Changes in visual evoked potentials in patients with multiple sclerosis treated with isoprinosine and amantadine

We studied 30 patients with clinically definite MS according to the Mc Alpine et al. clinical criteria (20 patients received isoprinosine and 10 amantadine for a period of 12 months). In each patient pattern reversal stimulation was presented to each eye successively and potentials were recorded over both occipital lobes. For each condition the average evoked response to 200 pattern reversals was computed on DISA 2000. During the 24 month-lasting observation high clinical improvement and simultaneous shortening of the latency to peak of the first major positive component of the response in visual evoked potentials was observed in 12 cases with relapsing form treated 12 months with isoprinosine. In 3 cases, despite of the treatment with isoprinosine, new relapses were observed; in these patients delayed response in VEP was observed. In cases treated with amantadine no shortening of the latency to the major positive peak of the potential was observed, also no diminish of relapses frequency was observed.