Living with multiple sclerosis (MS) is already tough, but ataxia — the inability to control muscle movements because of nerve damage — can be an especially unpredictable and frustrating symptom. From walking and writing to simply sitting upright, ataxia can make even the smallest movements feel like a challenge.

People living with multiple sclerosis commonly experience ataxia as a symptom of MS. According to the Multiple Sclerosis Trust, ataxia affects about 4 out of 5 people with the condition.

Having trouble controlling your muscles due to ataxia can cause difficulties in many parts of your life, including how you walk, talk, and eat, and even how you feel emotionally.

What Causes Ataxia in MS?

Ataxia refers to a loss of coordination due to nerve damage. Although you will notice its effect on your muscles, ataxia isn’t caused by muscle weakness.

Ataxia in multiple sclerosis is related to the way the disease harms nerve cells. MS is an autoimmune disorder in which the immune system mistakenly attacks the myelin sheath that surrounds and protects nerve fibers in the brain and spinal cord. This process is called demyelination. When the myelin sheath is damaged, the nerves can’t function as well. As the disease progresses, more nerve cells are damaged. When nerve fibers in the brain are demyelinated, it can cause lesions (areas of tissue damage) that impair your ability to coordinate movement.

Is MS a movement disorder?

While MS is not considered a movement disorder, it is closely tied to movement disorders, including ataxia. Ataxia can be a symptom of another disease (such as MS) or a condition on its own. Ataxia can be inherited or caused by factors like medication side effects, alcohol misuse, head injury, tumors, vitamin deficiencies, and other medical conditions like hypothyroidism (underactive thyroid).

Types of Ataxia

There are three main types of ataxia — cerebellar, sensory, and vestibular ataxia.

Cerebellar Ataxia

The cerebellum is found at the base of the brain and connects to the brainstem. The cerebellum’s main job is to coordinate muscle movements you control, such as moving your arms and legs. Cerebellar ataxia can occur when any part of the cerebellum is damaged. The way cerebellar ataxia affects your body depends on which specific area of the cerebellum has been damaged. In fact, a decrease in the size of the cerebellum can predict future disability in people with MS.

Sensory Ataxia

Sensory ataxia refers to a condition in which you can’t sense the location and movement of your body in space. This is called proprioception. It occurs when there is damage to the parts of the spinal cord or brainstem that tell your brain about the body’s position. As a result, you may have trouble determining where your limbs are in relation to your body.

Vestibular Ataxia

The vestibular system is responsible for your sense of balance. It involves your eyes, inner ears, and the muscles of your core (abdomen, pelvis, and back). Vestibular ataxia can occur when the vestibular system (in the brainstem) is damaged. If you have vestibular ataxia, you may experience a loss of balance, vertigo and dizziness, nausea and vomiting, frequent falls, and vision problems.

7 Symptoms of Ataxia

Your ataxia symptoms will depend on how your spinal cord, brainstem, and cerebellum are affected by MS. Here are seven ways ataxia may show up for you.

1. Walking Changes

When ataxia causes spasticity (damage to the nerves involved with muscle tone and balance), it can affect the way you walk — also called your gait. Changes in balance can make it appear as if you are drunk when you walk.

Walking and exercising less often can cause atrophy (the loss of muscle mass) and create further changes in your gait.

Common gait changes with ataxia include:

• Decreased speed
• Smaller steps
• Reduced movement of the hips, knees, and ankles
• Foot drop (dragging your toes)
• Stomping gait
• Wide stance

One MyMSTeam member shared how these walking difficulties are especially apparent in the morning hours. “I couldn't get out of bed. Then my toes went numb, I turned the corner, hit the wall, and fell down the step into the cat’s litter box.”

2. Falls

Ataxia can make you feel more clumsy and more likely to fall. “I tried to go to the store without my walker, and I feel that I paid the price with a horrible fall,” one member shared. People with ataxia have several risk factors for falls, including:

• Slow walking
• Dizziness
• Poor balance
• Impaired sense of where your body is in space
• Side effects of some MS medications
• Vertigo

Studies show that between 50 percent and 70 percent of people with MS report falling in the past two to six months. About 30 percent of people with MS are injured at some point from multiple falls.

3. Tremors

A tremor is an uncontrolled shaking movement. Tremors can affect the head, vocal cords, torso, arms, and legs. They can make daily activities — such as getting dressed or eating — difficult to complete. “I have been noticing tremors in my right hand that are worse with actions such as grasping things,” one MyMSTeam member shared.

Studies have found between 25 percent and 58 percent of people with MS experience tremors. In MS, tremors are usually not severe.

