Arachnoid Cyst

Arachnoid cysts are cerebrospinal fluid-filled sacs located within the arachnoid membrane, often congenital but occasionally acquired. Many are asymptomatic, but larger cysts may cause headaches, seizures, hydrocephalus, or focal neurological deficits. Diagnosis is established via MRI or CT, which delineates cyst location and size. Symptomatic cysts may require surgical intervention, such as fenestration or shunting. Prognosis is favorable in most cases, particularly for incidental, asymptomatic cysts.