Intracranial or spinal cavities containing a cerebrospinal-like fluid, the wall of which is composed of arachnoidal cells. They are most often developmental or related to trauma. Intracranial arachnoid cysts usually occur adjacent to arachnoidal cistern and may present with HYDROCEPHALUS; HEADACHE; SEIZURES; and focal neurologic signs. (From Joynt, Clinical Neurology, 1994, Ch44, pp105-115)

Synonyms: Diverticula, Arachnoid, Leptomeningeal Cysts, Cysts, Leptomeningeal, Arachnoid Cysts, Intracranial, Intracranial Arachnoid Cyst, Arachnoid Cysts, Cyst, Leptomeningeal, Cysts, Arachnoid, Leptomeningeal Cyst, Arachnoid Cyst, Intracranial, Diverticulas, Arachnoid, Cyst, Intracranial Arachnoid, Arachnoid Diverticula, Intracranial Arachnoid Cysts, Arachnoid Diverticulas, Cysts, Intracranial Arachnoid, Cyst, Arachnoid