Objective: To determine cognitive safety of globus pallidus interna (GPi) deep brain stimulation (DBS) in Parkinson’s disease (PD) patients receiving autologous sural nerve grafts to either the substantia nigra (SN) or nucleus basalis of Meynert (NBM).

Background: DBS is a standard of care treatment for PD resulting in improved motoric symptoms and quality of life. Relative to subthalamic nucleus (STN) DBS, GPi DBS typically results in better outcomes for cognitively comprised patients. Typical post-surgery changes include reduced verbal fluency, memory, and verbal processing speed. The current pilot study examined whether dopaminergic neurons can be regenerated via sural nerve graft implantation during GPi DBS. Current results assess the safety of this novel procedure and examine postoperative cognitive decline for two target sites: SN and NBM.

Method: Pre- and post-surgical cognitive data were analyzed for 14 patients with bilateral GPi DBS plus unilateral SN graft and 7 patients with bilateral GPi DBS plus unilateral NBM graft. Notably, GPi plus SN evaluations were on average 22.31 months post-surgery (SD = 4.57) while GPi plus NBM evaluations were on average 12.4 months post-surgery (SD = 3.05). Paired sample t-test and Cohen’s d effect sizes were calculated.

Results: GPi DBS plus SN patients showed moderate declines in phonemic fluency (FAS t = 2.95, p < .05; d = 0.50) and working memory (WAIS-IV Digit Span, t = 3.46, p < .01; d = 0.76) and small declines in verbally mediated processing speed (Stroop Color, t = 2.24, p < .05; d = 0.41). No significant changes were noted in GPi DBS plus NBM; only phonemic fluency neared significance (FAS t = 2.295; p = 0.061).

Conclusion: GPi plus SN showed worsened phonemic fluency, auditory working, and verbal processing speed consistent with STN DBS literature but somewhat larger than standard GPi DBS. GPi NBM patients did not evidence significant cognitive changes. Overall, results indicate initial safety evidence as sural nerve grafts do not likely add incremental cognitive change compared to standard DBS. NBM results show particular robustness and should be further examined for longitudinal change, as results suggest stabilization of cognitive abilities.

« Back to 2019 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/neurocognitive-changes-post-bilateral-globus-pallidus-interna-dbs-for-parkinsons-disease-with-autologous-sural-nerve-graft-to-the-substantia-nigra-or-nucleus-basalis-of-meynert/