SPECT neuroimaging and neuropsychological functions in different stages of Parkinson's disease.
OBJECTIVE
The present study investigated differences and associations between cortical perfusion, nigrostriatal dopamine pathway and neuropsychological functions in different stages of Parkinson's disease (PD).


METHODS
We recruited 53 non-demented PD patients divided into four groups according to the Hoehn and Yahr (HY) staging system and 20 healthy controls who were used in the comparison of the neuropsychological findings. Each patient underwent two separate brain single photon emission computed tomography (SPECT) studies (perfusion and dopamine transporter binding) as well as neuropsychological evaluation. Perfusion images of each patient were quantified and compared with a normative database provided by the NeuroGam software manufacturers. Mean values obtained from the cortical areas and neuropsychological measures in the different groups were also compared by analysis of covariance (ANCOVA) controlling for disease duration and educational level.


RESULTS
We found cognitive deficits especially in the late PD stages (HY 3, 4 and 5) compared to the early stages (HY 1 and 2) and associations between cognitive decrements and cortical perfusion deterioration mainly in the frontal and posterior cortical areas. Compared with controls, PD patients showed impairments of cognition and cerebral perfusion that increased with clinical severity. Furthermore, we found a significant correlation between the performance on the phonemic fluency task and regional cerebral blood flow (rCBF) in the left frontal lobe. Dopamine transporter binding in the left caudate nucleus significantly correlated with blood flow in the left dorsolateral prefrontal cortex (DLPFC), but not with measures of executive functions.


CONCLUSIONS
There are significant cognitive and perfusion deficits associated with PD progression, implying a multifactorial neurodegeneration process apart from dopamine depletion in the substantia nigra pars compacta (SNc).
Department of Nuclear Medicine, University of Patras Medical School, Patras, Greece. a_pashali@yahoo.gr
Anna
A
Paschali
Lambros
L
Messinis
Odysseas
O
Kargiotis
Velissarios
V
Lakiotis
Zinovia
Z
Kefalopoulou
Costantinos
C
Constantoyannis
Panagiotis
P
Papathanasopoulos
Pavlos
P
Vassilakos
D000368:Aged; D001921:Brain / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D016022:Case-Control Studies; D002560:Cerebrovascular Circulation; D018450:Disease Progression; D050483:Dopamine Plasma Membrane Transport Proteins / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D055420:Perfusion Imaging; D015899:Tomography, Emission-Computed, Single-Photon
D050483:Dopamine Plasma Membrane Transport Proteins