Head Injuries : Early Diagnosis, Brain Swelling, Coma

by Food and Drug Administration (FDA)

(Page 2 of 4)

Early Diagnosis Essential

Early recognition of the extent of damage is vital to survival and to immediate appropriate care. Indeed, the risk of dying increases tenfold when there's more than a four-hour delay of needed brain surgery. Some studies indicate any delay is harmful, for injured neuron cells in the patient's brain are easily killed by lack of oxygen, and the brain cannot long endure shifting fluid or tissue.

Once the diagnosis is made, critical care may go on for weeks or months to prevent further damage.

"When there's evidence that a patient has increased intracranial pressure — pressure in the skull — it is critical that the pressure be brought down," says Russell Katz, M.D., deputy director, neuropharmacological drug division at FDA's Center for Drug Evaluation and Research. "One way to do that is to place the patient on a respirator and artificially hyperventilate the patient."

This rapid breathing reduces the blood carbon dioxide content, he says, causing vessels in the brain to constrict and become smaller. The resultant decreased volume of tissue in the skull can help mitigate the effects of a major unsolved problem caused by head trauma: brain swelling.

"The swelling brain presses harder and harder against the rigid skull, which causes dysfunction of the nerve cells," he says. "In a worst case, the brain begins to herniate down to the brain stem, at the top of the spinal column. The brain stem controls the vital functions, so when the brain starts pushing on it, the person may stop breathing, go into cardiac arrest, lose consciousness, and, if the herniation goes unchecked, die."

Management of Brain Swelling

Modern management of brain swelling often requires continuous monitoring of pressure inside the skull, says Robert Munzner, Ph.D., who heads CDRH review of neurological devices such as electronic brain pressure sensors. The sensor is placed on the surface of the brain through a small hole drilled in the skull.

"But the physician needs to know the cause of increased pressure," he says. "For instance, a hole may be drilled in the skull to drain the blood from a large hematoma causing excessive pressure on the brain surface. Or, a catheter may be inserted into the interior of the brain to drain excess fluid, providing a connection for use also in measuring the pressure."

Other methods to reduce brain swelling include elevating the head to encourage blood to drain and giving diuretic drugs such as mannitol or Lasix (furosemide) through a vein.

If those measures fail, in a practice that is not uncommon Robinson may administer the barbiturate pentobarbitol to induce barbiturate coma. Though the physician labeling does not specifically list this use, it is a life-saving step that reduces pressure in about half the cases. It can cause liver damage and depress heart function, however, so it's only used in extreme cases, he says.

Early care includes follow-up CT scans as indicated to check for post - injury blood clots. Magnetic resonance imaging (MRI) may be used if it's available. MRI uses a large magnet and, like CT, produces computer-generated, cross-sectional pictures of the brain.

Anticonvulsant medication such as Dilantin (phenytoin) may be given to prevent seizures, and the body's chemical, fluid and nutritional balance is maintained. A plastic water-filled blanket can be temperature-regulated to heat or cool the patient, who may be left unclothed to provide total access and observation.

Thanks to increased knowledge about the brain, more accurate diagnosis, and earlier, aggressive care, 60 percent of head injury victims survive — compared with only 10 percent 25 years ago.

When patients become stable, they usually go to a regular bed in the hospital and then home or to a rehabilitation facility. About 1 percent require a chronic-care institution, says Robinson.

Coping with Coma

Rehabilitation should begin as early as possible to provide controlled stimulation and prevent further complications, even when the person is in coma, according to Beverly Whitlock, director of Head Injury Services in Gaithersburg, Md.

"There are many levels of coma, and nonresponsiveness is not always consistent and across the board," she says. "When impairment is primarily to the motor system, the person still mentally takes things in. Also, recovery from coma is a very slow process. It's not like on television where the hero wakes up before the end of the show and returns to his job as vice president of the firm. Rather, you may get nondirected motion, occasional response, some eye opening."

The survivors' cognitive (perceiving, thinking, remembering), behavioral, and physical disabilities can mean years of hopelessness and anguish, for neither medical science nor rehabilitation offers complete cure. The person is changed. Personality alteration, lack of inhibition, poor judgment, and impaired social perception can drive loved ones and their needed support from the patient, even to the point of family breakup — which is far more likely over a cognitive or behavioral handicap than a physical one. Financial ruin is not unusual.

Still, the brain continues healing for years, and medicine can support the body along the way while fine-tuned rehabilitation helps the person compensate for losses and accommodate the new self.

"The family should learn as much as possible about the problem," says Whitlock. "Otherwise they misunderstand some things that are going on and may begin to feel the person is having an emotional problem when it's really very organic."

She recommends getting in touch with the state head injury foundation or the National Head Injury Foundation for information and referral. Whitlock stresses that head injury rehabilitation requires professionals with special training in dealing with head injury patients. Since injuries vary, it's wise to keep close to the treatment team for specific advice, she says.

About the Author

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