Brain atrophy — or cerebral atrophy — is the loss of brain cells called neurons. Atrophy also destroys the connections that help the cells communicate. It can be a result of many different diseases that damage the brain, including stroke and Alzheimer’s disease.

As you age, you naturally lose some brain cells, but this is a slow process. Brain atrophy associated with disease or injury occurs more quickly and is more damaging.

Atrophy can affect different parts of the brain.

  • Focal atrophy affects cells in certain areas of the brain and results in a loss of function in those specific areas.
  • Generalized atrophy affects cells all over the brain.

Life expectancy among patients with brain atrophy can be influenced by the condition that caused the brain shrinkage. People with Alzheimer’s disease live an average of after their diagnosis. Those with multiple sclerosis can have if their condition is treated effectively.

The symptoms of brain atrophy vary depending on which region or regions of the brain are affected.

  • Dementia is the loss of memory, learning, abstract thinking, and executive functions such as planning and organizing.
  • Seizures are surges of abnormal electrical activity in the brain that cause repetitive movements, convulsions, and sometimes a loss of consciousness.
  • Aphasias involve trouble speaking and understanding language.

Injuries, diseases, and infections can damage brain cells and cause atrophy.

Injuries

  • Stroke happens when blood flow to part of the brain is interrupted. Without a supply of oxygen-rich blood, neurons in the area die. Functions controlled by those brain areas — including movement and speech — are lost.
  • Traumatic brain injury is damage to the brain that may be caused by a fall, motor vehicle accident, or other hit to the head.

Diseases and disorders

  • Alzheimer’s disease and other forms of dementia are conditions in which brain cells become progressively damaged and lose the ability to communicate with one another. It causes a loss of memory and thinking ability severe enough to be life-altering. Alzheimer’s disease, typically beginning after age 60, is the leading cause of dementia. It’s responsible for of all cases.
  • Cerebral palsy is a movement disorder caused by abnormal brain development in the womb. It causes a lack of muscle coordination, difficulty with walking, and other movement disorders.
  • Huntington’s disease is an inherited condition that progressively damages neurons. It usually begins in mid-life. Over time, it affects a person’s mental and physical abilities to include severe depression and chorea (involuntary, dance-like movements throughout the body).
  • Leukodystrophies are a group of rare, inherited disorders that damage the myelin sheath — a protective coating that surrounds nerve cells. Usually beginning in childhood, it can cause problems with memory, movement, behavior, vision, and hearing.
  • Multiple sclerosis, which usually begins in young adulthood and affects women more often than men, is an autoimmune disease in which the immune system attacks the protective coating around nerve cells. Over time, the nerve cells become damaged. As a result, problems in sensation, movement, and coordination can occur. However, like other diseases noted, it can also lead to dementia and brain atrophy.

Infections

  • AIDS is a disease caused by the HIV virus, which attacks the body’s immune system. Although the virus doesn’t directly attack neurons, it does damage the connections between them via proteins and other substances it releases. Toxoplasmosis associated with AIDS can also damage brain neurons.
  • Encephalitis refers to an inflammation of the brain. It’s caused by herpes simplex (HSV), but other viruses such as West Nile or Zika can also cause it. The viruses injure neurons and cause symptoms such as confusion, seizures, and paralysis. An autoimmune condition can also cause encephalitis.
  • Neurosyphilis is a disease that damages the brain and its protective covering. It can occur in people with the sexually transmitted disease syphilis who don’t get fully treated.

Some of these conditions — like neurosyphilis, AIDS, and traumatic brain injury — may be preventable. Practicing safe sex by wearing condoms can prevent syphilis and HIV infections. Wearing your seat belt in the car and putting on a helmet when you ride a bicycle or motorcycle can help prevent brain injuries.

Other conditions, like Huntington’s disease, the leukodystrophies, and multiple sclerosis, are not preventable.

Each condition that causes brain atrophy is treated differently.

  • Stroke is treated with medications like tissue plasminogen activator (TPA), which dissolves the clot to restore blood flow to the brain. Surgery can also remove a blood clot or fix a damaged blood vessel. Anticlotting and blood pressure-lowering drugs can help prevent another stroke.
  • Traumatic brain injury can also be treated with surgery that prevents additional damage to brain cells.
  • Multiple sclerosis is often treated with disease-modifying drugs like ocrelizumab (Ocrevus), glatiramer acetate (Copaxone), and fingolimod (Gilenya). These drugs help prevent the immune system attacks that damage nerve cells.
  • AIDS and certain forms of encephalitis are treated with antiviral drugs. Steroids and special antibody drugs can treat autoimmune encephalitis.
  • Syphilis is treated with antibiotics that help prevent nerve cell damage and other complications from the disease.
  • There is no real treatment or cure for brain damage from Alzheimer’s disease, other forms of dementia, cerebral palsy, Huntington’s disease, or the leukodystrophies. However, some medications can relieve the symptoms of these conditions but not attack their causes.

The diagnostic process depends on which condition your doctor suspects you have. It will usually involve a physical exam followed by certain tests.

Cerebral atrophy will show up on brain imaging scans like these:

  • Computerized tomography (CT) uses X-ray images from different angles to create detailed pictures of your brain.
  • Magnetic resonance imaging (MRI) creates brain images on film after exposing the brain to a brief magnetic field.

Your outlook or prognosis depends on which condition caused your brain atrophy. Some conditions — like stroke, encephalitis, multiple sclerosis, or AIDS — are manageable with treatment. Brain atrophy can be slowed or stopped in some situations. Others — like Alzheimer’s and Huntington’s disease — will get progressively worse in both symptoms and brain atrophy over time.

Talk to your doctor about the cause of your brain atrophy, possible treatments, and what outlook you can expect.