What is the definition or description of: brain damage?

Injury to the brain: Injury to the brain that is caused by various conditions, such as head trauma, inadequate oxygen supply, infection, or intracranial hemorrhage, and that may be associated with a behavioral or functional abnormality.

Tissue injury: Anything that disrupts tissue integrity can cause brain damage: lack of or reduced oxygen (stroke), viamin deficiency, pressure (hydrocephalus, or, bleeding or tumor inside the skull), blunt or penetrating trauma; infection; inflammation (immune system mediated or otherwise); toxins (alcohol, ecstasy, lead, mercury, arsenic, to name but a few); diseases (ms, diabetes, cushings d, and others.

Brain Damage: Is the destruction/degeneration of brain cells as result of internal or external factors. Some causes are hypoxia, poisoning (such as alcohol), infection, neurologic illnesses & traumas.