Concepts emerging from experimental manipulations of neurobiological systems in vivo and in vitro may provide explanations for some clinical observations following adrenal medulla autografting in patients with Parkinson's disease. These concepts are reviewed, and a proposed mechanism of action of adrenal autografts in Parkinson's disease is advanced.

The risk of losing consciousness while driving a motor vehicle and the need to drive a car in today's society are opposing forces at play in determining the fitness and ability of people with epilepsy to drive. We must remember that until some 20 years ago, in Canada and in many other countries people with epilepsy were not allowed to drive. A movement by Canadian neurologists to establish guidelines which would enable people with controlled or remitted epilepsy to drive was headed by the late Dr. Francis McNaughton and by Dr. Guy Courtois. At present, legislation allowing people with controlled epilepsy to drive exists in every province or state of Canada and the United States and in many other countries. The International League Against Epilepsy, the professional society concerned with research, teaching and patient care, has a standing committee devoted to the problems of driving a motor vehicle. The Canadian League Against Epilepsy, the national branch of the International League, has carried the issues raised by driving and by the legislation governing it on the agenda of its annual meetings for the past several years. A committee headed by Dr. Guy Rémillard has compared pertinent laws and rules in different provinces with a view to establishing universally acceptable criteria and guidelines.

Carotid Doppler is an accurate, safe and repeatable method of assessing arterial calibre, for distinguishing harmless neck bruits and to identify the stroke prone individual. It is completely non-invasive and can be used serially to monitor progression in carotid stenosis. It is a valuable clinical tool in diagnosis and management in patients at risk of stroke, but has definite limitations, such as in differentiating carotid occlusion from severe stenosis. B-mode imaging, although valuable in identifying arterial anatomy, and detecting plaques, cannot accurately evaluate the degree of stenosis. It is of limited value in identifying plaque hemorrhage and ulceration. Doppler ultrasound technology has advanced rapidly in the last decade, especially in the combination of B-mode imaging and Doppler (Duplex), as well as in evaluating of the intracranial circulation (transcranial Doppler). In the next decade, it may become the new gold standard for evaluating the extracranial and intracranial circulation.

A retrospective review of the medical records of 518 patients who underwent craniotomy over a 3 year interval was carried out to determine the rate of gastrointestinal bleeding and its relationship to the Glasgow Coma Score. There were 288 [55.5%] males and 230 [44.5%] females in the series; the mean age was 51.5±18.9 years. Forty percent had brain tumours, 18% had subarachnoid hemorrhage, 14% had spontaneous intracerebral hemorrhage, 19% had head injury and 8% had other diagnoses. Forty-eight [9.3%] of the patients had significant gastrointestinal bleeding, the distribution of which was as follows: hematemesis [37/518], melena [11/518] and/or hematochezia [4/518]. A further 51 [9.8%] had evidence of “coffee ground emesis” only. Of those with a Glasgow Coma Score of <10, 21% had significant GI bleeding while only 7% of patients with a Glasgow Coma Score >10 had such a bleed [p<0.005]. Further analysis showed that the incidence of GI bleeding in patients who underwent craniotomy increased with decreasing GCS. GI bleeding did not correlate with age, sex, steroid administration or casual use of anti-ulcer medication.

The major slowing of nerve conduction in the carpal tunnel syndrome is located in the palm to wrist segment. The aim of this study is to develop a reliable, sensitive and accessible approach to measure transcarpal median sensory nerve conduction. For this purpose, a fast recovery amplifier with a stimulus artifact suppressor was designed by the author. On stimulation of digits II or III, evoked orthodromic sensory nerve action potentials were simultaneously recorded at the palm and at the wrist. Distances were determined with a ruler. Median sensory nerve conduction velocity was estimated from digit to palm and from palm to wrist in 80 healthy hands and 253 hands with a presumptive diagnosis of carpal tunnel syndrome. According to conventional criteria, 131 of the 253 hands from those suspected of carpal tunnel syndrome were thought to have median nerve compression. When transcarpal median sensory conduction velocity was taken into account, the diagnostic yield increased by 18.1%. The described technique provides a simple, sensitive and reliable method of diagnosing mild or early carpal tunnel syndrome.

The visual evoked potential (VEP) latency was either abnormally prolonged or absent in the involved eye of 47 patients with optic neuritis. Twenty-two of these patients with known multiple sclerosis (MS), had similar abnormalities to 25 patients with no clinical evidence of MS. Follow-up clinical assessment and VEP were done 10 to 42 (mean 22) months later in 34 patients. In 15 of 34 patients with no VEP from the involved eye during initial examination, 6 returned to normal, 8 had prolonged latencies and 1 still had no response at follow up. Of 19 patients who initially had prolonged latencies in the involved eye, 6 returned to normal, 11 had prolonged latencies and 2 had no response at follow up. The VEP is helpful in confirming the diagnosis of ON. The examination must be performed when the patient is symptomatic or soon thereafter as 35% of our patients with an abnormal initial VEP had a normal VEP at follow up. This normalization was not related to the severity of the initial VEP abnormality.

We analysed the clinical features of 82 patients with dominantly inherited ataxia in a cohort survey. All patients fulfilled the diagnostic criteria for Machado-Joseph disease. The mean age of onset of symptoms was 39.8 (± 12.5) years and the duration of the disease was 9.2 (± 6.7) years. Ataxia, peripheral neuropathy, and fasciculation scores correlated with age of onset and duration of disease. Upper motor neuron scores failed to correlate with age of onset. In a follow-up study we analysed the clinical data of 46 patients two years after the first examination. A paired ttest was used to compare differences between observations. The results are in agreement with those of the cross-section in time, suggesting a deterioration of the symptoms with the evolution of the disease. We conclude that dynamic definition of the disease according to age of onset and duration of symptoms is preferable to subdivision into classical types.

