To compare the frequencies of brain lesions in locations considered typical for Multiple Sclerosis (MS) in a representative cohort of patients with MS, Neuromyelitis Optica Spectrum Disorders (NMOSD), and MOG Antibody Disorder (MOGAD).

Although no radiologic finding is pathognomonic for MS, brain lesions in MS tend to occur in characteristic locations (‘MS Lesion Checklist,’ Kister 2018). It is important to determine whether specific lesion locations can differentiate demyelinating-inflammatory disorders of central nervous system from each other.  

We retrospectively reviewed charts and brain MRIs of patients with MS (N=51), NMOSD (N=23), and MOGAD (N=8) who were referred to the NYU MS Care Center (New York) for evaluation. Brain MRIs were reviewed independently by two neuroradiologists who were blinded to clinical data and were scored based on lesion location (middle cerebellar peduncle, brainstem surface, brainstem ependymal surface, central brainstem, perpendicular to cerebellar folia, other cerebellar, abutting temporal horn, Dawson finger/periventricular, subcortical white matter, callososeptal interface, other corpus callosum, U-fiber, and other juxtacortical). Frequencies of lesions in each location in the three diseases were compared using Fisher’s exact test (p<0.05 considered significant). 

The only location in which frequency of lesions was significantly different in MS compared to NMOSD and MOGAD was ‘abutting temporal horn’ of lateral ventricle (MS 73%, NMOSD 22% (p<0.0001), MOGAD 25% (p<0.01)). Cerebellar lesions were more common in MS (53%) than NMOSD (26%) (p<0.04), but not MOGAD, while Dawson finger/periventricular and callososeptal interface lesions were more common in MS than MOGAD (p<0.0005 and p<0.0058, respectively), but not NMOSD. 

Our data suggests high degree of overlap in the distribution of brain lesions in demyelinating-inflammatory disorders of central nervous system.  Of the 13 locations, MS lesions were more common than NMOSD/MOGAD in only the anterior temporal lobe.