Biomedical subjects
Publications and source records attributed to J C Walsh.
Direct nerve infiltration by tumour tissue usually produces pain, and loss of motor, sensory, and autonomic function. Two patients are reported in whom a major symptom of nerve infiltration was sympathetic overactivity manifested by excessive spontaneous sweating.
A 48 year old woman is described who presented with increasing muscular rigidity and who was found to have a mediastinal tumour. Electrophysiological studies revealed that the muscular stiffness resulted from very high frequency motor unit activity which outlasted voluntary effort, and which was abolished by nerve block. The abnormal activity may have arisen at the anterior horn cell level. Marked improvement followed the administration of diphenylhydantoin.
Tests of autonomic function were performed on 16 subjects with diabetic neuropathy. Abnormal sweating occurred in 10/10 (100 per cent), postural hypotension in 7/16 (44 per cent), an abnormal Valsalva ratio in 7/11 (64 per cent), and denervation hypersensitivity to phenylephrine in 2/8 (25 per cent) of patients tested. A quantitative assessment of baroreceptor function was made. In diabetics, there was a reduced resting heart period, heart period range and mean gain. Quantitative histological studies were performed on the greater splanchnic nerves removed at autopsy from 9 control subjects and from 8 subjects with diabetic neuropathy. The fibre density was significantly reduced in the greater splanchnic nerve of diabetics. The predominant pathology on teased fibre preparations was that of demyelination. Disordered blood pressure control in diabetes correlated with the pathological abnormalities in the sympathetic nervous system. Light and electronmicroscopic studies were performed on the sural nerves of 2 diabetic subjects with autonomic dysfunction. The predominant change was active axonal degeneration affecting mainly unmyelinated and small myelinated fibres.
Tests of autonomic function were performed on 12 subjects with alcoholic neuropathy. Abnormal sweat patterns occurred in 8/8 (100 per cent) and an abnormal Valsalva ratio in 2/9 (22 per cent). Postural hypotension and denervation hypersensitivity were absent in all patients examined. A quantitative assessment of baroreceptor function was made. The resting heart period, heart period range and mean gain of alcoholics were within the control range. Quantitative histological studies were performed on the greater splanchnic nerves removed at autopsy in 4 alcoholic subjects. The myelinated fibre density fell within the control range. The absence of significant disturbance of blood pressure control correlates well with the absence of pathology in the greater splanchnic nerve.
Six major convulsions have been seen among 555 patients who had therapeutic second trimester abortion by intra-amniotic prostaglandin F2alpha (PGF2alpha). Five of 21 patients receiving intra-amniotic hypertonic saline and 5 of 16 patients receiving PGF2alpha showed abnormalities in electroencephalograms after treatment. These changes were relatively minor in all saline patients and in three receiving PGF2alpha, but two patients receiving PGF2alpha showed epileptiform spike activity after infusion. There was no correlation between the electroencephalographic (EEG) changes and peripheral venous levels of PGF2alpha or its metabolite, 13, 14 dihydro-15 keto PGF2alpha (15 keto-h2-f2alpha).
Tests of autonomic function were performed on 10 controls, 16 subjects with diabetic neuropathy and 12 subjects with alcoholic neuropathy. Abnormal sweating occurred in 10/10 alcoholics (100%) and 10/10 diabetics (100%) who were examined. An abnormal Valsalva ratio was present in 7/11 (64%) of diabetics and only 2/9 (22%) of alcoholics. Denervation hypersensitivity to phenylephrine occurred in 2/8 (25%) of diabetics and was absent in alcoholics. A quantitative assessment of baroreceptor function was made. In diabetics there was a reduced resting heart period, heart period range and mean gain, whilst these parameters were essentially normal in alcoholics.
Two cases of malignant infiltration of nerve are presented in whom a major feature was excessive spontaneous sweat secretion. The possible mechanisms for the production of this unusual symptom are discussed.
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Electrophysiological studies were performed on median and ulnar nerves in 234 cases of carpal tunnel syndrome. Abnormalities of the ulnar nerve sensory action potential were found in 39·3% of cases. The amplitude of the ulnar nerve sensory action potential was related to the amplitude of the median nerve sensory action potential, and to the median nerve motor conduction velocity in the forearm. The findings suggest that in a significant proportion of patients with carpal tunnel syndrome, a more generalized subclinical neuropathy may be present.
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The H reflex was studied in 13 patients with Parkinson's disease, and the results compared with those obtained in 22 control subjects. Pairs of identical stimuli near threshold intensity were delivered and the unresponsive period and time course of recovery of the amplitude of the H reflex were determined. The duration of the unresponsive period was significantly shorter in the patients with Parkinson's disease. In 10 patients the studies were repeated after treatment with l-dopa for six months. There was a significant increase in the period of unresponsiveness of the H reflex after treatment. The findings suggest that there is an increase in alpha motoneurone excitability in Parkinson's disease, and that it is reduced by treatment with l-dopa.
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Electrophysiological studies have been performed on 62 subjects with malignant lymphoma and the results compared with those of 35 control subjects matched for age. There was evidence of impairment of conduction consistent with a generalized peripheral neuropathy in 22 subjects (35%). Histological and electronmicroscopic studies were performed on sural nerve biopsy material from five subjects, and the pathological abnormalities of the myelinated fibres were those of axonal degeneration and segmental demyelination. The unmyelinated fibres were not affected.