The University of Connecticut Health Center states that almost everyone experiences atrophy of the brain, also called cerebral atrophy. Atrophy of the brain changes the structuring of the brain, specifically an enlargement of the sulci which are the indents on the brain, and a narrowing of the gyri, the ridges of the brain. While the loss of brain tissue can occur with aging, diseases and injuries that damage the brain tissue can cause atrophy of the brain as well.
Dementia
Dementia, a group of degenerative diseases, causes a loss of brain function due to tissue damage. For example, the National Institute of Neurological Disorders and Stroke states that Alzheimer's disease, frontotemporal dementia and Pick's disease, all types of dementia, cause atrophy of the brain. As the diseases progress, the patients' brains lose more tissue. The University of Connecticut Health Center notes that when a doctor examines brain tissue after a dementia patient dies, plaques and tangles and abnormal protein formations, along with the tissue loss can all be seen.
Brain Injuries
When the brain sustains injury, it can cause atrophy of the brain. For example, a stroke can result in cerebral atrophy, according to the National Institute of Neurological Disorders and Stroke. A stroke occurs when a blood vessel in the brain becomes blocked or bursts, causing an obstruction of blood flow. The blood flow disruption keeps oxygen from reaching the brain cells; without adequate oxygen, the cells die. Traumatic brain injury, a type of brain injury caused by an impact to the head, may cause atrophy to the brain. Another condition that can cause cerebral atrophy is cerebral palsy, which results from injuries to the brain during or after birth. The University of Connecticut Health Center adds that trauma that occurred earlier in a person's life can cause atrophy of the brain later.
Myelin Sheath Conditions
The myelin sheath is the protective covering of the neurons, or brain cells. When a condition damages the myelin sheath, it can also result in damage to the neurons. For example, multiple sclerosis, a degenerative disease that causes a loss of myelin sheath, can cause atrophy of the brain. Multiple sclerosis also causes lesions on the brain tissue. The National Institute of Neurological Disorders and Stroke adds that leukodystrophies such as Krabbe disease, also damage the myelin sheath and cause atrophy of the brain.
Infections
An infection that invades the brain or an infection that causes inflammation in the brain damages the neurons in the brain. The decrease in neurons result in a loss of brain tissue. The National Institute of Neurological Disorders and Stroke notes that AIDS, encephalitis and neurosyphilis can cause atrophy of the brain. For example, neurosyphilis, which is untreated syphilis, is a sexually transmitted disease that affects the brain and spinal cord.
Other Causes
Huntington's disease, an inherited neurological disorder, can cause cerebral atrophy. As the disease progresses, Huntington's disease can result in dementia. The National Institute of Neurological Disorders and Stroke adds that mitochondrial encephalomyopathies such as Kearns-Sayre syndrome affect neuronal function, leading to atrophy.
