Dorsal GPi/GPe Stimulation Induced Dyskinesia in a Patient with Parkinson’s Disease

CLINICAL VIGNETTE: A 68-year-old man with Parkinson’s disease (PD) had bilateral GPi DBS placed for management of his motor fluctuations. He developed stimulation-induced dyskinesia (SID) with left dorsal GPi stimulation. CLINICAL DILEMMA: What do we know about SID in PD patients with GPi DBS? What are the potential strategies used to maximize the DBS therapeutic benefit and minimize the side effects of stimulation? CLINICAL SOLUTION: Avoiding the contact implicated in SID and programming more ventral contacts, using lower voltage, frequency and pulse width and programming in bipolar configuration all appear to help minimize the SID and provide appropriate symptomatic motor control. GAP IN KNOWLEDGE: Little is known about SID in patients with PD who had GPi DBS therapy. More studies using volume of tissue activated and diffusion tensor imaging MRI are needed to localize specific tracts in or around the GPi that may be implicated in SID.