Many people with multiple sclerosis (MS) have problems with spasticity (spastic, immobile muscles), particularly in the lower limbs.
Spasticity might be experienced as sustained muscle stiffness caused by increased muscle tone, or as muscle spasms that come and go. Muscle spasms are most likely to occur at night.
MS-related spasticity is usually treated with muscle relaxants and tranquilizers, such as Baclofen (Lioresal), tizanidine (Zanaflex®), diazepam (Valium®), clonazepam (Klonopin®), or dantrolene (Dantrium®).
In severe cases, baclofen may be injected into the spinal cord. This approach is called "intrathecal baclofen" or ITB.
Botulinum toxin (Botox®) for the treatment of spasticity has recently become available and has been used for people with spinal cord injury and cerebral palsy. The benefits last only a few months, so repeat botulinum toxin treatments are required, but it is relatively safe.
Although its benefits are usually temporary, physical therapy (PT) may be useful and can help prevent the irreversible shortening of muscles known as contractures. Surgery to reduce spasticity is rarely appropriate for people with multiple sclerosis.
Reference: The National Institute of Neurological Disorders and Stroke (NINDS)