Giant axonal neuropathy, a generalised disorder or neurofilaments, presents as a chronic, progressive peripheral neuropathy in childhood. Evidence for central nervous system involvement is demonstrated in this study of four male patients with giant axonal neuropathy who had defective visual function and abnormal ocular motility. The visual system was studied by electroretinography, which showed normal retinal function, and by visual evoked potentials, which showed disease of both optic nerves and retrochiasmal visual pathways. The ocular motility disorder, studied by electrooculography, comprised defective pursuit, inability to maintain eccentric gaze with gaze paretic and rebound nystagmus, abnormal optokinetic responses and failure of suppression of the vestibulo-ocular reflex by fixation. These findings suggested involvement by giant axonal neuropathy of the cerebellar and brain stem pathways important in the control of ocular motility.

Seven members of a family succumbed to prolonged dementing illnesses. In two, whose dementia lasted 10 years, spongiform encephalopathy was found at autopsy. This duration of illness has not been a feature in other instances of familial Creutzfeldt-Jakob disease.

From 123 hospital charts with a diagnosis of migraine, seen between the years 1974 and 1978, ten cases have been selected of complicated migraine and three cases of migraine with special features. A review, and a discussion of the clinical characteristics, and of the treatment of these unusual migraines has been made. The three cases with special features include migraine in association with hyperlipidemia, with Raynaud's disease and with meningioma.

A 26 week gestation fetus with bilaterally symmetrical encephaloclastic lesions in the cerebral hemispheres is described. Information about gestation allows dating of the cerebral insult to the 3-4th fetal month. The history and morphology in this case suggest that insults occurring at or before the 3-4th fetal month interfere with normal neuroblast migration, producing a cerebral scar containing a band of neuroblasts arranged without order or lamination.

Using the Xel33 inhalation technique, measurements of the blood flow to the left and right parietal and temporal regions of the cerebrum were obtained in 5 healthy individuals while simultaneously recording their EEGs. Up to 3 measurements were obtained from each of the subjects the first while they were mentally at rest and the others while they were engaged in prescribed forms of mental activity. Relationships between the measured blood flow through grey matter, initial slope index, relative grey weight, percent grey flow and power in the delta, delta-theta, alpha, beta and gamma rhythms of the EEG were examined. The results showed that for the subject group as a whole there was a strong correlation between the power present in the low frequency components of EEG and the grey flow and relative grey weight parameters of blood flow. On an individual basis, the observed relationships were highly variable particularly at high flow rates and at low relative grey weights, but became much more definitive at low flows and high weights. The results as they relate to previous work of this kind are discussed.

A computer program was developed to analyse the relative amount of EMG activity in an agonist-antagonist pair of muscles while subjects performed voluntary flexion-extension movements at the wrist to track a visual target. The data were presented to the subjects in the form of a vector display, the angle and length of which was determined from calculation of EMG power in the two muscles.

This new approach to EMG biofeedback was evaluated in two hemiplegic patients and three patients with cerebellar incoordination. Over a training period of several weeks, all the subjects were able to modify the pattern of EMG activity in the muscles to reduce the amount of inappropriate coactivation of flexors and extensors and to produce more sustained and regular activation of individual muscle groups.

A 28 year old female presented with clinical and electrical evidence indicative of L5 motor radiculopathy. Subsequently she was found to have symptoms and signs of multiple sclerosis. When clinical assessment and investigation fail to disclose a cause then demyelinating disease should he considered in the differential diagnosis of motor radiculopath.

The case history to be presented spans most of the lifetime of a young lady who is now twenty-two years old, and it reflects the stages of development of our knowledge of several important neurosurgical concepts.

Constriction of a peripheral nerve may precipitate a primary problem or prevent recovery from a pre-existing one. Any surgical technique to minimize subsequent constrictive scar formation would be advantageous. In this study, using rat femoral nerves, various modes of protection were evaluated. Wrapping the nerve with free fat seemed to offer the best prophylaxis.

