Muscle spasms in multiple sclerosis can be reduced through a combination of trigger management, daily stretching, oral medications, and targeted treatments like injections or pump therapy for severe cases. Most people with MS-related spasticity use a layered approach, starting with the simplest strategies and adding treatments as needed. The key is understanding that these spasms have a specific neurological cause, which means both the solutions and the triggers differ from ordinary muscle cramps.
Why MS Causes Muscle Spasms
In MS, nerve damage disrupts the signals traveling between your brain and spinal cord. Normally, your brain sends inhibitory signals that keep your stretch reflexes in check. When MS lesions interrupt those signals, your spinal cord reflexes become hyperexcitable, essentially running without a brake. The result is involuntary muscle contractions that range from brief, rhythmic jerking (clonus) to sustained tightness that makes a muscle feel locked in place even at rest (spastic dystonia).
This distinction matters for treatment. Some people experience quick, painful spasms triggered by movement or position changes. Others deal with a constant background stiffness that limits range of motion and builds over time. Many have both. Because the root problem is nerve-driven rather than muscle-driven, treatments that work for ordinary muscle cramps often don’t apply here.
Triggers That Make Spasms Worse
One of the most effective things you can do is identify and eliminate the triggers that ramp up your spasticity. Anything that irritates or stresses the body can amplify the already-overactive nerve signals in your spinal cord. Urinary tract infections are one of the most common culprits. A UTI can cause a dramatic spike in spasm frequency and stiffness, and treating the infection often brings spasticity back to baseline within days.
Other common triggers include:
- Skin irritation or pressure sores: Tight clothing, poorly fitting splints or braces, catheter friction, or any area of skin breakdown can set off spasms.
- Infections of any kind: Chest infections, dental infections, even a common cold will temporarily worsen stiffness until the illness resolves.
- Temperature extremes: Getting too hot or too cold reliably increases spasticity for many people with MS. Keeping your body temperature stable helps.
- Fatigue and poor sleep: Physical exhaustion or sleep deprivation lowers your threshold for spasms.
- Stress and anxiety: Emotional tension has a direct, measurable effect on muscle tightness in MS.
- Vaccinations: Some people notice a temporary worsening of spasms after flu or COVID-19 vaccines.
Keeping a simple log of when your spasms are worst can help you spot patterns. If spasticity suddenly worsens without an obvious reason, a UTI or other hidden infection is worth investigating.
Daily Stretching and Exercise
Regular stretching is one of the most consistently recommended strategies for managing MS spasticity, and it’s something you can start today. The U.S. Department of Veterans Affairs recommends at least 10 to 15 minutes of stretching every day, ideally spread across multiple sessions. Flexibility exercises and range-of-motion work help prevent muscles from shortening over time, which is a real risk when spasticity keeps muscles in a contracted state for hours or days.
Focus on the muscle groups most affected by your spasms. For many people with MS, that means calves, hamstrings, hip flexors, and the muscles along the inner thigh. Hold each stretch gently and steadily rather than bouncing. A physical therapist familiar with MS can design a routine matched to your specific pattern of stiffness and your mobility level. Even people who use wheelchairs can benefit from assisted stretching and range-of-motion exercises performed with a caregiver’s help.
Heat and Cold Therapy
Applying warmth to stiff, spastic muscles can improve flexibility and increase blood flow, which many people find temporarily eases tightness. A warm (not hot) towel, a heating pad on a low setting, or a warm bath can help loosen muscles before stretching. Cold therapy, on the other hand, slows nerve conduction and can calm acute spasms, particularly the sharp, sudden contractions.
One important caution: MS can alter how well you sense temperature in your skin. If you have numbness or reduced sensation in the area you’re treating, you may not feel a burn developing. Use moderate temperatures, check your skin frequently, and limit sessions to 15 or 20 minutes.
First-Line Medications
When stretching and trigger management aren’t enough, oral medications are the standard next step. Clinical guidelines from a consortium including the American Academy of Neurology recommend starting with either baclofen or tizanidine as a first choice for spasticity that lasts most of the day.
Baclofen works by mimicking a calming brain chemical at the spinal cord level, turning down the overactive reflexes that cause spasms. It’s considered the first-line treatment. One limitation is that it doesn’t cross from your bloodstream into your nervous system very efficiently, so lower doses sometimes aren’t enough and the dose needs to be gradually increased to find the right level.
Tizanidine takes a different approach, reducing muscle tone by increasing the inhibition of motor nerve signals. Its effects wear off relatively quickly, so it typically needs to be taken every six to eight hours. Some people use it strategically, timing doses for periods when spasticity is worst (overnight, for example, when spasms disrupt sleep). Tizanidine is also commonly used alongside baclofen for an additive effect when one drug alone isn’t sufficient.
