Subarachnoid Hemorrhage Revealing a Cervical Intradural Extramedullary Cavernous Malformation: A Case Report and Literature Review.

Spinal cavernomas are uncommon among spinal vascular malformations. Most arise in the vertebrae, with some extending into the extradural space. A few are intramedullary, while intradural extramedullary cases are even rarer. This study reports a newly diagnosed case of a cervical intradural extramedullary cavernous malformation (IDEM) at the University Hospital Center of Agadir. A 48-year-old female patient presented with severe headaches of abrupt onset. A brain CT scan showed a diffuse subarachnoid hemorrhage in the basal cisterns, with extension into the ventricles. Following this finding, the patient was admitted to the neurosurgery department for further investigation and developed a sudden-onset right hemiparesis. A cerebral MRI scan showed ventricular flooding with triventricular hydrocephalus. Subsequently, a spinal cord MRI was performed, which identified an extramedullary intradural lesion at the C3/C4 level, characterized by a heterogeneous signal, consistent with an IDEM cavernoma. The patient underwent ventriculoperitoneal shunting for hydrocephalus, followed by surgical resection of the lesion. Histopathology confirmed a cavernous malformation. Postoperatively, the patient achieved full motor recovery, with no recurrence at the one-year follow-up.