Magnetic resonance spectroscopy in Parkinson’s disease

Abstract

Introduction. Modern neuroimaging methods allow to evaluate in vivo biochemical processes in the brain. Such methods include magnetic resonance spectroscopy (MRS) and positron emission tomography (PET). While PET is the “golden standard” in assessing the brain functional state and is widely used in neurodegenerative diseases, the diagnostic value of MRS remains undefined due to the inconsistency of the results obtained in different studies. At the same time, MRC allows obtaining information on the content of many metabolites in living tissues, including N-acetyl aspartate (NAA), which is considered to be a surrogate marker of neuronal integrity, choline (Cho), associated with membrane metabolism, Cr - energy metabolism, etc. The aim of this study is to compare MRS and PET data in patients with Parkinson’s disease (PD).Materials and methods. Twenty-six patients with PD stages I to III according to the Hoehn and Yahr Scale and age-matching control group of neurologically and cognitively intact people were examined. All patients underwent neurological examination, a multivoxel MRS of the supraventricular region, including white and gray matter, and PET with 18F-fluorodeoxyglucose (FDG) to assess cerebral metabolic rate of glucose (CMRglu).Results. Decrease of NAA/Cr and NAA/Cho in the white matter in the left hemisphere was revealed in PD group compared to control, with the NAA/Cr ratio negatively correlating with the stage of the disease of the Hoehn and Yahr Scale. The NAA content in the white matter and the cingulate cortex positively correlated with CMRglu in Brodmann fields 5–7, 8–10, 22, 23, 46. At the same time, Cho/Cr ratio negatively correlated with CMRglu in the cortical areas associated with the development of cognitive impairment in PD (Brodman areas 9, 10, 39, 47).