Background: All guidelines for DBS in Parkinson’s
disease (PD) include a contraindication for ‘dementia’. It is unclear where
this cut-off should occur and if patients with mild cognitive impairment
(MCI) do not do as well. This prospective cohort analysis assessed if
pre-operative cognition affected post-operative quality of life.
Methods: PD patients receiving bilateral STN-DBS
(n=100) were prospectively studied using STROBE guidelines. All had Montreal
Cognitive Assessment (MoCA), motor (UPDRS), mood (BDI-II), and quality of
life (Parkinson Disease Questionnaire summary index, PDQ-39-SI). Two
cohorts, pre-operative MCI (MoCA:18-25) and normal cognition (MoCA:26-30),
had post-operative PDQ-39-SI at 1-year. The primary outcome was the
proportion of patients with an improved PDQ-39-SI at 1-year.
Results: Cohorts were not significantly different
in age, severity of illness, response to dopamine, or mood. MCI was present
in 27/100. Improved quality of life at 1-year occurred in 75% with normal
cognition and 70% with MCI (p=0.54) with RR=1.1 (95% CI, 0.8-1.5). Linear
regression analysis showed no correlation between pre-operative cognition
and post-operative outcome (R2=0.02).
Conclusions: Parkinson’s patients with MCI should
be offered DBS if their motor symptoms require surgery. Guidelines for DBS
surgery in PD should change from “dementia is contraindicated” to “patients
require adequate cognitive functioning, MoCA318”.
Quality of Life and Mild Cognitive Impairment in Early Parkinson’s Disease: Does Subtype Matter?