A Case Series of Surgically Treated Spinal Dumbbell Tumors of Critical Parent Nerve Roots: To Cut or Not to Cut?
Vicki Marie Butenschoen1, Nikolaus Kögl2, Bernhard Meyer1
1Department of Neurosurgery, Klinikum rechts der Isar, School of Medicine, Technical University of Munich, Munich, Germany.
Background:
Dumbbell tumors present challenging cases, with either an incomplete tumor resection or a need to sacrifice nerve roots. Published literature suggests encouraging neurological outcomes after nerve root amputation.
Objective:
To determine the incidence of postoperative neurological deficits after amputating the parent nerve root.
Methods:
A retrospective consecutive analysis of all patients treated for dumbbell nerve sheet tumors with a reported amputation of the functional relevant parent nerve roots C5-Th1 and L3-S1.
Results:
Among 21 evaluated patients, minor postoperative neurological motor function deterioration occurred in 4 patients (19%). Most patients recovered to the preoperative level at the follow-up examination, and only one patient retained a new Medical Research Council (MRC) scale of 4/5 for deltoid weakness. The majority of tumors were resected at the lumbar level (nerve root L3: 28.6%, L5: 19%). Gross total resection was achieved in 90.5% of patients. Neuropathic pain was reported in one third of the patients during the long-term follow-up.
Conclusion:
Amputating critical parent nerve roots during the dumbbell tumor resections seems to result in a low incidence of postoperative motor deficits and may offer an acceptable sacrifice in otherwise only incompletely resectable dumbbell tumors. The cross-innervation of neighboring nerve roots and its, probably, per-se-reduced functionality may be a possible mechanism for maintaining motor function.
