title: A predictive model of neurodegeneration in idiopathic REM-sleep behavior disorder.
abstract: OBJECTIVE
  To investigate whether Parkinson's disease (PD) and dementia are competing risks in subjects with idiopathic rapid-eye-movement sleep behavior disorder (RBD).
  
  
  METHODS
  The number of incidental PD cases observed in 11 longitudinal RBD studies was compared with the corresponding expected number as estimated by a simple mathematical model based on population parameters for PD age-of-onset.
  
  
  RESULTS
  The expected number of incidental PD cases exceeded observed PD cases (p-value < 0.001) but was in agreement with the sum of observed PD cases and observed mild cognitive impairment/dementia cases (p-value = 0.34). Sensitivity analyses confirmed the results.
  
  
  CONCLUSIONS
  In the RBD population, PD and dementia cases are competing risks, suggesting that alpha-synuclein pathology occurs simultaneously in substantia nigra and neocortex. This observation has implications for the design and analysis of trials of neuroprotection.
authors.affiliation: Section of Neurology, Complejo Hospitalario Universitario de Ferrol (CHUF), Hospital A. Marcide, 15405 Ferrol, Spain. Electronic address: rfuente@medynet.com.
authors.forename: Raúl
authors.initials: R
authors.lastname: de la Fuente-Fernández
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003704:Dementia / Q000175:diagnosis* / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D033162:Incidental Findings; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D019636:Neurodegenerative Diseases / Q000175:diagnosis / Q000453:epidemiology; D010300:Parkinson Disease / Q000175:diagnosis* / Q000453:epidemiology; D011237:Predictive Value of Tests; D020187:REM Sleep Behavior Disorder / Q000175:diagnosis* / Q000453:epidemiology
keywords: Competing risks; Dementia; Lewy body dementia; Mild cognitive impairment; Parkinson's disease; Rapid-eye-movement sleep behavior disorder