Spine
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Randomized Controlled Trial Comparative Study Clinical Trial
Variability of somatosensory cortical evoked potentials during spinal surgery. Effects of anesthetic technique and high-pass digital filtering.
The effects of anesthetic technique (nitrous oxide or propofol) and high-pass digital filtering on within-patient variability of posterior tibial nerve somatosensory cortical evoked potentials (PTN-SCEP) were compared prospectively in two groups of 20 patients undergoing spinal surgery. Average P1N1 amplitude was significantly higher and P1N1 amplitude variability lower during propofol/alfentanil anesthesia than during nitrous oxide/alfentanil anesthesia. ⋯ This study shows the importance of maintaining the highest possible PTN-SCEP amplitudes during spinal surgery. Propofol/opioid anesthesia may be an alternative anesthetic technique to nitrous oxide/opioid anesthesia during spinal cord function monitoring.
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Serial motor and sensory examinations were conducted on 90 patients with bullet fragments lodged in the spinal canal. Annual follow-up examinations were completed on 66 patients. Despite the fact that approximately 20% of the bullets had perforated the alimentary canal, no cases of infection were noted. ⋯ However, bullet removal did have an effect on motor recovery, depending on the level at which the lesion occurred. Among those patients with lesions between vertebral levels T12 and L4, there was significantly greater (P less than 0.001) motor recovery in those patients from whom the bullet was removed from than in patients not having bullet removal. Bullet removal from the canal between T1 and T11 had no significant effect on motor recovery.
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Comparative Study
Clinical validation of functional flexion-extension roentgenograms of the lumbar spine.
The purpose of this study was to determine the clinical validity of functional flexion-extension roentgenograms of the lumbar spine in a defined patient population. One hundred and one adults with low-back pain or functional disorders underwent passive functional flexion-extension examinations. Their roentgenograms were analyzed using a computer-assisted method to determine segmental motion parameters such as rotation and translation of the lumbar vertebrae. ⋯ It was found that all of the patient groups exhibited significantly hypomobile motion, spread equally among all levels, in comparison to the normal population, except for the group of high-performance athletes, who had significant hypermobility. The uniform spread of hypomobility limits the ability to distinguish with any confidence between the four pathologic groups by their motion. Thus, we believe that the analysis of the segmental motion of the lumbar spine using passive flexion-extension roentgenograms does not aid in differentiating the underlying pathologic condition of patients with low-back pain, and that no useful information can be derived form this procedure, especially in relation to the need for surgical intervention.
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Case Reports
Diagnosis and treatment of cauda equina entrapment in the vertical lamina fracture of lumbar burst fractures.
Posterior dural lacerations associated with lumbar burst fractures are caused by impaction of the dural sac into the vertical lamina fracture. Neural elements may be extruded outside of the dura and become entrapped in the lamina fracture. ⋯ Entrapped neural elements can be successfully extracted from the lamina fracture by an opening laminoplasty of the posterior neural arch. Patients with lumbar burst fractures and radiographic evidence of posterior displacement of the neural elements in the lamina fracture should undergo posterior exploration of the spinal canal, extraction of cauda equina neural elements, and repair of the dural laceration before any spinal reduction maneuver.
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This study examined the ability of somatosensory-evoked and dermatomal-evoked potentials to predict motor return after acute spinal cord injury. Fifty-seven of 102 patients who were studied with somatosensory-evoked potentials and dermatomal-evoked potentials were followed for more than 1 year, and their initial electrophysiologic studies were correlated with motor improvement. ⋯ Both the initial physical examination and evoked potentials were reasonable predictors of further motor improvement. However, evoked potentials added little or no useful prognostic information to the initial physical examination in either complete or incomplete spinal cord injury patient groups.