Electrodiagnostic Evaluation of Peripheral Nervous System Changes in Patients with Multiple Sclerosis

Background: There is supportive evidence that multiple sclerosis (MS) could potentially affect the peripheral nervous system. We assessed peripheral sensory and motor nerve involvement in patients with MS by a nerve conduction velocity test.
Methods: We studied 75 patients who had a relapsing-remitting or secondary progressive pattern. We measured amplitude, latency, conduction velocity, Hoffmann reflex (H-Reflex), and F-Waves.
Results: The amplitude of the right tibial, right proneal, left tibial, left proneal, and left median motor nerves was less than the mean for the normal population. Right ulnar sensory conduction in the patients showed an amplitude that was less than that of the normal population; there was no significant change in the amplitude of other sensory nerves. Latencies of the right and left median and right proneal motor nerves and left ulnar sensory nerves were statistically less than that of the normal population. Mean motor conduction velocity and F-wave conduction did not differ significantly from the normal population. H-reflex latencies of the right and left lower limbs were significantly more prolonged than those of the normal population.
Conclusion: Our results suggest possible peripheral motor nerve abnormalities in MS patients, especially with the amplitude of the motor nerves; however, our results do not demonstrate any significant difference among the nerve conduction velocity parameters of sensory nerves between MS patients and the normal population.

Keywords
demyelination; latency; multiple sclerosis; nerve conduction velocity; peripheral neuropathy