Definition
Anoxic brain damage happens when the brain receives no oxygen for several minutes or longer. Brain cells begin to die after approximately four minutes without oxygen.
Progression of Anoxic Brain Damage
Causes
Anoxic brain damage may occur when:
• Oxygenated blood cannot reach the brain (for example, when a clot prevents blood flow to the brain)
• Blood that reaches the brain does not carry enough oxygen (for example, when lung disease prevents oxygen from crossing from the lungs into the blood for transport)
• People are exposed to poisons or other toxins that keep oxygen in the blood from being used by the cells in the brain (for example, carbon monoxide, which binds the oxygen carrying molecules in the blood and prevents transport of oxygen)
Risk Factors
A risk factor is something that increases one’s chance of getting a disease or condition. The following accidents and health problems increase your risk of anoxic brain damage:
• Choking
• Suffocation
• Near-drowning
• Electrical shock
• Malfunctioning gas appliances that produce carbon monoxide
• Heart attack
• Heart arrhythmia (abnormal heart beats)
• Stroke
• Brain tumors
• Illegal drug use
Symptoms
Recovery from anoxic brain damage can be uncertain and can take a long time. A person’s chance for recovery depends on the extent of the brain damage and the part of the brain involved. Severe damage may lead to a coma or a so-called vegetative state . Mild to moderate brain damage may cause:
• Headache
• Confusion
• Decreased concentration and attention span
• Mood swings and/or change is personality
• Intermittent loss of consciousness
Many people with mild brain damage can usually recover much of their neurologic function, or successfully learn to live with any remaining disabilities.
Diagnosis
The doctor will ask you about your symptoms and medical history (if you are conscious), and perform a physical exam. Patients may be referred to other doctors (a neurologist or neurosurgeon) who specialize in brain problems. Doctors use the following tests to learn the extent of the brain damage and the part of the brain that is involved:
• Head CT Scan –an x-ray test that uses a computer to make detailed images of the brain
• MRI (Magnetic Resonance Imaging) –a test that uses powerful magnets, radio waves, and a computer to make detailed images of the brain
• Electroencephalogram (EEG) –a test that measures the electrical activity generated by the brain
Treatment
Treatment of anoxic brain damage depends on the cause. Initially, barbiturates may be used to slow down brain activity; steroids and other medications may be used to reduce the swelling that accompanies injured brain tissue. This will help limit the amount of damage done to the brain. Efforts are also made to increase the amount of oxygen reaching the brain.
Recovery can take months, or even years; in many cases, full recovery is never achieved. In general, the sooner rehabilitation starts, the better the patient will fair.
During rehabilitation, the patient and his or her family work with a team of medical professionals, including:
• A physical therapist who helps retrain motor skills such as walking
• An occupational therapist who works on improving daily skills such as dressing and going to the bathroom
• A speech therapist who helps works on language problems
• A neuropsychologist who counsels on behavior and emotional issues related to the injury
Prevention
To reduce the risk of anoxic brain damage:
• Chew your food carefully
• Learn to swim
• Carefully supervise young children around water
• Stay clear of high voltage electrical sources (including exposure to lightning)
• Avoid chemical toxins and illicit drugs
• Check gas burning appliances for carbon monoxide production and install carbon monoxide detectors
