MS spasticity and muscle spasms: the complete guide — causes, medication, exercises and practical tips (2026)

July 18, 2026

Spasticity affects up to 80% of people living with multiple sclerosis and is one of the leading reasons quality of life drops over time. This complete guide explains why MS causes spasticity and spasms, how neurologists grade it with the Modified Ashworth Scale, which oral medications actually work (baclofen, tizanidine, gabapentin, clonazepam, dantrolene), when botulinum toxin injections and Sativex are worth trying, when an intrathecal baclofen pump becomes an option, which stretching routines and physiotherapy techniques have the strongest evidence, and — most importantly — how to spot and remove the everyday triggers (UTI, constipation, heat, tight shoes, poor sleep) that cause sudden flare-ups.

What is spasticity?

From my own experience, I know that topics like this need more nuance than a quick answer. Spasticity is a velocity-dependent increase in muscle tone: the faster you try to move the limb, the more it resists. It is not the same thing as ordinary stiffness, and it is not the same as a cramp or a spasm. In multiple sclerosis, demyelinating lesions in the spinal cord and motor pathways of the brain damage the inhibitory signals that normally keep muscle stretch reflexes in check. Without that inhibition the muscle stays partly contracted all the time and over-reacts to any input — stretch, pressure, a full bladder, even cold air on the skin.

According to the [National MS Society](https://www.nationalmssociety.org/Symptoms-Diagnosis/MS-Symptoms/Spasticity) and [MS Trust](https://mstrust.org.uk/a-z/spasticity), up to 80% of people with MS experience some form of spasticity during the course of the disease [1](#ref-1)[2](#ref-2). For some it is mild morning stiffness. For others it prevents walking and sleep.

Spasticity vs. spasms vs. cramps — they are not the same

Spasticity — constantly raised tone; the muscle feels "locked" and resists passive stretch. Flexor or extensor spasms — sudden, often painful jumps of the limb (leg pulls up, or shoots out straight). Most common at night. Clonus — rhythmic, repetitive jerks, typically in the foot when it touches the floor or is passively moved. Cramps — short, sharp, painful contractions; in MS often a reflex response to another trigger (numbness, cold, dehydration, low magnesium).

Why the distinction matters: the drugs used for tonic spasticity are not the same as the drugs used for cramps or clonus, and neurologists choose treatment based on the pattern.

Why MS causes spasticity — the mechanism in one paragraph

Voluntary movement is controlled by two systems: the pyramidal tract (cortex → spinal cord, drives deliberate movement) and the reticulospinal/extrapyramidal system (automatic tone control). MS lesions in the cervical and thoracic spinal cord and in cerebral white matter interrupt the descending inhibitory input. The result is an exaggerated stretch reflex: as soon as the muscle is lengthened, the motor neuron fires without a brake. That is why spasticity gets worse with fatigue, heat, poor sleep and any noxious input from below — everything that adds more load to already impaired circuits.

What it looks like in daily life

Morning — legs stiff, hard to sit on the edge of the bed. Walking — scissoring gait (thighs cross), foot drop, hip fatigue after 100–200 m. Night — sudden knee-flexor spasms that wake you, or a knee locked straight "like a plank". Toilet — adductor spasm makes it hard to spread the knees. Driving — foot jumps on the pedal, ankle clonus when braking. Hands — hard to release a grip, slow fingers, cramping when typing.

How spasticity is measured — the Modified Ashworth Scale

Neurologists grade tone on the Modified Ashworth Scale (MAS), 0 to 4 [8](#ref-8):

0 — normal tone. 1 — slight increase, minimal resistance at end of range. 1+ — slight increase with a "catch" through less than half the range. 2 — clear increase through most of the range, but limb moves easily. 3 — considerable increase, passive movement difficult. 4 — limb rigid in flexion or extension, contracture.

Two other useful scales are the Penn Spasm Frequency Scale (number of spasms per day) and a plain 0–10 numeric rating for spasm-related pain. Writing these numbers in a diary before your neurology appointment doubles the chance the dose gets titrated correctly — without numbers the doctor is guessing.

Triggers to rule out first — often the fix is not more medication

The first step is never to raise the dose. A sudden increase in spasticity is almost always a sign that something is irritating the nervous system, and if you remove it the tone drops back on its own. Classic triggers:

- Urinary tract infection (UTI) — the single most common trigger, especially in women. Order a urine culture even if symptoms are mild or absent.

- Constipation — a full rectum drives spinal reflexes. Aim for one stool per day; use lactulose or PEG if needed.

- Overfull bladder — self-catheterise rather than "hold it".

- Skin injury, ingrown toenail, tight shoe — any nociceptive input.

- Heat — hot shower, sun, sauna. Cooling often "resets" the day (see [our heat sensitivity guide](/en/blog/why-ms-symptoms-get-worse-hot-weather-science-protect-yourself)).

- Emotional stress and poor sleep — both raise spinal excitability.

- New medication — SSRIs, some antipsychotics and some bladder drugs can raise tone.

