Can provoke the attacks voluntarily. Head slightly inclined to right. No abnormality in central nervous system. Extension of neck to just beyond vertical limited by tingling. Various manceuvres of neck caused an audible and
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palpable click. Radiographs of neck showed a congenital fusion of C.I, 2, and 3 where the neural arches were bifid (Fig. 89), with some minor congenital abnormalities. Myelography showed an obstruction opposite the C.2-3 disk when the medium flowed from above and opposite C.3-4 disk when it flowed from below (Fig. 9o). Operation by Mr. Northfield and Mr. Osmond-Clarke showed various abnormalities, of which the chief was a large mass of bone occupying the normal position of the posterior arch of the atlas, the laminae and process of C.2, and the left lamina of C.3. This mass appeared fused to the occiput. T h e right lamina of C.3 was loose,
Fig. 9I.--Cervical spina bifida in a patient with a progressive lesion of the cervical spinal cord. and was removed. T h e patient did well until, two years after his operation, he was involved in a motor accident. He was thrown forwards and his head thrown back and he became quadriplegic, but he has partially recovered from this. I n t h e t h i r d case radiological d e m o n s t r a t i o n o f a cervical s p i n a bifida e s t a b l i s h e d a c o n g e n i t a l o r i g i n for t h e c o n d i t i o n a n d m a d e it p o s s i b l e to e x c l u d e d i s s e m i n a t e d sclerosis, w h i c h h a d b e e n a p r e v i o u s diagnosis.
Case 3.--Female, aged 35. T e n years previously noticed dragging of the right leg. Gradually increasing weakness of right leg, then left leg, then arms. T h e r e was a history of a fall many years previously. T h e clinical picture was a moderate spastic quadriplegia with normal cranial nerves, including a normal jaw-jerk and slight relative analgesia below C.5 on both sides. Radiographs showed cervical spina bifida at the level of C.z (Fig. 9I). No further investigations were possible. T h e s e cases i l l u s t r a t e t h e v a l u e of m y e l o g r a p h y w i t h a n o p a q u e m e d i u m , b u t i n s u i t a b l e cases m y e l o g r a p h y w i t h air o r gas m a y give as m u c h , or e v e n m o r e , i n f o r m a t i o n . The Klippd-Feil Abnormality.--The K l i p p e l - F e i l a b n o r m a l i t y is n o t u n c o m m o n l y associated w i t h t h e S p r e n g e l s h o u l d e r . I n o n e s u c h case t h e r e was w a s t i n g of t h e m u s c l e s o f t h e s h o u l d e r - g i r d l e o n o n e side, a n d o n t h i s a c c o u n t t h e p a t i e n t was s e n t for i n v e s t i g a t i o n w i t h a t e n t a t i v e diagnosis of poliomyelitis.
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Case 4 - - M a l e , aged i I. A t t h e age of 6 h e was noticed to have a p r o t r u d i n g s h o u l d e r - b l a d e . T h e right scapula was h i g h e r t h a n the left, a n d t h e right trapezius, r h o m b o i d s , a n d levator anguli scapulae were wasted a n d weak. Radiographs s h o w e d assimilation of t h e atlas a n d fusion of t h e bodies of C.z, 3, a n d 4 (Fig. 92).
Sometimes a half-vertebra may be present on one side and not on the other, giving rise to cervical scoliosis or torticollis. T h e following case is an instance of this. Case 5 . - - M a l e , aged 26, h a d always been smaller on t h e left side of his b o d y t h a n on t h e right. H e h a d a cervicodorsal scoliosis c o n v e x to t h e left. T h e r e was no evidence of organic disease of t h e central n e r v o u s
Fig. 9z.--Occipitalization of the atlas and fusion of C.2 and C.3. system, b u t he h a d hysterical t r e m o r a n d weakness of t h e left u p p e r a n d lower limbs. R a d i o g r a p h s s h o w e d fusion of the bodies of C.2 a n d 3, C.5 a n d 6, a n d C.7 a n d D . I with separated f r a g m e n t s , one of w h i c h appeared to be an additional h a l f - b o d y c a u s i n g t h e scoliosis (Fig. 93).
