Cerebral hypoxia, or brain hypoxia, develops when the brain does not receive enough oxygen to sustain its normal metabolism. Out of all the organs, a lack of oxygen is most dangerous to the brain. Neurons begin to die after they have been without oxygen for approximately five minutes (Ref 1). To minimize the chances of severe brain damage, coma or even death, rapid medical attention is required to restore oxygen supply.
Causes of Brain Hypoxia in Fetuses and Infants
Brain Hypoxia is common among fetuses and infants. The reasons for this are many. The placenta may not work properly, or it might abrupt. The umbilical cord is sometimes wrapped around the throat of the fetus and the baby does not get enough oxygen. Brain hypoxia is more common in premature infants and in babies that are smaller than you would expect based on the pregnancy week. A lack of oxygen during pregnancy and childbirth can lead to such complications as cerebral palsy.
Accidents Causing Brain Hypoxia
Brain hypoxia is common after choking, diving and strangulation accidents. Asphyxiation caused by smoke inhalation is frequent among fire accident victims. High altitude can sometimes caused limited flow of oxygen to the brain. Brain hypoxia can also happen after a drug overdose.
Diseases Causing Brain Hypoxia
Paralysis causing a loss of movement of the breathing muscles can shut down the oxygen supply to the brain. Cardiac arrest, stroke, or complications during general anesthesia can also cause insufficient supply of oxygen to the brain.
Causes of Mild Brain Hypoxia
A mild form of brain hypoxia can be caused by such conditions as asthma, anemia, or even low blood pressure. As long as a condition diminishes the amount of oxygen that the brain receivies, it is possible that the condition might lead to brain hypoxia..
If the brain does not receive enough oxygen for a short period of time, doctors may not even realize that a patient is suffering from cerebral hypoxia. His only symptoms might be that he seems inattentive, lightheaded, and has uncoordinated movement. In a more serious case of brain hypoxia, the symptoms are easier to spot. Severe cognitive impairments in memory or learning can occur as a result. A patient's heart rate increases, as it is trying to pump more oxygen to the brain. Eventually, the heart might stop, and a person's eyes would stop responding to light. Seizures, coma or even death can occur as a result.
The prognosis from brain hypoxia depends strongly on how long the brain has been deprived of oxygen and whether the oxygen has been cut off entirely. If the brain has received too little oxygen for only a brief period, the symptoms might disappear once the brain gets enough oxygen again and the patient can make a full recovery. More commonly, patient will experience some problems. These might include amnesia, or memory problems, hallucinations, and muscle spasm or seizures. In most severe cases, cerebral hypoxia might result in permanent comas or even death.