[Effect of electroacupuncture stimulation of "Huantiao" (GB 30) on walking ability and touch sensation in rabbits with lumbar intervertebral disc protrusion].

OBJECTIVE: To observe the effect of electroacupuncture (EA) stimulation of "Huantiao" (GB 30) on the walking ability and touch sensation in rabbits with lumbar intervertebral disc protrusion (LIDP).

METHODS: Forty New Zealand rabbits were equally randomized into normal control, model, EA-GB 30 and EA-non-acupoint groups. The LIDP model was established by surgical operation under anesthesia. EA (30 Hz/100 Hz, 2-4 V, 0.5 ms in pulse duration) was applied to bilateral "Huantiao" (GB 30) or non-acupoint. The rabbits' walking ability was assessed according to a 4-points scoring standard: 0 point: complete paralysis; 1 point: paralysis with muscular contraction and mild joint movement; 2 points: weaker strength of the affected limbs with bradykinesia and instable walking; 3 points: able to walk with only interphalangeal joint dyskinesia; 4 points: complete recovery. The rabbit's touch sensation was assessed according to another 4-points scoring standard: 0 point: no any response to cotton swab stimulation; 1 point: very mild response; 2 points: sluggish response; 3 points: relatively swifter response but weaker than the healthy limb; 4 points: normal. The ultrostructure changes of the sciatic nerve were analyzed by transmission electron microscope.

RESULTS: Following modeling, the scores for walking ability and touch sensation were significantly reduced in the model, EA-GB 30 and EA-non-acupoint groups (P < 0.01). While compared with the model group, both walking ability score and touch sensation score of the EA-GB 30 group were obviously increased (P < 0.01), rather than in the EA-non-acupoint group. Outcomes of the ultrastructure showed that in the model group, extensive onion-like state of the myelin sheath of the sciatic nerve fibers, shrink or disappearance of the axon, kytoplasm edema or lysis of Schwann cells tending to necrosis, and mitochondrium vacuolization of the Schwann cells were found. In the EA-GB 30 group, majority of the nerve fibers and vascular endothelium were normal, with delamination and vacuolization of partial myelin sheath, edema of partial mitochondria and vacuolization of Schwann cells were found. In the EA-non-acupoint group, delamination and twist of partial myelin sheath, Schwann cellular plasma edema and mitochondrial edema of the axon with vacuolization change were found, suggesting a poorer effect of EA of non-acupoint.

CONCLUSION: EA-GB 30 can improve LIDP rabbits' walking ability and touch sensation function and reduce ultrastructure of sciatic nerve.