Regional cerebral blood flow and episodic memory in Parkinson's disease: a single photon emission tomography study

In this paper we examined 46 nondemented Parkinson's disease (PD) patients by means of perfusion single photon emission computed tomography (SPECT) and neuropsychological testing. The aim was to detect correlations of regional cerebral blood flow with episodic memory performance, using an operator-independent technique for the analysis of SPECT data. A significant positive correlation was found between prefrontal blood flow and episodic memory performances. However, age was the most important determinant of memory scores. Age also correlated significantly negatively with prefrontal perfusion. Our methodology also allowed detection of an inverse correlation of left medial temporal lobe perfusion with the memory score. This had not been found in previous studies and might indicate compensatory mechanisms in the brain of PD patients. It is concluded that episodic memory in nondemented PD patients is most dependent on the effects of aging and that the aging effects on cerebral perfusion in the PD brain parallel to a large extent the findings in normal controls.