Is the functional decline of Parkinson's disease similar to the functional decline of Alzheimer's disease?

M. N. Sabbagh, N. Silverberg, S. Bircea, B. Majeed, S. Samant, J. N. Caviness, B. Reisberg, C. H. Adler

Research output: Contribution to journalArticle

17 Scopus citations


Since many Parkinson's disease (PD) subjects develop dementia, we determined whether the correlation between functional and cognitive decline seen in Alzheimer's disease (AD) is seen in PD. Seventy-five PD subjects with and without dementia and 103 AD/MCI subjects underwent the Functional Assessment Staging (FAST), the Global Deterioration Scale (GDS), the UPDRS motor portion, and the MMSE. In AD/MCI subjects, changes in FAST and GDS scores correlated with MMSE (ρ=-0.814, P<0.001; ρ=-0.840, P<0.001, respectively). In PD subjects, the FAST and GDS also correlated with MMSE (ρ=-0.675, P<0.001; ρ=-0.647, P<0.001, respectively). The UPDRS correlated with the GDS and FAST more closely in PD than in AD. Similar to AD, functional declines in PD correlates with cognitive decline and may be influenced by motor disability in PD.

Original languageEnglish (US)
Pages (from-to)311-315
Number of pages5
JournalParkinsonism and Related Disorders
Issue number5
StatePublished - Aug 1 2005



  • Alzheimer's
  • Cognitive decline
  • Function
  • Parkinson's

ASJC Scopus subject areas

  • Neurology
  • Geriatrics and Gerontology
  • Clinical Neurology

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