Lead Angle Matters: Side Effects of Deep Brain Stimulation Improved With Adjustment of Lead Angle.

BACKGROUND: Targeting the subthalamic nucleus (STN) for deep brain stimulation (DBS) using standard stereotactic coordinates in conjunction with high-resolution magnetic resonance imaging (MRI) generally results in effective symptomatic relief for the cardinal motor features of Parkinson's disease (PD). The angle of approach, however, influences the resultant field of stimulation and can lead to undesired side effects.

METHODS: We review a case where symptomatic improvement was accompanied by significant side effects despite reasonable STN stereotactic base coordinates. Revision of the lead using similar base coordinates but a significantly different angle of approach greatly improved the outcome.

RESULTS: Stimulation ventromedial to the STN improved tremors but brought about dysarthria and dystonia. Computer-based stimulation field modeling helped understand the regions associated with the side effects and illustrate the difference between pre- and post-revision stimulation fields.

CONCLUSION: Lead angle can impact DBS outcome and should be taken into consideration.