Other associated abnormalities include cervical ribs. One patient had a Klippel-Feil syndrome and bilateral cervical ribs, together with the characteristic spatulate expansion of seventh cervical spinous process (Figs. 94, 95). This patient's radiographs illustrate the common association of the Klippel-Feil abnormality with cervical spondylosis, which is no doubt to be explained by the undue stress upon adjacent intervertebral disks caused by the lack of mobility in the fused vertebra. This patient attended hospital on account of pain, tingling, numbness, and weakness in the right hand. In spite of all these abnormalities in the neck the symptoms proved to be due to compression of the median nerve in the carpal tunnel, and were cured by operation on that. Lesions involving the Odontold P r o e e s s . - - L e s i o n s involving the odontoid process are not uncommon, are of considerable clinical interest, and sometimes pass unrecognized. According to one classification the term dislocation of the atlas is used when the transverse ligament is torn and fracture-dislocation when the odontoid process is fractured at the base. It is perhaps more convenient to use the term atlanto-axial dislocation to cover all displacements of one bone on the other, whatever the cause. The following varieties may then be recognized. I. Dislocation secondary to the spread of infection to the atlanto-axial articulation : This, though rare to-day, was well recognized by the clinicians of fifty years or more ago. It was most frequently
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encountered in children as the result of tonsillitis, retropharyngeal abscess, acute mastoiditis and osteomyelitis of the occiput, tuberculous cervical adenitis, and tuberculous caries. Charcot (i88i) alludes to " the terrible accident which somewhat frequently happens in Pott's disease of the cervical region ", i.e., rupture of the transverse ligament resulting in sudden death. T h e symptoms in non-fatal cases may include headache and vomiting, hypoglossal paralysis, sensory loss over the ophthalmic division of the trigeminal nerve to pain, heat, and cold, motor
Fig. 93.--Klippel-Feil abnormality with asymmetry leading to cervical scoliosis.
weakness and spasticity in the limbs with impairment of superficial and deep sensibility. The head is likely to be tilted, with pain in the neck, especially on any attempt to move it. D u r i n g the war I saw a young soldier in whom this lesion had followed an acute retropharyngeal infection. His only symptom was bilateral paralysis of the tongue. More recently I saw another case. Case 6.--Female, aged 7- (A patient of Mr. Osmond-Clarke and Mr. Northfield.) A few days after an illness characterized by high fever, a septic throat, and a lump in the side of the neck, her head was noticed to be on one side. Head was held in torticollis with chin to right and occiput to left. Central nervous system normal. Radiographs showed atlanto-axial dislocation with destruction of the left lateral mass of the atlas (Fig. 96). She was treated with head traction and a minerva plaster, and later a plaster collar, with excellent result. W h e n the transverse ligament has been softened by disease the dislocation may be provoked by a normal movement of the head. I n the following case, however, there was evidence that both infection and trauma played a part. Case 7.--A male, aged 44, suffered 5 years previously from an attack of meningitis which followed a boil on the neck. He made a good recovery with chemotherapy, and was free from symptoms except for neck stiffness until he fell and hit the back of the head, after which he developed severe pain in the neck accompanied by
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Fig. 94.--Klippel-Feil abnormality. Note the abnormal spinous processes.
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Fig. 95.--Same patient as Fig. 94 showing bilateral cervical ribs and abnormal spinous processes.
Fig. 96,--Atlanto-axial dislocation associated with osteomyelitis of the lateral mass of the atlas (tomogram).
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occipital headaches, both made worse by coughing. On examination he exhibited nystagmus, analgesia over the ophthalmic division of the trigeminal nerve on both sides, weakness and cutaneous sensory loss in both upper limbs with general exaggeration of the tendon reflexes and bilateral extensor plantar reflexes. His cerebrospinal fluid contained i6o rag. of protein and there was little rise of pressure on jugular compression. Radiographs showed an atlanto-axial dislocation (Fig. 97). He was treated at first with a plaster collar, but subsequently required operation--cervical laminectomy and occipito-cervical fusion by Mr. Northfield and Mr. Osmond-Clarke.
