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.

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.

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 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.

We studied 34 Spanish children with hypomelanosis of Ito. This disease has an incidence of 1 per 1000 new patients consulting a paediatric neurological service, or 1 per 8000-10,000 unselected patients in a children's hospital. About 94% of our patients show noncutaneous abnormalities. Mental retardation (IQ below 70) was present in 64.7%; another 14.7% had an IQ between 70 and 90, usually associated with poor school performance. Four children exhibited autistic behaviour. Seizures of various types were present in 53% of cases. Other skin alterations in addition to the typical hypomelanosis were observed in 38% of our cases: caf6-au-lait spots, angiomatous nevi, nevus marmorata, nevus of Ota, Mongolian blue spot, heterochromia of the iris or hair, and other nonspecific pigmentations. Other associated disorders occur inconsistently and include macrocephaly, microcephaly, h6mihypertrophy, kyphoscoliosis, coarse facial features, genital anomalies, inguinal hernia, congenital heart disease, hypertelorism, and abnormalities of the teeth, feet and eyes. Autosomal dominant inheritance is demonstrated in some but not all cases.

The common vascular anomalies of cerebral aneurysm and arteriovenous malformation may exist independently, or together as part of a closely related hemodynamic pairing. Resection or embolization of an AVM may be followed by a decrease in local blood flow, and lead to regression of a suitably situated proximal aneurysm. However, aneurysms located outside the angioarchitecture of the AVM, which remain flow-unrelated to the malformation, will likely not regress, and may in fact enlarge. Two cases are presented which demonstrate these vascular relationships, in order to better understand the regional hemodynamics of these anomalies prior to surgical or endovascular treatment planning.

We have studied 11 patients with neurological deficits due to the pandemic of encephalitis lethargica, all of whom had remained in hospital for more than forty years. Retrospective information obtained from physicians and nurses dating back as far as 1931, our own Webster and Northwestern University Disability Rating Scales available from 1976, photographic records, published narrative and hospital charts all indicate that neurological disabilities attributable to basal ganglia damage frequently increase in late life. Deterioration was most marked in motor function and largely spared the intellect, special senses and somatosensory system. The findings are discussed in relation to current hypotheses concerning the aetiology of Parkinson's disease.

Parental age at the time of birth of 133 clinically diagnosed Alzheimer patients from the Saguenay-Lac-St-Jean area (Quebec, Canada) were compared with those of 6 control groups formed out a population registry. The birth order of the Alzheimer patients was also analyzed. The results did not show any parental age or birth order effect, which is in agreement with previous reports. The importance of control selection in such studies is stressed.

A family with familial Alzheimer's disease (FAD) inherited as an apparent autosomal dominant trait is presented. Twelve individuals (6 females; 6 males) in 4 generations were affected. The disease had its onset in the late 30's, early 40's with death by age 50. Although FAD which appears to be transmitted as an autosomal dominant trait is relatively rare, such families must be identified and carefully counselled with respect to recurrence risks for subsequent generations. In this family, there are currently 20 members of Generation IV, aged 15-37, and 9 members of Generation V, aged 1-11. The majority of these individuals appear to have a 50% risk for developing this disease.

This report describes a freeze fracture study of rat dorsal sympathetic chain in normal, streptozotocin diabetic on normal diet, and a group fed a 1% myoinositol normal diet. In nonmyelinated fibres, the diabetic group had significant loss of particles on the P face ofjuxta-axonal Schwann cell membranes, whilst myelinated nerves showed a profound loss of particles on P and E faces. In the group with adjuvant myoinositol the particle numbers were normal in both types of nerve. Axonal plasma membranes showed increased numbers of particles in the P face of the nonmyelinated membranes in the diabetic, but were normal in the myoinositol group. Myelinated axonal membranes showed no significant difference between the diabetic and the normal. Rats on a myoinositol diet showed a significant decrease in the E face particles. These results are consistent with those described in the sciatic myelinated nerves by earlier authors and reinforce the view that myoinositol is an important membrane constituent as phosphatidyhnositol and is essential for the expression of normal protein particle numbers.

This 60 year old male developed a right hemiplegia and aphasia. A C.T. head scan showed a cerebral infarct which appeared hyperdense on a subsequent scan done 18 days after presentation. This was interpreted as indicating a hemorrhagic transformation resulting in discontinuation of anticoagulation therapy. At autopsy, the area of infarction in the left frontoparietal hemisphere appeared intensely green due to breakdown of the blood-brain barrier in the presence ofjaundice. A striking finding on microscopy was the presence of calcium salts throughout the area of infarction but most prominent in the grey matter at the periphery of the infarct corresponding to the areas which appeared hyperdense on the CT head scan and stained intensely with bilirubin. There was no evidence of recent hemorrhage. This case illustrates that calcification can occur within weeks after the onset of a recent cerebral infarct and should be considered when interpreting the development of C.T. scan hyperdensity in recent cerebral infarcts.

Wernicke disease (WD) is a complication of alcoholism and malnutrition and usually presents acutely and is characterized by disturbances of consciousness, paralysis of the external ocular muscles, and ataxia. The disease results from deficiency of vitamin B 1, or thiamine, an essential coenzyme in intermediate carbohydrate metabolism. On the other hand, Jakob-Creutzfeldt disease (J-C) results from infection with an unconventional agent with a long incubation period and is characterized by a rapidly progressive dementia and histologically by a spongiform encephalopathy associated with neuronal destruction and pronounced astrogliosis. Combination of both diseases has not been reported in the literature previously and their relationship is uncertain. We present 3 cases with this interesting association and consider their relationship.

We report the case of a patient with meningio-angiomatosis, a rare disorder of the cerebral cortex often associated with Von Recklinghausen's neurofibromatosis. Previous reports have described a variety of radiological findings but in general they have been of little value in the diagnosis of this disorder. We describe the magnetic resonance image, which identified a well-defined lesion. The imaging techniques are reviewed.