Decreased amplitude of steady state pattern visually evoked cortical potentials in multiple sclerosis.

PURPOSE: We studied the amplitude of steady state (St) PVECP using the amplitude ratio to transient (Tr) PVECP clinically in patients with multiple sclerosis.

METHODS

Case report. A 25-year-old woman had multiple sclerosis without optic neuritis. She had normal vision and visual fields. She was followed by both St and TrPVECP. Statistical analysis. Patients with multiple sclerosis and no optic neuritis were retrospectively studied for both Tr and StVECP.

RESULTS

Six months later, she showed a decreased ratio in the left eye, corresponding to abnormalities in the center of the visual field. The peak latency of TrPVECP remained normal in both eyes. A decreased ratio was found in 27% of patients with multiple sclerosis and no optic neuritis.

CONCLUSIONS

Not only Tr, but StPVECP should be recorded in patients with multiple sclerosis and normal vision to detect abnormalities in the visual pathway.