[An experimental study of spinal cord traction syndrome].

An experimental study was carried out on the pathophysiology of spinal cord traction syndrome. In fifty dogs, spinal cord traction impairment was created by gradual lumbosacral cord traction. Physiological integrity of the spinal cord was monitored and recorded by the spinal evoked potentials. The earliest change of the spinal evoked potentials and lumbar roots potentials was transient augmentation of the amplitude. With greater traction force, the potentials gradually decreased in amplitude. The spinal cord vulnerability to compression was increased by spinal cord traction. Under 200 g traction, the vulnerability of the lower thoracic cord was most increased while those of the upper thoracic and lumbar cord were unchanged. The authors conclude that tethered cord syndrome is caused by the impairment of the spinal cord and lumbosacral roots due to traction, and that spinal cord traction not only causes spinal cord impairment but increases the spinal cord vulnerability to compression.