Fig. 9 7 . - - T o m o g r a m of atlanto-axial dislocation due to t r a u m a following meningitis,
Fig. 98.--Atlanto-axiat dislocation following ? congenital failure of fusion of odontoid and leading to myelopathy of late onset.
2. Traumatic atlanto-axial dislocation clue to rupture of the transverse ligament : T h i s condition calls for no special comment.
3. Atlanto-axial dislocation due to interruption of the odontoid process : T h e pathogenesis of this condition has recently been reviewed by Bachs, Barraquer-Bordas, Barraquer-Ferr4, Canadell, and Modolell (i955). T h e y recognize that the interruption of the odontoid process may be due to one of four causes : - i. Simple fracture of the odontoid. ii. Apophysiolysis. Since the odontoid does not unite to the body of the axis until the age of 3 years, trauma occurring before that age may result in separation of the odontoid through apophysiolysis. iii. Congenital absence of the odontoid process. iv. Failure of union of the odontoid with the rest of the axis. I n any of these four conditions atlanto-axial dislocation may occur after trauma. T o this must be added another cause. v. A b n o r m a l laxity of the transverse ligament in association with assimilation of the atlas (List, I94I ; McRae, I953). Bachs and others point out the distinguishing features of simple atlanto-axial dislocation and atlanto-axial dislocation following interruption of the odontoid process. I n the former there is slipping, usually moderate, between the atlas and the axis in two parallel planes, and when the head
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is flexed the abnormal mobility is reduced to a minimum. W h e n the odontoid process is separated, however, the skull and the atlas together show what they describe as an intense abnormal ' patellar ' mobility on the convex surface of the axis body. W h e n the head is flexed, the dislocation between the atlas and the axis is more severe than that occurring in simple atlanto-axial dislocation. Moreover the dislocation does not follow two parallel planes, because the atlas slips forwards and downwards, so that its plane makes with the plane of the axis a progressive angle open upwards and backwards. Another radiological diagnostic point, of course, is that when the transverse ligament is ruptured the odontoid process moves laterally together with the axis, whereas when the odontoid itself is fractured it is fixed to the atlas by the transverse ligament and therefore follows the displacements of the atlas. McRae (1953) measured the amount of slipping of the atlas on the axis. I n three cases of simple atlanto-axial dislocation the slipping was slight, up to 4 mm., but when the odontoid process was separated the slipping measured 5-25 mm., with an average of 14 mm. in the patients with symptoms and i o mm. in those without.
Late Myelopathy after Atlanto-axial Dislocation.--Several authors have recently drawn attention to the occurrence of symptoms resulting from atlanto-axial dislocation many years after the trauma which is likely to have been responsible for it (Salvini and Pelliccioli, 1955; Paillas, Legre, Pellegrin, and Bonnal, 1955; Bachs, BarraquerBordas, Barraquer-Ferr6, Canadell, and Modolell, 1955). Not infrequently head injury has occurred during childhood or adolescence. T h e onset of neurological symptoms was in one case delayed eig. 99.--Atlanto-axialdislocationdue to secondarycarcinoma for 44 years. By the time the patient comes under of atlas. observation there may be no way of deciding whether the initial lesion was a fracture of the odontoid or whether the injury caused trouble only because there was a pre-existing congenital abnormality, such as a failure of the odontoid to unite with the body of the axis. I n some cases, however, there is clear radiographic evidence of a congenital abnormality in the occipito-atlantal region and then the myelopathy may be presumed to be the delayed effect of this congenital abnormality upon the junction of the medulla and the spinal cord. Bachs and his fellow workers draw attention to the occurrence of subluxation of the odontoid owing to laxity of the transverse ligament as a result of which flexion of the head m a y produce repeated pressure by the odontoid upon the spinal cord. The following patient of m y own illustrates some of these points. Case 8.--Female, aged 56. For about a year had noticed increasing weakness and stiffness of the legs and later the arms. She denied injury. Her cranial nerves were normal except for nystagmus. She had a severe spastic quadriplegia with loss of postural sensibility in the right hand and both feet. Both plantar reflexes were extensor. Her cerebrospinal fluid was normal in both composition and dynamics. Radiographs showed that the skull, atlas, and odontoid had turned forwards on the axis, with arthritic changes between atlas and axis (Fig. 98). She was treated with head traction and a plaster collar.
