Programming Parameters and Techniques in Trigeminal Ganglion Stimulation for Intractable Facial Pain

Postherpetic Trigeminal Neuralgia of the V2 Branch Treated with Electrodes Placed through the Foramen Ovale: A Case Report

Varicella-zoster virus (VZV) is a deoxyribonucleic acid (DNA) virus that causes both primary and recurrent viral infections. Herpes zoster (HZ), also known as shingles, is a unique condition that is induced by VZV reactivation. Neuropathic pain, malaise, and sleep disruption are prodromal symptoms in such cases. Postherpetic trigeminal neuralgia is a neuropathic pain caused by VZV infection of the trigeminal ganglion or branches, which remains or reappears after herpes crusting. In this report, we present a case of post-herpetic trigeminal neuralgia of the V2 branch, exhibiting findings of unusual involvement of the trigeminal nerve. Notably, the patient was treated using electrodes placed through the foramen ovale.

Trigeminal ganglion itself can be a viable target to manage trigeminal neuralgia

Excruciating trigeminal neuralgia (TN) management is very difficult and severely affects the patient's quality of life. Earlier studies have shown that the trigeminal ganglion (TG) comprises several receptors and signal molecules that are involved in the process of peripheral sensitization, which influences the development and persistence of neuropathic pain. Targeting TG can modulate this sensitization pathway and mediate the pain-relieving effect. So far,there are few studies in which modulation approaches to TG itself have been suggested so far. "Trigeminal ganglion modulation" and "trigeminal neuralgia" were used as search phrases in the Scopus Index and PubMed databases to discover articles that were pertinent to the topic. In this review, we address the role of the trigeminal ganglion in TN and underlying molecules and neuropeptides implicated in trigeminal pain pathways in processing pathological orofacial pain. We also reviewed different modulation approaches in TG for TN management. Furthermore, we discuss the prospect of targeting trigeminal ganglion to manage such intractable pain.

Case Report: Novel Anchoring Technique and Surgical Nuances for Trigeminal Ganglion Stimulation in the Treatment of Post-Herpetic Trigeminal Neuropathic Facial Pain

Introduction

Trigeminal ganglion stimulation is a neuromodulatory surgical procedure utilized to treat trigeminal neuropathic pain. This technique involves the placement of a stimulating electrode adjacent to the trigeminal ganglion and can be trialed before permanent implantation. Wider adoption by surgical practitioners is currently limited by complications such as lead migration from the trigeminal ganglion, which can result in loss of therapy and cannot be rectified without repeat surgery. We describe a novel surgical modification that successfully anchors the trigeminal ganglion electrode long-term.

Objective

To describe a novel surgical technique for the anchoring of trigeminal ganglion stimulation electrodes and a case report of a patient with post-herpetic trigeminal neuropathic pain treated with this approach.

Methods

An electrode was inserted percutaneously through the foramen ovale into Meckel's cave, adjacent to the trigeminal ganglion. The lead was anchored using a modification of an existing anchoring device, which was inserted into the buccal incision. The lead was connected to a generator for therapeutic stimulation. The location of the lead was followed radiographically using serial lateral skull radiographs.

Results

A 74-year-old male with post-herpetic trigeminal neuropathic pain, who had failed prior surgical therapies, underwent trigeminal ganglion stimulation. The trial lead was anchored using standard techniques and migrated outward within 7 days, rendering the trial electrode ineffective. The permanent lead was anchored using the described novel technique and remained in position without clinically significant outward migration nor loss in targeted stimulation until the last follow-up at 6 months.

Conclusion

Trigeminal ganglion stimulation is an effective therapeutic option for medically refractory trigeminal neuropathic pain. The novel surgical adaptation described prevents the outward migration of the lead and enables stable long-term lead placement.