Eye movements and deep brain stimulation.

Abstract

Deep brain stimulation (DBS) is an established treatment for several neurological conditions, and is most commonly used to treat Parkinson's disease by implanting electrodes in the basal ganglia. Despite the fact that circuits involved in eye movement control traverse the basal ganglia and are thus likely to be affected by DBS, studies combining DBS with eye movement analysis have been infrequent. This review focuses on recent research studies that examine the relationship between DBS and various types of eye movements and which highlight the potential of this approach. Recent work shows that DBS in the subthalamic nucleus (STN) can improve smooth pursuit in Parkinson's disease. STN DBS has also been shown to modulate visuospatial attention, and has provided experimental evidence backing a Bayesian model of basal ganglia function. DBS in the pallidum can improve antisaccadic performance in Parkinson's disease, suggesting improvement in higher control of oculomotor function, and implying retrograde striatal stimulation as part of the mechanism of action. These studies show that the combination of DBS with eye movement analysis is a powerful research tool. It may be used to study oculomotor physiology, basal ganglia pathophysiology, and the mechanism of action of DBS.