We have prospectively reviewed the data on 52 children who presented with status epilepticus. Thirtyfour (65%) of the 52 had not had seizures before. Children who were previously abnormal were more likely to present with partial status epilepticus or to have seizures > 60 minutes than those who were previously normal. The median age (24 months) of those who presented with status epilepticus was the same as that of children with seizures of shorter duration. The causes were equally distributed among the idiopathic, acute encephalopathic and chronic encephalopathy groups. Three children died and 13 (28%) were left with neurological sequelae. The outcome was favorable for those in the idiopathic category.

Clobazam is a new benzodiazepine recently introduced in Canada on an experimental basis. We report our experience with 27 children (average age 9.1 years) with severe intractable seizure disorders. All had mixed seizures (41% focal plus generalized, 59% mixed generalized) and 93% were mentally retarded. Eighty-five percent had multiple daily seizures and all had been on an average of 6 other anticonvulsants in the past. Forty-one percent of our patients responded to clobazam with a reduction of greater than 75% in seizure frequency and 15% had no further seizures. Tolerance to clobazam which could not be overcome by dose increases developed in 26% of patients. Fortyfour percent of non-responders had exacerbations of their seizures shortly after starting clobazam, however 43% of these patients had reductions in comedications simultaneously. Side effects of clobazam in responders were minimal. We conclude that clobazam shows sufficient promise to warrant further trials in more benign seizure disorders in children.

Chickens homozygous for the epi gene (epileptics) suffer from spontaneous seizures throughout their life, whereas heterozygous (carriers) are phenotypically normal. Seizures can also be evoked in epileptics by photic stimulation. In addition, epileptic chickens' brains are 25% heavier than those of carriers. We have investigated whether hyperplasia or hypertrophy of astrocytes or increased numbers of astrocytic processes are involved in the development of seizures and the megalencephaly in this model by quantitative comparison of sections immunocytochemically stained for glial fibrillary acidic protein (GFAP). No statistically significant differences between epileptics and controls were found in any of seven areas selected for comparison. In this model gliosis is not involved in the development of epilepsy, nor does it result from repeated seizures.

In recent years there has been a tendency to abandon repeat cerebral angiography in patients with subarachnoid hemorrhage (SAH) if the initial angiogram is normal because prognosis is said to be excellent. Our experience does not support such a conclusion. We report our experiences in 25 patients with SAH, who had a normal initial angiogram. Aneurysms were seen in five of 20 cases when angiography was repeated. On subsequent review of the initial angiograms, the aneurysm was apparent in four of the five cases. When these four initial angiograms were shown to a second observer, unaware of the results of the second study, three of the four aneurysms were correctly identified. We suggest that if, under strong clinical suspicion of SAH, the angiogram is reported as normal the study should be reviewed by a second neuro-radiologist before proceeding to repeat angiography.

Subclavian “steal”, when blood siphons from one vertebral artery to the other, has been suggested as a cause of brain stem ischaemia and stroke. We investigated 33 patients using transcranial Doppler to determine the direction and velocity of basilar blood flow. All patients had severe subclavian stenosis with reversed vertebral blood flow in the ipsilateral artery previously demonstrated by extracranial Doppler. Basilar flow was normal in direction in all cases, but its velocity was significantly increased (p<0.0008) compared to age- and sex-matched controls. These findings, in conjunction with previous observations using extracranial Doppler techniques, suggest that subclavian steal is little more than a harmless haemodynamic phenomenon.

The records of fifteen patients referred for neurological assessment and found to have lupus anticoagulant or elevated anticardiolipin antibodies were reviewed. The mean age for females in the group was 29.4 years and for males was 35. A diagnosis of migraine, either as an acute or chronic problem, was made in 10 (66%) of these patients. Seven of the 15 patients had ischemic stroke and two patients had other thrombotic complications associated with lupus anticoagulant. Three of the nine female patients with migraine had histories of spontaneous abortions. All migraine patients experienced transient or more prolonged neurological deficits with their headaches. An association between lupus anticoagulant and migraine can only be suggested. Data on the incidence of migraine in patients with lupus anticoagulant in the general medical population does not exist. Furthermore the prevalence of lupus anticoagulant in migraine sufferers is unknown. Therefore further studies are required to investigate this possible association.

A previously healthy, 21-year-old female presented with acute dermatomyositis. Chest X-ray revealed bilateral hilar adenopathy, and mediastinal lymph node biopsy demonstrated noncaseating granulomata compatible with sarcoidosis. The patient improved spontaneously. The significance of bilateral hilar adenopathy in association with dermatomyositis and implications for management are discussed.

Moyamoya disease is an unusual vascular disorder highlighted by progressive bilateral internal carotid artery occlusion and collateralization of intracranial blood flow. Recurrent multifocal cerebral ischemic events and isolated intracerebral hemorrhage are known to occur in this disorder. We report a 52 year old man who over a nine year period had four apparent intracranial hemorrhages. Serial angiograms demonstrated the evolution of moyamoya disease. Pathologic examination confirmed multiple vascular lesions, including two that were clinically silent.

The case histories of two patients with clinically diverse forms of the very rare entity primary, spontaneous mesencephalic hemorrhage are presented. Each exhibited characteristic mesencephalic signs and neuroimaging profiles. However, both patients differed markedly in their predisposing factors, state of arousal, memory, temporal course and functional residua. One patient was unique in displaying a normal level of alertness throughout his clinical course and an isolated retrograde amnesia. The latter sign suggests a role for mesencephalic reticular activation in long-term retrieval and illustrates the differential effects of a subtle activation deficit on memory and arousal. These findings broaden the distinctive clinico-anatomical profile of primary, spontaneous mesencephalic hemorrhage.