Proton magnetic resonance spectroscopy (H-MRS) in rheumatic autoimmune diseases: A systematic review.

Background/purpose: Proton magnetic resonance spectroscopy (H-MRS) has been shown to be an important non-invasive tool to quantify neuronal loss or damage in the investigation of central nervous system (CNS) disorders. The purpose of this article is to discuss the clinical utility of H-MRS in determining CNS involvement in individuals with rheumatic autoimmune diseases.

Methods: This study is a systematic review of the literature, conducted during the month of November and December of 2019 of articles published in the last 16 years (2003-2019). The search for relevant references was done through the exploration of electronic databases (PubMed/Medline and Embase). We searched for studied including systemic lupus erythematosus (SLE), systemic sclerosis (SSc), juvenile idiopathic arthritis, rheumatoid arthritis (RA), psoriasis, Sjögren's syndrome (pSS), vasculitis and Behçet. Only studies published after 2003 and with more than 20 patients were included.

Results: We included 26 articles. NAA/Cr ratios were significant lower and Cho/Cr ratios increased in several brain regions in SLE, SS, RA, SSc. Associations with disease activity, inflammatory markers, CNS manifestations and comorbidities was variable across studies and diseases.

Conclusion: The presence of neurometabolite abnormalities in patients without ouvert CNS manifestations, suggests that systemic inflammation, atherosclerosis or abnormal vascular reactivity may be associated with subclinical CNS manifestations. MRS may be a usefull non-invasive method for screening patients with risk for CNS manifestations.