Peripheral nerves are progressively involved in multiple sclerosis – A hypothesis from a pilot study of temperature sensitized electroneurographic screening

Summary Multiple sclerosis (MS) is primarily a disease of the central nervous system. Although the involvement of the peripheral nervous system in MS was suggested over 100 years ago, the issue is still controversial, and it is generally accepted that except for the optic nerve the peripheral nerves are left unaffected by the disease. We hypothesize, that an electroneurographical study if thorough enough, may reveal differences in some nerve conduction parameters between MS patients and healthy subjects. Second, we assume that the sensitivity of nerve conduction measurements might be increased if performed at a range of temperatures, reflecting a differential effect of cooling and warming on the peripheral nerve conduction parameters in MS patients and controls. Finally, we expect that the differences in these parameters between controls and MS patients will increase with the progression of the disease. To test these hypotheses in a pilot study, we performed a detailed analysis of the motor and sensory nerve conduction features of the right median nerve in 13 MS patients and 13 controls at 5°C increments between 20 and 40°C, and repeated these measurements after 3 years. The motor latencies were 0.3–0.6ms longer in MS patients compared to the controls both initially and 3 years later (0.058 p p