Arachnoid cyst presenting as a neurosurgical emergency: a case report

Abstract

Introduction: Arachnoid cysts are intra-arachnoid lesions filled with cerebrospinal fluid (CSF). They account for approximately 1% of all intracranial mass lesions and are non-neoplastic collections of CSF within an anomalous arachnoid enclosure. Case presentation: The authors report a 35-year Arabian male who presented to ER with a history of sudden loss of consciousness, anisocoria, and right hemiparesis. Contrast tomography showed a large frontoparietotemporal cyst (7.7×5.8×5.4) with uncal herniation and a midline shift of 12 mm. Emergency Left FTP Craniotomy with excision of cyst was performed. Discussion: Arachnoid cysts can be categorized as primary or secondary, arising congenitally or due to factors like trauma, infection or neoplasia. It can rupture, leading to internal bleeding, causing symptoms such as headaches, seizures, and neurological decline. Rapid diagnosis is vital, with cranial CT scans preferred for emergencies. Treatment options include surgical intervention like craniotomy, fenestration or cyst peritoneal shunts. For uncal herniation, surgery can be successful and results depends on amount of herniation. Conclusion: Although benign, the arachnoid cysts led to uncal herniation when they become “tension” cysts. A high level of suspicion is crucial for early recognition of the condition. Timely intervention has shown positive recovery outcomes.