[Effects of tizanidine for refractory sleep disturbance in disabled children with spastic quadriplegia].

Tizanidine is a centrally acting alpha-2 adrenoreceptor agonist widely used in the treatment of spasticity in patients with cerebral or spinal injury, and it is causing drawsiness in some of them. Based on these drug actions, we administered tizanidine to 21 spastic quadriplegic children with severe sleep disturbance not improved by conventional therapies. All these patients were showing abnormalities of both the induction and maintenance of sleep. The dosage of tizanidine was 0.1 to 0.2 mg/kg/day, divided into two or three doses. If daytime drowsiness was severe, tizanidine admistration was restricted to just prior to bedtime. In 13 patients (61.9%), we found improvement in sleep induction and/or maintenance. Moreover, patients' families were satisfied with the treatment. There were no detectable side effects except facial pallor in two patients (9.5%) whose treatment was discontinued. Severe muscle hypertonia causes severe pain, which generates strong sympathetic nerve activity and subsequent sleep disturbance. We consider that tizanidine has direct effects on the induction of sleep, and promotes muscular relaxation bringing about good sleep. We conclude that tizanidine is useful for the treatment of refractory sleep disturbance in spastic quadriplegic patients.