Spasticity Treatment & Management

Updated: Feb 04, 2016
  • Author: Zeba F Vanek, MD, MBBS, DCN; Chief Editor: Stephen A Berman, MD, PhD, MBA  more...
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Treatment

Approach Considerations

A variety of strategies are available for the management of spasticity. The treatment of children with spasticity has been the subject of innumerable publications, most of them surprisingly uncritical and devoid of controls. A vital preliminary consideration is the indication and expectations for treatment. In a patient who can walk, for example, a reduction of leg muscle tone may worsen mobility if tone compensates for leg weakness, allowing the patient to stand. Manual dexterity and strength also do not improve by reducing muscle tone, which means that treatment of spasticity may not lead to an improvement in function.

Therefore, clearly identifying the goals of the patient and caregiver is vital. Tizard proposed that before treatment is initiated, the following should be considered [13] :

  • Does the patient need treatment?
  • What are the aims of treatment?
  • Do the patient and caregivers have the time required for treatment?
  • Will treatment disrupt the life of the patient and caregivers?

Specific functional objectives in the management of spasticity include strategies aimed at improving gait, hygiene, activities of daily living (ADLs), pain, and ease of care; decreasing the frequency of spasm and related discomfort; and eliminating noxious stimuli.

The ability of muscles to function after spasticity reduction varies. Treating spasticity does not always facilitate the acquisition of previously undeveloped skills.

Agonist versus antagonist muscle groups

When deciding to treat a spastic muscle, it is important to assess the impact of its antagonistic muscle groups. While often weak, these muscle groups themselves may be spastic. Treatment of the agonist muscle without treatment of the antagonist muscle may create an additional problem instead of a solution. Additionally, careful assessment of the role spasticity plays in substituting for strength (specifically, to facilitate with transfers) is important to avoid decreasing, rather than increasing, function.

Types of therapy

Interventions for spasticity vary from conservative (therapy and splinting) to more aggressive (surgery); most often, a variety of treatments are used at the same time or are employed interchangeably. Treatment options do not need to be used in a stepladder approach and indeed should not be. Current spasticity management options include the following:

  • Preventative measures
  • Therapeutic interventions (physical therapy, occupational therapy, hippotherapy, aquatics) and physical modalities (ultrasonography, electrical stimulation, biofeedback) [3, 4]
  • Positioning/orthotics: Including taping, dynamic and static splints, wheelchairs, and standers
  • Oral medications: Such as baclofen and dantrolene [5] }
  • Injectable neurolytic medications: Botulinum toxins and phenol
  • Surgical intervention

Surgery can play a very important role in the treatment of chronic spasticity. In most cases, complementary neurosurgical and functional orthopedic approaches are used. Children with spasticity represent a different challenge because their spasticity may change as they grow and develop so that, at times, surgery may be undertaken to allow more normal bone and muscle growth. While each surgical approach has certain strengths and weaknesses, none of them completely eliminate spasticity.

Considerations that impact treatment

These include the following:

  • Duration of spasticity and likely duration of therapy
  • Severity of spasticity
  • Location of spasticity
  • Success of prior interventions
  • Current functional status and future goals
  • Underlying diagnosis and comorbidities
  • Ability to comply with treatment and therapy
  • Availability of support/caregivers and follow-up therapy
Next:

Pharmacologic Therapy

The use of oral medications for the treatment of spasticity may be very effective. At high dosages, however, oral medications can cause unwanted adverse effects, including sedation and changes in mood and cognition. These adverse effects preclude their extensive use in children, since the intellectual function of the majority of children with spasticity is at best precarious, and sedation inevitably results in some degree of impaired learning or school performance.

Common oral medications include the following:

  • Diazepam (Valium)
  • Baclofen (Lioresal) [5]
  • Dantrolene (Dantrium)
  • Tizanidine (Zanaflex)
  • Clonidine (Catapres) [5]

Benzodiazepines (diazepam and clonazepam)

The benzodiazepines bind in the brainstem and at the spinal cord level and increase the affinity of gamma-aminobutyric acid (GABA) for the GABA-A receptor complex. This results in an increase in presynaptic inhibition and then reduction of monosynaptic and polysynaptic reflexes. These drugs may improve passive range of motion and reduce hyperreflexia, painful spasms, and anxiety.

Diazepam has a half-life of 20-80 hours and forms active metabolites that prolong its effectiveness. The half-life of clonazepam ranges from 18-28 hours.

Benzodiazepines should be started at low dosages and increased slowly. In adults, diazepam can be started at 5 mg at bedtime, and if daytime therapy is indicated, the dosage can be increased slowly to 60 mg/day in divided doses. Clonazepam can be started at 0.5 mg at night and slowly increased to a maximum of 20 mg/day in 3 divided doses.

Sedation, weakness, hypotension, adverse gastrointestinal effects, memory impairment, incoordination, confusion, depression, and ataxia may occur. Tolerance and dependency can occur, and withdrawal phenomena, notably seizures, have been associated with abrupt cessation of therapy. Patients who are taking benzodiazepines with agents that potentiate sedation and have central depressant properties (eg, baclofen or tizanidine) should be monitored carefully.

Baclofen

Baclofen is a GABA agonist, and its primary site of action is the spinal cord, where it reduces the release of excitatory neurotransmitters and substance P by binding to the GABA-B receptor. Studies show that baclofen improves clonus, flexor spasm frequency, and joint range of motion, resulting in improved functional status.

