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.

There is an unusual type of vascular episode in the territory of the posterior cerebral artery which remains relatively unknown. Ten cases are presented in which a posterior cerebral artery deficit developed suddenly in dramatic fashion with headache, visual symptoms, sensory and motor deficits and signs of third nerve involvement. Nine of the patients were female and one was male. Seven were under the age of 33. In all instances there was a permanent neurologic sequela, usually a hemianopia. A similar case was described in 1901. The nature of the underlying process remains obscure, but the evidence favors accompanied migraine in which a particularly severe attack results in permanent damage. The term “catastrophic migraine” is suggested.

The nucleus basalis of Meynert has been studied extensively in the recent literature. Interest in this nucleus has resulted from the discovery that it is a major source of cortical cholinergic input and that there is neuronal loss in the nucleus basalis in some dementing illnesses. Consistent and severe involvement of the nucleus basalis of Meynert has been found in Alzheimer's disease and in the dementia accompanying Parkinson's disease. Occasional involvement is present in other dementing illnesses, such as progressive supranuclear palsy, Parkinsonism-Dementia complex of Guam, dementia pugilistica, Pick's disease, Korsakoff's syndrome, Down's Syndrome and Creutzfeldt- Jakob disease. Huntington's disease spares this nucleus. However, the role of the nucleus in cognitive function is as yet undetermined. Even its alteration with normal aging remains controversial. This review details the pathological studies of this region to date, with particular emphasis on the dementias. Its role in the dementias of Alzheimer's disease and Parkinson's disease is specifically addressed.

The close cooperation of clinical and laboratory research has helped to clarify the etiology of some of the dementing processes of the senium. However, the necessary investigations are complicated, laborious, expensive and can be carried out only in well equipped centres in larger cities. This restricts the number of patients who eventually may benefit from these investigations to a small number. What is needed for the psychogeriatric practice particularly in rural areas and smaller cities are simple diagnostic guidelines for the psychiatrist to answer the question whether the patient suffers from a dementia and if so whether the dementia is in all probability due to a primary degenerative process of the brain parenchyma or of the cerebral vasculature or is it due to another cause.

If degeneration of the brain parenchyma seems the prevalent pathogenetic mechanism one would like to establish in a given case which of the known degenerative processes is most probably present in order to avoid mistakes in clinical judgement with their often life threatening consequences.

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.

Mitral valve prolapse has been reported to be associated with a variety of neurologic disorders, including cerebral ischemia, transient global amnesia, migraine, autonomic dysfunction, and psychiatric disease. The evidence supporting these associations and possible pathogenetic mechanisms are discussed. Some neurologic disorders may be direct complications of mitral valve prolapse, while others may occur as part of an underlying genetic defect or common link.

A solid phase radioimmunoassay was used to detect anti-myelin basic protein (MBP) antibodies in the CSF and serum of multiple sclerosis (MS) patients and controls. CSF and serum samples were assayed prior to acid hydrolysis in order to detect free anti-MBP as well as after acid hydrolysis to measure the total (free and bound) amount of antibody. An anti-MBP index controlling for serum levels as well as the degree of breakdown of the blood brain barrier was used to estimate intrathecal synthesis of anti-MBP. MS patients with acute exacerbations or chronically progressive disease have significantly elevated levels of both free and total CSF anti-MBP. The anti-MBP index is also significantly increased in MS patients with both forms of active disease. Anti-MBP antibodies are intrathecally produced in MS patients with active disease.

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.

As part of a prospective clinicopathological study a cohort of “normal” elderly volunteers (n = 110) has been investigated with CT scans, psychometric testing (Extended Scale for Dementia) and neurological examination. CT scans were evaluated by a neuroradiologist for the presence or absence of white matter lucencies (WML). WML were defined as patchy or diffuse areas of decreased attenuation involving only white matter and with no change in adjacent ventricles or sulci.

The 12 subjects with WML had lower scores on the ESD than the 98 subjects without WML (mean ESD with WML 229.5± 14; without WML 236.7±8.6, t-test p<.01) and the difference remains significant even after adjusting for the possible confounding effects of age (ANCOVA, P<.043).

Internal carotid artery infusion of bradykinin caused extensive breakdown of the blood-brain barrier to protein as demonstrated by the extravasation of the marker, horseradish peroxidase, into vessel walls and the adjacent parenchyma. Pretreatment of the animals with indomethacin, trifluoperazine, or imidazole significantly reduced the quantity of abnormally permeable vessels as determined by light microscopy. By electron microscopy, it was determined that bradykinin caused an intense increase in the number of pinocytotic vesicles in the permeable segments, but no change in the interendothelial junctions. After imidazole pretreatment, although the extent of the permeability change was markedly reduced, the intensity of pinocytotic activity in the involved areas was not altered.