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NEOPLASMS OF THE CERVICAL SPINE C a r c i n o m a t o u s I n v o l v e m e n t o f the A t l a s . - - T h i s rare o c c u r r e n c e is i l l u s t r a t e d b y the f o l l o w i n g case : -
Case 9.--Male, aged 53. One year previously suddenly noticed stiffness of the neck and that his head was twisted to one side. Pain and stiffness of the neck increased : 2 weeks previously developed double vision.
Fig. Ioo.--Enlargement of intravertebral foramen between C.3 and C.4 due to neurofibroma (dumb-bell tumour),
Fig. IOI.--Invasion of cervical spine by secondary carcinoma of prostate.
Head flexed to left : lateral flexion and rotation to left very limited and painful. Left external rectus palsy with slight weakness of left half of soft palate, left sternomastoid and left half of tongue. Radiographs showed extensive destruction of bone of skull on left side and of left half of anterior arch of atlas, due to metastatic carcinoma (Fig. 99). There was also a metastasis in the right 6th rib. No primary was found. N e o p l a s m s of t h e cervical s p i n e are rare. Fig. I 0 0 s h o w s e n l a r g e m e n t of a n i n t e r v e r t e b r a l f o r a m e n b y a n e u r o f i b r o m a . Fig. i o i is a n e x a m p l e of s e c o n d a r y c a r c i n o m a f r o m t h e p r o s t a t e .
CERVICAL S P O N D Y L O S I S T h e p r i n c i p a l n e u r o l o g i c a l m a n i f e s t a t i o n s of cervical s p o n d y l o s i s are n o w well d e f i n e d a n d I do n o t p r o p o s e to deal w i t h t h e m p r i m a r i l y h e r e . I t h i n k it w o u l d b e m o r e useful to discuss t h e i n t e r p r e t a t i o n of t h e radiological a p p e a r a n c e s i n r e l a t i o n to t h e clinical p i c t u r e a n d to t h e i r p a t h o logical basis. Fig. i 0 2 s h o w s a sagittal s e c t i o n t h r o u g h t h e cervical s p i n e i n a case of cervical spondylosis. T h e p o i n t to w h i c h I w o u l d d r a w a t t e n t i o n is t h a t a l t h o u g h a n u m b e r of i n t e r v e r t e b r a l disks s h o w d e g e n e r a t i o n , n o t all d e g e n e r a t e d disks are t h e site of o s t e o p h y t e s . S i n c e it is t h e o s t e o p h y t e s w h i c h
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are the chief cause of symptoms, it follows that disk degeneration in itself, as shown radiologicaUy, is not necessarily a cause of symptoms. Fig. Io 3 shows the myelogram of a patient with obvious disk degeneration, as indicated by narrowing of the intervertebral disk spaces, yet with no evidence of projection into the spinal canal at that level.
Fig. Io2.--Sagittal section of cervical spine in cervical spondylosis (kindly lent by Dr. Marcia Wilkinson).
Returning to the sagittal section you will note that where a posterior osteophyte has been formed there is a noticeable sclerosis of the posterior and inferior part of the bodies of the adjacent vertebrze. It follows that in radiographs of the neck of a patient suspected of symptoms due to cervical spondylosis the point to which attention should be directed is not only, or even chiefly, narrowing of the intervertebral disk spaces, but the presence or absence of an opacity projecting into the spinal canal from the posterior end of the disk space, and associated with sclerosis of the adjacent portions of the bodies of the vertebrae. The osteophyte is usually easy to distinguish, but may show up better when less penetration is used. Can we then dispense with myelography in many cases ? When posterior osteophytes are readily recognizable, and correspond in position to the level of the symptoms, it will often be unnecessary to do a myelogram. But it is important to remember that some osteophytes show up very little, or appear on plain radiographs to be much smaller than in fact they are. In such cases only a myelogram will give a reliable account of the size of the protrusion. In Fig. 104 the plain lateral view of the cervical spine shows how little disk narrowing there may be in spite of the presence of large posterior osteophytes and how little evidence the plain radiograph may give of the size of the osteophytes as shown in the myelogram.
