The present paper analyses the new data accumulated since 1972 concerning the etiology and pathogenesis of Huntington’s chorea. Particular attention is paid to the respective roles of the dopaminergic and GABA-ergic systems.

Lymphocytes of 29 subjects were assayed for MIF production in response to P2 peripheral nerve protein, crude human peripheral nerve and human central nervous system Al basic myelin protein. Seven were performed in normal control subjects, 12 in Guillain-Barré patients (GB), 5 with other polyneuropathies and 5 in patients with multiple sclerosis (MS). Only GB patients with acute illness produced MIF in response to neuritogenic P2 protein and crude human nerve. Two MS patients in the acute phase of an exacerbation and one GB patient produced MIF in Response to Al protein. The results of this study demonstrate cellular hypersensitivity to a neuritogenic constituent in peripheral nervous tissue and support the concept that this may be important in the pathogenesis of GB.

A study has been made of the neurophysiological changes that follow spinal cord lesions in man. The Achilles tendon reflex (ATR) is used to estimate transmission in the la monosynaptic pathway, and the tonic vibration reflex (TVR) to estimate transmission in the la polysynaptic pathway to motoneurons. The inhibition of the H reflex by vibration is used as an estimate of presynaptic inhibition of the la monosynaptic pathway. Immediately following a complete lesion of the spinal cord presynaptic inhibition of the la monosynaptic pathway appears to be greatly increased. This enhanced inhibition may last several months but it eventually declines and in some instances becomes less than normal. Transmission in the la polysynaptic pathway is permanently abolished by a complete spinal lesion. A hypothesis is developed from these findings to explain the evolution of some of the clinical features that follow complete spinal lesions in man. Distinct differences are observed when the spinal lesion is incomplete. Transmission in the la polysynaptic pathway may be preserved and there may be no increase in presynaptic inhibition. These differences may depend upon the integrity of certain spinal long tracts which cannot be tested clinically.

In 1975, medical neurology is a well established, viable, growing specialty in Canada. There are now almost 250 neurologists scattered across the country, congregated largely in the hospitals associated with our 16 medical schools. Neurology is a major component of the undergraduate curriculum in each of these schools, and the majority of schools are approved for postgraduate training in our specialty. The Royal College has certified an average of 18 new neurologists each year for the past five years. In our hospitals we work closely with our internist and neurosurgical colleagues and we receive the support of highly competent teams of neuropathologists, clinical electrophysiologists and neuroradiologists. We believe that we provide a generally high standard of consultation service to our medical and surgical colleagues. We accept direct responsibility for patients suffering from a host of acute neurological problems, but we accept long term responsibility for very few. We do a great deal of teaching at both the undergraduate and graduate levels. In fact, the major role which neurology plays in undergraduate curricula, and the stimulus of postgraduate education, probably have been the two most influential factors shaping the number, work patterns and distribution of Canadian neurologists. Many of us are engaged in clinical investigation, but relatively few medical neurologists in Canada make fundamental research contributions.

A retrospective analysis of 274 patients with intracranial aneurysms, diagnosed either angiographically or at autopsy between 1968 and 1973 at the University of Alberta, was carried out. One hundred and forty-six patients had intracranial clipping of the aneurysm. Clinical and radiologic data were abstracted from the chart and the angiographic studies. Probability of survival curves were constructed. Associations between various clinical factors and survival at two months were demonstrated. The most important prognostic factors were the clinical grade at angiography or surgery, followed by the presence of preoperative spasm, hematoma or focal edema, elevated blood pressure on admission, time interval from hemorrhage to surgery and age. The data lends some support to the policy of operating on patients in good neurological condition, even if their pre-operative angiogram shows spasm.

The clinical features of the Chiari Malformation in seven adult patients are presented. It is suggested that the clinical syndromes associated with this malformation, in adults, can be classified as (a) compression of structures at the level of the foramen magnum (with or without radiologically demonstrable associated bony anomaly at the cranio-vertebral junction) (b) increased intracranial pressure or obstructive hydrocephalus and (c) intramedullary cervical cord syndrome. The usefulness of tomography, and demonstration of the vertebro-basilar circulation in the neuro-radiologic investigation of these patients is emphasized. The surgical procedures performed in the management of these patients are outlined.

A five-year-old boy succumbed 24 days following an unusual farm accident in which considerable manure was deposited in multiple lacerations.Death was due to an extensive meningo-encephalomyelitis caused by a nematode that is ordinarily saprophagous.

A 45-year old man was referred to the Johns Hopkins Hospital with a seven-year history of repeated episodes of light-headedness, increasing irritability and forgetfulness. Examinations revealed a right superior, incongruous quadrantanopsia. EEG showed an abnormality in the left temporal lobe, and a cerebral angiogram outlined an avascular mass in the left cerebral hemisphere. At operation, the patient was found to have a giant dermoid cyst involving the left frontal, temporal and parietal lobes. Over the last 30 years we have encountered only 6 cases of intracranial epidermoids and 3 cases of intracranial dermoids. These cases are cited, and a discussion of the embryology, histology, clinical characteristics, and treatment of these lesions with a review of the literature is undertaken.

A 56 year old woman developed symptoms of lumbar nerve root compression caused by a granuloma arising in the ligamentum flavum. The histological features of the lesion are discussed and the clinical and radiological findings of the patient are described.

This is a single case report of an ovarian teratoma. It is a unique case of a primitive neuroepithelial tumor with many similarities to a medulloblastoma arising in an ovarian teratoma, and the second report of fetal cerebellum occurring in a teratoma of the ovary.

This patient presented as a subacute progressive cervical myelopathy and the differential diagnosis included cervical spondylotic myelopathy and intramedullary mass. Microscopically, vascular lesions plus a patchy myelomalacia indicated a vasculitis. However, there was no suggestion of a generalized vasculitis at autopsy and the only supporting laboratory study was a raised erythrocyte sedimentation rate. It would seem that a vasculitis similar to polyarteritis nodosa or other collagen disease may be confined to the spinal cord.