Spasticity: medical and surgical treatment.

Electromyographic (EMG) recordings from multiple muscle groups with surface electrodes during systematic evaluation of phasic and tonic stretch reflexes, cutaneomuscular reflexes, long loop reflexes, postural reflexes, and volitional activation have been used to provide a neurophysiologic basis for selection of the appropriate treatment for spasticity, and to gain further insights into the general mechanisms of spasticity. Pharmacologic methods are useful as a temporary measure. Hypertonia of a single muscle can be effectively treated with 40% alcohol injections to the motor points and hypertonia of a muscle group with partial denervation through 6% phenol in water injected into the nerve trunk. Hypertonia of several muscle groups can be treated by chemical or surgical rhizotomy or myelotomy. Generalized hypertonia involving limb and trunk muscles can be modified through chronic epidural stimulation of the spinal cord. Modification of reciprocal antagonistic muscle activity may be achieved through electrical stimulation of the involved nerve trunks.