Physiologic changes of nerve root during posterior lumbar discectomy.

摘要: STUDY DESIGN AND OBJECTIVES The effects of nerve root retraction in posterior discectomy on pressure, blood flow, and electrophysiologic changes the were investigated. This study was performed to assess root. SUMMARY OF BACKGROUND DATA compression tissue have been clinically studied mainly peripheral nerves. potential risk for lumbar injury has not evaluated precisely humans. METHODS Among 31 patients with intervertebral disc herniation, correlation between pressure flow evaluated. Retraction continuously monitored during length procedure measured. Threshold amplitude compound muscle action potentials before after discectomy. relationship intraoperative data physiology postoperative neurologic change analyzed. RESULTS Nerve decreased 18-30% initial value under around 70 g/cm2. An abrupt decrease observed even within 1 or 2 mm distance. threshold minimal asymptomatic side, but increased affected demonstrating sensory loss only, significantly showing sensory/motor deficit. Amplitude evoked by stimulation at distal from herniated mass lowest In 4 patients, high (> 170 g/cm2) required they showed temporary deterioration surgery. these 14.1 +/- 4.1 minutes, it 9.9 2.7 minutes remaining 27 patients. CONCLUSIONS discectomy, ischemia usually occurs retraction. magnitude time may be factors injury.