BOTULINUM TOXIN TREATMENT OF LUMBRICAL SPASTICITY - A BRIEF REPORT

Botulinum toxin A has been used to treat wrist and finger spasticity m ainly through injection of the forearm flexor muscles. This case study describes its first reported use in managing spastic lumbricals of th e hand. A 19-year-old male had significant flexion deformity and hyper tonicity of the left wrist and hand, particularly the second through f ifth metacarpophalangeal joints, after traumatic brain injury. By usin g the 0-4 Ashworth scale, spasticity of the lumbricals across the seco nd to fourth metacarpophalangeal joints was rated 2, with persistent c lonus of the finger flexors as confirmed by electromyography to the mi ddle and ring fingers, even after botulinum toxin A injection of the f lexor digitorum sublimis and profundus muscles. By using the electromy ography-guided technique, botulinum toxin A was injected into the firs t lumbrical of the index finger (12 units), second and third lumbrical s of the middle and ring fingers, respectively (15 units each), and fo urth lumbrical of the little finger (10 units). At follow-up, clinical and electromyographic examination revealed a significant reduction in tone and clonus of the injected lumbricals. Ashworth scores of the lu mbricals from the index to little finger improved to 1. Botulinum toxi n A injection of the lumbricals can be beneficial in managing spastici ty of these muscles. It is well tolerated and effective at doses of 10 to 15 units. Lumbrical injection of botulinum toxin A is a useful adj unct in our percutaneous armamentarium for managing the spastic hand.