engleski

VEP in RRMS patients before and after 1-year treatment with interferone beta-1 a

The visual pathway is a frequently involved system in relapsing-remitting multiple sclerosis (RRMS). In RRMS patients the visual evoked potentials (VEP) latency prolongation is considered as evidence of demyelination in the visual pathway, clinically evident as visual dysfunction, including optic neuritis (ON). In patients with no visual disturbance, the delayed VEP are associated with the so-called clinically silent demyelinating lesions. VEP were studied prospectively in nine (9) patients (18 eyes) with RRMS treated with interferon (IFN) beta-1a. Three of them have had an episode of unilateral ON. VEP were first recorded before treatment and then followed up for 12 months, at 3-months intervals, in the time when patients were receiving IFN beta-1a subcutaneously, 22 ug twice weekly. P100 latencies and P100 amplitudes were evaluated. Before IFN beta-1a treatment P100 latency was delayed in three eyes (16.7%) of three patients with a history of ON. After 12 months of treatment, for a group of 18 eyes, there was no statistically significant difference in P100 latencies and P100 amplitudes. At follow-up P100 remained delayed in three eyes with a history of ON. Further, in three eyes of two patients with normal P100 latency before treatment, P100 became delayed. Overall, at follw-up P100 was delayed in six eyes (33%) of five patients. IFN beta-1a low-dose regime was not sufficient to normalize VEP. However, VEP revealed electrophysiological evidence of clinically asymptomatic demyelinating lesions, which may progress into clinically manifested functional deterioration, including ON.

multiple sclerosis; optic neuritis; interferon therapy

nije evidentirano