Baclofen may be given orally or by intrathecal pump. An analysis by Rizzo et al of a database of 17,501 patients with multiple sclerosis found that the use of oral medication was proportional to the severity of spasticity, with 78% of patients who were severely affected using at least 1 drug and 46% using at least 2. [9] Baclofen was the most commonly used agent, followed by gabapentin, tizanidine, and diazepam. Comparison of 198 patients who used intrathecal baclofen (ITB) and 315 who used oral medications showed that those who used ITB had lower levels of spasticity, less leg stiffness, less pain, and fewer spasms.

The oral dose of baclofen used to treat spasticity ranges from 30-100 mg/day in divided amounts. Tolerance may develop, and the drug must be tapered slowly to prevent withdrawal effects such as seizures, hallucinations, and increased spasticity. Baclofen must be used with care in patients with renal insufficiency, as its clearance is primarily renal. Adverse effects include sedation, ataxia, weakness, and fatigue. When used in combination with tizanidine or benzodiazepines, the patient should be monitored for unwanted depressant effects. [14]

Adverse effects of baclofen can be minimized by intrathecal infusion of the drug, because the concentration gradient favors higher levels at the spinal cord versus the brain. Intrathecal baclofen is approved in the United States for the treatment of spasticity of spinal or cerebral origin.

In children, intrathecal baclofen is particularly effective for the treatment of spasticity of the lower extremities in a selected group of patients who have responded favorably to a trial intrathecal dose. Complications of the procedure are relatively few and usually are limited to mechanical failures of the pump or the catheter. Adverse drug effects are usually temporary and can be managed by reducing the rate of infusion.

Dantrolene sodium

Dantrolene sodium is useful for spasticity of supraspinal origin, particularly in patients with cerebral palsy or traumatic brain injury (TBI); it acts by decreasing muscle tone, clonus, and muscle spasm. The drug acts at the level of the muscle fiber, reducing muscle contraction by affecting the release of calcium from the sarcoplasmic reticulum of skeletal muscle. It is, therefore, less likely than the other agents to cause adverse cognitive effects. Its peak effect is at 4-6 hours, with a half-life of 6-9 hours. The dose range is 25-400 mg/day in divided doses (in children, the dose range 0.5-3.0 mg/kg/day).

Adverse effects include drowsiness, dizziness, fatigue, diarrhea, and generalized weakness, including weakness of the respiratory muscles. Hepatotoxicity occurs in less than 1% of patients; elevation in liver function test results is seen particularly in adolescents and women who have been treated for more than 60 days and at dosages of greater than 300 mg/day.

Dantrolene should not be used with other agents known to cause hepatotoxicity, including tizanidine. If no benefit is seen after 4-6 weeks of treatment at maximal therapeutic doses, the medication should be discontinued. [15]

Tizanidine

Data from approximately 50 clinical trials indicate that tizanidine (Zanaflex) is effective for the management of spasticity due to cerebral or spinal damage. Tizanidine is an imidazoline derivative and a central alpha2-noradrenergic agonist.

The antispasticity effects of tizanidine are the probable result of inhibition of the H-reflex. The drug also may facilitate inhibitory actions of glycine and reduce release of excitatory amino acids and substance P; it may have analgesic effects as well. While spasms and clonus are reduced in patients using tizanidine, the Ashworth Scale does not reveal significant differences from placebo groups. In the long term, however, tizanidine does improve spasms and clonus.

Patients report less muscle weakness from tizanidine than from baclofen or diazepam. In placebo-controlled studies, the efficacy of tizanidine in reducing muscle tone is comparable to that of baclofen and better than that of diazepam. When combined with baclofen, tizanidine presents the opportunity to maximize therapeutic effects and minimize adverse effects by reducing the dosages of both drugs.

If tizanidine is prescribed in conjunction with baclofen or benzodiazepines, the patient should be advised of possible potential additive effects, including sedation. In addition, when tizanidine is prescribed with benzodiazepines, liver enzymes should be monitored closely, since the combination increases the likelihood of liver toxicity.

Tizanidine is a short-acting drug with extensive first-pass hepatic metabolism to inactive compounds following an oral dose. The half-life is 2.5 hours, with peak plasma level at 1-2 hours, and therapeutic and side effects dissipate within 3-6 hours. Therefore, use must be directed to those activities and times when relief of spasticity is most important and titrated to avoid intolerance.

Tizanidine should be started at a low dose, 2-4 mg, preferably at bedtime. It should be titrated carefully to each patient, with the dosage increased slowly and gradually. The average maintenance dosage of tizanidine is 18-24 mg/day, with the maximum recommended dosage being 36 mg/day. Patients with impaired kidney function also require gradual titration, since they show a 2-fold increase in plasma concentration.

Dry mouth, somnolence, asthenia, and dizziness are the most common adverse events associated with tizanidine. Liver function problems (5%), orthostasis, and hallucinations (3%) are rare tizanidine-related adverse events.

Clonidine

Clonidine has shown efficacy for spasticity in open-label studies. It is a selective alpha2-receptor agonist and may inhibit presynaptic sensory afferents. Hypotension is the main adverse effect.

