Short-term neuropsychiatric outcomes following deep brain stimulation for Parkinson's disease

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) or globus pallidus internus (GPi) is effective for Parkinson's disease (PD) motor symptoms; however, effects on neuropsychiatric symptoms remain uncertain.

Baseline and post-operative neuropsychiatric outcomes were retrospectively reviewed among a cohort of patients with PD undergoing bilateral STN- or GPi-DBS, using the Beck Anxiety Inventory (BAI), Beck Depression Inventory (BDI), and Starkstein Apathy Scale (SAS). Absolute changes in psychiatric scores, rate of clinical meaningful score reduction (≥½ standard deviation below baseline scores), and number needed to treat (NNT) were calculated.

Fifty-nine PD patients received either STN-DBS (n = 40) or GPi-DBS (n = 19). Clinically significant baseline anxiety (BAI ≥16) was present in 35.6 % of patients (STN-DBS = 13.50 ± 7.18; GPi-DBS = 17.47 ± 13.78). STN-DBS patients demonstrated a statistically significant reduction in anxiety (d = -4.75, P = 0.002) at 10.0 ± 7.4 months follow-up. Clinically meaningful anxiety improvement was observed in 52.5 % of STN-DBS patients (NNT = 1.9) compared to 26.3 % of GPi-DBS patients (NNT = 3.8). Longitudinal depression and apathy scores were stable for both groups.

STN-DBS was associated with a statistically and clinically significant reduction in anxiety, while GPi-DBS did not reach statistical significance but still yielded clinically meaningful improvement in one-quarter of patients. These findings highlight the potential anxiolytic benefits of STN-DBS and suggest that GPi-DBS may also offer benefit for some individuals, warranting further investigation.