title: Assessment of pure single nerve root resection in the treatment of spinal schwannoma: focus on solitary spinal schwannomas located below the thoracolumbar junction.
abstract: BACKGROUND
  The incidence of neurological deficits is reportedly low after sacrificing the affected nerve root during spinal schwannoma treatment. Although the incidence has been widely reported, the operative method for nerve root resection has been not clarified. To evaluate the safety of pure nerve root resection, we focused on solitary spinal schwannomas below the thoracolumbar level and investigated the effect of affected nerve resection.
  
  
  METHODS
  Twenty-three spinal schwannoma patients were retrospectively examined. The mean age at surgery was 53 years. We investigated preoperative symptoms, duration of the disorder, postoperative neurological deficits, and clinical outcomes. In addition, we measured tumor size on computed tomography after myelography or on magnetic resonance images using image-analysis software. We retrospectively assessed correlations among duration of symptoms, tumor size, and postoperative neurological deficits.
  
  
  RESULTS
  The tumors comprised 19 intradural schwannomas and 4 dumbbell-shaped schwannomas. No postoperative neurological deficits were observed in the intradural schwannoma patients. In contrast, three of the four dumbbell-shaped schwannoma patients experienced postoperative neurological deficits. Among these three patients, two recovered quickly whereas one never recovered. The mean duration of the disorder was 29 months. The postoperative modified JOA score (13.0) was significantly improved compared with the preoperative score (8.9). The mean maximum tumor sizes were 97.2 mm(2) for the intradural schwannomas and 884.0 mm(2) for the dumbbell-shaped schwannomas. There were no correlations among tumor size, duration of the disorder, and postoperative neurological deficits.
  
  
  CONCLUSIONS
  On the basis of this study, we recommend pure single nerve resection for treatment of intradural spinal schwannomas before such tumors progress and involve other normal roots, because postoperative neurological deficits did not occur in our intradural schwannoma patients, irrespective of tumor size, when this procedure was used. However, dumbbell-shaped schwannoma patients should be carefully treated operatively, because high incidence of postoperative neurological deficits can be expected.
authors.affiliation: Department of Orthopaedic Surgery, Nara Medical University, 840 Shijyocho, Kashihara, Nara, 634-8522, Japan. Nobuhisa06s@aol.com
authors.forename: Nobuhisa
authors.initials: N
authors.lastname: Satoh
authors.forename: Yurito
authors.initials: Y
authors.lastname: Ueda
authors.forename: Munehisa
authors.initials: M
authors.lastname: Koizumi
authors.forename: Toshichika
authors.initials: T
authors.lastname: Takeshima
authors.forename: Jin
authors.initials: J
authors.lastname: Iida
authors.forename: Koji
authors.initials: K
authors.lastname: Shigematsu
authors.forename: Hideki
authors.initials: H
authors.lastname: Shigematsu
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Matsumori
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Tanaka
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D004576:Electromyography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008159:Lumbar Vertebrae; D008297:Male; D008875:Middle Aged; D009192:Myelography; D009431:Neural Conduction / Q000502:physiology*; D009442:Neurilemmoma / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D010524:Peripheral Nervous System Neoplasms / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D011184:Postoperative Period; D012189:Retrospective Studies; D013126:Spinal Nerve Roots / Q000503:physiopathology / Q000601:surgery*; D013904:Thoracic Vertebrae; D016896:Treatment Outcome; D055815:Young Adult