The effect of epidural application of opioids on spasticity of spinal origin.

The effect of epidural opioids on spinal spasticity is demonstrated in a patient suffering from multiple sclerosis. Flexor reflex spasms are abolished and muscle tone is markedly reduced by the epidural administration of morphine 3 mg or fentanyl 0.1 mg. In contrast, the oligosynaptic motor responses and voluntary movements were unaffected. This is documented by EMG-recordings. Sensory perception thresholds were elevated for pain, but unchanged for touch and vibration sense. Effects on enkephalinergic interneurons on the spinal level are discussed.