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Another common point of difficulty is what appears to be a lack of correlation between the level of the disk protrusion and the upper level of the spinal cord lesion. It is quite common to find that motor, reflex, and sensory functions of the spinal cord are disturbed up to a segment or two higher than that which should be compressed by the highest disk protrusion. The explanation of
Fig. io3.--Normal myelogram in cervical spondylosis.
Fig. io4.--Cervieal spondylosis. Plain radiograph and myelogram showing posterior osteophytes.
this is that the production of pathological changes in the spinal cord in cervical spondylosis is a complex matter, into which enter a number of factors, of which the direct pressure of the protruding intervertebral disk is only one. As the result of tension, traction, and interference with blood-supply the cervical myelopathy is more extensive than the area directly compressed. The same is true of radicular symptoms. Here again a number of factors come into play. Fig. lO5 illustrates the three common sites of intervertebral disk protrusion. A central protrusion, if large enough, will compress the spinal cord. A posterolateral protrusion will sometimes compress the spinal cord, but may compress the spinal roots within the spinal canal against the corresponding lamina. An intraforaminal protrusion will compress the spinal roots within the intervertebral foramen. There is one point in connexion with spinal root pressure which is liable to be overlooked. As one moves down the cervical cord one finds that the spinal roots run more and more obliquely to reach the intervertebral foramina. This, of course, is true throughout the spinal canal, and is due to the fact that the spinal cord is shorter than the spinal column. The result of this is that a spinal root from any segment of the cervical enlargement may be compressed at more than one level of the spine, either by a posterolateral protrusion of the intervertebral disk at the level at which it leaves the spinal cord, or, usually at one vertebra lower, by an intraforaminal protrusion into the foramen through which it leaves the spinal canal. There is yet another factor. Frykholm (1951) has pointed out that cervical spondylosis, by narrowing intervertebral disks, shortens the cervical spine. As the spinal cord remains the same length, shortening the spine must affect the position of the spinal roots within the intervertebral
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foramina, particularly in the case of the lower cervical vertebrae. As a result the spinal roots may be compressed against the lower border of intervertebral foramina which are themselves normal in that they are neither narrowed nor the site of osteophytes. Here, then, we have some of the explanations of apparent discrepancies between the level of a root lesion and the radiographic changes in the neck, and also of the common observation that a patient may appear to have multiple roots involved - - a typical picture of what used to be called ' brachial neuritis ' - - a n d yet the radiographic changes may
Fig. ~os.--Common sites of protrusion of intervertebral disks in cervical spondylosis (Frykholm).
Fig. Io6.--Barium swallow showing deformity of oesophagus caused by anterior osteophytes in cervical spondylosis.
appear to be limited to one intervertebral disk and the corresponding foramina. I suspect that there be yet another causal factor here. In the presence of even a limited amount of cervical spondylosis, if it is sufficient to tether the spinal roots within the foramina, it disturbs the normal reactions of the nerve-roots of the brachial plexus to comparatively slight everyday stresses and strains. Such patients may, therefore, very easily, as the result of perhaps unnoticed strains or postural stresses, develop the clinical picture of multiradicular brachial-root irritation. While limitation of both active and passive movement of the neck is the common result of cervical spondylosis, abnormal mobility is not rare. Slipping of the body of one vertebra upon another at the site of a degenerated disk on flexion and extension of the spine is a potent cause of increasing the damage.
