Coma Brain Injury
By Dave Kettner

Coma may result from a variety of conditions, including intoxication, metabolic abnormalities, central nervous system diseases, acute neurologic injuries such as stroke, and hypoxia.  Comas generally last a few days to a few weeks, rarely more than 2 to 5 weeks.  Brain injury can be at the site of impact, but can also be at the opposite side of the skull due to a contrecoup effect (the impact to the head can cause the brain to move within the skull, causing the brain to impact the interior of the skull opposite the head-impact).  caused by traumatic brain injury is treated by addressing the underlying brain injury. 

Coma and Brain Injuries

Coma may occur as an expected progression or complication of an underlying illness, or as a result of an event such as head trauma.  A comatose patient cannot be awakened, fails to respond normally to pain or light, does not have sleep-wake cycles, and does not take voluntary actions.  differs from sleep in that one cannot be aroused from a coma.  prognosis depends on the severity of brain injury.  patients with more moderate brain injury and fewer complications have a better prognosis than do patients with severe brain injury.  Contrary to popular belief, a patient in a does not always lie still and quiet. 

Brain injury can damage parts of the brain that control consciousness.  Brain injuries may be diffuse, occurring over a wide area, or focal, located in a small and



specific area.  Researchers believe that one of the important physiological processes that keep a person conscious is the transfer, or neurotransmission, of chemical signals from the brainstem to the cerebral hemispheres of the brain.  can begin suddenly, such as when a person suffers a brain hemorrhage or severe head trauma, or can develop slowly over time.  Severe brain injury occurs when a prolonged unconscious state or lasts days, weeks, or longer.

Injury or damage to the brain can also cause some areas of the brain to shift within the skull and exert pressure on surrounding tissues and structures, including blood vessels.  Injury to these blood vessels can lead to blood clots, which can exert damaging pressure against the brain's delicate tissue.  Abnormalities that can cause include injury or damage to the brain that leads to swelling (edema) in the brain, which results in an increased intracranial pressure (pressure within the skull).  If the person with a brain injury remains in what seems like a comatose state, and there is no clear cut reason for this, it is imperative to get a good evaluation.  This is vitally important as swollen brain tissues can compress, causing further injury or death.

Please be sure to check out the many and brain injury resources that we have put together on this website.  Please be sure to check back often as we will be continually adding to these resources and products as they become available.