Other oral agents

Additional agents that may be beneficial in selected patients include the following:

  • Gabapentin: A GABA analogue that modulates enzymes that metabolize glutamate; it may be useful in some patients with spasticity, but sedation can be a bothersome adverse effect
  • Lamotrigine: Blocks sodium channels and reduces the release of glutamate and other excitatory amino acids
  • Cyproheptadine: A 5-HT antagonist that may neutralize serotonergic inputs; it is beneficial in some patients
  • Cannabinoid-like compounds (dronabinol, nabilone): Act on the cannabinoid receptors (CB1 and CB2); may be useful in muscle spasms and spasticity
  • Standardized oromucosal whole-plant cannabis-based medicine (CBM): Contains delta-9 tetrahydrocannabinol (THC) and cannabidiol (CBD); may represent a useful agent for the relief of spasticity in multiple sclerosis (MS)

In a double-blind study performed over 6 weeks, in which 189 subjects with MS and spasticity received daily active preparation of standardized oromucosal whole-plant CBM (n=124) or placebo (n=65), the daily subject-recorded Numerical Rating Scale of spasticity showed the active preparation to be significantly superior. Secondary efficacy measures (Ashworth Score and a subjective measure of spasm) also were in favor of active preparation but did not achieve statistical significance. [16]

Another study, a meta-analysis, suggested that combined THC and CBD extracts may provide therapeutic benefit for spasticity in MS patients, although only subjective relief attained statistical significance. [17]

Neurolysis

Neurolysis with neurotoxins, chemodenervation, or local anesthetic (ie, injections of phenol, botulinum toxin, alcohol, or lidocaine) can offer significant benefits to the appropriately selected patient as part of a comprehensive spasticity management plan. Many clinicians use various combinations of treatments. The distribution of spasticity is vital in determining whether to use focal or global treatment and in deciding which measures should be used.

Phenol

Phenol is inexpensive, easily compounded, and has an immediate onset of action. It is injected, usually in a 5% concentration, near motor points in the affected muscle. A neurostimulator with a Teflon-coated needle electrode is used for guidance.

Gamma fibers are demyelinated for about 6 months, resulting in a less irritable, weakened muscle that can more easily be stretched.

Because 5% phenol injections do not cause permanent reduction in spasticity, a focus on obtaining functional improvements after injections is important.

Injections can be uncomfortable for some patients, and children may need to be sedated before injection. Possible adverse effects include pain and swelling at the site of injection. In a very small number of patients, dysesthesias may occur if injections are done near sensory-rich nerve branches.

If lengthening of a shortened muscle is desired, serial casting following injections may enhance effectiveness.

Intrathecal bolus injection of phenol

Jarret et al have reported that intrathecal bolus injection of phenol can reduce lower-limb spasticity. Twenty-five patients with advanced multiple sclerosis received 1.5-2.5 mL 5% phenol in glycerol at L2/3 or L2/4, and improvements were seen in the Ashworth score, spasm frequency, and pain, although the duration of the beneficial effect was not indicated. No serious adverse effects were reported. [18]

Botulinum toxin

A guideline from the American Academy of Neurology recommends offering botulinum toxin as a treatment option to reduce muscle tone and improve passive function in adults with spasticity (level A recommendation). It also recommends considering botulinum toxin injection to improve active function (level B). [19] (Collateral sprouting of the axon occurs in about 3 months, eliminating any permanent neurologic effect.)

Patients with focal spasms are candidates for focal treatment with botulinum toxin A (BoNT-A). Patients with segmental or nongeneralized spasticity may be candidates for systemic or intrathecal baclofen treatment, with BoNT-A added for focal symptom relief.

In 2009, the US Food and Drug Administration (FDA) required a boxed warning for all botulinum toxin products—types A and B—because of reports that the effects of the botulinum toxin may spread from the area of injection to other areas of the body, causing effects similar to those of botulism. These effects have included life-threatening, and sometimes fatal, swallowing and breathing difficulties. Most of the reports involved children with cerebral palsy being treated for spasticity. [20, 21, 22]

After botulinum injection, therapeutic interventions have multiple aims, including strengthening and facilitation, increasing range of motion, retraining of ambulation and gait, improving the fit and tolerance of orthoses, and improving functioning in activities of daily living (ADLs). Decreased spasticity and improvements in range of motion and strength have considerable implications for activities such as dressing, bathing, feeding, and grooming.

Combination therapy

Botulinum toxin and phenol may effectively be used together. [23] For instance, gait problems related to diplegic cerebral palsy may involve the hip adductors, knee flexors, and ankle plantar flexors.

Treatment of all muscle groups may not be possible with just 1 medication, because of dosage guidelines or adverse effects.

If phenol and botulinum toxin are used together, all muscle groups can be treated, leading to a more functional outcome.

Botulinum toxin type A

BoNT-A injections have been used as a safe and effective treatment for a variety of movement disorders, including muscle overactivity and spasticity. BoNT-A therapy is approved by the FDA for the treatment of cervical dystonia, primary axillary hyperhidrosis, strabismus, and blepharospasm in patients older than 12 years. The use of BoNT-A to treat spasticity in adults and children is therefore off-label. Controlled clinical trials of BoNT-A injections for focal muscle spasticity have demonstrated prolonged, yet reversible, clinical effects; few adverse effects; and minimal immunogenicity. [24, 25]

BoNT-A inhibits acetylcholine release at the neuromuscular junction. Once inside the cholinergic nerve terminal cell, BoNT-A inhibits the docking and fusion of acetylcholine vesicles at the presynaptic membrane. The effect of the toxin becomes evident within 12 hours to 7 days, and the duration of effect is usually 3-4 months but can be longer or shorter. Gradually, muscle function returns by the regeneration or sprouting of blocked nerves forming new neuromuscular junctions.

