Neurophysiological correlates of senile dementia: I. Motor and sensory nerve conduction velocity

Abstract

SUMMARY: This paper describes an investigation into the relationship between senile dementia and slowing of peripheral nerve conduction velocity. Twenty-eight demented patients and 19 controls were studied. Each patient was rated clinically and given a battery of simple psychological tests in addition to the physiological recordings. The results were as follows: (1) Motor nerve conduction was slower in the demented group than in the control group but this difference was not significant. (2) When subjects were divided according to their dementia score, those with scores above 7 were found to have motor nerve conductions which were significantly slower than those with scores of 7 or less. (3) There was a significant correlation between the severity of the dementia as measured by the rating scale and the psychological tests and the degree of slowing of motor nerve conduction. (4) In those patients who were retested after one year, increase in dementia was significantly correlated with a further slowing of conduction in motor nerves. (5) The possible role of vitamin deficiency was investigated in a small sub-group of demented patients. Deficiencies of thiamine, nicotinic acid, and vitamin B₁₂were not thought to be important but some patients had low folate levels. The significance of these results is discussed.