Therapeutics in the Management of Spasticity

Abstract

Spasticity is commonly defined as a velocity-dependent increase in tonic stretch reflexes that results from a variety of disorders affecting the brain and spinal cord. Treatment of spasticity is generally considered when the increase in tone interferes with functional activities, such as positioning, mobility, or daily cares, when it is painful, or when it leads to complications such as contractures or skin breakdown. This review discusses the pathophysiology of spasticity and details the various treatments available, including physical and occupational therapy modalities, use of splints and orthoses, oral and intrathecal medications, nerve blocks, botulinum toxin injections, and orthopedic and neurosurgical interventions.Neurorehabilitation and Neural Repair 1999;13:5-14 © 1999 Demos Medical Publishing Spasticity results from a variety of common central nervous system (CNS) insults, including stroke, traumatic bram injury, cerebral palsy, multiple sclerosis (MS), and spinal cord injury. It is commonly defined as a motor disorder characterized by a velocity-dependent increase m tonic stretch reflexes associated with exaggerated tendon jerks, and is often accompanied by abnormal cutaneous and autonomic reflexes, muscle weakness, lack of dexterity, fatigability, and co-contraction of agonist and antagomst muscles (1,2). Spasticity in and of itself is not always detrimental. For example, in some patients spasticity may help prevent muscle atrophy and calcium loss from bone, help decrease edema and the risk of deep vein thrombosis, and assist cardiovascular conditioning. In individuals with marked muscle weakness, an increase m muscle tone m antigravity muscles may actually facilitate transfers, standing, and ambulation. In such patients treatment From the 5530 not only may be unnecessary but also may worsen functional abilities.In other individuals spasticity may have negative consequences, interfering with rehabilitation and activities of daily livmg (ADLs). Spasticity may cause pain, mcrease the risk of fractures, and contribute to the development of decubitus skin ulcers. Increased disability may also result from spasticity-related impairment of posture, abnormal quality of movement, painful spasms, and poor hygiene (3,4). Treatment of spasticity is often considered m these patients. The following is a review of the pathophysiology of spasticity and pharmacologic and surgical management strategies that may be considered for patients in whom treatment is deemed appropriate. PhysiologyMuscle tone, which is defined as the resistance to passive muscle movement, is modulated by both peripheral and CNS influences on the alpha motor neuron in the spmal cord (5). The pathways that regulate tone are similar to those that regulate voluntary and involuntary motor movements and, m essence, involve the spmal reflex arc. For the purpose of illustration, if one considers at UNIV CALIFORNIA SAN DIEGO on June 13, 2015 nnr.sagepub.com Downloaded from

Open-Label Dose-Titration Safety and Efficacy Study of Tizanidine Hydrochloride in the Treatment of Spasticity Associated With Chronic Stroke

“…18,19 Treatment of spasticity is considered when it interferes with function, such as ambulation, transfers, and ADLs, or is painful. 4 Conservative interventions, such as physical therapy, splints, and orthoses, are often prescribed initially; however, when these measures are ineffective, medications are often necessary.…”

“…22,23 In addition, baclofen causes muscle weakness, especially at moderate and high doses, which is of obvious concern in stroke patients who are hemiparetic. 4 Studies have reported that Ͼ10% of patients discontinue baclofen therapy because of muscle weakness. 24 Benzodiazepines, such as diazepam and clonazepam, reduce muscle tone and painful spasms by increasing the affinity of GABA receptors for endogenous GABA, predominantly at the spinal cord level.…”

“…17 Quality-of-life issues were evaluated with a Functional Spasticity Questionnaire, the effect of spasticity-related pain was evaluated with the newly constructed Pain Questionnaire, and disability was evaluated with a physician rating scale (see Appendix). These assessments were repeated at weeks 4,8,16, and 18 (after 1 week off tizanidine). The safety profile of tizanidine was assessed through recording of adverse events, laboratory values, and vital signs.…”

“…However, in others, spasticity can interfere with the ability to position comfortably, transfer, walk, perform ADLs, or maintain adequate hygiene, and it can be painful or predispose to the development of decubitus ulcers and contractures. 4 In these individuals, treatment of spasticity is generally considered.…”

“…Although effective, these medications are limited in their use by side effects. 4 Diazepam is highly sedating and often causes tachyphylaxis and habituation. Baclofen is also sedating and tends to cause weakness, of both spastic and nonspastic muscles, which may lead to a worsening in function despite an improvement in muscle tone.…”