In pediatric patients, treatment should be initiated at a time when children still are developing their motor control apparatus. This may prevent them from entering a vicious cycle in which central nervous system (CNS) lesions affect the musculoskeletal system, thereby preventing the development of motor functions. In addition, experimental data on the formation of a cortical somatotopic map during early life indicate that the periphery plays an instructional role on the formation of central neuronal structures.

Proficiency in dosing and injecting BoNT-A demands the development of considerable skill. Each patient's treatment must be individualized, and appropriate patient selection is important. BoNT-A injections are most effective in relieving focal spasticity around a joint or series of joints.

Clinical data

The results of clinical trials strongly support the efficacy and safety of BoNT-A for the treatment of spasticity caused by cerebral palsy, MS, stroke, spinal cord injury, brain injury, or neurodegenerative disease. Major benefits of BoNT-A therapy for spasticity include improved function, increased ease of care and comfort, prevention or treatment of musculoskeletal complications such as contractures and pain, and cosmesis.

In a review of 18 open-label or double-blind, placebo-controlled trials by Simpson, botulinum toxin was shown to be an effective measure for reduction of focal spasticity. Improvements were documented in tone reduction, range of motion, hygiene, autonomic dysreflexia, gait pattern, positioning, and other criteria, though not all criteria tested showed improvement in all studies. Significant adverse effects were not reported in any of the studies. [26]

A systematic review of BoNT-A therapy in poststroke spasticity by Rosales et al found an odds ratio of 4.5 (95% confidence index 2.79-7.25) for an improvement of 1 or more points on the Modified Ashworth Scale at 4-6 weeks after BoNT-A treatment. [27]

Treatment objectives and effects

Even though BoNT-A is a focal treatment, untreated muscles may benefit from the disruption of the synergy patterns that often replace isolated muscle control. Increased range of motion, reduction in spasms, ease of caregiving, and reduced pain are primary goals leading to improved function and quality of life. Treatment begins with mutually agreed upon goals and expectations, a treatment plan that addresses all the clinical issues.

Generally, there is an inverse relationship between spasticity and voluntary motor control. Patients with severe spasticity often have less voluntary movement than patients with mild spasticity. Underlying motor control, strength, and coordination should be assessed to project the functional results of reducing spasticity. Since reduction of spasticity in patients with poor selective motor control may not provide mobility, treatment goals of improving positioning, caregiving, or comfort may be more appropriate.

Patients with cognitive deficits may not be able to take full advantage of their reduced spasticity; treatment aimed at easing their care or pain may be more beneficial. Patients with painful spasms or contracture often experience significant pain relief after treatment with BoNT-A.

In the upper limb, patterns of spasticity that may improve specifically from botulinum toxin include an adducted and internally rotated shoulder, flexed elbow, pronated forearm, flexed wrist, thumb-in-palm, and clenched fist. [28, 29] In the lower extremity, botulinum toxin injections may particularly improve spasticity causing flexed hip, flexed knee, adducted thighs, stiff (ie, extended) knee, equinovarus foot, and striatal toe. Outcomes should be evaluated by subjective and objective clinical measures, including rating scales and videotape recordings that clearly reflect defined goals and objectives.

In summary, common functional goals with neurolysis using the botulinum toxins (or phenol or alcohol) include improving gait, hygiene, and ADLs; easing pain and care; and decreasing spasm frequency. Technical objectives are to promote tone reduction and to improve range of motion and joint position. Once begun, treatment is evaluated constantly; follow-up is crucial to gauge the response and to fine-tune muscle selection and dose as necessary.

Dosages

BoNT-A dosing has to be individualized and is dependent upon muscles involved, prior response, and functional goals. Adverse effects are minimal; however, conditions requiring caution include patients who are hypersensitive to any ingredient in BoNT-A, those using aminoglycoside antibiotics, those with neuromuscular disease, and women who are pregnant or potentially lactating.

A consensus on the dosage has been recommended by the Spasticity Study Group. Examples of doses of BoNT-A in clinical trials for spasticity from MS, cerebral palsy, TBI, spinal cord injury (SCI), and stroke are as follows:

  • In MS, injection of 400 U of BoNT-A into the thigh adductors resulted in significant improvement in spasticity and hygiene compared with placebo [30]
  • In SCI, injection of 20-80 U of BoNT-A into the rhabdosphincter resulted in decreased urethral pressure and postvoid residual volume [31]
  • In adults suffering from cerebral palsy, injection of 1 U/kg of BoNT-A into the medial and lateral gastrocnemius of each leg resulted in an improvement in gait pattern compared with placebo [32]
  • For children with cerebral palsy, the American Academy of Neurology recommends offering injection of the calf muscles as a treatment option for equinus varus deformity (level A), but does not specify dosage [19]
  • In stroke, injections of 75-300 U of BoNT-A into the elbow and wrist flexors resulted in significant improvement in results of the Ashworth Scale compared with placebo [33]

Future trials of BoNT-A may be improved by attention to dose-effect response, dose escalation, broader randomization, and more uniform timing of injection in relation to the onset of neurologic deficit.

Injection strategies

BoNT-A is injected using a 23- to 27-gauge needle. Larger and superficial muscles are identified by palpation, while small or deep muscle groups are identified by electromyography (EMG) or electrical stimulation (ES). Ultrasonography, fluoroscopy, or computed tomography (CT) scanning also may be used. Local anesthetic cream, general anesthesia, or sedation may be necessary, particularly for some children.

Depending on the location and severity of spasticity, BoNT-A injections usually are needed at 3- to 6-month intervals to maintain therapeutic benefit. Reinjections should not be given any sooner than 3 months after the last injections to decrease the possibility of antibody formation.

