The electromyogram (EMG) is unique in that it gives the output of a single class of neurons, o-motoneurons, in a way that can be readily recorded and studied in normal subjects as well as in patients with a variety of disorders. Although the EMG has been used for many years, new applications continue to be found. This paper reviews in succession four recent approaches to EMG recording that have provided insight into the function of the normal and the disordered nervous system.

Extensive recent literature on drugs used to enhance cognitive functioning, reflects the growing social problem of dementia. Many clinical trials have been undertaken with variable success. In most cases the disorder studied has been Alzheimer's disease. The pharmacological approach has been designed to rectify the presumed pathophysiological processes characteristic of the condition. Agents tested include cerebral vasodilators, cerebral metabolic enhancers, nootropics, psychostimulants, neuropeptides and neurotransmitters with a special emphasis on drugs used to enhance cholinergic function. Ethical and practical issues concerning clinical drug trials in dementia will be discussed.

There have been trends to equate normal with an ideal state of health, and disease with disturbances that are determined solely by subclinical abnormalities. While in any living language there is a conflict between established definition and the need for change, modification in the use of words that are of such central importance to medical writing requires cogent justification that has not been forthcoming in these instances. To avoid further obscuration of the literature, the term normal should be limited to its traditional connotation of average, and the term disease should be reserved for disturbances of health that are clinically manifest.

This review summarizes the range of possible mechanisms of action of neuronal grafts in the central nervous system. It aims to illustrate the capacity and limitations of the transplanted tissue in the promotion of neurological recovery after experimental surgical insults.

Central nervous system (CNS) involvement in systemic lupus erythematosus is a major source of patient morbidity and mortality. The recognition of nervous system lupus is hampered by the diagnostic insensitivity and non-specificity of the various testing modalities that are currently available. A review of the effectiveness of diagnostic tests for CNS lupus is presented. Areas of current research in this area are examined. Because of the diversity of neurologic manifestations in this disorder and their complex pathogenesis, no single test is sufficient to establish the diagnosis rapidly and accurately in all cases, now or for the foreseeable future.

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.

As a resident of Dr. Penfield, I was impressed by his clinical analysis of each patient's complex medical problem. This always included a detailed history and physical examination by the “Neuro” staff with added information gathered by Dr. Penfield during his personal interviews with each patient. This clinical information was later reinforced by extensive operative notes and hand drawn pictures by Dr. Penfield along with photographic studies of the operative site. I soon realized how important it was to collect complete documentation on each patient.

The validity and reliability of clinical instruments, including clinical scales, need to be determined. This paper presents guidelines for development, validation, and reliability assessment of stroke assessment scales.

Assumptions regarding increased risk of dementia in Parkinson's disease and of depression mimicking the endogenous form are reviewed and challenged from the perspectives of recent findings in both the neuropsychological and anatomical domains. Evidence suggests that depression, while frequent, behaviourally resembles the reactive variety and that selective impairment of cognitive functions considered to depend upon the integrity of the frontal lobes accompanies this disorder. In this regard, it is speculated that the cognitive alterations seen in non-demented parkinson patients are the consequences of dysfunction of the caudate nucleus which contributes significantly to the normal activities processed through the frontostriate “complex loop”.

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.

Magnetic resonance imaging (MRI) has been shown to be a good method of visualizing the lesions in MS. We have studied several applications of MRI to the evaluation of patients and experimental models. In diagnosis, MRI is the most sensitive test for the demonstration of dissemination of lesions in space. Pathological correlation studies show that MRI reliably measures the extent of chronic demyelination. Experimental studies show that MRI detects acute inflammatory lesions and measures their evolution. MRI also is a reliable measure of the extent of the MS process, serial MRI scans detect evidence of disease activity in MS not always disclosed by clinical evaluation. MRI will have an enormous future impact on the evaluation of patients in clinical studies and in understanding the evolution of pathological processes.

Four patients with Multicore Myopathy, a rare morphologically distinct myopathy, are described. Although previously considered to be a non-progressive or only slowly progressive myopathy, progression to significant disability was seen in three of our cases. The association of cardiac disease with Multicore Myopathy has not been previously emphasised. All four patients in this study had a cardiomyopathy, and heart disease was the cause of death in two of the patients. Multicore Myopathy is not always a benign entity. Cardiac involvement, when present, adversely affects prognosis.

The peroxidase anti-peroxidase technique was used for localization of glial fibrillary acidic protein (GFAP) and vimentin (VM) in 19 ependymal tumors in order to determine if a unique pattern of intermediate filament (IF) expression could be demonstrated. Cytokeratin (CK) immunoreactivity was examined in a subgroup of 7 tumors with papillary pattern. Nineteen non-ependymal neuroectodermal tumors were used as controls. Ependymomas, subependymomas and astrocytomas were positive for both IF. Oligodendrogliomas, oligodendroglial portions of mixed gliomas and the majority of medulloblastomas were negative for GFAP and VM. Areas of poor differentiation in all tumors demonstrated little expression of any IF. A composite ependymoma/choroid plexus papilloma showed the presence of GFAP, VM and CK in the papillomatous portion only. Four papillary ependymomas were negative for CK. This study emphasizes the parallel distribution of GFAP and VM in well differentiated ependymomas and other glial tumors and casts doubt upon the concept of VM as a marker for de-differentiation in neuroectodermal neoplasia.

Six hundred and fifty-two patients with histologically proven primary malignant melanoma have been followed by the London Regional Cancer Centre from 1960 to 1985. Neurological signs and symptoms secondary to metastases to the brain developed in fifty-five patients (8.4%). The median age was 49 years; 71% were male and 29% female. Multiple lesions were found in 61% and a single metastasis in 39%. The most common site for the primary lesion was the trunk in males (44%) and the lower limb in females (37%). Six month survival for patients with a single metastasis was 58% if surgical excision was possible and 25% of these patients survived greater than two years. In patients with multiple metastases that received radiotherapy, survival times of greater than six months were found in 12% of the patients. Patients with a single metastasis appear to benefit by being managed by surgical removal of the lesion.

It is easy to imagine a new bumper sticker with the following message:

“If you think medical research is expensive, try disease.” Specifically in today's context, it might well read:

“If you think neurological research is expensive, try the diseases of the nervous system.”

That is precisely what we are doing as a country - “trying disease”! Canada spends $36 billion per year on health care, or $700 million per month. Every hour Canada spends $4 million on "health care" and only $16,000 on medical research.

Tizanidine (Sirdalud) was compared to baclofen (Lioresal) in a randomized, double-blind, cross-over trial. Each medication was introduced over a three week titration period and then maintained at the highest tolerated dose for five weeks. The two treatment phases were separated by a one week drug withdrawal and a two week washout period. Sixty-six patients entered the trial and forty-eight completed both treatment phases. At the end of the trial, neurologists and physiotherapists thought that baclofen was superior on the basis of perceived efficacy and tolerance (p≤0.05). Although the efficacy of tizanidine or baclofen was judged as good to excellent by 24 and 39% of patients respectively, this difference was not statistically significant. Muscle weakness was the most common adverse effect. This was significantly more troublesome in patients treated with baclofen. Somnolence and xerostomia were more common in patients treated with tizanidine. Both baclofen and tizanidine appear to be useful adjuncts in the treatment of spasticity in patients with multiple sclerosis. Preference of either drug is tempered principally by side-effects.

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.