Spontaneous electrical activity of rabbit trigger spot after transection of spinal cord and peripheral nerve

Objectives: To assess the changes in the prevalence and the morphology of s pontaneous electrical activity [SEA] after spinal cord transection and subs equent nerve transection in an animal model of myofascial trigger point [MT rP] in order to further understand the mechanism of MTrP. Spontaneous elect rical activity can be recorded from a minute locus in a human MTrP region, and also from that in the myofascial trigger spot [similar to human MTrP] o f rabbit skeletal muscle. Methods: Four adult albino rabbits were studied for the prevalence and ampl itude changes of SEA in the biceps femoris muscle before and after spinal c ord transection at the level of T4 or T5, and also after subsequent transec tion of the sciatic nerve. Results: There was no significant change in the prevalence and amplitude of SEA up to 60 minutes after spinal cord transection and 30 minutes after su bsequent nerve transection. Conclusions: The occurrence of SEA is not mediated through the spinal or su praspinal circuits. The origin of SEA appears to be a local motor endplate phenomenon.