Mild cognitive impairment in Parkinson's disease

Curr Neurol Neurosci Rep. 2011 Aug;11(4):371-8. doi: 10.1007/s11910-011-0203-1.


Prospective studies conducted during the last decade have shown that the majority of patients with Parkinson's disease (PD) develop dementia. In addition, using a variety of definitions and methods, more recent research suggests that approximately a quarter of PD patients without dementia have mild cognitive impairment (PD-MCI). Furthermore, several studies have shown that approximately 20% have MCI even at time of diagnosis of PD. The typical cognitive deficits include visuospatial, attentional, and executive deficits, but memory deficits have also been shown. The etiology of PD-MCI is not known, but it is likely that mechanisms known to contribute to dementia in PD (ie, limbic and cortical Lewy bodies, amyloid plaques, and cholinergic deficits) play a role, in addition to dysfunction of dopaminergic frontostriatal circuits. PD-MCI predicts a shorter time to dementia, and preliminary evidence suggests that this is particularly true for posterior cognitive deficits. There are currently no systematic clinical trials in PD-MCI.

Publication types

  • Review

MeSH terms

  • Cerebrospinal Fluid / chemistry
  • Clinical Trials as Topic
  • Cognition Disorders / epidemiology
  • Cognition Disorders / etiology*
  • Cognition Disorders / pathology
  • Cognition Disorders / physiopathology*
  • Humans
  • Neuropsychological Tests
  • Neurotransmitter Agents / deficiency
  • Parkinson Disease / complications*
  • Parkinson Disease / epidemiology
  • Parkinson Disease / pathology
  • Parkinson Disease / physiopathology*


  • Neurotransmitter Agents