An Unusual Case of Essential Tremor Deep Brain Stimulation: Where is the Lead?

Clinical Vignette: A 73-year-old female with essential tremor (ET) underwent bilateral thalamic ventralis intermedius (Vim) deep brain stimulation (DBS) surgery. The leads provided tremor benefit, but the location was suboptimal and contributed to stimulation-induced hemichorea. Clinical Dilemma: Can patients with ET derive benefit when stimulating outside the Vim? What do we know about stimulation-induced hemichorea in the setting of ET? Clinical Solution: Lead localization combined with advanced programming strategies can be employed to troubleshoot DBS in settings when benefits are observed along with adverse effects. Gap in Knowledge: Sparse information exists about DBS when applied to neuroanatomic regions outside the Vim for the management of ET. Subthalamic nucleus DBS-induced chorea has been reported in multiple movement disorders, but not in ET.