Chronic subdural hematoma associated with arachnoid cyst in young adults: a case report.

Intracranial arachnoid cysts are believed to be congenital; they can become symptomatic in pediatric patients. Chronic subdural hematomas tend to occur in elderly patients with a history of mild head injury a few months prior to the onset of symptoms. However, these two distinct clinical entities sporadically occur together in relatively young patients. We report a 29-year-old man who presented with headache and dizziness of 2 months' duration. Brain computed tomography revealed a huge chronic subdural hematoma over the left frontoparietal lobe, with an incidental finding of an arachnoid cyst over the left sylvian fissure. In light of a literature review, we discuss arachnoid cysts as a possible risk factor for subdural hematoma, especially in young adults.