Traumatic brain injury usually results from a violent blow or jolt to the head that causes the brain to collide with the inside of the skull. An object penetrating the skull, such as a bullet or shattered piece of skull, also can cause traumatic brain injury.

    Mild traumatic brain injury may cause temporary dysfunction of brain cells. More serious traumatic brain injury can result in bruising, torn tissues, bleeding and other physical damage to the brain that can result in long-term complications or death.

    Half of all traumatic brain injuries are due to motor vehicle accidents. Treatment and outcome depend on the injury. Traumatic brain injuries can cause a wide range of changes affecting thinking, sensation, language, or emotions. People with severe injuries usually need rehabilitation.

Symptoms of brain injury:

• excessive sleepiness,
  
• inattention,

• difficulty concentrating,
  
• impaired memory,
• faulty judgment,
  
• depression,
  
• irritability,
  
• emotional outbursts,
  
• disturbed sleep,
• diminished libido,
  
• difficulty switching between two tasks, and
  
• slowed thinking.