Peripheral sensory and motor abnormalities in patients with multiple sclerosis

Peripheral nerve abnormalities are uncommon in multiple sclerosis (MS). When present, they are usually attributed to factors associated with advanced disease, such as malnutrition or cytotoxic drugs or hereditary factors. However, a combination of MS and neuropathy has been reported. The aim of this study is to evaluate the question of possible peripheral involvement in MS.

We studied sensory and motor nerve conduction velocities (NCV) and amplitudes values in some sensory and motor nerves in upper and lower extremities in 20 definite multiple sclerosis patients diagnosed according to the criteria of Poser Scale and in 15 healthy subjects. The total number of studied nerves were 91 in patients group and 69 in control group.

The most frequent electrophysiological abnormalities noted in patients group were low amplitude of the ulnar and sural nerve and slow NCV of the tibial and sural nerves. Electrophysiological abnormalities were found in 15 of 91 nerves examined (16.5%). The neurological disability was not associated with the presence of electrophysiological abnormalities. The electrophysiological abnormalities in control group subjects were a slight slow conduction of sural nerve in 2 of 69 nerves examined (2.9%).

Our findings indicate a high frequency of sensory-motor electrophysiological nerve abnormalities in a selected group of multiple sclerosis patients. Electromyographers must be aware of these abnormalities when performing routine electromyography examinations in these patients.