title: Long-term cognitive outcome of bilateral subthalamic deep brain stimulation in Parkinson's disease.
abstract: The effect of subthalamic deep brain stimulation (STN DBS) on cognition in Parkinson's disease (PD) remains controversial, and it is unclear which factors are related to cognitive decline and dementia after STN DBS, especially over the long term. To this end, we analyzed the cognitive outcome of 103 non-demented patients with PD who were followed-up for at least 12 months after bilateral STN DBS surgery. Preoperatively, the patients were evaluated with the Unified Parkinson's Disease Rating Scale and neuropsychological tests. The rate of global cognitive decline and the incidence of dementia during follow-up for up to 7 years (mean 42.4 ± 24.5 months) were calculated, and preoperative clinical and neuropsychological factors associated with postoperative global cognitive decline or dementia were analyzed. The prevalence of mild cognitive impairment (MCI) and its relation to later cognitive decline or dementia were also evaluated. The annual decline in the mini-mental state examination score was 0.4 ± 1.7 with impaired attention and executive function and a higher levodopa equivalent dose at baseline being the predictors of a faster global cognitive decline after STN DBS. Dementia developed in 13 patients with an incidence rate of 35.7 per 1,000 person-years. Impaired executive function at baseline predicted dementia. At baseline, 63.1 % of the patients had PD-MCI, and these patients were more likely to develop dementia than those without PD-MCI. This study showed that dysfunctions in the frontostriatal circuitry at baseline were associated with a risk of subsequent global cognitive decline and dementia in patients with PD who underwent STN DBS. In addition, preoperative PD-MCI was a risk factor for dementia after STN DBS.
authors.affiliation: Department of Neurology and Movement Disorder Center, Parkinson Study Group, and Neuroscience Research Institute, College of Medicine, Seoul National University, 28 Yongon-dong, Chongno-gu, Seoul, 110-744, Korea.
authors.forename: Han-Joon
authors.initials: HJ
authors.lastname: Kim
authors.forename: Beom S
authors.initials: BS
authors.lastname: Jeon
authors.forename: Sun Ha
authors.initials: SH
authors.lastname: Paek
authors.forename: Kyoung-Min
authors.initials: KM
authors.lastname: Lee
authors.forename: Ji-Young
authors.initials: JY
authors.lastname: Kim
authors.forename: Jee-Young
authors.initials: JY
authors.lastname: Lee
authors.forename: Hee Jin
authors.initials: HJ
authors.lastname: Kim
authors.forename: Ji Young
authors.initials: JY
authors.lastname: Yun
authors.forename: Young Eun
authors.initials: YE
authors.lastname: Kim
authors.forename: Hui-Jun
authors.initials: HJ
authors.lastname: Yang
authors.forename: Gwanhee
authors.initials: G
authors.lastname: Ehm
mesh_terms: D000328:Adult; D003072:Cognition Disorders / Q000209:etiology* / Q000628:therapy*; D046690:Deep Brain Stimulation / Q000379:methods*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000150:complications* / Q000628:therapy; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D020531:Subthalamic Nucleus / Q000502:physiology*; D013997:Time Factors