Multiple sclerosis with intractable vomiting and atypical area postrema lesion

Background: Area postrema syndrome is considered as one of the most typical presentations of neuromyelitis optica spectrum disorders (NMOSDs) (Wingcrchuk et al., 2015). The involvement of area postrema is rarely seen in multiple sclerosis (MS). We are here report a case of a young woman with multiple sclerosis, presented with intractable vomiting, and her MRI brain showed acute T2 hyperintense signal over the area postrema. Case presentation: A 36-year-old Asian woman who is known to have schizophrenia and multiple sclerosis since 2012. She was noted to have spastic gait, and the MRI brain in 2012 showed multiple perpendicular periventricular T2 lesions suggestive of multiple sclerosis (MS). However, she defaulted her neurologist follow-up and was not on any treatment for MS. She was admitted in 2016 with intractable vomiting, and her MRI brain showed T2 hyperintense signal over area postrema with focal contrast enhancement. Her MRI cervical spine was normal. The visual evoked potential study showed bilateral prolonged P100 latencies. Oligoclonal bands were detected in her CSF analysis. Both the serum aquaporin-4 IgG (AQP4 IgGs) antibody and myelin oligodendrocyte glycoprotein (MOG-IgGs) were negative. Her intractable vomiting resolved after a short course of intravenous methylprednisolone. She was treated as MS with interferon-beta la. She has been in remission since 2016, and her functional status also improved from the expanded disability status scale (EDSS) of 2.0 (in 2016) to 1.0 (in 2020). Conclusion: We proposed that although area postrema lesion is typically seen in NMOSDs, it may also be seen in MS. Current MRI criteria for MS and NMOSDs are not sufficiently specific, and the diagnostic criteria should only be used in the appropriate clinical context.