SPASTICITY is one of the most common symptoms of multiple sclerosis (MS) that is seen in up to 75% of patients. It is a complex, poorly understood symptom that is often associated with muscle weakness. Often in MS, the lower limbs are more affected by spasticity than the arms. MS-related spasticity is usually the result of increased co-contraction of muscles during movement. Increased stiffness, or tone, can lead to decreased range of motion of major joints and result in shortening of connective tissue around the joints. This, in turn, can result in contractures. Fortunately, this common symptom responds to a variety of therapeutic approaches.
Clinical indications of spasticity are highly variable and may include:
* An increase in deep tendon reflexes
* Clonus, a repetitive rhythmic beating movement of a foot or wrist
* Difficulty initiating movements
* Impaired voluntary control of muscles
* Difficulty relaxing muscles once a movement has ceased
* Sensation of muscle tightness or pain
* Flexion or extension synergy patterns
* Decreased range of motion
These clinical signs and symptoms may be aggravated by fatigue, stress, urinary tract infections, infections of other origins, and pain. Additionally, spasticity may lead to increased fatigue due to the extra energy needed to overcome excessive muscle tone during voluntary movements involved in activities of daily living.
A thorough assessment includes consideration of function in addition to increased tone, since some spasticity can be beneficial. Totally eliminating spasticity is not always a goal; some individuals with muscle weakness use their tone to stand and transfer.
Consideration of how much spasticity is actually beneficial is important when determining pharmacologic treatment, and medications should be titrated accordingly.
Treatment of spasticity will vary from patient to patient, based on the wide spectrum of factors presented. Specific interventions are determined after performance abilities and limitations are clearly identified. Long-term rehabilitation for MS-related spasticity is essential and should be initiated as early as possible. The most effective management approach involves the use of a multidisciplinary team including the physician, nurse, and occupational and physical therapists.
Spasticity usually requires both pharmacological and non-pharmacologic interventions. Oral medications are often effective, especially in the early stages of the disease. Significant changes in spasticity may signal the need to review the patient’s medications. In exceptionally difficult cases, surgical intervention may be necessary, including tenotomy, neurectomy and rhizotomy.
Pharmacologic interventions include the following:
- Oral baclofen (Linosenil®) is often used as a first line drug for management of spasticity. Many patients get good to excellent reduction in tone with this medication. It is started at a low dose and slowly titrated up to minimize sedation and to identify the lowest effective dose. Patients and family members become adept at making minor dose adjustments to control changes in tone that occur secondary to infection, stress, and other causes previously discussed. Patients may experience fatigue or weakness as a side effect. Tizanidine (Zanaflex®), which can also be sedating, is an effective anti-spasticity medication that may be used alone or in combination with baclofen. Dantrolene sodium (Dantrium®), which works at the muscle level and may cause liver toxicity, may also be considered.
- Other oral drugs used off label include diazepam (Valium®), which is very sedating at therapeutic levels, and may be habit-forming; clonazepam (Klonopin®), which is a benzodiazepine used in multiple sclerosis primarily for the treatment of tremor, pain, and spasticity; and gabapentin (Neurontin®), an anti-epileptic medication that has had some success in management of spasticity.
- For more severe spasticity, phenol nerve block injections are often effective for up to six months and are especially useful for conditions such as severe adductor (inner thigh) spasm. More recently, botulinum toxin (Botox®) injections have been used successfully for small muscle groups.
- Implantation of a pump to deliver Intrathecal Baclofen™ may be helpful for patients who do not respond well to oral medication or cannot tolerate the side effects at the required dosage level. It is also an option for individuals wanting to avoid ongoing nerve injections. Very small amounts of baclofen are required for symptom relief, avoiding the side effects of systemic administration. Problems with the pump include pump failure, infection, and lead displacement.