Relationship between apathy and cognitive dysfunctions in de novo untreated Parkinson's disease: a prospective longitudinal study.
OBJECTIVE
Apathy may be either a symptom of major depression or a behavioral disturbance occurring in concomitance with depression or alone in Parkinson's disease (PD). The aim of the present study was to determine the progression of cognitive impairment in drug-naïve untreated PD patients with or without clinically significant apathy.


METHODS
Sixty-two PD patients with a disease duration <2 years and without history of present or past therapy with pro-dopaminergic agents were included and underwent the Apathy Evaluation Scale (S-AES), a clinical interview based on diagnostic criteria for apathy and a comprehensive neuropsychological battery to assess memory, frontal functions and visuospatial functions. Two years after the first assessment, all patients were re-evaluated on the S-AES, a clinical interview and neuropsychological tests.


RESULTS
According to the cut-off value of the S-AES and diagnostic criteria for apathy, eight patients experienced apathy at both baseline and follow-up (A+A+), nine patients had apathy only at follow-up (A-A+), 37 patients never experienced apathy (A-A-) and eight patients showed apathy at the baseline only (A+A-). Cognitive performance significantly declined in all four groups. At both baseline and follow-up A+A+ performed worse than A-A- on visuospatial and frontal tests; A-A+ had lower scores than A-A- on the interference task of the Stroop test (IT-ST). Regression analysis showed that poor performance on the IT-ST at baseline was the only independent predictor of onset of apathy at follow-up.


CONCLUSIONS
The results indicated a relationship between apathy and dysexecutive syndrome in early PD. Reduced scores on the IT-ST may predict development of apathy in PD patients.
Department of Psychology, Second University of Naples, Caserta, Italy; IDC-Hermitage-Capodimonte, Naples, Italy.
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G
Santangelo
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Vitale
L
L
Trojano
M
M
Picillo
M
M
Moccia
G
G
Pisano
D
D
Pezzella
S
S
Cuoco
R
R
Erro
K
K
Longo
M T
MT
Pellecchia
M
M
Amboni
A
A
De Rosa
G
G
De Michele
P
P
Barone
D000368:Aged; D057565:Apathy / Q000502:physiology*; D003072:Cognition Disorders / Q000209:etiology* / Q000503:physiopathology; D018450:Disease Progression; D056344:Executive Function / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000150:complications* / Q000503:physiopathology
Parkinson's disease; apathy; behavioral disorders; cognitive dysfunctions; frontal dysfunctions