For other uses see Brain damage (disambiguation).
Brain damage may occur due to a wide range of conditions, illnesses, injuries, and as a result of iatrogenesis. Possible causes of widespread (diffuse) brain damage include prolonged hypoxia (shortage of oxygen), poisoning by teratogens (including alcohol), infection, and neurological illness. Chemotherapy can cause brain damage to the neural stem cells and oligodendrocyte cells that produce myelin. Common causes of focal or localized brain damage are physical trauma (traumatic brain injury), stroke, aneurysm, surgery, neurological illness, and heavy metals poisoning including by mercury and its compounds and lead.
Brain injury does not necessarily result in long-term impairment or disability, although the location and extent of damage both have a significant effect on the likely outcome. In serious cases of brain injury, the result can be permanent disability, including neurocognitive deficits, delusions (often specifically monothematic delusions), speech or movement problems, and mental handicap. There may also be personality changes. Severe brain damage may result in persistent vegetative state, coma, or death.
Brain injury whether from stroke, alcohol abuse, traumatic brain injury, or B vitamin deficiency can sometimes result in Korsakoff's Psychosis, where the individual engages in confabulations. Confabulations involve the inability to separate daydream memory from real memory and the filling in of memory lapses with daydreams. Korsakoff's Psychosis can be easily mis-diagnosed as schizophrenia. Lithium treatment is sometimes helpful.
Various professions may be involved in the medical care and rehabilitation of someone who suffers impairment after brain damage. Neurologists, neurosurgeons, and physiatrists are physicians who specialise in treating brain injury. Neuropsychologists (especially clinical neuropsychologists) are psychologists who specialise in understanding the effects of brain injury and may be involved in assessing the extent of brain damage or creating rehabilitation programmes. Occupational therapists may be involved in running rehabilitation programs to help restore lost function or help re-learn essential skills. Registered nurses, such as those working in hospital Intensive Care Units, are able to maintain the health of the severely brain-injured with constant administration of medication and neurological monitoring, including the use of the Glasgow Coma Scale used by other health professionals to quantify extent of orientation.
The effects of impairment or disability resulting from brain injury may be treated by a number of methods, including medication, psychotherapy, neuropsychological rehabilitation, snoezelen, surgery, or physical implants such as deep brain stimulation.
It is a common misconception that brain damage sustained during childhood has a better chance of successful recovery than similar injury acquired in adult life. It is contested that in recent studies, severe brain damage inflicted upon children can be alleviated by the interaction of nicotinamide repropagation in nerve cells. In fact, the consequences of childhood injury may simply be more difficult to detect in the short term. This is because different cortical areas mature at different stages, with some major cell populations and their corresponding cognitive faculties remaining unrefined until early adulthood. In the case of a child with frontal brain injury, for example, the impact of the damage may be undetectable until that child fails to develop normal executive functions in his or her late teens and early twenties.