title: Impact of mild cognitive impairment on outcome following deep brain stimulation surgery for Parkinson's disease.
abstract: BACKGROUND
  Unlike dementia, the effect of mild cognitive impairment (MCI) on outcomes after deep brain stimulation (DBS) in Parkinson's disease (PD) is less clear. We aimed to examine the effect of MCI on short- and long-term DBS outcomes.
  
  
  METHODS
  To study the effect of MCI type, cognitive domains (attention, language, visuospatial, memory, executive function), and Dementia Rating Scale (DRS) score on immediate postoperative outcomes (postoperative confusion, hospitalization days), PD patients who underwent DBS at our Center from 2006 to 2011 were analyzed. To determine cognitive predictors of intermediate (6-month) and long-term (1-year) post-operative outcomes, the changes in functional and quality-of-life (QOL) scores were analyzed in a smaller group with available preoperative health status measures.
  
  
  RESULTS
  We identified 130 patients [71% male, mean age: 63 ± 9.1, mean PD duration: 10.7 ± 5.1]. At preoperative assessment, 60% of patients had multiple-domain MCI, 21% had single-domain MCI, and 19% had normal cognition. MCI presence and type as well as DRS performance did not affect immediate outcomes. Attention impairment predicted longer postoperative hospitalization (P = 0.0015) and showed a trend towards occurrence of postoperative confusion (P = 0.089). For intermediate and long-term outcomes we identified 56 patients [73.2% male, mean age: 61.3 ± 9.6, mean PD duration: 10.6 ± 4.7]. Visuospatial impairment showed a trend towards less improvement in 6-month functional score (P = 0.0652), and 1-year QOL score (P = 0.0517).
  
  
  CONCLUSIONS
  The presence of MCI did not affect DBS outcomes. However, the types of impaired domains were more detrimental. Detailed cognitive testing can help stratify low- and high-risk patients based on their pattern of cognitive dysfunction.
authors.affiliation: Center for Neurological Restoration, Cleveland Clinic, 9500 Euclid Avenue, Mail Code U2, Cleveland, OH 44195, USA; Neurology Department, Faculty of Medicine, Alexandria University, Alexandria, Egypt. Electronic address: abboudh@ccf.org.
authors.forename: Hesham
authors.initials: H
authors.lastname: Abboud
authors.affiliation: Center for Neurological Restoration, Cleveland Clinic, 9500 Euclid Avenue, Mail Code U2, Cleveland, OH 44195, USA.
authors.forename: Darlene
authors.initials: D
authors.lastname: Floden
authors.affiliation: Department of Quantitative Health Sciences, Cleveland Clinic, 9500 Euclid Avenue, Mail Code JJN3-01, Cleveland, OH 44195, USA; Neurological Institute, Center for Outcomes Research and Evaluation, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, USA.
authors.forename: Nicolas R
authors.initials: NR
authors.lastname: Thompson
authors.affiliation: Center for Neurological Restoration, Cleveland Clinic, 9500 Euclid Avenue, Mail Code U2, Cleveland, OH 44195, USA.
authors.forename: Gencer
authors.initials: G
authors.lastname: Genc
authors.affiliation: Center for Neurological Restoration, Cleveland Clinic, 9500 Euclid Avenue, Mail Code U2, Cleveland, OH 44195, USA.
authors.forename: Srivadee
authors.initials: S
authors.lastname: Oravivattanakul
authors.affiliation: Center for Neurological Restoration, Cleveland Clinic, 9500 Euclid Avenue, Mail Code U2, Cleveland, OH 44195, USA.
authors.forename: Faisal
authors.initials: F
authors.lastname: Alsallom
authors.affiliation: Center for Neurological Restoration, Cleveland Clinic, 9500 Euclid Avenue, Mail Code U2, Cleveland, OH 44195, USA.
authors.forename: Bengwei
authors.initials: B
authors.lastname: Swa
authors.affiliation: Center for Neurological Restoration, Cleveland Clinic, 9500 Euclid Avenue, Mail Code U2, Cleveland, OH 44195, USA.
authors.forename: Cynthia
authors.initials: C
authors.lastname: Kubu
authors.affiliation: Center for Neurological Restoration, Cleveland Clinic, 9500 Euclid Avenue, Mail Code U2, Cleveland, OH 44195, USA.
authors.forename: Mayur
authors.initials: M
authors.lastname: Pandya
authors.affiliation: Center for Neurological Restoration, Cleveland Clinic, 9500 Euclid Avenue, Mail Code U2, Cleveland, OH 44195, USA.
authors.forename: Michal
authors.initials: M
authors.lastname: Gostkowski
authors.affiliation: Center for Neurological Restoration, Cleveland Clinic, 9500 Euclid Avenue, Mail Code U2, Cleveland, OH 44195, USA.
authors.forename: Scott
authors.initials: S
authors.lastname: Cooper
authors.affiliation: Center for Neurological Restoration, Cleveland Clinic, 9500 Euclid Avenue, Mail Code U2, Cleveland, OH 44195, USA.
authors.forename: Andre G
authors.initials: AG
authors.lastname: Machado
authors.affiliation: Center for Neurological Restoration, Cleveland Clinic, 9500 Euclid Avenue, Mail Code U2, Cleveland, OH 44195, USA.
authors.forename: Hubert H
authors.initials: HH
authors.lastname: Fernandez
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001289:Attention Deficit Disorder with Hyperactivity / Q000209:etiology; D060825:Cognitive Dysfunction / Q000209:etiology*; D015331:Cohort Studies; D046690:Deep Brain Stimulation / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000628:therapy*; D012720:Severity of Illness Index; D013997:Time Factors; D016896:Treatment Outcome
keywords: Deep brain stimulation; Hospitalization; Mild cognitive impairment; Parkinson's disease