Two types of tremors are common in MS: intention tremor and postural tremor.

An intention tremor usually gets worse when you’re moving purposefully, like when you reach out to grab an object. A postural tremor can happen when you’re supporting your body against gravity — so you’d shake while standing or sitting up, but not as much when lying down.

4. Speech Challenges

“Having speech problems. How do I increase my volume?” one MyMSTeam member asked. Speech problems can be the result of damage in the parts of the brain that control physical speech or the processes that your brain uses to choose your words. Dysarthria is the name given to ataxia that affects speech. Dysarthria is caused by abnormal coordination of the muscles and nerves that move your mouth, tongue, and diaphragm.

Changes in speaking with MS can include:

• Slurred speech
• Low speaking volume
• Difficulty controlling pitch (how high or low your voice is)
• Speaking through your nose (speaking with a nasal-sounding voice)
• Long pauses between words

5. Difficulty Eating

“While eating oatmeal this morning, I almost choked on it. I thought it was just me not paying enough attention to what I was doing,” one MyMSTeam member shared. “Then at lunch I had the same problem, but it was much worse. It scared me more than anything.”

Damage to nerve cells in the cerebellum can cause dysfunction in several areas that your brain uses to help you eat. If the nerves controlling the muscles of the mouth, tongue, or esophagus are damaged, it may cause dysphagia (trouble chewing or swallowing). Some people may notice it’s especially hard to swallow thin liquids like water. Numbness can also increase the possibility of biting your tongue or cheek.

If you have a tremor, it may be difficult to bring food to your mouth. Adaptive devices such as weighted utensils can make it easier.

Additionally, up to 30 percent of people living with MS lose some of their ability to taste specific flavors, including sweetness and saltiness. It can be harder to eat when food isn’t enjoyable.

6. Vision Problems

Vision problems are often the first symptom people with MS notice. Ataxia can cause blurred or double vision, making it hard to read or watch moving objects. It may also cause involuntary jittery eye movements called nystagmus. “I was doing my exercises Monday and Wednesday night and noticed that while doing them my vision became blurry,” one member of MyMSTeam noted.

7. Fatigue

Multiple sclerosis and ataxia can cause fatigue. Fatigue is one of the most common symptoms of MS. Although fatigue is difficult to measure, most people with MS experience fatigue, even if they have minimal limitations in other areas.

The way ataxia causes fatigue is unknown, but it could be related to the effort it takes to compensate for a lack of coordination and interrupted sleep.

What about MS and Depression?

“Does anyone know how MS can affect your mood?” one member asked. “For example, some days I get depressed out of nowhere.”

People with MS are more likely than the general population to experience depression. This might be due to the stresses of adapting to a chronic illness or a result of neurological changes caused by MS. For example, damage to the cerebellum and other areas involved in emotional regulation may contribute to mood changes.

How Is Ataxia Treated?

Because your neurologist specializes in treating diseases of the brain and spinal cord, they should be able to help you improve your symptoms of ataxia. If you experience any of the symptoms described in this article, talk to them.

There isn’t a specific treatment for ataxia. Symptoms may improve when you treat the underlying causes of ataxia. However, in multiple sclerosis, the goal of most treatments is to prevent damage that future relapses might cause, not to improve current symptoms. This means that when doctors treat ataxia caused by MS, they focus on rehabilitative therapies that can help you better control your muscle movement. These include:

• Physical therapy to improve your mobility and coordination
• Occupational therapy to help with daily activities, such as eating and getting dressed
• Speech therapy to improve your ability to swallow and talk
• Some medications such as acetazolamide, baclofen (Lioresal), botulinum toxin, and tizanidine (Zanaflex)

Adaptive devices can make life with ataxia easier. Examples of adaptive devices include:

• Canes and walkers
• Wheelchairs
• Long-handled grabbers
• Modified utensils
• Button hooks
• Wide pens
• Communication devices or apps
• Grab bars

Ataxia is a common symptom of MS that can significantly affect your quality of life. Treatment for vestibular, cerebellar, and sensory ataxia may include a combination of physical therapy, medication, and assistive devices. Your neurologist can help you find the best way to treat your MS and refer you to specialists who can help you adapt to your abilities.

Talk With Others Who Understand

MyMSTeam is the social network for people with multiple sclerosis and their loved ones. More than 217,000 MyMSTeam members come together to ask questions, give advice, and share their stories with others who understand life with MS.

Have you noticed any symptoms of ataxia? Do you have advice for others on managing ataxia symptoms? Share your experience in the comments below, or start a conversation by posting on MyMSTeam.