Stephanie Syc-Mazurek, MD, PhD
(Credit: The MOG Project)
In a new study published in the Journal of Neurology, Neurosurgery and Psychiatry, researchers from Mayo Clinic used paired MRI at attack and remission to differentiate characteristics of myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) and multiple sclerosis (MS). Findings revealed that a resolution of 1 or more brain T2-lesions could differentiate MOGAD from MS with high sensitivity and specificity, suggesting that a 1-year follow-up MRI may aid diagnosis and serve as a new baseline for those with MOGAD who have initial parenchymal involvement.1
Among 43 patients with MOGAD (median age, 31 years; women, 63%) and 49 patients with MS (median age, 39 years; women, 65%), researchers reported that a resolution of 1 or more T2-lesions on follow-up examination after 1 year was highly suggestive of MOGAD rather than MS with sensitivity of 95% (95% CI, 77%-100%), specificity of 95% (95% CI, 86%-99%; likelihood ratio 19.05, Youden’s index [YI] = .9). Additionally, investigators observed that a resolution of 2 or more T2-lesions had a sensitivity of 62% (95% CI, 41%-79%) and specificity of 100% (95% CI, 94%-100%; YI = .62).
“This study leverages paired attack and remission scans to provide clear MRI biomarkers that are predictive of differentiating MOGAD from MS. Specifically, we identified: (1) T2-lesion resolution was the strongest MRI predictor of MOGAD versus MS and (2) resolution of one T2-lesion had very high sensitivity and specificity while resolution of 2 T2-lesions completely separated MOGAD from MS,” lead author Stephanie Syc-Mazurek, MD, PhD, clinical fellow in autoimmune neurology at Mayo Clinic Rochester, and colleagues wrote.1 “These data provide a simple tool for differentiation of MOGAD and MS in the clinical setting that is widely accessible to the practicing neurologist.”
In this study, researchers compared MRIs between patients diagnosed with either MOGAD or MS from Mayo Clinic.2 These included patients who had a diagnosis of MOGAD or MS; MRI of the brain or spine completed in 30 days of a clinic attack and subsequent MRI completed at least 12 months later without development of interval new clinical symptoms. Many patients with MOGAD and MS received acute therapy at the time of clinical attack (MOGAD, 93%; MS, 76%; P = .03). Most of the patients were also on disease-modifying therapy at the time of remission assessment though treatment during remission scans was more frequent in patients with MS (MOGAD, 37%; MS, 61%; P = .04).
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At follow-up, remission brain and spine MRI assessments were significantly more likely to appear normal in patients with MOGAD compared with those with MS. Normal brain MRIs were observed in 14 of 44 patients with MOGAD versus 0 of 60 patients with MS (P < .001), and normal spine MRIs were seen in 21 of 27 MOGAD cases versus 7 of 36 MS cases (P <.001). Additional findings showed that T1-hypointense lesions, ovoid periventricular T2 lesions, and contrast-enhancing lesions were more frequently observed in MS than in MOGAD, both during attacks and at remission. In the spine, longitudinally extensive T2 lesions were reported in 8 of 27 patients with MOGAD during attacks (8 of 27 patients).
Authors noted that this study had notable limitations, including variability in MRI timing, scanners, and field strengths, as well as differences between the MS and MOGAD cohorts, which may affect generalizability. The MS group came from a community-based epidemiological study, whereas the MOGAD group was drawn from a tertiary care center and included more pediatric and severe cases. Researchers also acknowledged selection bias and lack of correction for multiple comparisons, given the exploratory nature of the analysis.
“In conclusion, we used paired attack and remission scans to identify clear MRI biomarkers predictive of differentiating MOGAD from MS. Resolution of a single T2-lesion at follow-up is a strong predictor of a diagnosis of MOGAD while resolution of 2 T2-lesions completely separates MOGAD from MS. In addition, we identified imaging findings that differentiate patients with MOGAD and MS at the time of clinical attack and remission and demonstrate the utility of paired MRI scans when there is diagnostic uncertainty,” Syc-Mazurek et al noted.1