Surface texture differences of the medulla may be able to differentiate neuromyelitis optica spectrum disorder (NMOSD) from multiple sclerosis (MS) and other neurological diseases, according to a study published in the Journal of Neuroimaging.
Cross-sectional and longitudinal surface texture of the dorsal medulla were found to be different between patients with NMOSD and those with MS. Spatial differences were also observed.
Patients with NMOSD had a significantly higher (P <.0001) median number of inverted triangle counts (median, 100; interquartile range (IQR), 23.5) in a region of interest around the area postrema compared to those with MS (median, 65; IQR, 20.25) and other neurological diseases of the central nervous system (median, 66; IQR, 13.75). The introverted triangle counts represent a more complex and concave topography of the tissue.
Read more about NMOSD differential diagnosis
“The early recognition and accurate diagnosis of neurodegenerative diseases is critical in ensuring rapid treatment implementation aimed at reducing irreversible damage and permanent neurological disability,” the authors said.
“Cross-sectional and longitudinal dorsal medulla surface texture differences within selective regions of vulnerability differentiate NMOSD from MS,” the study team continued.
When comparing patients with NMOSD, no difference in the number of inverted triangles was observed between patients seropositive and seronegative for aquaporin-4 immunoglobulin-G. No difference was observed between patients with MS, healthy controls, and those with other neurological disorders.
Using an inverted triangle count cutoff value of 86 or more was able to produce a model that could identify patients with NMOSD with an out-of-sample sensitivity of 83%, specificity of 100%, positive predictive value of 100%, and a negative predictive value of 60%.
A distinct spatial distribution pattern was also observed in patients with NMOSD compared to MS (P <.0001). The pattern of inverted triangles tended to extend more craniocaudally within the region of interest around the area postrema in the patients with NMOSD. Patients with MS were also found to be significantly different from patients with other neurological disorders of the CNS (P =.01).
The number of inverted triangles in patients with NMOSD was also found to be consistent between repeat measures. A total of 20 patients with NMOSD were randomly selected to have their region of interest reselected and the triangle counts redone, yielding a difference between 0 and 3 triangles between reassessments.
When observing longitudinal changes, patients with MS appeared to have a much faster increase in inverted triangles over time compared to those with NMOSD (P =.005). Patients with MS did have fewer triangles at baseline measurements (median, 61.95) compared to patients with NMOSD (median, 100.7; P <.0001).
A total of 60 patients with NMOSD, 100 patients with MS, 12 patients with other neurological diseases, and 5 healthy controls who had at least 1 3D MRI timepoint were recruited. The patients with NMOSD and patients with MS were predominantly female (83.3% and 68%, respectively).
Okuda DT, Stanley T, McCreary M, et al. Dorsal medulla surface texture: differentiating neuromyelitis optica spectrum disorder from multiple sclerosis. J Neuroimaging. Published online October 1, 2022. doi:10.1111/jon.13059