Delayed Steroid-Responsive Perianeurysmal Inflammation Mimicking Infectious Meningitis Seven Years after Coil Embolization

Delayed inflammatory complications after the coil embolization of intracranial aneurysms appearing years after angiographic cure are rare. We describe a patient who underwent coil embolization for a ruptured internal carotid-posterior communicating artery aneurysm at 61 years of age and developed recurrent transient neurological symptoms seven years later. A cerebrospinal fluid analysis revealed marked neutrophilic pleocytosis and hypoglycorrhachia, strongly suggesting infectious meningitis. However, extensive tests for infection and autoimmune reactions were negative. Magnetic resonance imaging revealed perianeurysmal vasogenic edema with intra-aneurysmal enhancement. Corticosteroid therapy resulted in a rapid clinical and radiological resolution of the symptoms. This case highlights a rare delayed inflammatory complication that mimics infectious meningitis.