The use of diversionary CSF shunting devices for the treatment of hydrocephalus has been surveyed in Canada. Various factors influencing the operation of shunting devices, the characteristics of commercial shunts and the causes of shunt malfunction are described. Suggestions are made as to how to reduce the incidence of shunt malfunction.

A decrease in spinal cord blood flow (SCBF) is a known sequela of spinal cord injury. The radioactive microsphere technique permits repeated measurement of spinal cord blood flow (SCBF) and cardiac output (CO) in the same experimental animal. The purpose of this study was to adapt the radioactive microsphere technique for use in the rat extradural clip compression injury model used in our laboratory.

Thirteen adult Wistar rats were anaesthetized and ventilated. Mean systemic arterial pressure (MSAP) was recorded continuously. Control animals (n = 8) did not have a surgical procedure whereas the injured animals (n = 5) underwent a C7-T1 laminectomy followed by a one minute, 50 gram extradural clip compression injury at Tl. Radioactive microspheres were used for two blood flow and CO determinations in both groups.

MSAPfell 59% in the injured animals (p<0.01), but this was not accompanied by significant changes in heart rate or CO. There was a 50% reduction in SCBF in the injured cord (p<0.02), and there were significant reductions in cerebral blood flow (p<0.05) and cerebellar blood flow (p<0.02) following spinal cord injury.

Mechanisms responsible for load compensation during fast voluntary movements were investigated in 20 normal subjects trained to carry out rapid wrist flexions against a standard load. When an unanticipated increase in load occurred, there was a compensatory increase in agonist EMG and decrease in antagonist EMG. Unanticipated decreases in load produced reciprocal changes with a decrease in agonist EMG and an increase in antagonist EMG. The latency of these EMG changes was quite short and compatible with a spinal reflex mechanism rather than a long loop response. The results suggest that mechanisms exist at the spinal level to allow rapid modification of motor programs when unanticipated load conditions are encountered on initiation of movement.

This paper reports two children who had mental retardation as the predominant manifestation of vein of Galen malformations. C.T. scans demonstrated extensive intracerebral calcification. Surgery reversed the progressive downhill course in one patient and may have arrested further deterioration in the other. The pathophysiological mechanisms underlying the clinical and radiographic features are discussed.

We report a case of intermittent compression of the lingual nerve due to sialolithiasis and presenting with episodic unilateral numbness of the tongue. Removal of the obstruction has relieved the patient of symptoms over a 21 month period to date.

A patient with a submandibular gland carcinoma was found clinically to have a unilateral chorda tympani, lingual and hypoglossal nerve deficit. This unique neurological entity of loss of taste sensation of one-half of the tongue (hemiageusia), hemianaesthesia and hemiatrophy of the tongue, has not previously been reported.

A case of motor neuron disease with clinical and pathological resemblance to amyotrophic lateral sclerosis (ALS) in a woman who was severely bitten on the ankle by a cat is described. Weakness first appeared at the ankles and relentlessly advanced proximally, terminating in death from pulmonary failure in a year. A number of unusual features that are uncharacteristic of ALS were found that included a markedly elevated antinuclear antibody titre in the serum and the presence of prominent oligoclonal bands in the cerebrospinal fluid. The spinal cord showed loss of anterior horn cells and pyramidal degeneration that are characteristic of ALS, but an extraordinary finding was the presence of transmural granulomatous inflammation of numerous small and medium sized vessels, especially veins, in the subarachnoid space around the cord. There were also inflammatory changes in the brainstem and spinal cord consisting of microglial and astrocytic nodules and perivenous cuffing by mononuclear cells. Ill-defined hyaline eosinophilic cytoplasmic inclusions were seen in some remaining anterior horn cells. No viral particles were found by electron microscopy despite an extensive search. Virological studies were inconclusive but there is reason to believe that this patient's illness was caused by an as yet unidentified virus.

We report a 50 year old woman with primary hypothyroidism and nemaline myopathy to call attention to the rare coexistence of these two disorders.

Three patients are described with pathologically verified Creutzfeldt-Jakob disease (CJD) who presented with localizing clinical signs accompanied by focal electroencephalographic abnormalities including periodic lateralized epileptiform discharges (PLEDS). With further progression of the disease, diffuse background slowing and continuous bisynchronous periodic discharges appeared in all three cases. There was good correlation between the initial focal clinical manifestations and the EEG findings.

A Tourette-like syndrome (TLS) may occur after long-term neuroleptic treatment. A review of 11 cases reported in the literature is given. We describe the onset of a TLS in a 13-year old boy with childhood schizophrenia after short term, low-dose treatment with thioridazine. The syndrome resolved 5 months after neuroleptic withdrawal. Subsequent exposure to neuroleptics (mainly perphenazine) induced a recurrence of motor tics and involuntary vocalizations which resolved on drug discontinuation. Awareness that neuroleptics may induce a TLS may lead to prompt recognition and avoidance of labelling the manifestations as symptoms of the underlying psychosis or attention-seeking behaviour.

The optic neuritis of systemic lupus erythematosus (S.L.E.) more frequently results in the persistence of a central scotoma or complete blindness after a single attack than demyelinating optic neuritis, although the initial clinical presentations may be identical. A significant number of patients, however, recover normal vision. Optic neuritis may be the presenting symptom of S.L.E. and as myelopathy may also occur in the course of the disease, confusion with multiple sclerosis may result, especially if there are no arthritic, cutaneous nor visceral manifestations. We report a case of lupus optic neuritis associated with anticardiolipin antibodies and a circulating lupus anticoagulant and suggest these may be a marker for vasculitic optic neuritis and play a role in its aetiology.

Amongst the many patients with persisting neck pain and headache following cervical injuries are a small number in whom the mechanism is compression of the second cervical nerve root and ganglion. This paper describes the clinical features in 14 patients seen by the author. The main features are unilateral pain in the upper cervical and occipital region, tenderness in the suboccipital region, and diminished sensation in the C2 dermatome. The anatomical basis for this syndrome is discussed and illustrated with dissections from a cadaver.

Two cases of malignant intracranial fibrous histiocytoma are presented. In Case 1 the tumour arose from the meninges and showed a disseminated spread throughout the neuroaxis. In the second case the tumour appeared to arise from within the brain substance. In this case surgical intervention and radiotherapy appeared to have achieved a cure, since no residual tumour was found at autopsy.

The tumours were examined using ultrastructural and immunohistochemical techniques, which appeared advantageous in delineating this rare tumour from other intracranial neoplasms.

We report a case of primary malignant schwannoma of the trigeminal nerve, and review the 5 previously reported cases. Clinical presentation, along with radiological and pathological features are discussed.