Post-ischaemic paraesthesiae in diabetes mellitus.

A quantitative assessment of post-ischaemic paraesthesiae has been made in 50 diabetic subjects and in a group of healthy age-matched controls. The results show a highly significant diminution of the paraesthetic response in the diabetic subjects. The degree of depression of the paraesthetic response was associated with the duration of the disease and the severity of the metabolic abnormality as determined by the degree of insulin dependence. Diabetics with the juvenile onset type of the disease were more adversely affected than those with the maturity onset type. There was no consistent relationship between the degree of depression of the paraesthesiae and the presence of peripheral neuropathy. The significance of these results is discussed in relation to the factors which determine the composition of the ionic micro-environment of myelinated nerve and the level of electrical excitability of the nerve fibre.