Relationship between muscle motor evoked potentials and hindlimbs motor function in rabbits with spinal cord injury

OBJECTIVE: To study the relationship between muscle motor evoked potentials (MEP) and hindlimbs motor function in rabbits with spinal cord injury. METHODS: Forty-five rabbits were randomly divided into 9 groups, including one control group and 8 injured groups (receiving Allen's injury of 0, 50, 75, 100, 125, 150, 175, 200, or 250 gcf). Hindlimb strength and muscle MEP were recorded at the 1st day and 4th week postoperatively. At 4 weeks after spinal section, the spinal cord tissue was sampled for histological examination with HE staining and immunohistochemistry with anti-NF antibody of the corticospinal tract fibers. RESULTS: During the operation, MEP showed an all-or-none pattern with significant correlations to postoperative optical density of NF and postoperative hindlimb motor function. The latency prolongation of the muscle MEP at the 4th week showed a linear correlation to the hindlimb Tarlov's score, whereas the MEP amplitude was not correlated to postoperative hindlimb motor function. CONCLUSIONS: The all-or-none pattern of muscle MEP can be used to evaluate the severity of spinal cord injury.