The role of Right Anterior White Matter area in Multiple Sclerosis-related fatigue: A Magnetic Resonance Spectroscopy (MRS) Study (P3.392)

Objective: To study the longitudinal neurometabolites alterations in white matter of Multiple Sclerosis (MS) patients who reported fatigue using MR spectroscopy. Background: Approximately 80% of patients with Multiple Sclerosis (MS) report fatigue. Neurochemical alterations in white matter (WM) caused my demyelination and tissue injury may be involved in the pathogenesis of MS-related fatigue. However, the selective involvement of white matter regions that may be implicated in fatigue pathology remains unclear. Design/Methods: We used proton magnetic resonance spectroscopy (MRS) in a retrospective longitudinal study of 45 MS patients who reported fatigue measured by Fatigue Severity Scale (FSS: 1–7). We examined the neuro-chemical changes in MRS grid localized to centrum semiovale of High Fatigue (HF, FSS ≥ 5.1) and Low Fatigue (LF, FSS ≤ 3) subgroups at baseline and year 1. Results: At baseline, N-acetyl aspartate to creatine ratio ((NAA+NAAG)/Cr) was significantly lower in HF ((NAA+NAAG)/Cr: 1.89 ± 0.06) group compared to LF group ((NAA+NAAG)/Cr: 2.09 ± 0.068) in Right Anterior White Matter (RAWM) region of MRS grid (p = 0.039) placed in centrum semiovale. At year 1, we observed a similar trend in N-acetyl aspartate to creatine ratio ((NAA+NAAG)/Cr) between HF ((NAA+NAAG)/Cr: 1.88 ± 0.04) group and LF group ((NAA+NAAG)/Cr: 2.07 ± 0.07) in Right Anterior White Matter (RAWM) region. However, correlation between FSS score and (NAA+NAAG)/Cr in RAWM region did not reach statistical significance. Furthermore, glutamate, choline, phosphocholine levels and choline/creatine ratio did not show a significant correlation with fatigue severity in any area of the MRS grid. Conclusions: Our findings suggest that the involvement of RAWM in frontoparietal area may contribute to the development of MS-related fatigue. Larger prospective clinical trials with longer follow-up periods may explain the role of RAWM region in the pathophysiology of MS-related fatigue. Disclosure: Dr. Sriwastava has nothing to disclose. Dr. Yarraguntla has nothing to disclose. Dr. Lichtman-Mikol has nothing to disclose. Dr. Razmjou has nothing to disclose. Dr. Bao has nothing to disclose. Dr. Sood has nothing to disclose. Dr. Seraji-Bozorgzad has nothing to disclose. Dr. Bernitsas has nothing to disclose.