Deep Brain Stimulation Target Selection in an Advanced Parkinson’s Disease Patient with Significant Tremor and Comorbid Depression

CLINICAL VIGNETTE: A 67-year-old female with advanced Parkinson’s disease (PD), medically refractory tremor, and a history of significant depression presented for evaluation of deep brain stimulation (DBS) candidacy. CLINICAL DILEMMA: Traditionally, the subthalamic nucleus (STN) has been preferred over the globus pallidus interna (GPi) as a DBS target for PD patients with levodopa-responsive fluctuations in rigidity and akinesia, for whom tremor is also a significant source of impairment. However, STN stimulation is avoided in patients with a significant pre-surgical history of mood disorder. CLINICAL SOLUTION: Bilateral DBS of the GPi led to significant short-term improvement in PD motor symptoms, including significant tremor reduction. GAP IN KNOWLEDGE: There is insufficient evidence to support or refute clinicians’ traditional preference for STN stimulation in treating refractory PD tremor. Similarly, the available evidence for risk of worsening depression and/or suicidality after STN DBS is mixed. Both questions require further clarification to guide patient and clinician decision-making.