A third option, dantrolene, is unique because it works directly on the muscle rather than the nervous system. It reduces contraction force by interfering with calcium release inside muscle cells. Because it acts peripherally, it can cause muscle weakness as a side effect, which limits its usefulness for people who rely on some degree of spasticity to maintain posture or walking ability.
All three medications involve tradeoffs between spasm relief and side effects like drowsiness, dizziness, or weakness. The goal is finding the dose that reduces spasms enough to improve comfort and function without creating new problems.
Botulinum Toxin Injections for Focal Spasms
When spasticity is concentrated in specific muscles rather than spread across the whole body, injections of botulinum toxin (commonly known as Botox) can target those muscles directly. The toxin blocks nerve signals at the injection site, reducing muscle contractions without affecting the rest of your body.
Clinical evidence shows these injections are effective in about 79% of studies reviewed in a large umbrella analysis. The effect builds over the first two weeks, peaks around four to six weeks after injection, and gradually fades by about 12 weeks. That means most people need repeat injections roughly every three months.
One thing to be aware of: with repeated use over time, your body can develop antibodies that make the injections less effective. Spacing treatments appropriately and avoiding unnecessarily high doses helps reduce this risk. If one type of botulinum toxin stops working, switching to a different formulation is sometimes an option.
Cannabis-Based Treatments
Nabiximols, an oral spray containing compounds from cannabis, is the most studied cannabinoid treatment for MS spasticity. A meta-analysis of six randomized trials found it produced a meaningful reduction in patient-reported spasticity scores. In one of the larger trials included, participants rated their spasticity at about 6.8 out of 10 before treatment and 5.3 after 14 weeks of use.
An earlier large-scale trial of 630 patients found that about 60% of those receiving cannabis-based treatment reported improvement in spasticity, compared to 46% on placebo. That gap suggests a real effect, though a significant placebo response exists as well.
Nabiximols is approved for MS spasticity in many countries but not universally available. Where it is prescribed, it’s typically added when first-line oral medications haven’t provided adequate relief. Smoked cannabis has also shown spasticity reduction in smaller trials, but dosing is harder to control and the evidence base is thinner.
What About Magnesium?
Magnesium supplements are widely recommended online for muscle cramps, but the evidence doesn’t support this for MS-related spasms. A Cochrane Review found that magnesium supplementation, at doses ranging from 100 to 520 mg daily, made little or no difference in cramp frequency, intensity, or duration compared to placebo. The review rated this finding as moderate to high certainty. Because MS spasms are neurologically driven rather than caused by electrolyte imbalance, this isn’t surprising. If you’re already taking magnesium, it’s unlikely to cause harm at standard doses, but it’s also unlikely to meaningfully reduce your spasms.
Intrathecal Baclofen Pumps for Severe Spasticity
For people with severe, widespread spasticity that doesn’t respond adequately to oral medications, a surgically implanted baclofen pump delivers medication directly into the fluid surrounding the spinal cord. This bypasses the blood-brain barrier problem that limits oral baclofen’s effectiveness, allowing much smaller doses to have a much larger effect with fewer systemic side effects like drowsiness.
You won’t be offered a pump as a first step. Candidates are typically people who have tried oral medications for at least six weeks without adequate relief, or who can’t tolerate the side effects of oral drugs at the doses needed to control their spasticity. Before implantation, you’ll receive a test dose of baclofen injected into your spinal fluid via lumbar puncture. If your spasticity scores drop by at least two points on a standard scale for four to eight hours, that confirms you’re likely to benefit from the pump. If there’s no response to the test dose, implantation isn’t recommended.
The pump itself is a small disc-shaped device implanted under the skin of your abdomen, connected to a thin catheter threaded into your spinal canal. It requires periodic refills, typically every few months, and eventual battery replacement surgery. For people with advanced MS who spend most of the day in a wheelchair, this treatment carries a strong recommendation in clinical guidelines.
Building a Layered Approach
Managing MS spasms rarely comes down to a single solution. The most effective approach combines several strategies: eliminating triggers, stretching daily, using oral medication as a baseline, and adding targeted treatments like injections for problem areas. What works changes over time as MS progresses or stabilizes, so regular reassessment with a neurologist or rehabilitation specialist helps keep your plan matched to your current needs. Physical therapy, in particular, is recommended alongside nearly every other treatment, whether you’re managing mild stiffness with stretching alone or recovering function after a botulinum toxin injection.