Atrophy defines a decrease in the size of an organ or tissue in relation to inadequate nutrition: this results in an imbalance between the formation of new cells which does not compensate for apoptosis or programmed cell death. Cerebral atrophy, then, signifies a decrease in the size of the brain that affects part or all of the brain. It causes a loss of brain mass and neurological disorders. In Alzheimer's disease, cerebral atrophy detected by a CT scan or an MRI is common. We also distinguish cerebellar atrophy which affects the cerebellum and may be the effect of gastrointestinal cancer, chronic and excessive consumption of alcohol, or may be hereditary. It appears then through a cerebellar syndrome with impaired balance and coordination of movements.