Coma: Types, Causes, Treatments, Prognosis
What Are the Different Types of Coma?
Types of coma can include:
- Toxic-metabolic encephalopathy. This is an acute condition of brain dysfunction with symptoms of confusion and/or delirium. The condition is usually reversible. The causes of toxic-metabolic encephalopathy are varied. They include systemic illness, infection, organ failure, and other conditions.
- Anoxic brain injury. This is a brain condition caused by total lack of oxygen to the brain. Lack of oxygen for a few minutes causes cell death to brain tissues. Anoxic brain injury may result from heart attack (cardiac arrest), head injury or trauma, drowning, drug overdose, or poisoning.
- Persistent vegetative state. This is a state of severe unconsciousness. The person is unaware of his or her surroundings and incapable of voluntary movement. With a persistent vegetative state, someone may progress to wakefulness but with no higher brain function. With persistent vegetative state, there is breathing, circulation, and sleep-wake cycles.
- Locked-in syndrome. This is a rare neurological condition. The person is totally paralyzed except for the eye muscles, but remains awake and alert and with a normal mind.
- Brain death. This is an irreversible cessation of all brain function. Brain death may result from any lasting or widespread injury to the brain.
- Medically induced: This type of temporary coma, or deep state of unconsciousness, is used to protect the brain from swelling after an injury. The patient receives a controlled dose of an anesthetic, which causes lack of feeling or awareness. Doctors then closely watch the person’s vitals. This happens only in hospital intensive care units.
Is There Effective Treatment for a Coma?
Treatment for a coma depends on the cause. People close to the comatose patient should give doctors as much information as possible to help the doctors determine the cause of coma. Prompt medical attention is vital to treat potentially reversible conditions. For example, if there is an infection that's affecting the brain, antibiotics may be needed. Glucose may be required in the event of a diabetic shock. Surgery may also be necessary to relieve the pressure on the brain due to swelling or to remove a tumor.
Certain drugs may also help relieve the swelling. Medication may also be given to stop seizures if necessary.
In general, treatment for a coma is supportive. People in comas are looked after in an intensive care unit and may often require full life support until their situation improves.
What's the Prognosis for a Coma?
The prognosis for a coma varies with each situation. The chances of a person's recovery depend on the cause of the coma, whether the problem can be corrected, and the duration of the coma. If the problem can be resolved, the person can often return to his or her original level of functioning. Sometimes, though, if the brain damage is severe, a person may be permanently disabled or never regain consciousness.
Comas that result from drug poisonings have a high rate of recovery if prompt medical attention is received. Comas that result from head injuries tend to have a higher rate of recovery than comas related to lack of oxygen.
It can be very difficult to predict recovery when a person is a coma. Every person is different and it is best to consult with your doctor. As we would expect, the longer a person is in a coma, the worse the prognosis. Even so, many patients can wake up after many weeks in a coma. However, they may have significant disabilities.