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Updated: Dec 11, 2025

Preparation of Peripheral Nerve Stimulation Electrodes for Chronic Implantation in Rats
Published on: July 14, 2020
VNS implantation in a NF1 patient: massive nerve hypertrophy discovered intra-operatively preventing successful
Hussein Hamdi1,2,3, Gilles Brun4, Marc Zanello5
1Department of Functional and Stereotactic Neurosurgery, Timone University Hospital, Aix Marseille University, Marseille, France.
Abstract:
For the vast majority of surgeons, no specific investigation is necessary before vagal nerve stimulation (VNS) implantation. We report our intraoperative unexpected finding of a massively enlarged vagus nerve in a patient with neurofibromatosis type 1 (NF1). The nerve hypertrophy prevented wrapping the coils of the helical electrode. The patient had no signs of vagus nerve dysfunction preoperatively (no hoarseness or dysphonia). This exceptional mishap is undoubtedly related to NF1-associated peripheral nerve sheath tumors. Even though it is not advisable to routinely perform any imaging prior to VNS, in such specific context, preoperative imaging work-up, especially cervical ultrasound, might be judicious to rule out any asymptomatic enlarged left vagus nerve.

