Spinocerebellar Ataxia Life Expectancy

Spinocerebellar ataxia (SCA) is a group of inherited conditions in which the cerebellum, the part of the brain that coordinates movement, and its connections slowly degenerate. It is progressive and currently has no cure. In the most common types it shortens life, but the outlook differs a lot from one type to another, and most people live for many years after symptoms begin.

How long do people live with SCA?

The best evidence comes from large European studies (EUROSCA and RISCA) that followed people with the four most common types for many years:

• SCA1: symptoms usually start around age 30; average survival is about 18 years after ataxia begins.
• SCA2: symptoms usually start in the late 30s; average survival is about 22 years.
• SCA3 (Machado-Joseph disease): symptoms usually start in the late 30s; average survival is about 20 years.
• SCA6: symptoms usually start in the late 40s; average survival is about 35 years, and many people live a near-normal lifespan.

These figures are measured from when symptoms start, not from birth. They are averages: individual outcomes vary widely, and many of the 40-plus rarer types progress very slowly. Learn more about the different types of SCA.

How SCA usually progresses

SCA usually begins with unsteady walking and poor balance, followed by clumsy hands, slurred speech and changes in eye movements. Over years, many people need a walking aid and later a wheelchair. Swallowing often becomes harder in the later stages. In SCA1, SCA2 and SCA3 there may also be muscle stiffness, nerve damage in the limbs or other movement problems; SCA6 mostly affects coordination alone.

In the common types the cause is an expanded stretch of repeated DNA (a "CAG repeat"). Longer repeats generally mean earlier symptoms and faster progression. See what to expect as SCA progresses.

What causes death in SCA?

People with SCA usually die from complications rather than the ataxia itself:

• Chest infections and pneumonia, mainly from food or drink going into the airway (aspiration) when swallowing is weak.
• Breathing problems in advanced disease.
• Effects of reduced mobility and falls.

SCA isn't known to raise the risk of cancer. (An increased risk of lymphoma and leukaemia is a feature of a different condition, ataxia-telangiectasia.)

Can anything improve the outlook?

No treatment yet slows SCA itself, though several are being tested in clinical trials. Good supportive care can reduce complications and help people stay independent for longer:

• Regular swallowing assessments with a speech and language therapist, and prompt treatment of chest infections
• Physiotherapy and staying active. See physical therapy for SCA
• Mobility aids and home adaptations to prevent falls
• Help with nutrition if eating becomes difficult. See diet and nutrition for SCA
• Treatment for symptoms such as stiffness, tremor, poor sleep or low mood

Inheritance

Most SCAs are autosomal dominant: each child of an affected parent has a 50% chance of inheriting the gene change. Genetic counselling can help families make informed decisions about testing. Read more about SCA and inheritance.

This page is for general information and isn't a substitute for advice from your own doctor.