Striatal dopamine transporter levels correlate with apathy in neurodegenerative diseases A SPECT study with partial volume effect correction.
OBJECTIVE
The aim of the present study was to stress the relationship between neuropsychiatric symptoms and most particularly apathy and striatal dopamine uptake in patients with Alzheimer's disease (AD) or dementia with Lewy body (DLB).


METHODS
Twenty-two patients (AD n=14; DLB n=8) were included. All patients had neuropsychological and behavioral examination including Mini Mental Test Examination (MMSE), Neuropsychiatric Inventory (NPI), and UPDRS for the motor activity assessment. Apathy dimensions, emotional blunting, lack of initiative and lack of interest were assessed using the Apathy Inventory (AI). Dopamine transporter (DAT) striatal uptake was assessed using (123)I-FP-CIT (DaTSCAN) SPECT. Quantitative measurements were obtained in 3D using a method which compensates for physical detection biases including partial volume effect.


RESULTS
We observed a correlation between DAT uptake and NPI's domains only for apathy. More specifically using the AI, lack of initiative significantly correlated with bilateral putamen DAT uptake. Using partial correlation coefficients controlling for the UPDRS score, the correlation remained significant between lack of initiative and right and left putamen DAT uptake.


CONCLUSIONS
These results demonstrate a relationship between apathy and DAT levels independent from motor activity. They suggest that the patients with neurodegenerative diseases presenting with apathy are characterized by some degree of dopaminergic neuronal loss.
David
Renaud
R
Centre Mémoire de Ressource et de Recherche, CHU Nice, France. vadner@hotmail.com
Koulibaly
Malick
M
Benoit
Michel
M
Garcia
René
R
Caci
Hervé
H
Darcourt
Jacques
J
Robert
Philippe
P
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000523:psychology; D002540:Cerebral Cortex / Q000000981:diagnostic imaging / Q000378:metabolism*; D050483:Dopamine Plasma Membrane Transport Proteins / Q000378:metabolism*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D020961:Lewy Body Disease / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000523:psychology; D008297:Male; D009483:Neuropsychological Tests; D015899:Tomography, Emission-Computed, Single-Photon
D050483:Dopamine Plasma Membrane Transport Proteins