Differences between Cervical Schwannomas of the Anterior and Posterior Nerve Roots in Relation to the Incidence of Postoperative Radicular Dysfunction

Ohnishi, Yu Ichiro; Iwatsuki, Koichi; Ohkawa, Toshika; Ninomiya, Koshi; Moriwaki, Takashi; Yoshimine, Toshiki

Abstract

STUDY DESIGN: A retrospective study. PURPOSE: To assess the case files of patients who underwent surgery for cervical dumbbell schwannoma for determining the differences between schwannomas of the anterior and posterior nerve roots with respect to the incidence of postoperative radicular dysfunction. OVERVIEW OF LITERATURE: The spinal roots giving origin to schwannoma are frequently nonfunctional, but there is a risk of postoperative neurological deficit once these roots are resected during surgery.
METHODS
Fifteen patients with cervical dumbbell schwannomas were treated surgically. Ten men and 5 women, who were 35-79 years old (mean age, 61.5 years), presented with neck pain (n=6), radiculopathy (n=10), and myelopathy (n=11).
RESULTS
Fourteen patients underwent gross total resection and exhibited no recurrence. Follow-ups were performed for a period of 6-66 months (mean, 28 months). Preoperative symptoms resolved in 11 patients (73.3%) but they persisted partially in 4 patients (26.7%). Six patients had tumors of anterior nerve root origin, and 9 patients had tumors of posterior nerve root origin. Two patients who underwent total resection of anterior nerve root tumors (33.3%) displayed minor postoperative motor weakness. One patient who underwent total resection of a posterior nerve root tumor (11.1%) showed postoperative numbness.
CONCLUSIONS
Appropriate tumor removal improved the neurological symptoms. In this study, the incidence of radicular dysfunction was higher in patients who underwent resection of anterior nerve root tumors than in patients who underwent resection of posterior nerve root tumors.