title: Effects of levodopa and subthalamic nucleus stimulation on cognitive and affective functioning in Parkinson's disease.
abstract: In Parkinson's disease (PD), levodopa and subthalamic nucleus (STN) stimulation lead to major improvement in motor symptoms. Effects of both treatments on cognition and affective status are less well understood. Motor, cognitive, and affective symptoms may relate to the dysfunctioning of parallel cortico-striatal loops. The aim of this study was to assess cognition, behavior, and mood, with and without both treatments in the same group of PD patients. A group of 22 nondemented PD patients was included in this study. Patients were tested twice before surgery (off and on levodopa) and twice 3 months after surgery (OFF and ON STN stimulation, off levodopa). Cognitive and affective effects of STN stimulation and levodopa had some common, but also different, effects. STN stimulation improved performance on the planning test, associated with the dorsolateral prefrontal cortex. However, the treatments had opposite effects on tests associated with the orbitofrontal cortex; specifically, levodopa impaired while STN stimulation improved performance on the extinction phase of a reversal/extinction task. Acutely, both treatments improved motivation and decreased fatigue and anxiety. On chronic treatment (3 months after surgery), depression improved, whereas apathy worsened 3 months after surgery. To conclude, there were significant but contrasting effects of levodopa and STN stimulation on cognition and affective functions.
authors.affiliation: Department of Clinical and Biological Neurosciences, University Hospital of Grenoble, and INSERM U318, Joseph Fourier University of Grenoble, Grenoble, France. a.funkiewiez@tiscali.fr
authors.forename: Aurélie
authors.initials: A
authors.lastname: Funkiewiez
authors.forename: Claire
authors.initials: C
authors.lastname: Ardouin
authors.forename: Roshan
authors.initials: R
authors.lastname: Cools
authors.forename: Paul
authors.initials: P
authors.lastname: Krack
authors.forename: Valérie
authors.initials: V
authors.lastname: Fraix
authors.forename: Alina
authors.initials: A
authors.lastname: Batir
authors.forename: Stephan
authors.initials: S
authors.lastname: Chabardès
authors.forename: Alim-Louis
authors.initials: AL
authors.lastname: Benabid
authors.forename: Trevor W
authors.initials: TW
authors.lastname: Robbins
authors.forename: Pierre
authors.initials: P
authors.lastname: Pollak
mesh_terms: D000339:Affect / Q000187:drug effects* / Q000502:physiology*; D000978:Antiparkinson Agents / Q000627:therapeutic use*; D002540:Cerebral Cortex / Q000187:drug effects / Q000503:physiopathology; D003071:Cognition / Q000187:drug effects* / Q000502:physiology*; D003131:Combined Modality Therapy; D003342:Corpus Striatum / Q000187:drug effects / Q000503:physiopathology; D046690:Deep Brain Stimulation; D003866:Depressive Disorder / Q000503:physiopathology / Q000628:therapy; D005108:Extinction, Psychological / Q000187:drug effects / Q000502:physiology; D005260:Female; D006801:Humans; D007980:Levodopa / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009042:Motivation; D009434:Neural Pathways / Q000187:drug effects / Q000503:physiopathology; D009460:Neurologic Examination / Q000187:drug effects; D009483:Neuropsychological Tests; D011340:Problem Solving / Q000187:drug effects / Q000502:physiology; D012193:Reversal Learning / Q000187:drug effects / Q000502:physiology; D020531:Subthalamic Nucleus / Q000503:physiopathology*
chemical_list: D000978:Antiparkinson Agents; D007980:Levodopa