title: Predicting dementia in Parkinson disease by combining neurophysiologic and cognitive markers.
abstract: OBJECTIVE
  To assess the ability of neurophysiologic markers in conjunction with cognitive assessment to improve prediction of progression to dementia in Parkinson disease (PD).
  
  
  METHODS
  Baseline cognitive assessments and magnetoencephalographic recordings from 63 prospectively included PD patients without dementia were analyzed in relation to PD-related dementia (PDD) conversion over a 7-year period. We computed Cox proportional hazard models to assess the risk of converting to dementia conveyed by cognitive and neurophysiologic markers in individual as well as combined risk factor analyses.
  
  
  RESULTS
  Nineteen patients (30.2%) developed dementia. Baseline cognitive performance and neurophysiologic markers each individually predicted conversion to PDD. Of the cognitive test battery, performance on a posterior (pattern recognition memory score < median; hazard ratio (HR) 6.80; p = 0.001) and a fronto-executive (spatial span score < median; HR 4.41; p = 0.006) task most strongly predicted dementia conversion. Of the neurophysiologic markers, beta power < median was the strongest PDD predictor (HR 5.21; p = 0.004), followed by peak frequency < median (HR 3.97; p = 0.016) and theta power > median (HR 2.82; p = 0.037). In combination, baseline cognitive performance and neurophysiologic measures had even stronger predictive value, with the combination of impaired fronto-executive task performance and low beta power being associated with the highest dementia risk (both risk factors vs none: HR 27.3; p < 0.001).
  
  
  CONCLUSIONS
  Combining neurophysiologic markers with cognitive assessment can substantially improve dementia risk profiling in PD, providing potential benefits for clinical care as well as for the future development of therapeutic strategies.
authors.affiliation: From the Department of Neurology, Neuroscience Campus Amsterdam (K.T.E.O.D., D.S., H.W.B.), Department of Clinical Neurophysiology and Magnetoencephalography Center (A.H., C.J.S.), and Department of Clinical Epidemiology and Biostatistics (J.W.R.T.). VU University Medical Center, Amsterdam; Department of Clinical Neuropsychology (J.B.D.), VU University, Amsterdam; and Department of Psychology (B.A.S.), University of Amsterdam, the Netherlands.
authors.forename: Kim T E
authors.initials: KT
authors.lastname: Olde Dubbelink
authors.forename: Arjan
authors.initials: A
authors.lastname: Hillebrand
authors.forename: Jos W R
authors.initials: JW
authors.lastname: Twisk
authors.forename: Jan Berend
authors.initials: JB
authors.lastname: Deijen
authors.forename: Diederick
authors.initials: D
authors.lastname: Stoffers
authors.forename: Ben A
authors.initials: BA
authors.lastname: Schmand
authors.forename: Cornelis J
authors.initials: CJ
authors.lastname: Stam
authors.forename: Henk W
authors.initials: HW
authors.lastname: Berendse
mesh_terms: D000368:Aged; D015415:Biomarkers; D003704:Dementia / Q000175:diagnosis* / Q000209:etiology; D018450:Disease Progression; D056344:Executive Function / Q000502:physiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015225:Magnetoencephalography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000150:complications / Q000175:diagnosis*; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D011569:Psychiatric Status Rating Scales; D012307:Risk Factors
chemical_list: D015415:Biomarkers