Different types of brain injuries can occur that cause severe, lasting symptoms and may be difficult to manage. The two common types of injuries that can occur are anoxic brain injuries and hypoxic brain injuries. If you or a loved one sustained a brain injury, you need to know which type of injury has occurred. Thomas J. Henry Law gives you insight into what these injuries are and how they happen. An anoxic brain injury occurs when there is no supply of oxygen to the brain at all.
When the brain has been deprived of oxygen for more than four minutes, the brain cells die, and the injured person may be declared braindead. It is uncommon for someone to recover from a severe anoxic brain injury. However, if a lack of oxygen occurred for less than four minutes, it is possible for an individual to slowly recover. Even so, it will take some time, and the individual will likely continue to experience different symptoms that tend to come along with such an extensive injury.
These symptoms would include:. Why is oxygen important to us? Our bodies require oxygen in order to metabolize glucose. This process provides energy for the cells. Cells of the brain will start to die within a few minutes if they are deprived of oxygen.
The result is a cascade of problems. In particular, the disruption of the transmission of electrochemical impulses impacts the production and activity of important substances called neurotransmitters , which regulate many cognitive, physiological, and emotional processes. There are many neurotransmitters, and they perform a wide variety of important functions, although the specific ways neurotransmitters work are not fully understood. Some neurotransmitters, such as serotonin , dopamine, and norepinephrine , play an important role in regulating moods.
Endorphins are critical for controlling pain and enhancing pleasure, while acetylcholine is important for memory functions. A variety of disease processes and injuries can cause HAI. The most common is called hypoxicischemic injury , also known as HII or stagnant anoxia. This occurs when some internal event prevents enough oxygen-rich blood from reaching the brain. While strokes and cardiac arrhythmia can both result in HII, the most frequent cause is cardiac arrest.
Anesthesia accidents and cardiovascular disease each account for just under a third of cardiac arrests, according to a study. Other possible causes are asphyxia, generally caused by suicide attempts or near-drownings 16 percent , chest trauma 10 percent , electrocution 6. Occasionally, HAI is caused by anoxic anoxia , which is when the air itself does not contain enough oxygen to be absorbed and used by the body. This can occur at high altitudes, where the air is thinner than at sea level, but is extremely unusual otherwise.
Another syndrome, toxic anoxia , involves the presence in the body of toxins or other substances that may interfere with the way an individual processes oxygen. Another occasional cause of HAI is anemic anoxia , which can occur when someone does not have enough blood or hemoglobin, a chemical in the red blood cells, which carry oxygen throughout the body.
Acute hemorrhage, chronic anemia, and carbon monoxide poisoning are conditions that can result in anemic anoxia. Acute hemorrhage is essentially massive bleeding, caused, for example, by a gunshot or other wound. Chronic anemia is an ailment in which a person suffers from persistently low levels of red blood cells or hemoglobin. Carbon monoxide poisoning , which appears to damage parts of the brain controlling movement, occurs in suicide attempts using automobile exhaust, but can also happen due to malfunctioning furnaces and other accidents involving machinery and industrial equipment.
HAI is generally marked by an initial loss of consciousness or coma, a condition which looks like sleep but from which a person cannot be awakened. The period of unconsciousness, whether short or long, might be followed by a persistent vegetative state , in which a person is neither comatose nor responsive to external stimuli.
Even when a person has fully recovered consciousness, he or she might suffer from a long list of symptoms. In many ways, these symptoms are similar to those commonly seen after a blow to the head.
The effects can vary widely depending upon the part of the brain that has been injured and the extent of the damage. Some of the major cognitive thought problems are:. Other symptoms can include: hallucinations and delusions; increased agitation and confusion; depression and other mood disorders; personality changes, such as irritability and a reduced threshold for frustration; and an inability to focus or concentrate.
Because people with HAI have often suffered extensive damage, complete recovery is not assured. In fact, predicting the outcome of HAI is a bit like estimating how high a rocket will go. There are some general factors that are helpful in making initial forecasts, but the actual course of the rocket is also dependent upon real-world conditions and many unforeseeable variables. Studies that have been done suggest that recovery may be more limited than in cases where a person has suffered a traumatic brain injury of comparable severity.
Nonetheless, there are some clues that can clearly offer a bit of guidance in judging the likelihood of at least a partial recovery. These include:. Many patients come out of a coma but remain in what is called a persistent vegetative state , a sort of wakeful unresponsiveness in which some brain functions continue to operate but with no apparent consciousness. Some doctors believe that if the persistent vegetative state in a patient with HAI continues for more than three months, there is virtually no chance of further recovery.
Unfortunately, direct treatment of anoxia is limited. Recovery can take many months and even years, and in many cases the person never regains his or her prior level of functioning. In general, the sooner rehabilitation starts, the better. Notify me of followup comments via e-mail.
Written by : Dr. Boston: Springer. Hartmann, Becker, J. Michael, H. Makic, E. Louis: Saunders Elsevier. User assumes all risk of use, damage, or injury. You agree that we have no liability for any damages. If hypoxia affects the brain the symptoms include: Difficult concentration; Temporary memory loss; Reduced ability to move; Difficulty making sound decisions; Coma; Seizure. If hypoxia affects the brain, it can quickly cause brain damage or death. The types of hypoxia are: Hypoxic hypoxia — lowering of the partial pressure of the oxygen in the inhaled air or difficulty in penetration of oxygen through the airways; Hematological hypoxia — decreased ability of hemoglobin to bind and transport oxygen molecules; Circulatory hypoxia — impaired function of the cardiovascular system; Mixed hypoxia — a combination of the above types.
Hypoxia may be due to: Respiratory diseases — bronchial asthma, chronic obstructive pulmonary disease, pulmonary edema, pneumonia, emphysema, etc. Infectious and parasitic diseases — hoof, diphtheria, hantavirus infection; Congenital abnormalities, deformations, and chromosomal aberrations — pulmonary arteriovenous malformation, congestive heart failure, etc.
What is Anoxia? The untreated lack of oxygen is extremely harmful and can even be deadly. If the anoxia affects the brain, the symptoms include: Personality and mood changes; Changes in judgment; Loss of memory; Slurred speech; Troubles in moving of the limbs; Weakness; Dizziness; Disorientation; Headache; Concentration problems.
The causes of anoxia are: Low concentration of hemoglobin or ineffective hemoglobin in the blood; Intake of toxins or other chemicals; Poisoning with carbon monoxide; Cardiovascular problems: heart failure, stroke, heart attack, irregular heartbeat, etc.
Limited amount of oxygen at high altitudes; Hindered work of the lungs, ex. Difference Between Hypoxia and Anoxia Definition Hypoxia: Hypoxia is a medical term that describes the partial lack of oxygen in the body tissues.
Types Hypoxia: The types of hypoxia are: hypoxic hypoxia, hematological hypoxia, circulatory hypoxia, and mixed hypoxia. Harm Hypoxia: The more complete the oxygen deprivation, the more severe the effect to the affected tissue. Anoxia: The effect is more severe than in hypoxia due to the full lack of oxygen.
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