Researchers compared the diagnostic performance of imaging criteria that differentiated aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder (AQP4+NMOSD) and multiple sclerosis (MS) and discovered that it had high applicability at the earliest disease stages and is thus useful in clinical practice, as published in the European Journal of Radiology.
Differentiating MS from AQP4+NMOSD early can help physicians make the right clinical decisions. Given that the diagnostic assessments of antibody status can be time-consuming and not readily available, several magnetic resonance imaging (MRI) criteria have been proposed to differentiate MS and AQP4+NMOSD at the diagnostic stage.
“Features suggestive of AQP4+NMOSD include a single, centrally located, longitudinally extensive, enhancing spinal cord lesion; longitudinal extensive optic nerve involvement with extension into the optic chiasm; brain lesions involving circumventricular organs; and the relative absence of cortical lesions,” Zrzavy et al wrote.
Read more about NMOSD diagnosis
To investigate the usefulness of these MRI criteria upon initial diagnosis and follow-up, the research team conducted a monocentric, clinical routine cohort study. They retrospectively analyzed MRI scans in 10 patients with AQP4+NMOSD and 25 with relapsing-remitting MS (RRMS) from their local database.
The results demonstrated that 20% of patients had AQP4+NMOSD at disease onset and 33% at follow-up met the Matthews criteria; among patients with RRMS, the figure was 96% at disease onset and 100% at follow-up. Statistical analysis revealed that specificity and sensitivity were high at both time points.
With regards to the Cacciaguerra criteria, 90% of patients with AQP4+NMOSD met the criteria at disease onset and 88.9% at follow-up; among patients with RRMS, the figure was 24% at disease onset and 14% at follow-up.
“In conclusion, in this monocentric, real-life cohort study, we provide evidence that high diagnostic accuracy of published imaging criteria was preserved for the discrimination of RRMS and AQP4+NMOSD at disease onset, further emphasising the value of their use in clinical practice,” the research team wrote.
Zrzavy T, Leutmezer F, Rommer P, et al. Imaging features to distinguish AQP4-positive NMOSD and MS at disease onset: a retrospective analysis in a single-center cohort. Eur J Radiol. 2021;146. doi: 10.1016/j.ejrad.2021.110063