Locations:
Search IconSearch

Muscle Matters: What’s the Difference Between Spasticity and Dystonia?

These neurological conditions affect muscle movement in separate ways

Physical therapist working with a patient with their arm

Spasticity is a neurological condition that disrupts muscle movement. Dystonia shares the same resume. In many ways, the two conditions resemble each other ― so much so that they can be difficult to tell apart.

Advertisement

Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy

But while spasticity and dystonia may be similar, they’re distinctly different on multiple levels. How so? Let’s find out from neurologist Junaid Siddiqui, MD.

Spasticity vs. dystonia

In a basic explanation, spasticity and dystonia sound pretty much the same. Both trace their cause to a brain condition or brain damage that scrambles instructions sent to certain muscles within the body.

This faulty messaging results in muscles not behaving as they should. Symptoms from both conditions can appear in your arms, hands or legs, limiting your ability to move or do everyday tasks.

“Both dystonia and spasticity are physical manifestations of neurological dysfunction,” says Dr. Siddiqui.

It can be difficult for someone experiencing these symptoms to differentiate between spasticity and dystonia, notes Dr. Siddiqui. “It’s even possible to have dystonia, as well as spasticity from the same condition.”

But there are key differences that set spasticity and dystonia apart. Let’s break them down.

Effect on muscles

Spasticity brings a continuous muscle contraction that seems to lock a muscle into place, reports Dr. Siddiqui. These spasms apply constant tension that makes the muscle stiff and unable to move.

If spasticity affects your arm, for instance, you might have a bend at your elbow that you can’t straighten without applying force to move it. This results from overactivity of one set of muscles while the opposing muscles may be weak.

Advertisement

“You can feel increased tone from spasticity in the muscle, especially with passive movement,” adds Dr. Siddiqui.

But Dystonia brings spasms to opposing muscles ― the agonist (which contracts to bring movement) and the antagonist (which relaxes to allow or control the movement at the same time).

“This co-contraction means both muscles are firing at once, meaning they don’t cooperate with each other,” explains Dr. Siddiqui.

This tug of war between opposing muscles can cause a shaky back-and-forth movement similar to a tremor. The competing muscles may also cause contortions by forcing limbs to twist and turn, leading to what looks like unusual poses.

When it happens

Spasticity is a static (or continuous) condition. The pose or positioning created by the continuous muscle contraction doesn’t change on its own. “It results in a posture that is there regardless of what the person is doing,” clarifies Dr. Siddiqui.

Dystonia, though, is a dynamic (or fluctuating) situation that can come and go. It’s usually triggered by a motion that uses the affected muscles. “It comes out with activation,” he says. “It’s not present at rest.”

Starting point in the brain

While both spasticity and dystonia are neurological disorders rooted in your brain, they typically originate in different parts of it, says Dr. Siddiqui. Specifically:

  • Spasticity often involves an issue within your cerebral cortex, the “gray matter” that initiates muscle movement by sending signals through nerve pathways within your central nervous system. A problem with any of the “wires” along the tract within your brain or the spinal cord may result in spasticity.
  • Dystonia usually involves damage to your basal ganglia, a group of structures near the center of your brain that manage signals to your muscles. It can sometimes be seen with problems in other areas of your brain or nervous system.

Causes

Stroke or a severe head injury can cause the sort of internal brain damage that leads to either spasticity or dystonia. (As noted, the resulting condition often depends on where the damage takes place.)

But a host of other issues may also trigger either condition.

Spasticity could be caused by:

Dystonia could be linked to:

Advertisement

A medical history can help determine whether someone is dealing with spasticity or dystonia.

Treatments

Spasticity and dystonia are both lifelong conditions that can vary in severity, but they can be managed, states Dr. Siddiqui. Common nonsurgical approaches to reduce symptoms may include:

Each condition also has surgical options. Deep brain stimulation from implanted electrodes can sometimes tame dystonia, while intrathecal baclofen (ITB) therapy from a surgically implanted pump can be used for spasticity.

“For both conditions, there are a lot of ways we can help,” reassures Dr. Siddiqui.

Advertisement

Learn more about our editorial process.

Related Articles

Healthcare provider talking to person sitting on exam table in medical office
December 27, 2024/Brain & Nervous System
Can Botox Injections Offer Relief From Spasticity?

This treatment can be an effective way to calm muscle stiffness and spasms from nerve damage

person riding a bike
December 19, 2024/Brain & Nervous System
Exercises That Can Help Manage Spasticity

Stretching, water-based activities, cycling and treadmill training can all bring benefits

A person drops CBD oil into a clear glass of liquid.
December 29, 2021/Primary Care
CBD Oil — Are the Benefits Claimed Too Good To Be True?

Studies suggest CBD has wide-ranging benefits, but there’s a catch or two

Person drying off feet with towel
April 1, 2025/Orthopaedics
How To Get Rid of Smelly Feet: 8 Home Remedies That Work

If soaking your feet, disinfecting your shoes and making lifestyle changes don’t do the job, it’s time to talk to a doctor

Hand spraying foot spray on foot
March 31, 2025/Orthopaedics
Here’s Why Your Feet Smell

Genetics, hormones, medications and stress are just a few reasons your feet could be extra funky

Woman wearing cancer head scarf, being held by her partner
Navigating Cancer and Sex

The side effects of cancer and treatment can impact desire, sexual function and intimacy, but there are ways you can keep the flame going

Woman sitting on couch at home, holding a pill and a glass of water, about to take the medication
March 31, 2025/Mental Health
How Are NDRI and SSRI Antidepressants Different?

The medications target different chemicals in your brain to improve mood

A salmon and greens sandwich on whole-grain bread being served on a plate
March 31, 2025/Digestive
What To Eat (and Avoid) When You Have Gallbladder Issues

A low-fat, high-fiber diet can help prevent gallbladder attacks and keep you pain-free

Trending Topics

Person in bed sleeping on their side, covers off
Breathing Problems? Try These Sleep Positions

If you’re feeling short of breath, sleep can be tough — propping yourself up or sleeping on your side may help

A couple looking at skyline, with one person slightly behind the other, head bent down
What Is Anxious Attachment Style — and Do You Have It?

If you fear the unknown or find yourself needing reassurance often, you may identify with this attachment style

Glasses and bottle of yellow-colored prebiotic soda, with mint, lemon and ginger garnish
Are Prebiotic Sodas Good for You?

If you’re looking to boost your gut health, it’s better to get fiber from whole foods

Ad