[Arachnoid cysts and subdural hematomas].

Arachnoid cysts of the middle cerebral fossa is a not uncommon lesion which can occur in young subjects, sometimes after minimal head trauma. Subdural hematomas and sometimes intracystic hemorrhage may develop. We report a personal series of seven cases seen in young subjects (6-24 years). Clinical presentation was not specific, the complication usually being revealed by signs of intracranial hypertension. The pathogenesis of subdural hematoma is discussed. Magnetic resonance imaging is the most useful diagnostic tool, providing excellent tissue specificity, although CT scan is often used to visualize a subdural hematoma and subsequent arachnoid cyst. Treatment relies on surgery to empty the subdural hematoma and remove compression. There has been no real consensus on treatment modalities. Long-term prognosis is good in most cases.