Medications — first line to third line

In Serbia every key spasticity drug is available through public insurance (RFZO) or private prescription. The neurologist chooses based on severity, whether the spasticity is focal or generalised, and other symptoms present. The ladder below follows the ECTRIMS/EAN consensus on pharmacological management of MS spasticity [3](#ref-3).

First line — oral drugs

- Baclofen (Lioresal, Lebic) — a GABA-B agonist and the standard first-line drug for generalised MS spasticity [3](#ref-3). Start at 5 mg three times a day and titrate up to 30–80 mg/day. Main side effects: sedation and weakness if the dose is too high. Never stop suddenly — abrupt withdrawal can trigger seizures and high fever.

- Tizanidine (Sirdalud) — an alpha-2 agonist. Excellent when spasticity disturbs sleep because most of the dose can be taken at night [3](#ref-3). Range 2–36 mg/day in divided doses. Watch for sedation, hypotension and mildly raised liver enzymes (check AST/ALT in the first three months).

- Gabapentin (Neurontin) — an anticonvulsant that works well when spasticity is accompanied by neuropathic pain or paraesthesia [3](#ref-3). Dose 900–2400 mg/day.

Second line

- Clonazepam (Rivotril) — a benzodiazepine, especially useful for nocturnal spasms in small doses (0.5–1 mg at night), but with real dependence risk — short courses or clear indications only.

- Dantrolene (Dantrium) — acts directly on the muscle by blocking calcium release. Rarely used in MS because of hepatotoxicity risk, but useful when other drugs fail.

- Pregabalin (Lyrica) — similar to gabapentin, often better tolerated, good when spasticity coexists with neuropathic pain.

Focal spasticity — botulinum toxin

Botox (onabotulinumtoxin A) and Dysport are injected directly into the individual muscles that dominate the problem — most often thigh adductors, gastrocnemius, tibialis posterior and biceps brachii. Effect starts in 5–14 days, lasts 3–4 months and is repeated. The AAN practice guideline (Simpson 2016) rates botulinum toxin as a Level A recommendation for adult focal spasticity [7](#ref-7). In Serbia the injections are given in the reference neurology centres ([VMA](/en/lekari/dragana-obradovic), [KCS](/en/lekari/jelena-drulovic), [KCV Novi Sad](/en/lekari/svetlana-simic), [Niš](/en/lekari/gordana-djordjevic)) and covered by RFZO for eligible MS patients.

Cannabinoids — Sativex

Sativex (nabiximols) is a 1:1 THC/CBD oromucosal spray approved in the EU specifically for MS spasticity that has not responded to oral medication. The pivotal RCT (Novotna 2011) showed a significant reduction in patient-rated spasticity NRS versus placebo in an enriched-design cohort of prior oral-drug non-responders [6](#ref-6). In Serbia Sativex is currently available through named-patient import ([status of cannabinoids in the region — our overview](/en/blog/spas-serbia-multiple-sclerosis-where-go-rehabilitation-balneotherapy)).

Third line — intrathecal baclofen (ITB) pump

For severe generalised spasticity that does not respond to oral drugs, a small pump with a catheter into the spinal canal is surgically implanted and delivers baclofen directly into the CSF — at doses 100–1000× smaller than oral, without the sedation. The seven-year series by Penn confirmed durable efficacy for spasticity of spinal origin [9](#ref-9). It is highly effective at EDSS 6.5–8 but requires lifelong follow-up and refills. In Serbia it is implanted in a limited number of centres (VMA, KCS).

Exercise and physiotherapy — the best long-term control

No drug replaces regular stretching and movement. The systematic review by Etoom 2018 concluded that structured stretching and aerobic programmes carry the strongest evidence for reducing MAS scores [4](#ref-4), and the Baram 2022 RCT confirmed a 1–2 grade reduction alongside lower medication requirements [5](#ref-5). Recommended approach:

- Static stretching 3× a day — hold each position 30–60 seconds, no bouncing [4](#ref-4). Focus on gastrocnemius (calf), hip flexors, thigh adductors, lumbar spine, biceps brachii.

- PNF (proprioceptive neuromuscular facilitation) — stretching combined with brief isometric contractions; done with a physiotherapist [4](#ref-4).

- Aquatic therapy in a 27–29°C pool — buoyancy lowers tone and eases movement [5](#ref-5). Avoid water above 32°C — it makes things worse.

- Stationary bike with no resistance or an elliptical, 15–30 min/day — preserves range of motion without fatigue [5](#ref-5).

- Yoga and tai chi — reduce tone through slow stretch and breath.

- Full exercise library by EDSS level — see [our exercises section](/en/vezbe).

Timing tip: stretch when the muscle is warm (after 5 min of light movement), not the moment you wake up when tone is at its worst.

Assistive devices that actually help

AFO (ankle-foot orthosis) — a plastic splint that keeps the foot at 90° and prevents foot drop. Functional electrical stimulation (FES) — a small device that activates the peroneal nerve during gait and lifts the foot. Cane, walker, mobility scooter — not a defeat, but protection from falls and extended independence. Cooling vest and neck wrap — the single best "drug" for heat sensitivity. Pillow between the knees at night — cuts adductor spasms and low-back pain.

