Until recently, the therapeutic use of non-cosmetic BOTOX (onabotulinumtoxinA) for adult upper extremity spasticity was considered off-label use. Last week, the U.S. Food and Drug Administration (FDA) approved Botox to treat spasticity in the upper extremity flexor muscles in adults.
Spasticity is common after stroke, traumatic brain injury, or the progression of multiple sclerosis. Spasticity is defined as
“a motor disorder characterized by a velocity-dependent increase in tonic stretch reflexes (muscle tone) with exaggerated tendon jerks, resulting from hyper-excitability of the stretch reflex as one component of the upper motor neuron syndrome.”
Spasticity often creates problems with mobility, self-care, and function. The spastic muscles can become stiff. Associated joints can be affected by lack decreased range-of-motion with contractures forming.
Botox works by temporarily blocking the connections between nerves and muscles, resulting in a temporary paralysis of the spastic muscle. Advantages of using Botox to treat muscle spasm include the ability to target specific muscles which when successful allows reduction of other systemic medications (ie Zanaflex, Baclofen, Dantrium).
Botox does not take the place of conservative measures, such as positioning, stretching and exercise in spasticity management. These measures remain essential.
Botox can decrease the dosage or use of oral antispastic medications which often provide only limited effects with short duration and frequent unwanted systemic side effects, such as weakness, sedation and dry mouth.
Botox has a Black Box Warning that states the effects of the botulinum toxin may spread from the area of injection to other areas of the body, causing symptoms similar to those of botulism. Those symptoms include swallowing and breathing difficulties that can be life-threatening.
The most common adverse reactions to Botox reported by patients with upper limb spasticity were nausea, fatigue, bronchitis, muscle weakness, and pain in the arms.
Botox has not been shown to be safe and effective treatment for other upper limb muscles, spasticity in the legs, or for treatment of fixed contracture – a condition that affects range of motion. Treatment with Botox is not intended to substitute for physical therapy or other rehabilitative care.
Botulinum toxin type A in the treatment of upper extremity spasticity: A randomized, double-blind, placebo-controlled trial; NEUROLOGY 1996;46:1306; D. M. Simpson, MD, D. N. Alexander, MD, C. F. O'Brien, MD, M. Tagliati, MD, A. S. Aswad, MS, J. M. Leon, PhD, J. Gibson, MD, J. M. Mordaunt, MS and E. P. Monaghan, PhD
Botulinum Toxin in Poststroke Spasticity; Clin Med Res. 2007 June; 5(2): 132–138; Suheda Ozcakir, MD and Koncuy Sivrioglu, MD