Ataxia describes a lack of muscle coordination during voluntary movements, such as walking or picking up objects. A sign of an underlying condition, ataxia can affect your movements, your speech, your eye movements and your ability to swallow. Persistent ataxia usually results from damage to your cerebellum — the part of your brain that controls muscle coordination. Many conditions may cause ataxia, including alcohol abuse, stroke, tumor, cerebral palsy and multiple sclerosis. It’s also possible to inherit a defective gene that may cause one of many ataxia variants.
Ataxia can develop over time or come on suddenly, depending on the cause. Ataxia causes poor coordination, but other signs and symptoms vary depending on the type of ataxia. Signs and symptoms may include:
- 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
- Abnormal eye movements
- Difficulty swallowing
The part of your brain that controls muscle coordination, your cerebellum, comprises two ping-pong-ball-sized portions of folded tissue situated at the base of your brain, near your brainstem. The right side of your cerebellum controls coordination on the right side of your body; the left side of the cerebellum controls coordination on the left side of your body.
When nerve cells in the cerebellum are lost or damaged or degenerate, they provide less control to muscles, resulting in loss of coordination or ataxia. Diseases that damage the spinal cord and peripheral nerves that connect your cerebellum to your muscles also may 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 sudden-onset ataxia, also known as acute cerebellar ataxia.
Stroke. When the blood supply to a part of your brain is interrupted or severely reduced, depriving brain tissue of oxygen and nutrients, brain cells begin to die.
Transient ischemic attack (TIA). Caused by a temporary decrease in blood supply to part of your brain, most TIAs last only a few minutes. Loss of coordination and other signs and symptoms of a TIA are temporary.
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.
Chickenpox. Ataxia can be an uncommon complication of chickenpox and other viral infections. It may appear in the healing stages of the infection and last for days or weeks. Normally, the ataxia resolves completely 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 may appear months or years before the cancer is diagnosed.
Tumor. A growth on the brain, cancerous or noncancerous (benign), can damage the cerebellum.
Toxic reaction. Ataxia is a potential side effect of certain medications, such as phenobarbital and sedatives such as benzodiazepines. Alcohol and drug intoxication; heavy metal poisoning, such as with lead or mercury; and solvent poisoning, such as with paint thinner, also can cause ataxia.
There’s no treatment specifically for ataxia. In some cases, treating the underlying cause resolves the ataxia. In other cases, such as ataxia that results from chickenpox or other viral infection, it’s likely to resolve on its own over time. Your doctor may recommend adaptive devices or therapies to help with your ataxia.
For ataxia caused by conditions such as multiple sclerosis or cerebral palsy, ataxia might not be treatable. In that case, your doctor may be able to recommend adaptive devices. They include:
- Canes or walkers for walking
- Modified utensils for eating
- Communication aids for speaking
You might benefit from certain therapies, including:
- Physical therapy to help you build strength and enhance your mobility
- Occupational therapy to help you with daily living tasks, such as feeding yourself
- Speech therapy to improve speech and aid swallowing