The causes of acquired brain injury may be traumatic and/or non-traumatic. A detailed list of traumatic injuries is provided in the "TBI- causes" section.
NON-TRAUMATIC BRAIN INJURIES:
Stroke:
Also known as cerebrovascular accident (CVA) occurs when blood flow to an area of the brain is interrupted by the blockage of a blood vessel or artery or by the rupturing of an artery.
The following are causes of strokes:
- Embolism: The obstruction of a blood vessel by a foreign substance (such as air bubbles, amniotic fluid, globules of fat, clumps of bacteria, chemicals and drugs) or a blood clot that travels through the bloodstream, lodging in a blood vessel, plugging the vessel.
- Thrombosis: it is an obstruction of a blood vessel caused by a thrombus, a foreign body (such as a blood clot).
- Aneurysm: a dilation or ballooning of a blood vessel because of weak arterial walls and it predominantly occurs where arteries branch. It can cause pressure on brain structures or rupture if the walls are too weak to withstand the added pressure, thereby resulting in bleeding of the space surrounding the brain.
Brain tumors:
- Brain tumors are a mass of tissue that are formed by an accumulation of abnormal cells. Symptoms vary, depending on the location of the brain tumor as well as the surgical methods that may be used to remove the tumor.
- Possible side effects include:
- Headaches
- Seizures
- Anemia
- Fatigue
Infections in the brain:
The brain and surrounding membranes are very prone to infections if the special blood-brain protective system is breached. Viruses and bacteria can cause serious and life-threatening diseases of the brain (encephalitis) and its membranes, the meninges (meningitis) that protect the brain.
- Encephalitis: inflammation of the brain. Viral infections are the most common cause of this condition.
- Meningitis: inflammation of the membranes surrounding your brain and spinal cord. The swelling associated with meningitis often triggers signs and symptoms such as headaches, fever and a stiff neck.
Toxic exposure:
It occurs when harmful chemicals such as the ones listed below damage the neurons:
- Overexposure to carbon monoxide
- Inhalation of toxic chemicals
- Excessive and prolonged use of drugs and/or alcohol
Fluid build-up in the brain:
- Hydrocephalus: excessive accumulation of cerebrospinal fluid (CSF), which is a clear fluid that surrounds the brain and spinal cord. The excessive accumulation of CSF results in an abnormal widening of the ventricles (spaces) in the brain. This widening creates potentially harmful pressure on the tissues of the brain.
Lack of oxygen to the brain:
If the brain is depleted of oxygen, then irreversible brain injury can occur from anoxia or hypoxia.
- Anoxia: An injury to the brain due to a lack of oxygen. Causes include near-drowning, cardiac arrest and drug-overdose.
- Hypoxia: low oxygen supplied to the brain. This condition may be caused by heart attacks, drops in blood pressure, a low oxygen environment and certain medications, which depress breathing (e.g., narcotics, anesthetics).