Cerebral atrophy denotes a decrease in brain size or shrinkage of the brain. The decrease in brain size normally occurs as people grow older, but it can also be due to several conditions such as ischemic infarcts, malnutrition, Pick's disease, chronic HIV infection, Alzheimer's disease and Huntington's disease, among many others. Atrophy of the brain is also associated with loss in the number of nerve cells and their connections, and it can affect the whole brain or just some regions or portions of it.
In cerebral atrophy, the grooves or sulci in the brain are usually widened and the gyri or folds are narrowed. The ventricles, or cavities where cerebrospinal fluid (CSF) flows, inside the brain also undergo dilatation or enlargement.
Atrophy of the brain can be graded according to its size and appearance during autopsy. Grade 1 cerebral atrophy is associated with mild cerebral atrophy, and the changes in the brain are usually minimal and are mostly related to the normal aging process. Grade 2 cerebral atrophy is indicated in moderately severe atrophy of the brain, where moderate widening of the sulci and dilatation of the ventricles are seen. And the changes in Grade 3 mostly corresponds with severe brain atrophy, where there are extreme expansion of the ventricles and dramatic changes in the sulci and gyri.
In the mild form of cerebral atrophy, the shinkage of the brain is usually compatible with the age and sex of the person. It may be seen during a magnetic resonance imaging (MRI) scan of the brain.