Cholinergic-dependent cognitive deficits in Parkinson's disease

Ann Neurol. 1987 Jul;22(1):26-30. doi: 10.1002/ana.410220108.


In a double-blind cross-over study, the effects of a subthreshold dose of scopolamine (0.25 mg) on memory were compared in 32 control subjects and 32 parkinsonian patients who were without any sign of intellectual and mnemic impairment. Although the scores of the controls in the memory test battery showed no deterioration after the administration of scopolamine, the same dose resulted in significantly reduced memory performance in parkinsonian patients in two tests which involved the recognition of meaningless drawings. The selective vulnerability of parkinsonian subjects without cognitive impairment to a subthreshold dose of scopolamine suggests the existence of an underlying alteration of central cholinergic transmission. The neuropsychological findings in our study agree with postmortem biochemical data, which showed decreased cortical choline acetyltransferase activity in all parkinsonian patients, suggesting the existence of neuronal compensation in parkinsonian patients who are without cognitive impairment.

Publication types

  • Clinical Trial
  • Controlled Clinical Trial

MeSH terms

  • Acetylcholine / metabolism
  • Cholinergic Fibers / drug effects
  • Cholinergic Fibers / physiopathology*
  • Cognition Disorders / etiology
  • Cognition Disorders / metabolism
  • Cognition Disorders / physiopathology*
  • Double-Blind Method
  • Humans
  • Memory
  • Mental Recall
  • Middle Aged
  • Parkinson Disease / complications
  • Parkinson Disease / metabolism
  • Parkinson Disease / psychology*
  • Psychological Tests
  • Scopolamine / administration & dosage
  • Wechsler Scales


  • Scopolamine
  • Acetylcholine