Objective To research the direct electrophysiological evidence of discomplete spinal cord injury (SCI) and the effect of 4-aminopyridine on it.Methods Motor evoked potentials (MEPs), both spinal cord recorded MEPs (...Objective To research the direct electrophysiological evidence of discomplete spinal cord injury (SCI) and the effect of 4-aminopyridine on it.Methods Motor evoked potentials (MEPs), both spinal cord recorded MEPs (scMEPs) and extracellularly recorded MEPs (exMEPs) were recorded and characterized on a T13 epidural electrode (scMEPs) and an extracellular microelectrode (exMEPs) for 10 normal rats and 40 rats with lesions of various severity (sham, 35?g*cm force (gcf), 70?gcf, 100?gcf impact injury) at the T8-T9 cord using the Allen's drop model. The incline plane and Tarlov techniques were used to assess clinical neurological function. Results MEPs in the normal rats were elicited by applying transcortical suprathreshold stimulation consisting of 3-4 early negative peaks (N1, N2, N3 and N4) followed by several late waves. The N1 and N2 peaks were largest in the anterior and ventrolateral funiculus, respectively, which was indicative of extrapyramidal pathways. The 100?gcf impact injuries and the cord transection abolished the MEP distal to the lesion, whereas the 35?gcf injuries resulted in a latency shift and amplitude decrement of the MEP peaks. Eighteen of the 20 rats with 70?gcf injuries showed clinical paraplegia. Among them, 7 rats had neurophysiological evidence of residual conduction pathways through the lesioned cord segment, such as the presence of N1 and N2 peaks in the scMEPs or exMEPs. After 4-aminopyridine (4-AP) administrations (1?mg/kg), the amplitude of the spared exMEP increased significantly and spread more widely. Conclusions MEPs evoked by transcortical stimulation travel mostly in the extrapyramidal tract. MEP monitoring could provide an excellent method of detecting the functional integrity of the motor tracts after SCI, and could even detect spared motor fibers after discomplete SCI. Furthermore, the use of 4-AP or other K+ channel blocking agents may be a potential treatment for patients with chronic moderate to severe SCI.展开更多
Aim:The aim of this study was to assess the pattern of voluntary movements in patients with spinal cord injury(SCI)post intensive whole-body training vs.upper body training with brain motor control assessment(BMCA).Me...Aim:The aim of this study was to assess the pattern of voluntary movements in patients with spinal cord injury(SCI)post intensive whole-body training vs.upper body training with brain motor control assessment(BMCA).Methods:Twelve neurologically intact participants and 18 patients with SCI participated in this study as part of a multi-centre randomised controlled trial.All participants received 12 weeks training(three times per week),which comprised trunk,upper and lower limb exercises and locomotor training and functional electrical stimulation-assisted cycling in whole-body training group and an upper body strength and fitness program for upper body training group.Results:Generalised linear model analysis showed significant effect of the main effect of the Task(P<0.001)on the similarity index of voluntary movement patterns but not on the other factors or the interactions between them(P>0.05).Some participants showed significant improvement in muscle strength post 12 weeks training;however,this improvement was not reflected in the pattern of muscle activation which was captured by BMCA.Conclusion:BMCA is a valuable objective assessment tool that could add resolution to the clinical evaluation of patients with SCI post different therapeutic techniques.展开更多
基金thegrantsfromtheAdvanceDepartment FoundationfromtheMedicalMinistryofShanghai China! (No 1995 Ⅲ 0 0 8)
文摘Objective To research the direct electrophysiological evidence of discomplete spinal cord injury (SCI) and the effect of 4-aminopyridine on it.Methods Motor evoked potentials (MEPs), both spinal cord recorded MEPs (scMEPs) and extracellularly recorded MEPs (exMEPs) were recorded and characterized on a T13 epidural electrode (scMEPs) and an extracellular microelectrode (exMEPs) for 10 normal rats and 40 rats with lesions of various severity (sham, 35?g*cm force (gcf), 70?gcf, 100?gcf impact injury) at the T8-T9 cord using the Allen's drop model. The incline plane and Tarlov techniques were used to assess clinical neurological function. Results MEPs in the normal rats were elicited by applying transcortical suprathreshold stimulation consisting of 3-4 early negative peaks (N1, N2, N3 and N4) followed by several late waves. The N1 and N2 peaks were largest in the anterior and ventrolateral funiculus, respectively, which was indicative of extrapyramidal pathways. The 100?gcf impact injuries and the cord transection abolished the MEP distal to the lesion, whereas the 35?gcf injuries resulted in a latency shift and amplitude decrement of the MEP peaks. Eighteen of the 20 rats with 70?gcf injuries showed clinical paraplegia. Among them, 7 rats had neurophysiological evidence of residual conduction pathways through the lesioned cord segment, such as the presence of N1 and N2 peaks in the scMEPs or exMEPs. After 4-aminopyridine (4-AP) administrations (1?mg/kg), the amplitude of the spared exMEP increased significantly and spread more widely. Conclusions MEPs evoked by transcortical stimulation travel mostly in the extrapyramidal tract. MEP monitoring could provide an excellent method of detecting the functional integrity of the motor tracts after SCI, and could even detect spared motor fibers after discomplete SCI. Furthermore, the use of 4-AP or other K+ channel blocking agents may be a potential treatment for patients with chronic moderate to severe SCI.
基金The study was funded by the Transport Accident Commission(Victorian Neurotrauma Initiative),and the University of Melbourne
文摘Aim:The aim of this study was to assess the pattern of voluntary movements in patients with spinal cord injury(SCI)post intensive whole-body training vs.upper body training with brain motor control assessment(BMCA).Methods:Twelve neurologically intact participants and 18 patients with SCI participated in this study as part of a multi-centre randomised controlled trial.All participants received 12 weeks training(three times per week),which comprised trunk,upper and lower limb exercises and locomotor training and functional electrical stimulation-assisted cycling in whole-body training group and an upper body strength and fitness program for upper body training group.Results:Generalised linear model analysis showed significant effect of the main effect of the Task(P<0.001)on the similarity index of voluntary movement patterns but not on the other factors or the interactions between them(P>0.05).Some participants showed significant improvement in muscle strength post 12 weeks training;however,this improvement was not reflected in the pattern of muscle activation which was captured by BMCA.Conclusion:BMCA is a valuable objective assessment tool that could add resolution to the clinical evaluation of patients with SCI post different therapeutic techniques.
