A rare, mostly benign, primary tumor of the meninges (arachnoid cap cells), usually located in the supratentorial compartment, commonly appearing in the sixth and seventh decade of life, clinically silent in most cases or causing hyperostosis close to the tumor and resulting in focal bulging and localized pain in less than 10% of cases. Additional features may include headache, seizures, gradual personality changes (apathy and dementia), anosmia, impaired vision, exophthalmos, hearing loss, ataxia, dysmetria, hypotonia, nystagmus, and rarely spontaneous bleeding.

A sudden episode of intense fear in a situation in which there is no danger or apparent cause. The panic attack is accompanied by symptoms such as palpitations, sweating and chills or hot flushes. There may be a sensation of dyspnea (being out of breath), chest pain, or abdominal distress. Some indiviudals with panic attacks may experience depersonalization, a fear of going crazy, or a fear of dying.