We describe a rare presentation of gradual onset BCS with characteristic concentric lesions on MRI in a Hispanic patient with MS

BCS is a rare CNS demyelinating disease characterized by concentric, lamellated lesions on MRI. Common presenting symptoms of BCS are hemiparesis and hemianesthesia, while only 3% of patients present with seizures. In an analysis of 68 BCS cases, most patients were of Asian ethnicity, and only four patients showed gradual symptom onset. Literature describes BCS as distinct from MS due to lack of oligoclonal bands (OCB), normal IgG index, and lack of pleocytosis. However, 22% of patients with BCS exhibit positive IgG OCB.

A 29-year-old Hispanic woman with a history of MS and catamenial epilepsy presented with increasing seizure frequency over the past month and seven recurrent seizures on the day preceding admission. Physical exam demonstrated left homonymous hemianopia, right gaze preference, relative afferent pupillary defect, left-sided hemiparesis, left-sided hemianesthesia, and left-sided plantar extension. MRI showed a new 3.2cm right occipital T1 hypointensity and T2-Flair hyperintensity with irregular concentric, whorled enhancement, and extensive T2 hyperintensities. CSF analysis was significant for elevated IgG with OCB. After five days of treatment with 1g methylprednisolone, the patient demonstrated improvement in hemiparesis and hemianasthesia.

This patient was unique due to acute on insidious presentation with status epilepticus, which is unusual for BCS. Most reports describe BCS in patients of Asian ethnicity, while there are no reported cases of BCS in Hispanic patients. Moreover, her history of MS with known lesions on MRI and acute concentric, lamellated T2 hypointensities with subsequent improvement on methylprednisolone are consistent with rare case reports in BCS literature. Finally, it is important to recognize the characteristic appearance of BCS lesions to prevent unnecessary biopsies and missed treatment opportunities in patients with pre-existing lesions.