Journal of neurosurgery. Spine
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Multicenter Study
Spontaneous improvement of cervical alignment after correction of global sagittal balance following pedicle subtraction osteotomy.
Sagittal spinopelvic malalignment is a significant cause of pain and disability in patients with adult spinal deformity. Surgical correction of spinopelvic malalignment can result in compensatory changes in spinal alignment outside of the fused spinal segments. These compensatory changes, termed reciprocal changes, have been defined for thoracic and lumbar regions but not for the cervical spine. The object of this study was to evaluate postoperative reciprocal changes within the cervical spine following lumbar pedicle subtraction osteotomy (PSO). ⋯ Adults with positive sagittal spinopelvic malalignment compensate with abnormally increased cervical lordosis in an effort to maintain horizontal gaze. Surgical correction of sagittal malalignment results in improvement of the abnormal cervical hyperlordosis through reciprocal changes.
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A patient with failed back surgery syndrome reported paresthesia in his hands and arms during a spinal cord stimulation (SCS) screening trial with a low thoracic electrode. The patient's severe thoracic stenosis necessitated general anesthesia for simultaneous decompressive laminectomy and SCS implantation for chronic use. Use of general anesthesia gave the authors the opportunity to characterize the patient's unusual distribution of paresthesia. ⋯ Stimulation of the dorsal columns at T-8 evoked potentials in the legs (common peroneal nerves) and at similar thresholds, consistent with the sensation of paresthesia in the arms, in the right ulnar nerve. The authors' electrophysiological observations support observations by neuroanatomical specialists that primary afferents can descend several (in this case, at least 8) vertebral segments in the spinal cord before synapsing or ascending. This report thus confirms a physiological basis for unusual paresthesia distribution associated with thoracic SCS.