Posterior cingulate metabolic changes occur in Parkinson's disease patients without dementia

The basis for cognitive deficits in Parkinson's disease (PD) is unknown. Hippocampal atrophy has been shown in Alzheimer's disease (AD) and PD. N-Acetyl aspartate (NAA)/creatine (Cr) ratio in the posterior cingulate gyrus (PCG) is decreased in AD, but unknown in PD. Volumetric magnetic resonance (MR) imaging (at 1.5 T) determined corrected HC volume and MR spectroscopy (MRS) PCG metabolites in 12 non-demented mild to moderately affected PD patients (six male, six female) and ten controls (five male, five female). Age (PD=60.6 years, control=62.2; P=0.62), education (PD=14.1 years, controls=13.8; P=0.89) and global cognition (Mini-Mental State Exam score: PD=28.7, controls=29.6; P=0.14) did not differ. Only recall (CVLT-II, P=0.046) and NAA/Cr (PD=1.53, controls=1.78; P=0.03) were decreased in PD. Memory correlated with NAA/Cr ( r=0.65, P=0.02) in PD. In conclusion, cingulate metabolic changes occur in PD.