[Transcutaneous electric stimulation at acupoints in the treatment of spinal spasticity: effects and mechanism].

To study the effect and mechanism of electrical stimulation in treating spinal spasticity, we used electroacupuncture (EA) on the surface of 2 couples of acupoints. The short term application (30 min) of high-frequency EA (100 Hz) produced an immediate antispastic effect in contrast to the low-frequency EA (2 Hz). After application of high-frequency EA (2 times/day, 30 min/time) for 3 months, antisplastic effect was stable. To keep this antispastic effect, the high-frequency EA must be used permanently. Recent experimental results showed that low and high frequency EA release MEK and dynorphin respectively from the spinal cord in humans. We infer that by enhancing the production of dynorphin in CSF, high-frequency EA decrease the excitability of the motor neurons in the anterior horns through the kappa opiate receptors, thus ameliorating the muscle spasticity of spinal origin.