APA Dictionary of Psychology

degeneration and shrinkage of the brain, usually due to aging, disease, or injury. It is marked by enlargement of the surface clefts (sulci) and inner cavities (ventricles) of the brain. In normal aging there may be few or no cognitive effects, but cerebral atrophy may be secondary to more serious disorders, such as cerebrovascular disease, encephalitis, Alzheimer’s disease, or head injury. Also called brain atrophy.