Neuropsychological and quality of life changes following unilateral thalamic deep brain stimulation in Parkinson's disease: A one-year follow-up

Background. The long-term neuropsychological and quality of life (QOL) outcomes of unilateral thalamic deep brain stimulation (DBS) in patients with intractable Parkinson's disease (PD) have not heretofore been described. Method. Six patients diagnosed with PD underwent unilateral DBS implantation into a verified thalamic VIM nucleus target. Participants completed presurgical neuropsychological evaluation and follow-up assessment at approximately one year postsurgery. Findings. Compared to their presurgical scores, PD patients exhibited significant improvement on measures of conceptualization, verbal memory, emotional adjustment, and QOL at one-year followup. A few nominal declines were observed across the battery of tests. Interpretation These data provide preliminary support for the long-term neurocognitive safety and QOL improvements following thalamic stimulation in patients with PD.