H-1-MR-SPECTROSCOPIC IMAGING IN PATIENTS WITH ALZHEIMERS-DISEASE

Purpose: To detect regional differences in accompanying metabolic chan ges, H-1-Magnetic Resonance Spectroscopic Imaging (MRSI) was performed in 16 patients with Alzheimer's disease (AD); the clinical diagnosis was based upon DSM-III-R and NINCDS-ADRDA. guidelines. Methods: In the hippocampal region metabolic maps of the local distribution of N-acet ylaspartate (NAA), choline (Cho), creatine compounds (P(Cr)) and lacta te were determined. Ratios of Cho/NAA, (P)Cr/NAA and Cho/(P)Cr calcula ted from selected hippocampal spectra were compared to those from heal thy volunteers (n=17). Results: AD patients demonstrated an increase o f Cho/NAA and (P)Cr/NAA ratios caused by increased choline compounds a nd decreased NAA. These alterations were observed in (11)/12 cases in the hippocampal and in (7)/12 in the temporo-occipital region. Hippoca mpal Cho/NAA ratios (0.56 +/- 0.19) were significantly elevated compar ed with controls (0.33 +/- 0.04; p<0.0001). Conclusion: The observed e levation of choline compounds in the hippocampus supports the hypothes is that alterations in the cholinergic system play an important role i n Alzheimer's disease. The observed reduction of NAA is due to neurona l degeneration.