The purpose of this study was to evaluate the effect of peripheral nerve stimulation on recovery of locomotor functions following spinal cord injury. Sprague-Dawley rats weighing 200-250g were divided into two groups in this study: one group was
with
cord injury group(INJ. N=10) and the other with cord injury pluse electrical stimulation of the sciatic nerve(INJ+ES. N=10). Each rat was supjected to 150g/cm weight drop injury on L4 S2 spinal cord levels. Square pulse stimulation with 1-3 V.
0.2ms,
40Hz, and 5 sec ON-OFF type was applied to right and left sciatic nerves through teflon coated stainless steel electrodes(0.45mm in diameter )with 3 mm exposed tip for 6 hours per day up to 7 days. The recovery of locomotor function of hindlimb
was
tested daily for 7 days by modified. Tarlov scale, footprint analysis, and rolling bar test. Alos maximum twitch and tetanic tensions of the soleus muscle were measured by means of force transducer.
@ES Results of this study were as followings:
@EN 1. Rats with cord injury caused by 150g/cm weight drop could walk on the plate board of modified Tarlov examination at first postoperative day, which means that 150g/cm weight drop injury caused mild cord injury in this study.
2. Many parameters of foot print analysis, such as degree of base of support, angle of hindpaws, length of hindpaw, and angle between forepaw and hindpaw, were increased significantly just after cord injury, then progressively decreased with a
time.
The INJ+ES group showed more rapid recovery in parameters of footprint analysis than INJ group. Especially angle between forepaw and hindpaw of INJ+ES group was significantly improved than that of INJ group from postoperative three days to six
days.
3. In rolling bar test, electrical stimulation of both sciatic nerves produced more rapid recovery of walking time from postoperative two days to five days.
4. The INJ+ES group showed significant increase of maximum twitch and tetanic tension of the soleus muscle than INJ group(P<0.05).
5. These above results suggest that electrical stimulation of the sciatic nerve may be effective on promotion of locomotor function following spinal cord injury.
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