Ataxia vs. Dystonia: How to Tell the Difference (movement disorders)

Dystonia is classified as a movement disorder that occurs in most cases for unknown reasons, though there's evidence of a family history in about 10-25% of cases. Movement disorders cause a person's muscles to contract uncontrollably, leading to jerky and repetitive movements.

Ataxia is another movement disorder. It’s caused by an underlying medical condition, which also leads to uncontrolled and jerky muscle movements. And, like dystonia, it may affect a single muscle, a muscle group, or muscles throughout the entire body.

Since both present similarly, how can you tell the difference?

At Memphis Neurology, our expert team of neurologists sees many movement disorders, including dystonia and ataxia. Though, on the surface, they appear very similar, we know they’re really two distinct disorders with different causes and treatments. Here’s what you need to know about them and what we can do to help.

More about dystonia

Dystonia results from improper functioning of the basal ganglia, a part of the brain that helps control the coordination of movement, including speed and fluidity, and prevents unwanted movements. Patients with dystonia can experience uncontrollable twisting, repetitive movements, speech deficits, and/or abnormal postures and positions from misfiring of nerves in the brain. Any body part can be affected, especially the arms, legs, trunk, eyelids, and vocal cords.

Cervical dystonia, medically called spasmodic torticollis, is the most common type, affecting about 1% of the population, mostly those in middle age. In this type, the neck muscles are affected, and the spasming causes the head to twist or turn to one side or to tilt forward or backward. Most commonly, the chin twists toward one of the shoulders. Symptoms usually start gradually, build up, then reach a plateau, after which they don’t worsen substantially. At this time, there’s no cure.

More about ataxia

Ataxia results from damage to the brain, brainstem, or spinal cord, leading to clumsiness, instability, imbalance, tremors, jerky movements, and/or a lack of coordination during voluntary movements. Patients may fall frequently due to shakiness and an unsteady gait. Like dystonia, ataxia can also affect speech and movement of the eyes.

Symptoms of ataxia generally arise from an underlying condition, such as a vitamin deficiency or a metabolic syndrome.

Diagnosing dystonia and ataxia

Because dystonia and ataxia appear similar on the surface, it’s important to run various tests to determine which, if either, you have.

If your doctor suspects you have ataxia, they seek a treatable cause. They start with a physical and neurological exam, including checks for vision, balance, coordination, and reflexes. Additional tests may include:

• Blood tests
• Imaging studies: MRI of the brain might show shrinkage of the cerebellum and other brain structures; it may also show blood clots or benign tumors.
• Lumbar puncture (spinal tap): collects cerebrospinal fluid that surrounds and protects your brain and spinal cord and sends it for testing

If your doctor suspects you have dystonia, they also start with a physical and neurological exam and may also request the following:

• Blood or urine tests: Can reveal signs of toxins or other conditions
• MRI or CT scan: identify problems in your brain, including tumors, lesions, or evidence of a stroke
• Electromyography (EMG): measures electrical activity within muscles
• Genetic testing: Some forms associated with certain genes; genetic markers can help guide treatment

Sometimes, the end diagnosis is made by ruling out all other possibilities.

Treating dystonia and ataxia

Having different causes and affecting different brain areas, dystonia and ataxia also have different treatments.

Treating dystonia uses a three-tiered approach: Botox® injections, medication, and surgery, used either alone or in combination. Botox temporarily paralyzes the nerves that tell the errant muscle to contract. Without that communication, the muscles relax, which may lessen abnormal movements and postures. Physical, occupational, and speech therapy may also improve symptoms. Surgery is considered when all other treatments have proven ineffective.

There isn’t a specific treatment for ataxia, though treating the underlying cause may help improve symptoms. Ataxia resulting from chickenpox or other viral infections generally resolves on its own.

For ataxia resulting from Parkinson’s disease, the go-to treatment is oral L-DOPA, which addresses dopamine levels in the brain. Other medications, such as anticholinergics and dopamine agonists, are also used.

Do you or a loved one struggle with uncontrollable muscle spasms? You might have a movement disorder. Memphis Neurology can help. Call us at our Germantown, Tennessee, or Southaven, Mississippi, office to schedule a consultation with a neurologist, or book your appointment online with us today.