Spinocerebellar Ataxia

Spinocerebellar ataxia (SCA) comprises more than 40 types of similar inherited brain disorders. SCA affects your cerebellum, a part of your brain vital to physical movement. It causes problems with coordination and movement. There’s no cure, so treatment aims to relieve symptoms and improve function.


What is spinocerebellar ataxia?

Ataxia is a degenerative condition that affects your nervous system. It involves problems with coordination and movement. There are many different kinds of ataxia with varying causes and symptoms.

Spinocerebellar ataxia (SCA) is a group of inherited brain disorders. It affects your cerebellum, a part of your brain vital to coordination of physical movement, and sometimes your spinal cord. This inherited condition worsens over time and causes specific problems with coordination, usually affecting:

  • Eyes.
  • Hands.
  • Legs and mobility.
  • Speech.


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What are the spinocerebellar ataxia types?

Experts have discovered more than 40 types of SCAs so far, and that number may increase. They identify types by number (for example, spinocerebellar ataxia type 1, spinocerebellar ataxia type 2 and so on).

All types of SCAs have similar causes and symptoms. The numbers indicate the order in which experts discovered the associated mutations. In other words, SCA1 was the first type linked to an inherited chromosomal problem. SCA2 was the second, etc.

The most common type is spinocerebellar ataxia type 3, also known as Machado-Joseph disease.

How common is spinocerebellar ataxia?

SCA is rare. It affects about 1 to 5 people per 100,000.


Symptoms and Causes

What causes spinocerebellar ataxia?

An inherited gene mutation causes SCA. Experts have linked this specific gene to many types of spinocerebellar ataxias, but not all.

Some types of SCAs occur because a segment of DNA abnormally repeats several times (called trinucleotide repeat expansion).

The condition is usually inherited in an autosomal dominant fashion. This means that it takes only one copy of the mutated gene from one biological parent to cause the condition. Therefore, when a person with SCA has children, each child has a 50% chance of inheriting the mutated gene.

There are also autosomal recessive spinocerebellar ataxias. In these cases, a person inherits an abnormal gene from both biological parents, who are generally asymptomatic.

What are the symptoms of spinocerebellar ataxia?

Signs and symptoms of SCA usually appear after age 18 and slowly worsen over several years.

Spinocerebellar ataxia symptoms often include:

  • Involuntary eye movements.
  • Poor hand-eye coordination.
  • Problems with balance and coordination.
  • Slurred speech.
  • Trouble processing and remembering information (learning disabilities).
  • Uncoordinated walking.


Diagnosis and Tests

How is spinocerebellar ataxia diagnosed?

A healthcare provider might diagnose SCA based on:

  • Family history.
  • Personal medical history.
  • Physical exam.
  • Symptoms associated with SCA.

Genetic testing can confirm many types of SCA. However, some types aren’t associated with a specific mutation, so experts can’t confirm all types of SCAs this way.

In those cases, healthcare providers might order tests and images of your brain to look for abnormalities. The tests include CT scan and MRI.

Genetic testing is also available for people who think they might be carrying an SCA genetic mutation. Testing can help them with decisions about family planning. Healthcare providers also can test babies before they’re born with prenatal testing.

Management and Treatment

Is there a cure for spinocerebellar ataxia?

There’s no known cure for SCA. Treatment aims to reduce symptoms and improve functioning.

Spinocerebellar ataxia treatment may include:

  • Assistive devices to help people get around, such as crutches or a cane, walker or wheelchair.
  • Physical therapy to strengthen muscles and improve gait and balance.
  • Medications to reduce shakiness, stiffness and muscle spasms.

Researchers are still exploring ways to help people manage and treat SCA.


How can I prevent spinocerebellar ataxia?

There aren’t any proven strategies to prevent SCA. Some families who know they carry the mutation may choose not to have children. That’s the only way to prevent passing down the condition to the next generation.

Outlook / Prognosis

What can I expect if I have spinocerebellar ataxia?

Ataxia life expectancy varies widely, depending on the type and severity. Sadly, many cases of SCA cause premature death.

How quickly the condition progresses also depends on type and severity. As a result, genetic testing may help with predicting course in addition to making a definitive diagnosis. Many people need a wheelchair within 10 to 15 years of their first symptoms. It’s common for people with SCA to eventually need help with daily tasks.

Living With

What else should I ask my doctor about spinocerebellar ataxia?

If you have spinocerebellar ataxia (SCA), consider asking your healthcare providers the following questions:

  • What type of SCA do I have?
  • What body functions will it affect?
  • What specialists should I see?
  • How often should I have follow-up appointments and tests?
  • What treatments should I have?
  • Will this condition shorten my life expectancy?
  • Can I pass this on to my kids?
  • Should members of my family have genetic testing?
  • Do you know of any support groups that might help me cope?

How can I best learn to cope with SCA?

A diagnosis of spinocerebellar ataxia raises many questions and emotions. Some of the following strategies may help you cope:

  • Ask for support and help from those close to you.
  • Be an active participant in your care. Attend all of your follow-up appointments, follow your healthcare provider’s instructions and ask questions.
  • Consider talking to a mental health counselor who can teach you coping skills.
  • Don’t try to ignore or suppress your feelings. Discuss the condition and your feelings with friends and families.
  • Join a support group to meet others with similar challenges.
  • Set realistic expectations, including exploring limitations.
  • When you lose abilities, try to focus on the things you can do.

A note from Cleveland Clinic

Spinocerebellar ataxia (SCA) is a group of inherited brain disorders. The various types all cause issues with coordination and movement, which worsen over time. If you have SCA, talk to your healthcare provider about ways to relieve symptoms and improve function.

Medically Reviewed

Last reviewed on 08/29/2022.

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