title: Predictors of cognitive and psychosocial outcome after STN DBS in Parkinson's Disease.
abstract: OBJECTIVE
  To find predictors of cognitive decline and quality of life 1&emsp14;year after bilateral subthalamic nucleus deep brain stimulation (STN DBS) in Parkinson's disease (PD).
  
  
  METHODS
  A total of 105 patients were evaluated with a comprehensive neuropsychological assessment before and 12 months after surgery. A control group of 40 PD patients was included to control for effects of repeated testing and disease progression. The authors determined individual changes in cognition, mood and quality of life using a statistical method that controls for multiple comparisons, and performed logistic regression analyses to assess predictors of cognitive changes and quality of life.
  
  
  RESULTS
  12 months after surgery, the improvement in motor function was 41% (Unified Parkinson's Disease Rating Scale Part 3 score in off). The STN group showed a large improvement in quality of life compared with the control group (Cohen d=0.9). At the individual level, 32% (95% CI 22 to 40) of the STN group showed a substantial improvement in quality of life. 36% (95% CI 27 to 46) of the STN patients showed a profile of cognitive decline compared with the control group. Mood improved in 16 STN patients and declined in 16 subjects. Impaired attention, advanced age and a low l-dopa response at baseline predicted cognitive decline, whereas a high l-dopa response at baseline predicted an improvement in quality of life. Postoperative decrease in dopaminergic medication was not related to cognitive decline.
  
  
  CONCLUSIONS
  STN DBS improves quality of life. However, a profile of cognitive decline can be found in a significant number of patients. l-dopa response, age and attention at baseline are predictors of cognitive and psychosocial outcome.
authors.affiliation: Department of Neurology of Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
authors.forename: Harriet M M
authors.initials: HM
authors.lastname: Smeding
authors.forename: Johannes D
authors.initials: JD
authors.lastname: Speelman
authors.forename: Hilde M
authors.initials: HM
authors.lastname: Huizenga
authors.forename: P Richard
authors.initials: PR
authors.lastname: Schuurman
authors.forename: Ben
authors.initials: B
authors.lastname: Schmand
mesh_terms: D000339:Affect / Q000502:physiology; D000978:Antiparkinson Agents / Q000627:therapeutic use; D001519:Behavior / Q000502:physiology; D014695:Cerebral Ventriculography; D003071:Cognition / Q000502:physiology*; D046690:Deep Brain Stimulation; D056344:Executive Function / Q000502:physiology; D006801:Humans; D007206:Individuality; D007980:Levodopa / Q000627:therapeutic use; D008279:Magnetic Resonance Imaging; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000523:psychology* / Q000628:therapy*; D011788:Quality of Life; D016634:Radiosurgery; D020531:Subthalamic Nucleus / Q000502:physiology*; D011795:Surveys and Questionnaires; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D000978:Antiparkinson Agents; D007980:Levodopa