Affiliations: UQAM and Laboratoire de Neuropharmacologie Cognitive,
CHUM, Notre-Dame, Montréal, Canada | Université de Montréal and Service de neurologie,
CHUM, Notre-Dame, Montréal, Canada
Note: [] Corresponding author: Marc-André Bédard, Laboratoire de
neuropharmacologie cognitive, CHUM, Pavillon Notre-Dame, 1560, rue Sherbrooke
Est, Montréal, Québec, Canada H2L 4M1. E-mail: bedard.marc-andre@uqam.ca.
Abstract: Parkinson's Disease (PD) is often associated with a
subcortico-frontal syndrome (SCFS) that is mainly characterized by executive
dysfunctions. The complete biochemistry of these dysfunctions remain
misunderstood although many studies have suggested a role of the dopaminergic
lesions. However, cholinergic lesions in this disease may also account for the
SCFS occurrence. The present study has assessed the effects of an acute
subclinical dose of scopolamine in normal controls and in PD patients who were
devoid of cognitive deficit. Results indicates that PD patients but not normal
controls developed a transient SCFS for the duration of the drug action. In
contrast to other populations with cholinergic depletions - such as
Alzheimer's disease - cholinergic blockage in PD exacerbates specifically the
dysexecutive syndrome without inducing amnesia or sedation. Such a discrepancy
between these two neuropsychological profiles are discussed in terms of the
specificity of the underlying cholinergic lesions.