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Among the curiosities of cervical spondylosis may be mentioned pressure upon the eesophagus by large anterior osteophytes. Fig. lO6 illustrates this. The disk protrusion was discovered in the course of a barium swallow and it was then realized that the pains in the arms of which the patient had complained were due to cervical spondylosis. Whether oesophageal symptoms can be produced by cervical spondylosis, either as the result of the pressure of osteophytes or as the result of interference with the innervation, is a point which we are at present investigating. Another point which
Fig. IO7.--Paget's osteitis of cervical spine : a case in which quadriplegia followed a blow on the head.
would repay investigation is the importance of changes in the occipito-atlantal and atlanto-axial joints as a cause of symptoms, particularly headache. T h e Effect o f T r a u m a u p o n C e r v i c a l Spondylosis. Attention has recently been drawn to the effect of trauma to the head and neck upon patients suffering from cervical spondylosis. In such patients a blow on the head, particularly one producing forcible extension of the neck, or even hyperextension in the course of an anesthetic or operation (Symonds, I953), may cause severe and largely irreparable damage to the cervical spinal cord. This is the result of the complex factors which limit movement and tend to impair the blood-supply of the cervical spinal cord in spondylosis. It is well established that this type of traumatic myelopathy may, and usually does, occur in the absence of any gross change produced by the injury in the ligaments or bones of the spine. Less attention has been directed to the similar damage to the cervical nerve-roots which may be produced in the same way. This may be unilateral or bilateral and may, or may not, be associated with damage to the spinal cord. Fig. IO7 shows that the same thing may happen when the cervical spine is the site of a lesion other than spondylosis. Case i o . - - A n elderly m a n s l i p p e d w h i l e w a l k i n g d o w n s t a i r s and s t r u c k his head against the wall. H e fell d o w n a n d f o u n d t h a t he was u n a b l e to get up again. H e was f o u n d to h a v e m o d e r a t e q u a d r i p l e g i a from w h i c h he m a d e a partial recovery, so t h a t he b e c a m e able to walk. R a d i o g r a p h s of his cervical spine s h o w e d the c h a n g e s of P a g e t ' s osteitis.
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ARTHROPATHIES
T h i s case leads n a t u r a l l y to t h e c o n s i d e r a t i o n of b o n y c h a n g e s i n t h e cervical s p i n e w h i c h m a y closely s i m u l a t e cervical s p o n d y t o s i s a n d w h i c h t h e r e f o r e e n t e r i n t o its differential diagnosis. T h e s e are the cervical a r t h r o p a t h i e s , a n d as i n t h e s e cases t h e b o n y c h a n g e s are always associated w i t h evidence of a lesion of t h e cervical s p i n a l cord, t h e y m a y give rise to a c o n s i d e r a b l e difficulty.
Case i i . - - F e m a l e , aged 53. W h e n she was about a6 she noticed that the left foot began to twist. In her early thirties she noticed numbness and pains in the hands, and that she would burn the right hand without
Fig. io8.--Cervical arthropathy in syringomyelia radiographed in 1947.
A larninectomy had previously been carried out.
Fig. IO9.--$ame patient as in Fig. lO8.
Radiograph taken in
1953.
knowing it. Weakness developed in the upper limbs, where she said the left was weaker and the right the more numb. She also complained of numbness of the right leg and of pains in the head and neck. When she was 33 she had a laminectomy done, after which it was stated that there was some doubt whether she had a lesion of an intervertebral disk or syringomyetia. On examination her fundi and cranial nerves were normal. There was no wasting of the right upper limb, but the left upper limb showed wasting mainly in the muscles innervated from the 7th and 8th cervical and ist dorsal spinal segments with corresponding weakness, and there was also slight weakness of movements at the shoulder and elbow. T h e lower limbs were the site of spastic weakness which was more pronounced on the left side than on the right. T h e tendon reflexes in the upper limbs were brisker on the right side than on the left : in the lower limbs on the left side than on the right. There was left ankle clonus and both plantar reflexes were extensor. Relative analgesia and thermo-an~esthesia were present over both upper limbs below the 5th cervical dermatome, the right half of the trunk, and the right lower limb. There was loss of postural sensibility in the left fingers and toes. T h e r e was thickening of the articular margins of the interphalangeal joints of the right hand. T h e r a d i o g r a p h s are of i n t e r e s t as s h o w i n g a p r o g r e s s i v e c h a n g e . T h e lateral view of t h e cervical s p i n e i n 1947 (Fig. 108) s h o w s gross c h a n g e s i n v o l v i n g C.4, 5, 6, a n d 7 a n d D . I . T h e r e are 6
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osteoporosis and diminution of the intervertebral disk spaces, particularly that between C. 5 and 6, which has almost disappeared. There are also large anterior and posterior osteophytes, and there are suggestions of hyperostosis in the region of the atlanto-axial articulation. A further radiograph taken in 1953 (Fig. lO9) shows that all these changes are further advanced. T h e osteoporosis is
Fig. I Io.--Arthropathyof interphalangealjoints, predominantlyin right hand, in same patient as Figs. io8 and Io9.
