The Influence Of Impingement Nerve On Electrical Signal Conduction By Simulating Myofascial Trigger Point

Objective Myofascial pain accounts for 13.7%-47% of the causes of chronic musculoskeletal pain.Myofascial pain syndrome(MPS)is a common diagnosis of musculoskeletal pain,which is characterized by the presence of myofascial trigger points(MTrPs)in the relevant muscle group.MTrPs are highly concentrated sensitive points in skeletal muscle.In MPS,muscle weakness,numbness,pain and other symptoms related to nerve compression are often presented,which is related to the impaction of nerve branches in the muscle group by MTrPS.When nerve branches are impounded,their ability to transmit electrical signals is altered,leading to sensory or motor dysfunction.Neurologic function changes differently with different levels of stress.In this study,different clamping forces were applied to the sciatic nerve of mice for compression injury modeling,and the changes of compound muscle action potential,sensory nerve action potential and spinal dorsal horn wave amplitude were compared,so as to understand how the ability of nerve to conduct electrical signals changes after MTrPs in MPS exerted embedded pressure on nerve branches.Methods In this study,C57BL/6JGpt mice were selected as research objects and randomly divided into five groups.Each group was further divided into five subgroups with different clamping forces,namely 0 N,1.07 N,1.27 N,1.47 N and 2 N,with six mice in each subgroup.Proximal and distal stimulation of sciatic nerve injury was performed in mice,and compound muscle action potential was recorded in gastrocnemius muscle.The mouse toe mucosa was stimulated and the proximal and distal sensory nerve action potentials were recorded at the sciatic nerve injury.After stimulation of the sciatic nerve,the amplitude of the wave was recorded at the spinal dorsal horn.Results1.Compound muscle action potential The amplitude of the proximal nerve stem was lower than that of 0 N after different clamping force.LSD-t test showed that the amplitude of 0 N was significantly different from that of 1.07 N,1.27 N,1.47 N and 2 N(P < 0.05).The proximal incubation period is increased compared with 0 N.LSD-t test showed that there was significant difference between the incubation period of 2 N clamping force and that of0 N,1.07 N,1.27 N and 1.47 N clamping force(P < 0.01).The amplitude measured in the distal nerve stem stimulation was not statistically significant among the groups.The latency measured by distal stimulation was increased compared with 0 N.The sciatic nerve conduction velocity was lower than that of 0 N,and significant difference was found between 0 N and 1.07 N,1.27 N and 1.47 N clamping forces(P< 0.01).2.Sensory nerve action potential The amplitude of nerve stem was lower than that of 0 N after different clamping force.LSD-t test showed that the amplitude of 0 N was significantly different from that of1.07 N,1.27 N,1.47 N and 2 N(P < 0.01).The incubation period measured by nerve stem was increased compared with 0 N.LSD-t test showed that there was significant difference in the incubation period between 0 N and 1.07 N,1.47 N and 2 N(P <0.01).The sciatic nerve sensory conduction velocity was reduced in comparison with0 N.LSD-t test showed that there was significant difference in sensory nerve conduction velocity between 0 N and 1.07 N,1.27 N,1.47 N and 2 N(P < 0.01).3.Amplitude of spinal dorsal horn wave The amplitude of spinal dorsal horn wave measured by proximal nerve stem stimulation was increased compared with 0 N.LSD-t test showed that there was significant difference between the amplitude of 0 N and 1.07 N,1.27 N,1.47 N and 2N(P < 0.01).The amplitude of spinal dorsal horn wave measured by nerve stem stimulation was decreased compared with 0 N.LSD-t test showed that there was significant difference between the amplitude of 0 N and 1.07 N,1.27 N,1.47 N and 2N(P < 0.05).Conclusion1.After nerve compression,the proximal amplitude of compound muscle action potential decreased,proximal incubation period increased,and motor nerve conduction velocity decreased.The amplitude of sensory action potential decreased,incubation period increased,and sensory nerve conduction velocity decreased.The amplitude of the wave transmitted to the spinal dorsal horn increased and the excitability of the neurons in the spinal dorsal horn increased.2.It can lay a foundation for the treatment of nerve compression diseases and broaden the treatment ideas.