<unk>  is a common feature of many of the diseases that affect the brain. Atrophy of any tissue means a decrement in the size of the cell, which<unk> n be due to progressive loss of cytoplasmic proteins. In brain tissue, atrophy describes a loss of neurons and the connections between them. Brain atrophy<unk> n be classified into two main<unk> tegories: generalized and focal atrophy. Generalized atrophy occurs across the entire brain whereas focal atrophy affects cells in a specific location. If the<unk>  hemispheres (the two lobes of the brain that form the cerebrum) are affected, conscious thought and voluntary processes may be impaired. Some degree of<unk>  shrinkage occurs naturally with the dynamic process of aging. The human brain completes growth and attains its full maturity at 25 years of age. Structural changes continue during adulthood as brain shrinkage commences after the age of 35, at a rate of 0.2% per year. The rate of decline is accelerated when individuals reach 70 years old. By the age of 90, the human brain will have experienced a 15% loss of its initial peak weight. Besides brain atrophy, aging has also been associated with<unk>  microbleeds.
Cerebral atrophy
Acrania
Posterior cortical atrophy
Ventriculomegaly
Cerebellar degeneration
Hippocampal sclerosis
Geographic atrophy
Macular hypoplasia