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Effective Management of Spasticity in Persons with Upper Motor Neuron Syndromes By Benjamin O. Henkle, M.D., Division of Pain Medicine
Spasticity is a common phase of recovery following a neurological injury. In many people, it is a very problematic condition affecting their level of function, activities of daily living, and overall quality of life. Spasticity is a velocity-dependent increase in muscular tone and is just one common finding associated with upper motor neuron syndromes from brain injury, spinal cord injury, stroke, cerebral palsy, multiple sclerosis, and other neurological conditions. Physical exam findings in patients with upper motor neuron syndromes include contracture, spastic dystonia, increased stretch reflexes, weakness, and loss of selective limb control. It is estimated that spasticity impacts approximately one million Americans.
The problems with untreated spasticity
It should be noted that spasticity is not always detrimental and may actually assist patients with transfers, ambulation, or other weight-bearing activities. However, spasticity can also cause disability, pain, deformities, gait disturbances, and difficult hygiene. These sequelae can limit the ability of individuals to perform their activities of daily living and can increase the risk of complications such as infection, poor posture, and pain which can in-turn exacerbate the spasticity. Spasticity can also lead to limb contracture, defined as shortening of the muscle, tendons, or ligaments which is permanent and can prevent normal movement and cause deformity.
The exact nature of these problems varies depending on the location and extent of the central nervous system damage. Therefore, spasticity is an individualized condition that may lead to varying degrees of functional impairment, reduced work productivity, and caregiver dependence.
Treatment of spasticity
Early treatment of spasticity may avoid secondary mal-adaption, functional impairment, and loss of activity and participation. However, spasticity can manifest weeks, months, or even years after the original injury, possibly after a patient has stopped seeing a neurologist, physiatrist, or their rehabilitation specialist, which is why it is severely undertreated. Treatment focuses on increasing function, decreasing pain, and optimizing hygiene. Physiotherapy modalities are paramount and focus on stretching and maximizing function. Often, anti-spasticity medicines are necessary, including oral medicines as well as intramuscular botulinum toxin and intrathecal administration of baclofen. In some cases, surgical measures such as tendon lengthening and selective dorsal rhizotomy are helpful.
Botulinum toxin administration
Intramuscular injection of botulinum toxin offers a focal treatment for spasticity, effectively minimizing or eliminating side effects, drug-drug interactions, and non-compliance. There are two different serotypes of botulinum toxin available for medical use in the United States: Type A (BOTOX®, Dysport®, Xeomin®) and Type B (Myobloc®). BOTOX® is the most studied, and it has a well-established, long-term safety profile in use for limb spasticity over the past 20 years. There have been over 2,000 peer-reviewed publications on BOTOX® in scientific and medical journals. Botulinum toxin is injected by a trained specialist directly into the affected muscles, blocking the pre-synaptic release of acetylcholine, thus reducing muscle contractions to reduce the severity of increased muscle tone in the extremity. In clinical studies, the efficacy of BOTOX® persisted up to three months on average; therefore, repeated injections are necessary.
Intrathecal baclofen administration (baclofen pump)
Oral baclofen is absorbed well, but it does not readily cross the blood-brain barrier. When taken orally, baclofen has not been very effective in reducing spasticity of cerebral origin, and sedation is often a problematic side effect. However, intrathecal administration allows for approximately 1/100 of the dose, effectively eliminating side effects and allowing for much greater titration and effectiveness. Intrathecal baclofen is more effective in treating spasticity in the lower extremities than in the upper extremities, and it is reserved for those patients who have failed more conservative treatments. A screening trial is performed first when considering a baclofen pump to note its effects on tone. After implantation of the programmable pump and the intrathecal catheter, the pump is programmed to deliver the optimal continuous dose and needs to be refilled about every 2 to 3 months.
Conclusion
Effective treatment of spasticity is best done after a comprehensive evaluation and discussion of goals with the patient. A multidisciplinary approach is taken with collaboration among specialists in physiatry, neurology, pain medicine, neurosurgery, and physical and occupational therapy. Patients experience optimal outcomes when their needs are addressed by an integrated and highly motivated team.
The treatment of spasticity is performed by a number of New England Neurological Associates physicians. We have particular interest in treating spasticity conservatively, as well as with botulinum toxin and intrathecal baclofen. We also see patients in need of interventional chronic pain management.
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