In a subdural hematoma bleeding occurs between the brain 's outer layer, the dura mater, and the tissue beneath it, called the arachnoid membrane. An epidermal hematoma occurs when an artery outside the dura mater breaks and forces blood into the space between the skull and the dura mater. With medical treatment recovery from moderate head injuries may take from one to six weeks. It may take longer to recover some lost brain function, and in more severe brain injuries, disability may be permanent. Thinking and memory disorders, slurred speech, muscle weakness, coordination problems, and personality changes all can follow brain damage.
Some patients also suffer occasional seizures .
Prevention Routine safety precautions can prevent many common causes of head injury. For example, always wear a seat belt when traveling in a car. Wear a helmet when riding a bicycle or on a motorcycle.