Brain networks underlining verbal fluency decline during STN-DBS in Parkinson's disease: An ECD-SPECT study

We prospectively evaluated 20 patients with Parkinson's disease (PD) preoperatively and 12 months after subthalamic nucleus-deep brain stimulation (STN-DBS). All patients had clinical (UPDRS III) and neuropsychological evaluations as well as brain perfusion SPECT-ECD. Clinical and cognitive data were compared with 12 matched PD patients who had not undergone surgery. STN-DBS patients improved in motor symptoms and reduced medications but selectively declined in category fluency (p<0.01). No clinical and cognitive changes were found in the control group at follow-up. Worsening fluency was associated with perfusion decrements in left dorsolateral prefrontal cortex, anterior cingulate cortex and ventral caudate nucleus (p<.001).