Abstract
A 28-year-old woman presented with subacute relapsing left-sided weakness. MRI demonstrated both enhancing C3-C6 and nonenhancing T2-T4 lesions. Initial provisional diagnosis was inflammatory/autoimmune. Her left-sided weakness progressed despite immunosuppressive therapies. We reassessed our original suspected diagnosis because of an atypical clinicoradiologic course, leading to biopsy and a definitive diagnosis.