Steroid-Responsive Edema Interfering With Deep Brain Stimulation Programming

Deep brain stimulation (DBS) surgery–associated complications are most commonly due to infections and issues with surgical hardware. An uncommon postsurgical complication hindering effective programming is noninfectious edema appearing as an abnormal peri-electrode T2 signal hyperintensity on brain magnetic resonance imaging (MRI). A 72-year-old woman with Parkinson disease underwent bilateral subthalamic nucleus (STN) implantation for medication-refractory motor symptoms. Worsening balance shortly after surgery and suboptimal response to DBS programming prompted brain MRI, which showed an abnormal T2 hyperintensity around the left STN electrode. Although intravenous antibiotics were considered, the absence of clinical signs and lack of postcontrast T2 signal enhancement argued against infection. Suspecting vasogenic edema, a short course of oral dexamethasone steroids was initiated, with gradual improvement in balance and resolution of the abnormal MRI signal. The mechanism of steroid-responsive vasogenic edema after DBS surgery is not well-understood. This case underscores the importance of being vigilant about this rare complication, differentiating it from infection based on clinical presentation and radiographic characteristics, and treating it appropriately.