Optokinetic reflex dysfunction in multiple sclerosis

The aim of this study was to further investigate optokinetic reflex functio n in multiple sclerosis. Gaze-holding in darkness, optokinetic nystagmus, o ptokinetic afternystagmus and latency to circularvection were measured usin g electro-oculography and a rotating optokinetic drum. Gaze-holding was not significantly different between the multiple sclerosis and control groups; however, four of 23 multiple sclerosis patients exhibited eccentric gaze-e voked nystagmus. There were no significant differences in either optokineti c nystagmus frequency or latency to circularvection. However, optokinetic n ystagmus slow phase velocity during rise time and amplitude during beat tim e were significantly reduced in the multiple sclerosis group (p<0.05 and p< 0.0001, respectively). The time constant of optokinetic afternystagmus was also significantly reduced in the multiple sclerosis group (p < 0.005). The se results indicate that optokinetic nystagmus and optokinetic afternystagm us are significantly impaired in multiple sclerosis. NeuroReport 12:1399-14 02 (C) 2001 Lippincott Williams & Wilkins.