An experiment was tonducted to evaluate the effect of various frequencies of brain stimulation on kindling behavior induced by 60-Hz sine wave stimulation. The effective threshold intensity (ETI) to elicit a convulsion was determined on four separate occasions with 5 days of daily trials between determinations. On each day experimental rats were stimulated with current of a specific frequency on the first and third trials for 60 seconds duration and with 60-Hz current for 30 seconds on the second trial (one hour intertrial interval). There were five experimental groups, one each for I, 5, 10, 30, and 60-Hz stimulation. A sixth group received no stimulation on trials I and 3 and 60-Hz current on trial 2. Suppression of convulsive behavior induced by the 60-Hz stimulation trial was present for all ETI determinations with I-Hz and5- Hz stimulation; the mean ETI increased on each successive determination. Suppression was prominent also for the 10-Hz group until the ETI4 determination. Suppression was moderate for the 30-Hz and 60-Hz groups. Overall, it appeared that the interference effect gradually increased with remoteness from the 60-Hz point.

Anxiety seems to be an inherent and perhaps necessary component of civilization. However, the biological basis of anxiety has always been as obscure as the definition of anxiety itself. The importance of anxiety to our mental wellbeing was noted by Freud (1933) who considered it a “nodalpoint”. As in the case of schizophrenia, there have been as many hypotheses to explain anxiety as there have been investigators with different techniques for studying it. The benzodiazepines, introduced clinically in I960, are now the most widely-used anxiolytic drugs. From the time of their introduction, it was felt that an explanation of the mode of action of benzodiazepines might shed considerable light on the basis of anxiety. The discovery, in 1977, of a specific benzodiazepine receptor, uniquely localized in the CNS, was the major turning point in this search (Squires and Braestrup, 1977; Mohler and Okada, 1977).

Experimental evidence is cited in support of the proposal that benzodiazepines exert their anxiolytic effects by inhibiting the uptake of adenosine by central neurons and glia.

Nuclei of the extrapyramidal system contain among the highest levels of GABA and its synthesizing enzyme glutamic acid decarboxylase (GA D) in the central nervous system. In recent years the anatomical organization of GABAergic neurons in the extrapyramidal system has been the subject of considerable experimental enquiry. In this note, current knowledge concerning the origin and projections of GABAergic neurons in certain extrapyramidal nuclei is briefly reviewed.

The validity of a synaptosomal model to monitor drug-induced changes in the y-aminobutyric acid (GABA) content of nerve endings is reviewed. Examples of data obtained using the model are presented and the possibility of using the model for research on antipsychotic drugs is discussed.

During the past decade a number of reports have appeared suggesting that alterations in GABAergic transmission may play a role in the symptoms of a variety of neurosychiatric disorders (Enna, 1980; Enna and Maggi, 1979). In the present communication, some of the evidence supporting this contention will be briefly summarized and reviewed.

In this brief review it will be possible to mention only superficially the bioclinical, behavioral, neurochemical, neuropharmacological and neurophysiological evidence to support the view that some of the trace amines [meta- and paratyramine (m-TA, p-TA), β-phenylethylamine (PE) and tryptamine (T)] may play a significant role in the propagation of nervous impulses and perhaps be involved in the etiology of certain mental disorders. More detailed comments will be found in some recent papers and reviews (Axelrodet al, 1976; Boulton, 1974, 1976, 1978, 1979; Boulton and Baker, 1975; Boulton and Juorio, 1979; Faurbye, 1968; Mosnaim and Wolfe, 1978; Sandler and Reynolds, 1976; Wyatl et al, 1977).

In studies of post-partum women, the oral tyramine loading test is shown to be of predictive value in identifying those subjects with a lifetime history of depressive illness. The cause of the decreased output of conjugated tyramine, after tyramine ingestion, is still unclear. Some possible mechanisms have been under scrutiny.

Antithetical hypotheses as to CNS noradrenergic function in depressed patients can be constructed from results of pharmacological studies of the effects of antidepressant drugs. The experimental data supporting each of these opposing propositions is briefly reviewed in this paper. Finally, the results of clinical studies of noradrenergic function in depressed patients are noted and discussed in terms of these disparate hypotheses.

Benzodiazepine derivatives are neuropharmacologically similar but may appear clinically distinct due to pharmacokinetic differences. The clinical effects of single doses depend mainly on rates of drug absorption and distribution, whereas drug accumulation is a major determinant of clinical action during multiple dosage. This paper outlines potential clinical implications of benzodiazepine pharmacokinetics.