Not all brain injuries involve a blow to the head or lesion. Indeed, your brain can be injured even when nothing comes into contact with your head. Anoxic brain injuries occur when the brain is deprived of oxygen. The aftermath of a lack of oxygen to the brain is largely dependent on the extent of the oxygen deprivation, also known as hypoxia. Some people recover with little to no consequences, while others need years of rehabilitative therapy.
Doctors typically refer to two distinct forms of oxygen deprivation: anoxic brain injuries occur when the brain is totally deprived of oxygen due to sudden cardiac arrest, choking, strangulation, and other sudden injuries. Hypoxic brain injuries occur when the brain receives less oxygen than it needs, but is not completely deprived of oxygen. Because the effects of the two injuries are similar, many brain experts use the terms interchangeably.
A few seconds of oxygen deprivation won't cause lasting harm, so a child who holds his breath in frustration, a combatant choked unconscious during a Jiu-Jitsu match, and a diver who needs a few extra seconds to come up for air are unlikely to experience brain damage. The precise timeline of anoxic brain injuries depends on a number of personal idiosyncrasies, including overall brain and cardiovascular health, as well as the level of blood oxygenation at the time of injury. Generally speaking, injuries begin at the one-minute mark, steadily worsening thereafter.
There are, of course, exceptions to every rule. Some training routines help the body make more efficient use of oxygen, enabling the brain to go longer periods without this vital element. Free divers routinely train to go long periods without oxygen, and the current record holder, Aleix Segura held his breath for 24 minutes and 3 seconds without sustaining brain damage!
The brain represents just 2% of a person's body weight, yet it uses about 20% of the body's oxygen supply. Without it, the brain can't perform even the most basic functions. The brain relies on glucose to power the neurons that control everything from conscious functions like planning and thought to automatic, unconscious processes like managing heart rate and digestion.
Without oxygen, the brain's cells cannot metabolize glucose, and therefore cannot convert glucose into energy.
When your brain is deprived of oxygen, then, the ultimate cause of brain death is inadequate energy to power the brain's cells.
Most cases of oxygen deprivation have an immediate, obvious cause. A person is at risk of oxygen deprivation under a number of circumstances, including:
from oxygen deprivation, call 911 immediately. Rapid intervention can be life-saving, and may reduce the risk of serious, lifelong brain damage.
The effects of oxygen deprivation are similar to those of other brain injuries. The prognosis depends on how severe the lack of oxygen to the brain was, the extent of neuron death, and the quality of medical and rehabilitative care. With quality physical therapy, your brain may learn to compensate for damaged regions, so even severe injuries warrant an ongoing commitment to physical therapy.
Common long-term effects of oxygen deprivation can include
Treatment should always begin with addressing the source of oxygen deprivation, since the longer oxygen deprivation continues, the more severe the damage will likely be. Your doctor may use a tracheotomy to ensure you get sufficient oxygen if something blocks your wind pipe. Other treatment options may include surgery to remove a blockage or lesion, and steroids to reduce swelling in your brain.
In the days following your injury, your treatment team will turn its attention toward long-term recovery. Your brain is highly adaptive to its environment, so continued challenges are the best option for helping your brain recover and work around your injuries. Your treatment plan may include:
You may also need follow-up treatments, such as chemotherapy to further shrink a brain lesion, medication to prevent a blood clot, or regular MRI scans to assess brain damage.