Verbal fluency deficits in Parkinson's disease: A meta-analysis

J. D. Henry, John Robertson Crawford

Research output: Contribution to journalArticle

208 Citations (Scopus)

Abstract

A meta-analysis of 68 studies with a total of 4644 participants was conducted to investigate the sensitivity of tests of verbal fluency to the presence of Parkinson's disease (PD) relative to healthy controls. Both phonemic and semantic fluency were moderately impaired but neither deficit qualified as a differential deficit relative to verbal intelligence or psychomotor speed. However, PD patients were significantly more impaired on semantic relative to phonemic fluency (rs = .37 vs. .33, respectively), and confrontation naming, a test of semantic memory that imposes only minimal demands upon cognitive speed and effortful retrieval, was associated with a deficit that was of a comparable magnitude to the deficits upon each of these types of fluency. Thus, the disorder appears to be associated with particular problems with semantic memory. Tests that impose heavy demands upon switching may also be disproportionately affected. Demented and non-demented PD patients differ quantitatively but not qualitatively in terms of the relative prominence of deficits on tests of phonemic and semantic fluency. However, patients with dementia of the Alzheimer's type and demented PD patients can be differentiated from one another by the relative magnitude of deficits upon these two measures.

Original languageEnglish
Pages (from-to)608-622
Number of pages14
JournalJournal of the International Neuropsychological Society
Volume10
DOIs
Publication statusPublished - 2004

Keywords

  • Parkinson's
  • fluency
  • semantic memory
  • switching
  • PROGRESSIVE SUPRANUCLEAR PALSY
  • ALZHEIMERS-DISEASE
  • EXECUTIVE FUNCTIONS
  • FRONTAL-LOBE
  • COGNITIVE IMPAIRMENT
  • WORD FLUENCY
  • HUNTINGTONS-DISEASE
  • SEMANTIC FLUENCY
  • REACTION-TIME
  • MEMORY

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