Changes in Anticholinergic Burden in Parkinson's Disease After Deep Brain Stimulation

Objective: This study aimed to evaluate the effect of deep brain stimulation (DBS) on anticholinergic burden in Parkinson's disease (PD) and the association of anticholinergic burden with cognition.

Materials and methods: A retrospective chart review in patients with PD who underwent bilateral subthalamic nucleus (STN) or globus pallidus internus (GPi) DBS from 2010 to 2020 reviewed medications with anticholinergic burden at baseline, six months, and one year (N = 216) after surgery. The cumulative anticholinergic burden at each visit was calculated using the Anticholinergic Risk Scale (ARS).

Results: ARS scores were significantly lower for patients six months and one year after surgery than at baseline (z = 6.58, p < 0.0001; z = 6.99, p < 0.0001). Change in ARS scores at both six months and one year were driven by down-titration of PD medications (z = 9.35, p < 0.0001; z = 8.61, p < 0.0001), rather than changes in pain, psychiatric, or urinary medications with anticholinergic effects. There was no significant difference in change in ARS scores at one year between targets (t = 0.41, p = 0.68). In addition, there was no significant association between anticholinergic burden and cognitive performance.

Conclusion: GPi and STN DBS are associated with decreased anticholinergic burden due to PD medications in the first year after surgery.