greater, and the bodies of C.4, 5, and 6 are now fused together. T h e changes at the atlanto-axial articulation are also more pronounced. Radiographs of the hands (Fig. i I o) show trophic changes in the interphalangeal joints on the right side. This is a case of syringomyelia with secondary arthropathy of the cervical spine which was severe enough at an early stage to give rise to difficulty in diagnosis. T h e disappearance of intervertebral disk space may suggest the Klippel-Feil syndrome, b u t in this case the bodies of the vertebrae have not the characteristic narrow anteroposterior diameter of the Klippel-Feil vertebrre, and by comparing the two radiographs at an interval of six years we can see the intervertebral disk in process of disappearing. T h e bony changes of a cervical arthropathy may be in themselves severe enough to add to the neurological symptoms by compressing the spinal cord and nerve-roots. T h e other principal disorder in which cervical arthropathy can occur is, of course, tabes. The following case illustrates this : Case I2.--A man known to be suffering from tabes of long standing, who had had what was felt to be adequate treatment, complained of severe pains and increasing weakness of the upper limbs. These were the site of muscular wasting and weakness, together with both superficial and deep sensory loss, of a degree quite unusual in tabes. Radiography of the cervical spine showed that he had the gross bony changes of a cervical arthropathy (Fig. 11 i).
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There is a natural tendency when patients known to be suffering from tabes complain of severe radicular symptoms to attribute these to the tabes itself. I t should be borne in mind, however, that they may be the result of a severe arthropathy of the spine, which may cause radicular symptoms by compressing the intervertebral foramina, or even spinal cord symptoms by compressing the cord itself. These changes may occur at any level from the cervical to the lumbar region.
Fig. iii.--CervicaI arthropathy in tabes.
In conclusion let me r e m i n d you that much of what I have been discussing this afternoon was unknown ten years ago, and it is owing to radiology that we know it now. I should like to end, therefore, by paying a tribute to m y radiological colleagues at the L o n d o n Hospital, Dr. Jupe, Dr. Rae, and Dr. Murray, and to my past and present colleagues at the Maida Vale Hospital, Dr. Bull, Dr. Sutton, and Dr. du Boulay. T h e pictures you have seen are all their work. I am only the guide to the gallery. REFERENCES BACHS, A., BARRAQUER-BORDAS,L., BARRAQUER-FERRf~,L., CANADELL, J. M., and MODOLELL, A. (I955) , Brain,
78, 537BULL, J. W. D., NIXON, W. L. B., and PRATT, R. T. C. (I955), Ibid., 78, 229. CHAMBERLAIN,W. E. (I939) , YaleJ. Biol. Med., II, 487 . CHARCOT,J. M. (I88I), Lectures on the Diseases of the Nervous System, 121. Second series. London : Sydenham Society. FRYKHOLM,R. (I95I), Acta chir. scand., IOI, 457. GARClN, R., and OECONOMOS,D. (I953), Les Aspects Neurologiques des Malformations Congdnitales de la Charni~re Craniorachidienne. Paris : Masson. LIST, C. F. (i94i), Arch. Neurol. Psychiat., Chicago, 45, 577. MCGREGOR, M. (i948), Brit. J. Radiol., 21, 171. MCRAE, D. L. (I953), Acta. radiol., Stockh., 4o, 335. PAILLAS,J. E., LEQI~, J., PELLEGRIN,J., and BONNAL,J. (1955), Neurochirurgie, I, 76. SALVINI,L., and PELLICClOLI,V. (I955), Rev. Neurol., 92, 122. SYMONDS,C. P. (I953), Lancet, I, 451.