Symptoms, and causes, of Ataxia

Beryl_Park · March 30, 2022, 2:45pm

Symptoms

Ataxia can develop over time or come on suddenly. A sign of a number of neurological disorders, ataxia can cause:

Poor coordination
Unsteady walk and a tendency to stumble
Difficulty with fine motor tasks, such as eating, writing or buttoning a shirt
Change in speech
Involuntary back-and-forth eye movements (nystagmus)
Difficulty swallowing

When to see a doctor

If you aren’t aware of having a condition that causes ataxia, such as multiple sclerosis, see your doctor as soon as possible if you:

Lose balance
Lose muscle coordination in a hand, arm or leg
Have difficulty walking
Slur your speech
Have difficulty swallowing

Request an Appointment at Mayo Clinic

Causes

Damage, degeneration or loss of nerve cells in the part of your brain that controls muscle coordination (cerebellum), results in ataxia. Your cerebellum comprises two portions of folded tissue situated at the base of your brain near your brainstem. This area of the brain helps with balance as well as eye movements, swallowing and speech.

Diseases that damage the spinal cord and peripheral nerves that connect your cerebellum to your muscles also can cause ataxia. Ataxia causes include:

Head trauma. Damage to your brain or spinal cord from a blow to your head, such as might occur in a car accident, can cause acute cerebellar ataxia, which comes on suddenly.
Stroke. Either a blockage or bleeding in the brain can cause ataxia. When the blood supply to a part of your brain is interrupted or severely reduced, depriving brain tissue of oxygen and nutrients, brain cells die.
Cerebral palsy. This is a general term for a group of disorders caused by damage to a child’s brain during early development — before, during or shortly after birth — that affects the child’s ability to coordinate body movements.
Autoimmune diseases. Multiple sclerosis, sarcoidosis, celiac disease and other autoimmune conditions can cause ataxia.
Infections. Ataxia can be an uncommon complication of chickenpox and other viral infections such as HIV and Lyme disease. It might appear in the healing stages of the infection and last for days or weeks. Normally, the ataxia resolves over time.
Paraneoplastic syndromes. These are rare, degenerative disorders triggered by your immune system’s response to a cancerous tumor (neoplasm), most commonly from lung, ovarian, breast or lymphatic cancer. Ataxia can appear months or years before the cancer is diagnosed.
Abnormalities in the brain. An infected area (abscess) in the brain may cause ataxia. A growth on the brain, cancerous (malignant) or noncancerous (benign), can damage the cerebellum.
Toxic reaction. Ataxia is a potential side effect of certain medications, especially barbiturates, such as phenobarbital; sedatives, such as benzodiazepines; antiepileptic drugs, such as phenytoin; and some types of chemotherapy. Vitamin B-6 toxicity also may cause ataxia. These causes are important to identify because the effects are often reversible.Also, some medications you take can cause problems as you age, so you might need to reduce your dose or discontinue the medication.Alcohol and drug intoxication; heavy metal poisoning, such as from lead or mercury; and solvent poisoning, such as from paint thinner, also can cause ataxia.
Vitamin E, vitamin B-12 or thiamine deficiency. Not getting enough of these nutrients, because of the inability to absorb enough, alcohol misuse or other reasons, can lead to ataxia.
Thyroid problems. Hypothyroidism and hypoparathyroidism can cause ataxia.
COVID-19 infection. This infection may cause ataxia, most commonly in very severe cases.

For some adults who develop sporadic ataxia, no specific cause can be found. Sporadic ataxia can take a number of forms, including multiple system atrophy, a progressive, degenerative disorder.

Hereditary ataxias

Some types of ataxia and some conditions that cause ataxia are hereditary. If you have one of these conditions, you were born with a defect in a certain gene that makes abnormal proteins.

The abnormal proteins hamper the function of nerve cells, primarily in your cerebellum and spinal cord, and cause them to degenerate. As the disease progresses, coordination problems worsen.

You can inherit a genetic ataxia from either a dominant gene from one parent (autosomal dominant disorder) or a recessive gene from each parent (autosomal recessive disorder). In the latter case, it’s possible neither parent has the disorder (silent mutation), so there might be no obvious family history.

Different gene defects cause different types of ataxia, most of which are progressive. Each type causes poor coordination, but each has specific signs and symptoms.

Autosomal dominant ataxias

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These include:

Spinocerebellar ataxias. Researchers have identified more than 40 autosomal dominant ataxia genes, and the number continues to grow. Cerebellar ataxia and cerebellar degeneration are common to all types, but other signs and symptoms, as well as age of onset, differ depending on the specific gene mutation.
Episodic ataxia (EA). There are eight recognized types of ataxia that are episodic rather than progressive — EA1 through EA7, plus late-onset episodic ataxia. EA1 and EA2 are the most common. EA1 involves brief ataxic episodes that may last seconds or minutes. The episodes are triggered by stress, being startled or sudden movement, and often are associated with muscle twitching.EA2 involves longer episodes, usually lasting from 30 minutes to six hours, which also are triggered by stress. You might have dizziness (vertigo), fatigue and muscle weakness during your episodes. In some cases, symptoms resolve in later life.Episodic ataxia doesn’t shorten life span, and symptoms might respond to medication.

Autosomal recessive ataxias

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