Massive Foramen Magnum Meningioma Mimicking a Stroke.

Foramen magnum meningiomas (FMMs) are skull base tumors that arise from the arachnoid layer of the meninges at the cranio-cervical junction. They typically present gradually, with symptoms ranging from asymmetric, progressive quadriparesis and sensory impairment to involvement of the lower cranial nerves. We report a case of a 50-year-old Asian female who presented with sudden-onset left-sided numbness. Neurologic examination revealed hemisensory loss over her left extremities. Imaging studies showed a meningioma within the spinal canal at the level of C1-C2. She underwent surgical intervention, and there was resolution of the symptoms upon discharge. This case highlights the importance of recognizing atypical manifestations of FMM, such as a sudden-onset hemianesthesia, mimicking a stroke.