Giant Intracranial Arachnoid Cyst Causing Acute Neurologic Symptoms

Intracranial arachnoid cysts (IAC) are benign lesions containing cerebrospinal fluid (CSF). Most of them are clinically silent and remain static in size. However some may present with mild and slow progressive symptoms caused by the cyst. The authors present the case of 54-year-old woman who presented with acute symptoms of severe headache, vomiting, and gait disturbance of 2 day’s duration. She had no history of head trauma. On admission, neurological examination revealed that the patient had a Glasgow Coma Scale score of 15, and a left side hemiplegia. A CT scan revealed a hypodense fluid collection in the right frontoparietal region that mimicked an arachnoid cyst. The symptoms were improved after an emergency marsupialisation via craniotomy.