A study by Molenaers et al of 577 patients with cerebral palsy, all of whom were younger than 24 years at the time of treatment, found that Goal Attainment Scale scores were higher for patients who received multilevel injections of BoNT-A or injections of the drug only in the distal muscle groups than they were for patients who received the injections only in the proximal muscles of the lower limb. [34]

Complementary treatments and additional medications

When used in the management of spasticity, treatment with BoNT-A is almost never used as monotherapy. Complementary therapies, such as physical and occupational therapy, frequently are utilized to maximize anticipated outcomes. These therapies usually are instituted or modified after injection. For example, in a controlled study in 20 children with upper limb spastic cerebral palsy, Kanellopoulos et al found that use of a static night splint after of BoNT-A injection resulted in significantly better results after 6 months. [27]

The above-mentioned study by Molenaers and colleagues found that, in addition to the injection strategy, factors in achieving a successful outcome in BoNT-A therapy included the following [34] :

  • Amount of physical therapy per week
  • Postinjection casting
  • Frequency with which day and night orthoses were used after injection

Treatment with BoNT-A can be combined with various oral medications, the baclofen pump, and sometimes with phenol or alcohol neurolysis. The primary reason for combining BoNT-A with phenol or alcohol neurolysis would be to avoid loss of responsiveness by remaining under the maximum dose per visit.

The decision to combine therapies usually depends on the location and number of target muscles involved. If both lower and upper extremities are to be injected, the combination of BoNT-A and phenol may be warranted. Although using phenol or alcohol neurolysis is associated with certain difficulties, they provide inexpensive, long-term chemodenervation for some patients, mainly adults.

Antibody formation

Resistance to BoNT-A is characterized by absence of any beneficial effect and by lack of muscle atrophy following the injection. Antibodies against the toxin are presumed to be responsible for most cases of resistance. Resistance has been reported to occur in 3-10% of people.

Repeated, high-dose injections are far more likely to result in antibody formation than are less frequently repeated, low-dose injections. The smallest amount of BoNT-A necessary to achieve therapeutic benefit should be used, the interval between treatments should be extended for as long as possible, and booster injections should be avoided. When the amount injected totals the maximum of 400 U, further injections should not be given before 3 months after the last treatment.

Several types of assays are available to detect the presence of antibody in serum. The most widely used is the in vivo mouse neutralization assay. Injecting 10-20 U into 1 corrugator/frontalis muscle and testing for the ability to elevate 1 eyebrow and frown 2-3 weeks later is a simple clinical way to check for resistance. Checking for a marked decrease in compound motor action potential (CMAP) amplitude in an injected muscle may be helpful. This would indicate that resistance has not developed and that the dose or injection site may have been suboptimal.

A number of studies have confirmed that patients with BoNT-A resistance may benefit from injections with other serotypes such as botulinum toxin type B (BoNT-B). BoNT-B, which is now available commercially, and other serotypes, when they become available, may offer hope to patients with resistance to BoNT-A.

Botulinum toxin type B

Schwerin et al reported the following results of a pilot study in which 29 children with spasticity underwent 62 treatment sessions with BoNT-B:

  • Motor function improvement goals were attained or surpassed in 28 of 46 sessions and partially attained in 12
  • Care, hygiene, or orthotic management goals were attained in 5 of 12 sessions and partially attained in 6
  • Correction of limb position goals were attained in 3 of 4 sessions
  • Of 17 BoNT-A nonresponders, 11 attained therapy goals with BoNT-B

Side effects included dry mouth (9.7% of sessions), diarrhea (6.5%), and swallowing difficulties (6.5%). Systemic side effects were more likely when the dose surpassed 400 U/kg. The authors recommended a starting dose of BoNT-B not to exceed 400 U/kg for children up to 25 kg and a total dose for older children and adults of not more than 10,000 U. [35]

Intrathecal Baclofen

Lack of substantial therapeutic benefit from oral baclofen, a mainstay of drug therapy, can result from an inadequate penetration of the blood-brain barrier by the drug. Since unacceptable CNS effects often occur when high doses of baclofen are taken orally, the therapeutic effect usually cannot be improved by increasing the dose. Sedation, somnolence, ataxia, and respiratory and cardiovascular depression are the drug's CNS depressant properties.

ITB therapy consists of long-term delivery of baclofen to the intrathecal space. This treatment can be helpful for patients with severe spasticity affecting the lower extremities, particularly those patients whose conditions are not sufficiently relieved by oral baclofen and other oral medications. [36, 37]

ITB can be used to treat severe spasticity from various causes. Benefits of ITB typically include reduced tone, spasms, and pain, and increased mobility. Other benefits may include improved sleep quality, bladder control, self care, and self-image. It also may allow patients to decrease and often discontinue other spasticity medications.

ITB should be considered in patients who have disabling spasticity unresponsive to conservative pharmacotherapy or in whom therapeutic doses induce intolerable side effects. Pharmacotherapy should include, but need not be limited to, a trial of oral baclofen. The Ashworth Scale and Spasm Frequency Scale appear to be clinically useful measures of spasticity; a severity of 3 on the Ashworth and 2 on the Spasm Frequency for at least 12 months are considered reasonable criteria for ITB therapy consideration.

