Objective:

To identify baseline factors predictive of cognitive decline following STN DBS and understand cognitive outcomes in PD patients post-STN DBS using a comprehensive neuropsychological battery.

Background:

While subthalamic nucleus deep brain stimulation (STN-DBS) offers substantial motor benefit in Parkinson’s disease (PD), cognitive trajectories post-DBS remain variable and incompletely understood. Identifying preoperative predictors of post-operative cognitive decline may help to improve patient selection, counseling, and surgical outcomes.

Design/Methods:

A retrospective case series of 32 PD patients (6 females, 26 males; age range: 53–82 years) who underwent STN-DBS, with 3 patients receiving staged procedures. All patients completed standardized neuropsychological testing at baseline (pre-operatively) and at 1–3 years postoperatively. A comprehensive neuropsychological evaluation included assessment of attention/working memory, processing speed, visuospatial functioning, expressive language (including verbal fluency), memory, and executive functioning in addition to assessment of mood. At baseline, 9/32 exhibited normal cognitive performance, while the remainder showed mild cognitive impairment.

Results:

At 1-year follow-up, the majority of patients exhibited largely similar and stable cognitive performances relative to baseline. By 3 years post-DBS, a notable subset showed cognitive decline, particularly in executive function domains. Only 2 patients met clinical criteria for dementia. Cognitive decline was more frequently observed in older patients and those with pre-existing impairments. Importantly, cognitive stability was associated with better optimization of both motor and non-motor symptoms postoperatively. 

Conclusions: