What Is Ataxia?

Ataxia refers to a loss of the ability to coordinate movements due to a disorder of the nervous system. People with ataxia have difficulty controlling arm and leg movements and experience problems with balance and gait (how you walk).

Ataxia is estimated to affect 26 out of every 100,000 children. It is often inherited—though some types occur due to other diseases. More of a class of symptoms than a disease in its own right, ataxia arises due to disorders in the cerebellum (known as cerebellar degeneration) of the brain or related nervous pathways (called spinocerebellar degeneration).

This condition can vary in terms of the duration of symptoms as well as their severity. Some people experience acute cases, which last from several hours to days, while others have subacute cases that last a couple of weeks, and chronic ataxias are those that last months to years. Treatments depend on the specific symptoms you have, their frequency, and how long they last. That said, there are several treatment options for acute, subacute, and chronic ataxia.  

Types

There are many types of ataxias. Most broadly, distinctions are made between cases that are inherited (passed down from parent to child) and secondary, acquired ones. Furthermore, inherited ataxias are categorized based on their pattern of inheritance.

Autosomal Recessive Cerebellar Ataxia (ARCA)

ARCAs follow an autosomal recessive pattern, meaning they’re inherited only when both parents carry a faulty gene. They usually begin in childhood and progress in severity over time. The most common type, Friedreich ataxia, usually causes an impaired ability to walk within 10 to 20 years. Another ARCA, ataxia telangiectasia, has a faster progression, with those affected generally losing their ability to walk by age 10.

Spinocerebellar Ataxia (SCA)

Another inherited type of ataxia, spinocerebellar ataxias follow an autosomal dominant inheritance pattern. This means they’re passed on when only one parent has the faulty gene, so a child has a 50% chance of developing the condition. There are many types of SCA, including SCA 3 or Machado Joseph disease, which is the most common. Unlike ARCA, this type generally begins in adulthood.

Other Hereditary Ataxias

In addition, there are several other types of hereditary ataxia:

• Episodic hereditary ataxia: This type causes briefer periods of symptoms accompanied by vertigo (a loss of balance). Attacks last anywhere from seconds to three hours.
• X-linked ataxia: This ataxia is predominantly seen in people assigned male at birth over the age of 50.
• Mitochondrial ataxia: Mitochondrial ataxia arises due to abnormalities in the mitochondria, the part of cells that convert sugar to energy.

Acquired Ataxias

Acquired or secondary ataxias are those caused by outside factors that occur during your life, such as illness and injury, among others. People who have acquired ataxia usually have no familial connection to the condition.

Symptoms

Primarily, ataxia is a disorder of motor coordination. It’s characterized by your muscles' inability to work together and move. Different parts of the body can be affected, and different types can range in severity and cause different sets of symptoms. Your symptoms may include some or all of the following.

Abnormal Gait

Difficulty walking is a common sign of ataxia. You may have an abnormal gait and stagger or shuffle your feet in a characteristic, uncoordinated manner. Clinically, this is referred to as “gait ataxia.”

Loss of Balance

An inability to maintain balance, known as sensory ataxia, is another common sign of the condition. You may also experience a loss of proprioception, which is the awareness of your body within space. This can make it difficult to assess where external objects are in relation to your body.

Loss of Motor Coordination

Ataxia also affects your ability to coordinate and control their movements. This leads to difficulty with writing by hand, typing, tying shoelaces, and other actions. In addition, progressive cases can lead to a complete loss of walking ability.

Tremors

Having tremors—uncontrollable shaking of the hands, arms, legs, or feet—is also a sign of ataxia. The condition also causes chorea, characterized by sudden, uncontrolled jerky movements.

Speech Difficulties

The loss of motor function due to ataxia can also impact your ability to form words and talk, leading to slurred speech. This is known as dysarthria. Often related is another symptom, dysphagia, which is characterized by difficulty with or inability to swallow.

Nystagmus

Nystagmus refers to uncontrolled, rhythmic side-to-side, up and down, or circular motion of the eyes. This condition can affect vision and cause blurring.

What Causes Ataxia?

Ataxia occurs due to problems with sensory signaling in the cerebellum (the area of the brain responsible for standing, walking, and other motor functions) due to the formation of lesions (areas of damage). This can be due to dysfunction within the cerebellum or as the result of disruptions in vestibular (inner ear) and proprioceptive (muscle, tendon, and joint) signaling.

As noted, ataxias can arise due to genetic factors or as the result of injury, disease, or other health conditions. Mutations in a wide range of genes are associated with ataxia, including ATXN3, FXN, and ATM, among others.

Factors that can cause acquired ataxia include:

• Conditions that can cause damage to the brain and spinal cord, including multiple sclerosis (MS), stroke, a brain tumor, traumatic brain injury (TBI), and peripheral neuropathy
• Metabolic disorders
• Certain cancers, including lung and ovarian cancer and Hodgkin’s lymphoma  
• Exposure to toxins, such as frequent use of drugs and alcohol
• Infections
• Nutritional deficiencies, such as vitamin B12 deficiency
• The side effects of medications, including antiepileptics, benzodiazepines, and immunosuppressants

Risk Factors

A number of conditions and health factors increase the risk of developing ataxia. These include:

• Family history of ataxia
• Younger age
• A history of infectious diseases
• A history of neurological disease
• Excessive alcohol use
• Head trauma
• Type 2 diabetes
• High blood pressure

How Is Ataxia Diagnosed? 

The goals of the diagnosis of ataxia are two-fold: to get at what may be causing the symptoms and to rule out other conditions that produce them. Heat stroke, alcohol use, ischemic stroke, and brain hemorrhage (brain bleed) are among issues that present similarly and therefore need to be ruled out.

The process typically begins with a thorough evaluation of your current health status, family history of ataxia, medications you’re taking, and current symptoms. In addition, several other tests and evaluations may be performed:

• Neurological tests: These are tests of your ability to coordinate movements, walk, and your mental status (memory and speaking ability), strength, and balance.  
• Grading: There are several assessment scales used for ataxia to help providers with the assessment of symptoms, including the International Cooperative Ataxia Rating Scale (ICARS) and Scale for the Assessment and Rating of Ataxia (SARA), among others.
• Blood test: Blood tests may be used to screen for potential causes, such as alcohol or drug use, low vitamin levels, cancer, or other diseases that can cause ataxia.
• Computerized tomography (CT) scan: CT scans are a type of X-ray that produces high-definition images of the brain, which are useful for diagnosis and can help rule out tumors and TBIs.
• Magnetic resonance imaging (MRI): This type of imaging relies on magnetic waves to create two or three-dimensional images of brain areas.
• Genetic testing: If hereditary ataxia is suspected, genetic testing allows providers to find DNA abnormalities that may be at the root of the issue.

Treatments for Ataxia 

The treatment of ataxia depends on the underlying cause. While hereditary ataxias aren’t curable, cases caused by vitamin deficiency, infection, or other treatable conditions can be reversed. Therapies for these types may include:

• Vitamin E supplements
• Diamox Sequels (acetazolamide), a medication also used for glaucoma and epilepsy
• Antibiotics or antiviral drugs (if the ataxia is due to infection)
• Lifestyle changes, such as stopping alcohol use

When ataxia can’t be cured, medical management may help with prevention, reduce the frequency of attacks, and make the condition easier to live with. There are a range of therapeutic approaches to ataxia, and these are tailored to the individual case.

Prescription Medications

Depending on the case, some medications may help manage the symptoms of ataxia. Since medication regimens for ataxia are based on what symptoms you're experiencing, they are highly personalized.

Skeletal muscle relaxants are often used to treat muscle spasticity. These include Gablofen (baclofen), Zanaflex (tizanidine), Dantrium (dantrolen), and Botox (botulinum toxinA).

To treat associated nerve pain, you may be prescribed amitriptyline (an antidepressant), gabapentin (an anticonvulsant), or pregabalin (a pain reliever specifically for neuropathic pain). More traditional painkillers, such as Advil (ibuprofen) or Tylenol (acetaminophen) are generally ineffective. 

Physical Therapy

To help with the physical impact of ataxia, physical therapy may be recommended. This involves working with a physical therapist to learn exercises that promote strength and mobility in affected limbs and can help with postural instability.

Speech and Language Therapy

Speech and language therapy can help take on the dysarthia and dysphagia associated with ataxia. This involves working with a specialist and can include learning breathing exercises, working on posture, or exercises to strengthen muscles used for vocalization or chewing.

Assistive Devices

Since loss of strength and mobility are features of ataxia, management can also include occupational therapy and using assistive devices. This may mean using a walker or wheelchair or installing railings or lifts in the home.

Prevention

While many types of ataxia aren’t preventable, there may be effective strategies that reduce the frequency and severity of symptoms. As with treatments, prevention strategies depend on specific cases and can include:

• Regularly monitoring the progression of your condition
• Taking supplements of vitamin E, B12, and others for cases due to vitamin deficiency
• Steering clear of gluten, found in wheat products, candy, beer, and other foods
• Stopping alcohol
• Ensuring sufficient physical activity and exercise
• Managing diet and ensuring you’re getting sufficient nutrients

Comorbid Conditions  

Because of its effects on the body, ataxia makes people with it more susceptible to certain health conditions. Occurring alongside ataxia are several comorbid conditions, the most common of which are:

• Scoliosis: Especially prevalent in the earlier course of ataxia is scoliosis, a curvature of the spine. In a 2022 study, researchers found that 53.3% of people with Friedreich ataxia also had scoliosis.
• Hypertrophic cardiomyopathy: This is a thickening of the walls of the heart, a condition seen in nearly half of ataxia cases.
• Pes cavus: This is the development of an abnormally high arch in the foot, which is seen in approximately one in three cases.
• Diabetes: The genetic mutations that cause Friedreich ataxia predispose people with the condition for diabetes.
• Bone fractures: Because of ataxia’s effect on balance and coordination, it can cause falls and raise the risk of broken bones.
• Hearing loss: Abnormalities in the inner ear associated with spinocerebellar ataxia can affect hearing loss and cause deafness.
• Vision loss: The nerve damage (neuropathy) associated with Friedreich ataxia can affect the optic nerve of the eye, severely impairing vision.
• Depression: Living with a progressive condition like ataxia can also impact mental health, leading to an increased chance of developing clinical depression.

Living With Ataxia

Ataxias can have a profound effect on both quality of life and life expectancy. Hereditary forms are associated with shorter life spans. In more severe cases, ataxia can cause death in childhood or during adolescence or young adult years.

Furthermore, living with a chronic condition like ataxia can significantly affect your quality of life and impact to live independently. That said, with medical treatment and accommodations, many live well with ataxia, and as research continues, novel therapies are emerging.