In a study of the long-term effects (>5 y) of ITB on impairment, disability, and quality of life in patients with severe spasticity of spinal origin, Zahavi et al found that the most prominent improvements reported by the patients were increased ease of transfer, better seating posture, ease of care in ADLs (passive), and decrease in pain. [38]

Of 21 patients treated in the study, 11 had MS, 6 had SCI, and the rest had a variety of nonprogressive spinal disorders. The mean length of treatment was 6.5 years. Significant sustained improvement was seen for spasticity and spasm score. The Expanded Disability Status Scale score worsened, as did the ambulation index and overall incapacity status scale score. No significant changes were seen on the Sickness Impact Profile or the Hopkins Symptom Checklist. No significant differences were found for any measure between patients with MS and those with static spinal disorders.

The most common complications were muscle weakness, somnolence, catheter malfunction, and surgery complications. The authors reported that all patients but 2 were satisfied with their treatment and would undergo treatment again.

A review of ITB therapy in 174 children with cerebral palsy by Borowski et al found that ITB therapy is safe and effective for severe spasticity in this population, and that patients and caregivers find it highly satisfactory, but that the technique does have a 31% rate of complications requiring surgical management over a 3-year treatment period. [39]

Treatment goals

As some degree of muscle tone may be required to assist in the support of circulatory function, prevent deep vein thrombosis, and optimize ADLs and ease of care, optimizing the change of tone with ITB requires striking a balance between the patient's condition, functional goals, and physiologic demands.

Since ITB may be appropriate for a broad range of disabilities, from ambulatory to vegetative states, treatment and functional goals must be individualized, clearly understood, and agreed upon by the patient, family, caregivers, and care-provider team before treatment begins. Thus, appropriately chosen patients with clearly defined and realistic treatment objectives benefit the most from this form of treatment.

Intrathecal pump technology

ITB (SynchroMed Infusion System) provides direct, pattern-controlled delivery of baclofen to its target via an implanted, programmable pump. This precise delivery yields better spasticity reduction at lower doses; doses 100 times the intrathecal dose are needed to produce similar benefits if baclofen is taken orally. Thus, adverse effects associated with high dosages of oral baclofen are minimized.

The pump is a small titanium disk that is about 3 inches in diameter and 1 inch thick. It contains a refillable reservoir for the liquid baclofen as well as a computer chip that regulates the battery-operated pump. A telemetric wand programs the dose of baclofen to be received. A flexible silicone catheter serves as the pathway through which the baclofen flows to the intrathecal space. To prevent accidental depletion of baclofen, the pump contains a programmable alarm that sounds when the reservoir needs to be refilled, the battery is low, or the pump is not delivering the baclofen.

The ITB pump generally is implanted near the waistline. The tip of a catheter rests between the first and second lumbar vertebrae in the intrathecal space. The distal end of the catheter loops around the torso and connects to the pump. The dose delivered by the pump is adjusted using the programmer and telemetry wand. This system is noninvasive and affords flexibility in individualizing doses.

Dosages

The screening process requires the administration of an intrathecal test dose of baclofen (typically 50 mcg, usually not to exceed 100 mcg) via lumbar puncture. Peak effect of the drug usually occurs within 4 hours. Patients who respond positively to the test dose can be considered for long-term ITB therapy. The test dose must be monitored closely in a fully equipped and staffed setting because of the rare risk of respiratory arrest and other life-threatening adverse effects.

The initial total daily dose of ITB after implantation may be up to double the screening dose that resulted in a beneficial response. The initial doses should be adjusted and increased carefully and have to be individualized.

About 60 days following surgery or when a stable dose program has been established, dose delivery can start to be fine-tuned. Maintenance doses of ITB are as follows:

  • For spasticity of spinal cord origin, the dose ranges from 12-2000 mcg/day, with most patients requiring 300-800 mcg/day
  • Patients with spasticity of cerebral origin receive doses ranging from 22-1400 mcg/day; for most patients, doses of 90-703 mcg/day result in therapeutic benefits
  • For children younger than 12 years, the average daily dose is 274 mcg/day, with a range of 24-1199 mcg/day

The dose may be increased if greater therapeutic benefits are needed, or reduced to alleviate adverse effects. Dose should always be reduced in a stepwise fashion. Sudden withdrawal of ITB can result in cardiovascular instability, fever, and rash and requires emergency treatment. The pump's reservoir must be refilled every 4-12 weeks, depending on the daily dose. The pump hardware can last 4-6 years, depending upon the battery life, and generally is replaced within 4-5 years.

Adverse effects

As with any surgical procedure, the implantation of the pump exposes a patient to risks of infection and spinal fluid leakage, as well as the general risks of general anesthesia. Drowsiness, nausea, headache, muscle weakness, and lightheadedness can stem from the pump delivering an inappropriate dosage of baclofen.

The pump itself can malfunction, and the catheter can become kinked or fractured. A large and sudden escalation in dose requirement, for example, suggests a catheter complication. In cases such as these, surgical intervention may be necessary. In cases in which overdose is possible, the patient should be brought immediately to the hospital for evaluation.

Transcranial Magnetic Stimulation

Centonze et al reported that repetitive transcranial magnetic stimulation (rTMS) may improve spasticity in patients with MS. They used high-frequency (5 Hz) and low-frequency (1 Hz) rTMS protocols in 19 patients with relapsing-remitting MS and lower limb spasticity. [40]

In the study, rTMS was applied over the leg primary motor cortex, measuring the H/M amplitude ratio of the soleus H reflex, a reliable neurophysiologic measure of stretch reflex. A significant improvement of lower limb spasticity was observed when rTMS applications were repeated over 2 weeks, lasting at least 7 days after the end of treatment; no effect was obtained after a 2-week sham stimulation. These results, though promising, need to be verified by larger well-designed studies.

