title: Postoperative symptoms of psychosis after deep brain stimulation in patients with Parkinson's disease.
abstract: OBJECTIVE
  Cases of postoperative psychosis in Parkinson's disease patients receiving deep brain stimulation (DBS) treatment have previously been published. However, the magnitude of symptom incidence and the clinical risk factors are currently unknown. This retrospective study sheds light on these issues by investigating psychosis in a group of 128 Parkinson's disease patients who received DBS implants.
  
  
  METHODS
  A retrospective chart review was performed to obtain surgery dates, follow-up clinic visit dates, and associated stimulation parameter settings (contacts in use and the polarity of each along with stimulation voltage, frequency, and pulse width) for each patient. Unified Parkinson's Disease Rating Scale II Thought Disorder scores, used as a clinical assessment tool to evaluate the presence of psychosis at each visit, were also collected. The data were compiled into a database and analyzed.
  
  
  RESULTS
  The lifetime incidence of psychosis in this cohort of patients was 28.1%. The data suggest that risk of psychosis remains fairly constant throughout the first 5 years after implantation of a DBS system and that patients older at the time of receiving the first DBS implant are not only more likely to develop psychosis, but also to develop symptoms sooner than their younger counterparts. Further analysis provides evidence that psychosis is largely independent of the clinically used electrode contact and of stimulation parameters prior to psychosis onset.
  
  
  CONCLUSIONS
  Although symptoms of psychosis are widely seen in patients with Parkinson's disease in the years following stimulator placement, results of the present suggest that most psychoses occurring postoperatively are likely independent of implantation and stimulation settings.
authors.affiliation: 1University of Maryland School of Medicine;
authors.forename: Azam A
authors.initials: AA
authors.lastname: Qureshi
authors.affiliation: 2Department of Neurosurgery, Johns Hopkins Hospital;
authors.forename: Jennifer J
authors.initials: JJ
authors.lastname: Cheng
authors.affiliation: 2Department of Neurosurgery, Johns Hopkins Hospital;
authors.forename: Abraham N
authors.initials: AN
authors.lastname: Sunshine
authors.affiliation: 3Johns Hopkins School of Medicine;
authors.forename: Adela
authors.initials: A
authors.lastname: Wu
authors.affiliation: 4Department of Psychiatry, Johns Hopkins School of Medicine;
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Pontone
authors.affiliation: 5Sheppard and Enoch Pratt Hospital, Baltimore; and.
authors.forename: Nicola
authors.initials: N
authors.lastname: Cascella
authors.affiliation: 2Department of Neurosurgery, Johns Hopkins Hospital;
authors.forename: Frederick A
authors.initials: FA
authors.lastname: Lenz
authors.affiliation: 6The Parkinson's and Movement Disorders Center of Maryland, Elkridge, Maryland.
authors.forename: Stephen E
authors.initials: SE
authors.lastname: Grill
authors.affiliation: 2Department of Neurosurgery, Johns Hopkins Hospital;
authors.forename: William S
authors.initials: WS
authors.lastname: Anderson
mesh_terms: D000367:Age Factors; D000368:Aged; D046690:Deep Brain Stimulation / Q000009:adverse effects*; D005260:Female; D005500:Follow-Up Studies; D005917:Globus Pallidus / Q000502:physiology*; D006801:Humans; D015994:Incidence; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000453:epidemiology / Q000628:therapy*; D011183:Postoperative Complications / Q000209:etiology*; D011569:Psychiatric Status Rating Scales; D011618:Psychotic Disorders / Q000453:epidemiology / Q000209:etiology*; D012189:Retrospective Studies; D012720:Severity of Illness Index
keywords: DBS = deep brain stimulation; GPi-DBS = globus pallidus interna-DBS; PD = Parkinson’s disease; Parkinson’s disease; STN-DBS = subthalamic nucleus-DBS; UPDRS = Unified PD Rating Scale; UPDRS II TD = UPDRS II Thought Disorder; deep brain stimulation; neurosurgery; psychiatry; psychosis