A comparative study of posterior cingulate metabolism in patients with mild cognitive impairment due to Parkinson’s disease or Alzheimer’s disease

Mild cognitive impairment (MCI) precedes both Alzheimer’s disease (AD)- and Parkinson’s disease (PD)-associated dementia^2,3,4,13. This is the first comparative study to examine metabolic patterns in the PCC (via single voxel ¹H-MRS) between these two commonly neurodegenerative diseases. In the current study, the main findings were as follows. (1) Among the groups investigated, only the PCC in ADMCI cases showed significantly altered glial metabolism (Ins levels). (2) The levels of tCr were significantly reduced in the progression of cognitive impairment in PD, while in ADMCI, tCr remained unchanged. (3) Unlike ADMCI patients, individuals with PDMCI showed significantly reduced NAA, tCr, GSH, Cho and Glx levels in the PCC, but no changes were found in the PDN group. These findings suggest that ¹H-MRS of the PCC demonstrate distinct metabolic brain abnormalities in potential PDMCI…