Neurosurgical Therapy

The surgical treatment of spasticity aims at 4 different levels: the brain, spinal cord, peripheral nerves, and muscle. Each approach has its strengths and weaknesses, but none of them completely eliminates spasticity.

Stereotactic brain surgery, whether involving the globus pallidum, ventrothalamic nuclei, or cerebellum, has had little success. Cerebellar pacemakers have been tried, but with mixed results that were not ultimately encouraging.

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Selective dorsal rhizotomy

Selective dorsal rhizotomy (SDR) is currently the most widely used and effective CNS procedure. It is used to treat severe spasticity of the lower extremities that interferes with mobility or positioning.

Also known as selective posterior rhizotomy, this technique, which is performed under general anesthesia, involves the cutting of selective nerve roots between the levels of L2 and S1 or S2, the fibers lying just outside the vertebral column that transmit nerve impulses to and from the spinal cord. "Dorsal" or "posterior" indicates that the target nerve roots enter the posterior spinal cord. These fibers carry sensory information to the cord from muscle. [41]

Sensory nerves are targeted because of the probable role they play in generating spasticity. Under normal physiologic conditions, excitatory signals from these sensory nerves are counterbalanced by inhibitory signals from the brain, maintaining normal muscle tone. In simplistic terms, when brain or spinal cord damage upsets this balance, excess sensory signaling can lead to spasticity. SDR is thought to improve spasticity by partially restoring the proper physiologic balance between these circuits.

The surgery is employed only when less-invasive procedures are unable to control spasticity adequately. The candidate nerve rootlets are stimulated electrically and those that lead to abnormal responses are cut; usually 25-50% of all tested rootlets are cut.

SDR has been performed mostly on children with cerebral palsy and less often in adults with spasticity from cerebral palsy or other etiologies. Studies have shown that most children with cerebral palsy experience a reduction in spasticity and an increase in range of motion that occurs immediately after SDR and persists for at least a year.

Cole et al emphasized the importance of applying strict selection criteria when considering children for SDR, as this is more likely to result in encouraging results. Of 53 children referred for SDR, only 19 (35%) fulfilled their selection criteria. These children showed improvement in cosmesis of gait, clinical examination, and temporal, kinetic, and kinematic parameters of gait analysis. [42]

Physical and occupational therapy are important postsurgical interventions to achieve the best outcome in patients who have undergone SDR. Most often, therapy is recommended 5 times per week for 6 months after the operation.

The relatively few longer-term follow-up studies that have been done on SDR indicate that tone reduction may last for a number of years. Reduction of spasticity can in some instances improve function, with most studies showing some benefit in mobility for subjects with spastic diplegia but less for those with spastic quadriplegia.

The extent of functional improvement after SDR therefore varies. Positive prognostic factors include the extent of mobility before the operation, underlying strength and balance, availability of regular physical therapy after SDR, and the patient's motivation and ability to undertake the rehabilitation process.

The possible complications from the surgery include those involving general anesthesia. Pain, altered sensation, and fatigue may continue for a number of weeks after the operation, as may changes in sleep and bladder or bowel function. Rare, long-term complications include low back pain, scoliosis or kyphosis (ie, spinal curves), and hip displacement.

Spinal cord stimulation

Implanted percutaneously, stimulators currently are used more for pain reduction than for reduction of spasticity, but they may prove to be clinically effective in the future.

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Orthopedic Surgery

These surgeries constitute the most frequently used procedures for spasticity. The following types of surgery are employed:

  • Lengthening or release of muscles and tendons
  • Procedures involving bones

These operations aim to reduce spasticity, increase range of motion, improve accessibility for hygiene, increase tolerance to braces, or reduce pain. The timing of the procedures is critical. If they are performed too early, repetitive procedures may be necessary or developmental milestones may be delayed. If the procedures are delayed too long, future pain or irreversible bone deformity may occur. The majority of these operations are performed in children aged 4-8 years.

Contracture release

Contracture release is the most commonly performed orthopedic procedure. The most common site for contracture release is the Achilles tendon. The tendon is lengthened to correct "equinus" deformity. Other common targets are contractures involving muscles of the knees, hips, shoulders, elbows, and wrists.

The tendon of a contractured muscle is cut, and the joint is then positioned at a more normal angle; a cast is then applied. Regrowth of the tendon to this new length occurs over several weeks, and serial casting may be used to gradually extend the joint. Following cast removal, physical therapy is used to strengthen the muscles and improve range of motion.

Tendon transfer

In a tendon transfer, the attachment point of a spastic muscle is moved. The muscle can no longer pull the joint into a deformed position, and in some situations, the transfer allows improved function. In others, the joint retains passive, but not active, function. Ankle-bracing procedures that follow surgery are among the most effective interventions.

Osteotomy

Osteotomy also can be used to correct a deformity. A small wedge is removed from a bone to allow it to be repositioned or reshaped. A cast is applied while the bone heals in a more natural position. This procedure is used most commonly to correct hip displacements and foot deformities. Arthrodesis is performed most commonly on the bones in the ankle and foot. It is a fusing together of bones that normally move independently, and this limits the ability of a spastic muscle to pull the joint into an abnormal position. Osteotomy and arthrodesis usually are accompanied by contracture release surgery for fuller correction of the joint deformity.

