Traumatic brain injury can also result from a "closed head injury." In such a case, there is no penetration of the skull. Often times, there are no obvious signs of external damage. A closed head injury often occurs when there is a rapid acceleration or deceleration of the head, like in the case of shaken baby syndrome. Closed head injuries usually result in more widespread damage to the brain and, therefore, cause more extensive neurological defects.

Possible effects of traumatic brain injury include:

Coma. A person is considered "comatose" when he or she remains unconscious for a long period of time. The longer a person is comatose, the more severe the traumatic brain injury. You need not be in a coma to suffer a traumatic brain injury, however. You can be conscious and have suffered a traumatic brain injury. In such a case, you may exhibit one or more of the following effects:

• Paralysis

• Impaired cognitive or thinking functions, including difficulties with reading and writing and limited concentration.

• Memory loss

• Behavior changes, including fatigue, mood swings, sexual dysfunction, lack of motivation and problems with interpersonal skills.

• Disorientation

• Confusion

• Dizziness

• Loss of coordination

• Depression

• Anxiety

• Personality changes

• Impaired speech and/or vision

• Hearing loss

If you or someone you know hits their head in an accident and exhibits any of the above symptoms or any other unusual behavior, a traumatic brain injury may have been suffered. Even if you remotely suspect a traumatic brain injury, you should immediately go to an emergency room or see another health-care professional.