Evaluation of electrical stimulation as a treatment for the reduction of spasticity.

The purpose of this study is to examine ways in which electrical stimulation, both transcutaneously and via implanted stimulators, may be used to treat spasticity . Spasticity is one of the complications which frequently follows CNS (central nervous system) lesion, and it is commonly identified in the following ways : The involved muscles develop a pathological resistance to passive stretch . This resistance increases with the rate of stretch and also exhibits the "knife-clasp" release phenomenon. The involved muscle groups also exhibit exaggerated flexor and extensor reflexes . Another neuromuscular complication, the muscle spasm (sometimes included as a characteristic of spasticity), frequently accompanies the spasticity of CNS lesion and is often observed in the spinal-cord-injured patient. Spasticity is generally considered to be detrimental to the patient (1). Gross spasm in the paralyzed limbs of a spinal-cord-injured patient can obviously interfere with activities of daily living . Also, spasm can lead to contractures, dislocation of joints, and can mask volitional control in case of paresis. Currently, spasticity is managed in a variety of ways (2) . These methods include drug therapy, chemical and surgical denervation, physical therapy, and sometimes surgical alteration of tendons . The physical therapy treatment involves passive exercise of the spastic muscles . This treatment, in addition to preventing contracture, has a lasting effect in quieting the spasticity . Apparently, when the paralyzed muscles are exercised, muscle stretch receptors and tendon organs are activated. This sensory information flow into the spinal cord and/or the passive activation of the reflex loop appears to quiet the spasticity . Unfortunately, the therapeutic effect that exercise has on the spasticity lasts only for a period of hours . With electrical stimulation we hope to utilize the same exercise-triggered mechanisms that reduce spasticity in passive exercise. The scheme includes equipping the patient with a portable electrical muscle stimulator . Thus equipped, the patient is free to exercise his paralyzed muscles at his convenience . The potential secondary