Influence of slow eye movements and nystagmus on pattern induced visual evoked potentials

Abstract

The authors checked the effect of pursuit and combined slow and fast eye movements on the VEP in normal subjects. The results were compared with those in patients showing a horizontal nystagmus of various origin. The main effect of slow and nystagmic eye movements on VEP was a reduction of P2 amplitude without significant shift of P2 latency. It is concluded that the main reason for decreased VEP responses is the decrease of visual contrast due to retinal blurring. In patients with nystagmus, stimulus patterns should be used that match the respective plane of eye rotation.

Key Words:

• VEP
• eye movement
• nystagmus
• evoked potential