Cognitive impairments in advanced PD without dementia.
OBJECTIVE
To determine the nature and frequency of cognitive impairments in nondemented patients with advanced PD and their relationship to other variables potentially predictive of neuropsychological performance.


METHODS
The neuropsychological performance of nondemented, nondepressed patients with idiopathic PD (n = 61) was quantified with respect to clinically available normative data. The relationship of neuropsychological measures to motor symptoms, age, years of education, disease duration, age at disease onset, disease deterioration rate, and dopaminergic therapy was assessed.


RESULTS
Impairment was most frequent on measures sensitive to frontal lobe function (67% on Wisconsin Card Sorting Test number of categories, 30% on letter fluency, 30% on verbal learning). Poorer performance on multiple neuropsychological measures was related to greater overall motor abnormality (total Unified Parkinson's Disease Rating Scale score), increased bradykinesia on medication, older age, longer disease duration, and reduced education.


CONCLUSIONS
Even in the absence of dementia or depression, patients with advanced PD are likely to show clinically significant impairments on neuropsychological measures sensitive to changes in dorsolateral prefrontal regions participating in cognitive basal ganglia-thalamocortical circuits.
Green
J
J
Department of Neurology, Emory University School of Medicine, Emory University, Atlanta, GA, USA. jgreen@emory.edu
McDonald
W M
WM
Vitek
J L
JL
Evatt
M
M
Freeman
A
A
Haber
M
M
Bakay
R A E
RA
Triche
S
S
Sirockman
B
B
DeLong
M R
MR
D000328:Adult; D000367:Age Factors; D017668:Age of Onset; D000368:Aged; D000978:Antiparkinson Agents / Q000627:therapeutic use; D003072:Cognition Disorders / Q000175:diagnosis* / Q000453:epidemiology*; D003704:Dementia; D018450:Disease Progression; D004522:Educational Status; D006801:Humans; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000188:drug therapy / Q000453:epidemiology*; D011237:Predictive Value of Tests
D000978:Antiparkinson Agents