title: Negative impact of borderline global cognitive scores on quality of life after subthalamic nucleus stimulation in Parkinson's disease.
abstract: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) significantly improves quality of life (QoL) in Parkinson's disease (PD). Dementia is considered as a contraindication for STN-DBS. However, no controlled study assessed the impact of STN-DBS on the QoL and motor outcome in PD patients with a borderline global cognitive impairment. We studied clinical baseline and progression parameters in a cohort of STN-DBS patients with a global cognitive score still in the non-demented range but scoring in the lowest quartile of the Mattis Dementia Rating Scale (MDRS), a measure of global cognitive functioning. Data from a German randomised controlled study comparing DBS (60 patients) with best medical treatment (BMT, 59 patients) were analysed. Changes in patients' QoL scores were assessed using the Parkinson's disease questionnaire (PDQ-39) at baseline and at the 6 months follow up. Patients were split into four groups according to their MDRS performance at baseline and these groups were compared in the context of motor outcome and QoL. Twelve out of sixty patients of the STN-DBS group scored in the lowest quartile of the MDRS (range between one hundred thirty and one hundred thirty seven points). An individual analysis revealed that 3 of 12 patients showed a clinical relevant improvement in QoL whereas the group statistics did not reveal any significant improvement in QoL measures after STN-DBS compared to the BMT group. Since this failure to improve in QoL cannot be explained by a failure to improve in motor functions, stimulation settings and psychiatric scales after STN-DBS, the failure to improve in QoL in patients with a borderline global cognitive score might be specifically related to lower cognitive functioning.
authors: Department of Neurology, Christian-Albrechts-University, Kiel, Germany. k.witt@neurologie.uni-kiel.de
authors: Karsten
authors: K
authors: Witt
authors: Christine
authors: C
authors: Daniels
authors: Paul
authors: P
authors: Krack
authors: Jens
authors: J
authors: Volkmann
authors: Markus O
authors: MO
authors: Pinsker
authors: Manja
authors: M
authors: Kloss
authors: Volker
authors: V
authors: Tronnier
authors: Alfons
authors: A
authors: Schnitzler
authors: Lars
authors: L
authors: Wojtecki
authors: Kai
authors: K
authors: Bötzel
authors: Adrian
authors: A
authors: Danek
authors: Rüdiger
authors: R
authors: Hilker
authors: Volker
authors: V
authors: Sturm
authors: Andreas
authors: A
authors: Kupsch
authors: Elfriede
authors: E
authors: Karner
authors: Günther
authors: G
authors: Deuschl
mesh_terms: D000368:Aged; D003072:Cognition Disorders / Q000175:diagnosis* / Q000209:etiology*; D046690:Deep Brain Stimulation / Q000009:adverse effects*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D017063:Outcome Assessment, Health Care; D010300:Parkinson Disease / Q000628:therapy*; D011788:Quality of Life; D015203:Reproducibility of Results; D020531:Subthalamic Nucleus / Q000502:physiology; D011795:Surveys and Questionnaires