This may include drilling a small hole in the skull to relieve pressure and allow blood to be drained. Chronic subdural hematoma may result in death or permanent brain injury if untreated or, occasionally, even if treated. Symptoms such as seizures may persist for several months even after treatment. Seizures may begin as much as 2 years after the injury. In adults, most recovery occurs in the first 6 months, with some improvement over approximately 2 years.
Children usually recover more quickly and completely than adults.
Incomplete recovery is the result of brain damage.