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Physical and Occupational Therapy

Physical, occupational, speech, and recreational therapists often are involved in providing the following for patients with spasticity [43, 44, 45, 46] :

  • Sustained stretching
  • Massage [47]
  • Vibration
  • Heat modalities
  • Cryotherapy
  • Functional electrical stimulation/biofeedback [48]
  • Strengthening of antagonistic muscle groups
  • Hippotherapy
  • Hydrotherapy

These treatments are designed to reduce muscle tone, maintain or improve range of motion and mobility, increase strength and coordination, and improve comfort. The choice of treatments is individualized to meet the needs of the person with spasticity.

Stretching

Stretching forms the basis of spasticity treatment, helping to prevent contracture and maintain the full range of motion of a joint.

Strengthening

Strengthening exercises are aimed at restoring the proper level of strength to affected muscles, so that as tone is reduced through other treatments, the affected limb can be used to its fullest potential. However, no clear evidence exists yet that intensive physiotherapy (1 h/day, 5 days/wk) is more beneficial than routine physiotherapy (6-7 h over 3 mo).

Orthoses, casts, and braces

Application of these allows a spastic limb to be maintained in a more normal position. For instance, an ankle-foot orthosis can help to keep the foot flexed and reduce contracture of the calf muscles. A cast is a temporary brace, and serial casting gradually stretches out a contractured limb through the application of successive casts. Proper limb positioning improves comfort and reduces spasticity.

Children may require a new orthosis every few months because of growth. When a child is undergoing new casting, splinting, or positioning, his or her skin should be closely monitored for signs of breakdown.

Cold packs

Brief application of cold packs to spastic muscles may be used to improve tone and function for a short period of time or to ease pain.

Electrical stimulation

Electrical stimulation may be used to stimulate a weak muscle to oppose the activity of a stronger, spastic one. It also may reduce spasticity for short periods of time. Electrical stimulation is used most often to help flex the ankle for walking and to help extend spastic fingers. [49]

Biofeedback

Biofeedback is the use of an electrical monitor that creates a signal, usually a sound, as a spastic muscle relaxes. In this way, the person with spasticity may be able to train himself/herself to reduce muscle tone consciously, and this may play a modest role in reducing spasticity.

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Outcome Measures

Measures designed to assess technical and functional outcomes, patient satisfaction, and the cost-effectiveness of treatment can be used to evaluate status and track changes in spasticity management. While double-blind, placebo-controlled studies remain the standard for clinical testing, the single-subject design is a useful alternative in many treatment protocols.

However, the development of validated and reliable outcome measures for spasticity rehabilitation has been hampered by the difficulty of quantifying functionally important parameters such as pain, ease of care, and mobility. Because no single tool can measure the many types of changes possible with treatment, the choice of assessment tools must be based on the functional changes expected from the treatment. A wide range of assessment tools have been reviewed critically for their sensitivity, reliability, validity, and ease of administration. [50]

Most spasticity rating scales are ordinal. Equal intervals between units on an ordinal scale cannot be assumed automatically. Noninterval scaling can be addressed using Rasch analysis, though care must be taken to avoid inappropriate extrapolation. Ratio scales, such as before/after measurements, are useful, reliable, and easy to administer.

A technical outcome is an expected change in a measurable variable, based on the technical goals of a procedure. A functional outcome is an expected change in a patient's ability to perform a task. Patient satisfaction measures are concerned with both the result and the process of care delivery. The choice of test must be based on the change expected, and the sensitivity must match the range of expected improvement. Otherwise, the results will be meaningless. Changes in technical measures of spasticity may not correlate well with clinical improvement.

Because agreement among clinical spasticity scales is poor, a comprehensive set of tests is needed to evaluate the effects of treatment. Some of the more commonly used spasticity rating scales are as follows:

  • Spasm Frequency Scale
  • Medical Research Council Motor Testing Scale
  • Modified Ashworth Scale,
  • Adductor Tone Rating
  • Global Pain Scale

Prevention

Prevention of spasticity consists of the alleviation or treatment of precipitating factors, such as the following:

  • Pressure areas
  • Infections (eg, bladder, toenail, ear, or skin infections)
  • Deep venous thrombosis
  • Constipation
  • Bladder distention
  • Fatigue
  • Cold
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Consultations

Plastic surgeons, orthopedic surgeons, and neurosurgeons can play an important role in managing spasticity and its sequelae; thus, their contributions to the spasticity management team may be beneficial.

Neurologists and urologists can assist with issues such as seizure control and neurogenic bladder, which may affect spasticity control. [51]

Physical, occupational, speech, and recreational therapists can assist with family/patient training and education, as well as with therapeutic interventions.

Physical medicine and rehabilitation physicians lead a patient’s spasticity management team by reinforcing the role of function in guiding treatment decisions and by implementing those medical interventions that may be helpful.

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Long-Term Monitoring

Because tolerance can occur with medications, drug dosages should regularly be reviewed and implantable devices (pumps, stimulators) should be checked.

Ongoing documentation of compliance with therapeutic interventions and evaluation of orthotic or positioning devices is important.

Children with spasticity should be monitored regularly for onset of orthopedic or other abnormalities, because rapid growth may result in permanent contractures, scoliosis, or loss of function.

If spasticity worsens, caregivers may have difficulty transferring patients safely or providing adequate hygiene and general care. Recognizing caregiver difficulties and intervening to educate and help caregivers ensure that patients receive proper care.

Monitoring skin integrity is essential in patients with spasticity, because pressure ulcers can lead to sepsis and death.

Overly aggressive surgical lengthening of severe contractures should be avoided because compression or overstretch injuries to the nerves and arteries of the limb may occur.

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