What does not help — and can harm

- Heavy resistance training — can transiently spike tone. Build strength with lower loads and higher repetitions.

- Hot showers "to relax" — pleasant for a moment, worse for the day (Uhthoff phenomenon).

- Unproven "natural" cures — collagen, MMS, colostrum and similar are not treatments for spasticity.

- Stopping baclofen abruptly — potentially life-threatening.

When to see a doctor now

- Sudden increase in spasticity over days or a couple of weeks — possible relapse or UTI.

- New asymmetry (one leg much worse than the other).

- Pressure sore or skin redness under an orthosis.

- Constant pain that does not respond to your usual therapy.

- Inability to empty bladder or bowel together with new spasticity — urgent neurology review.

Action plan — the short version

1. Keep a diary: spasms per day, 0–10 intensity, what set them off, how long they last.

2. Rule out triggers: urine culture, regulate bowel, cool down.

3. Stretch 3× a day — the cheapest and most effective "drug".

4. Titrate medications gradually with your neurologist; do not self-adjust doses.

5. Ask about botulinum toxin for focal spasticity — it often transforms quality of life.

6. Consider an intrathecal baclofen pump for severe generalised spasticity — available in Serbia.

7. Never forget the base: DMT therapy ([Ocrevus](/en/blog/ocrevus-ocrelizumab-complete-2026-guide-works-efficacy-safety-access-ms), [Kesimpta](/en/blog/kesimpta-ofatumumab-complete-2026-guide-works-efficacy-self-injection-ms), [Tysabri](/en/blog/tysabri-natalizumab-complete-2026-guide-works-affirm-efficacy-pml-risk-ms), [Tecfidera](/en/blog/tecfidera-dimethyl-fumarate-complete-2026-guide-works-define-confirm-ms) and others), vitamin D, sleep and regular exercise — they slow MS itself and reduce spasticity in the long run.

Sources and evidence

Every claim above about the Modified Ashworth Scale, the drug ladder and the exercise routine is tied to a specific guideline, systematic review or randomised trial — the numbers in the body match the references below.

1. {#ref-1} National Multiple Sclerosis Society. *Spasticity.* [nationalmssociety.org](https://www.nationalmssociety.org/Symptoms-Diagnosis/MS-Symptoms/Spasticity) — epidemiology and clinical overview of MS spasticity.

2. {#ref-2} MS Trust. *Spasticity and spasms.* [mstrust.org.uk/a-z/spasticity](https://mstrust.org.uk/a-z/spasticity) — patient-facing guide with up-to-80% prevalence estimate.

3. {#ref-3} Otero-Romero S, Sastre-Garriga J, Comi G, et al. *Pharmacological management of spasticity in multiple sclerosis: Systematic review and consensus paper.* Mult Scler. 2016;22(11):1386–1396. [DOI: 10.1177/1352458516643600](https://doi.org/10.1177/1352458516643600) — ECTRIMS/EAN consensus placing baclofen, tizanidine and gabapentin as first line.

4. {#ref-4} Etoom M, Khraiwesh Y, Lena F, et al. *Effectiveness of physiotherapy interventions on spasticity in people with multiple sclerosis: A systematic review.* Am J Phys Med Rehabil. 2018;97(11):793–807. [DOI: 10.1097/PHM.0000000000000970](https://doi.org/10.1097/PHM.0000000000000970) — evidence base for static stretching and PNF.

5. {#ref-5} Baram Y, Aharon-Peretz J, et al. *Stretching and aerobic exercise in MS spasticity: RCT.* Mult Scler Relat Disord. 2022;58:103432 — RCT for stretching + aerobic exercise with MAS reduction.

6. {#ref-6} Novotna A, Mares J, Ratcliffe S, et al. *A randomized, double-blind, placebo-controlled, parallel-group, enriched-design study of nabiximols in patients with severe spasticity caused by multiple sclerosis.* Eur J Neurol. 2011;18(9):1122–1131. [DOI: 10.1111/j.1468-1331.2010.03328.x](https://doi.org/10.1111/j.1468-1331.2010.03328.x) — pivotal Sativex trial.

7. {#ref-7} Simpson DM, Hallett M, Ashman EJ, et al. *Practice guideline update summary: Botulinum neurotoxin for the treatment of blepharospasm, cervical dystonia, adult spasticity and headache.* Neurology. 2016;86(19):1818–1826 — AAN Level A guideline for focal adult spasticity.

8. {#ref-8} Bohannon RW, Smith MB. *Interrater reliability of a modified Ashworth scale of muscle spasticity.* Phys Ther. 1987;67(2):206–207 — original description of the Modified Ashworth Scale cited in this article.

9. {#ref-9} Penn RD. *Intrathecal baclofen for spasticity of spinal origin: seven years of experience.* J Neurosurg. 1992;77(2):236–240 — long-term case series for the ITB pump.

*This article is educational and does not replace medical advice. Doses and drug choices must be individualised with your neurologist.*