The effects of extracorporeal shock waves on the lumbar spinal cord / 中华物理医学与康复杂志

ABSTRACT

Objective To investigate whether or not extracorporeal shock wave (ESW) treatment is safe for treating low back pain caused by lumbar facet joint degeneration by observing its effects on the lumbar segment of the spinal cord.Methods Five adult dogs were used for this study.ESWs were focused on their right L_(4～5) facet joints. The energy output was set at 40% of the maximum output,and a total of 1000 shocks were delivered at a frequency of 120/min.Before and 3 days after the treatment,the somatosensory evoked potentials (SEPs) induced by stimulating the tibial nerve were recorded from the animals' scalps,and the motor function of their hind limbs was evaluated with Tarlov's scale.The animals were then sacrificed and the L_(4～5) segments of their spinal cords were taken for histopatho- logical observation,with the T_(12) segments taken as controls.Results Three days after ESW treatment,the left and the right hind limbs scored 5 and 4 on the Tarlov scale.The amplitude of SEPs decreased and their latency increased. Histopathological observation showed mild swelling of the L_(4～5) segment of the spinal cord with congested veins on the surface.Erythrocyte and leukocyte exudation as well as myelin sheath swelling in the spinal cord were also observed un- der the microscope,but with no demyelination.Conclusion ESW had some adverse effects on the spinal cord when focused on the facet joint.Further studies of the safety range of ESW energy and distance are needed.