3.

Study Design Retrospective analysis of 169 adult patients operated for a conventional spinal schwannoma from the AOSpine Multicenter Primary Spinal Tumors Database. Objective To identify risk factors for local recurrence of conventional spinal schwannoma in patients who had surgery. Summary of Background Data Schwannomas account for up to 30% of all adult spinal tumors. Total resection is the gold standard for patients with sensory or motor deficits. Local recurrence is reported to be approximately 5% and usually occurs several years after surgery. Methods Rates and time of local recurrence of spinal schwannoma were quantified. Predictive value of various clinical factors was assessed, including age, gender, tumor size, affected spinal segment, and type of surgery. Descriptive statistics and univariate regression analyses were performed. Results Nine (5.32%) out the 169 patients in this study experienced local recurrence approximately 1.7 years post-operatively. Univariate analyses revealed that recurrence tended to occur more often in younger patients (39.33 ± 14.58 years versus 47.01 ± 15.29 years) and in the lumbar segment (55.56%), although this did not reach significance (HR=0.96, p = 0.127; and p = 0.195, respectively). Recurrence also arose in the cervical and sacral spine (22.22%, respectively) but not in the thoracic area. Tumors were significantly larger in patients with recurrence (6.97 ± 4.66 cm versus 3.81 ± 3.34 cm), with extent in the cranial-caudal direction posing the greatest hazard (HR=1.321, p = 0.002). The location of the tumor, whether epidural, intradural, or both (p = 0.246) was not significantly related to recurrence. Regarding surgical technique, over four times as many patients who underwent intralesional resection experienced a recurrence proportionally to patients who underwent en bloc resection (HR = 4.178, p = 0.033). Conclusions The pre-operative size of the conventional spinal schwannoma and intralesional resection are the main risk factors for local post-operative recurrence.

MSCC was associated with upper limb manifestations, and SCR was associated with upper limb, lower limb, and general neurological deficits. Hoffmann sign occurred more commonly in patients with a greater MSCC, MCC and SCR. The Lhermitte phenomenon presented more commonly in patients with a lower SCR and may be an early indicator of mild spinal cord involvement. Research to validate these findings is required.