Surgical Options for Complex Craniofacial Pain

Outcome of Surgical Treatments of Chronic Pain Caused by Trigeminal Neuropathy

BACKGROUND

Trigeminal neuropathy represents a subset of several facial pain syndromes that are difficult to diagnose and treat. Although many surgical modalities are available, outcomes remain suboptimal. The aim of this study is to present our experience in management of trigeminal neuropathy with a focus on the effectiveness and long-term efficacy of the different surgical procedures.

METHODS

A single-center retrospective cohort study was conducted from December 2012 until February 2020.

RESULTS

Twenty-eight patients (19 females, 9 males) were included in this study. They had 40 surgical interventions. At last follow-up, 1 patient (33.3%) treated by spinal cord stimulation (SCS) had no pain recurrence and 2 patients (66.6%) had their devices removed because of therapeutic failure. Median time to pain recurrence after SCS was 19.5 months (interquartile range [IQR], 29.79 months). Six patients were treated with peripheral nerve stimulation (PNS). At last follow-up, 2 patients had satisfactory pain relief, whereas half of the patients had no improvement. For the 17 patients treated with computed tomography-guided trigeminal tractotomy/nucleotomy, true failure occurred 7 times in 6 patients. Median time to pain recurrence was 5.6 months (IQR, 6.2). Of the 6 patients treated with caudalis DREZ, 3 (50%) had satisfactory pain relief for >1 year and the median time to pain recurrence was 3.9 months (IQR, 29.53).

CONCLUSIONS

Trigeminal neuropathy is a difficult to treat entity of facial pain syndromes. The long-term efficacy of available interventions does not meet patients' satisfaction. More organized prospective studies with longer follow-up are needed to define the patient population best served by each surgical modality.

A Review of Medical and Surgical Options for the Treatment of Facial Pain

Facial pain is a common medical complaint that is easily misdiagnosed. As a result, this pain often goes mistreated. Despite this, there are a variety of pharmacologic, surgical, and neuromodulatory options for the treatment of facial pain. In this review, the authors detail the forms of facial pain and their treatment options. They discuss the common medications used in the first-line treatment of facial pain and the second-line surgical and neuromodulatory options available to patients when pharmacologic options fail.

Deep Brain Stimulation and Motor Cortex Stimulation for Chronic Pain

Deep brain stimulation (DBS) and Motor Cortex stimulation (MCS) have been used for control of chronic pain. Chronic pain of any origin is complex and difficult to treat. Stimulation of various areas in brain-like sensory thalamus, medial nuclei of thalamus including centro-lateral nucleus of thalamus (CL), periaqueductal gray, periventricular gray, nucleus accumbence and motor cortex provides partial relief in properly selected patients. This article reviews the pain pathways, theories of pain, targets for DBS and rationale of DBS and MCS. It also discusses the patient selection, technical details of each target.

Peripheral Neuromodulation for Chronic Pain

BACKGROUND

Chronic, focal, neuropathic pain is difficult to treat. Local nerve blocks are either ineffective or do not last. Regular neuromodulation modalities like spinal cord stimulation (SCS) or pain pump are invasive and affect a larger area.

OBJECTIVES

To discuss the indications, technique, nuances, programming, and outcomes of peripheral neuromodulation.

METHODS

The article reviews published literature and the author's own experience of over 500 cases of peripheral neuromodulation.

RESULTS AND CONCLUSION

Peripheral neuromodulation using peripheral nerve field stimulation (PNFS) is an effective, minimally invasive, targeted method of treatment. It is a relatively new modality in the field of neuromodulation but is used more often.

Craniofacial Peripheral Nerve Stimulation: Analysis of a Single Institution Series

OBJECTIVE

Objective real-world experience with peripheral nerve stimulation (PNS) is limited. Furthermore, the lack of robust outcome metrics, long-term follow-up and data comparing responders and nonresponders limit the refinement of selection criteria to better identify patients likely to benefit from PNS.

MATERIALS AND METHODS

We retrospectively analyzed 22 patients with craniofacial pain treated with PNS, and responders were classified as having ≥50% postoperative improvement in the numeric rating scale (NRS). In a subset of patients (n = 11), detailed prospective outcomes metrics were obtained preoperatively and postoperatively, including NRS, Beck Depression Index (BDI), Pain Catastrophizing Scale (PCS), and McGill Pain Questionnaire (MPQ).

RESULTS

About 59.1% (13 of 22) of subjects were classified as responders at a mean follow-up of 37.5 ± 5.27 months. Diagnoses included migraine (n = 6), occipital neuralgia (n = 9), trigeminal neuropathic pain (TNP; n = 6), and central poststroke pain (n = 1). Within the TNP subgroup, responders were more likely to have undergone two or more trigeminal neuralgia procedures prior to PNS (p < 0.05). In the 11 patients with comprehensive preoperative and postoperative outcome data, we noted significant improvement in NRS (p = 0.0005), BDI (p = 0.04), PCS (p = 0.01), as well as components of PCS (helplessness and magnification, p = 0.02) and MPQ (affective, p = 0.02).

CONCLUSIONS

The present study adds to the PNS literature by providing long-term data and multiple outcome metrics in a subset of patients. We suggest that BDI, PCS, and MPQ may provide more insight into meaningful response over time. Evaluating functional and quality of life outcomes in patients with craniofacial pain may be more informative than assessing benefit solely based on pain intensity and responder rates.

Placement and Anchoring of Trigeminal Neurostimulation Electrodes: Technical Report

BACKGROUND

Peripheral neurostimulation (PNS) for medically refractory trigeminal and craniofacial pain is an emerging alternative to traditional surgical approaches. Technical problems with craniofacial PNS have included electrode migration and erosion, limiting the utility and cost-effectiveness of this procedure.

OBJECTIVE

To review our institutional surgical technique for trigeminal PNS implantation, focusing on a novel technique for electrode anchoring.

METHODS

Consecutive cases of permanent craniofacial PNS placement by a single surgeon over 36 months were reviewed for surgical technique and technical outcomes. Electrodes were placed percutaneously with open anchoring to the pericranium at a separate parietal incision.

RESULTS

Sixteen systems (53 electrodes) were implanted in 14 patients. Median follow-up was 13 months (range, 5-29 months). Electrode placement was successful in all cases with no intraoperative complications. There was 1 lead migration (6.3% per patient; 1.8% per lead) and no cases of erosion. Two patients (14.3%) required explant for infection, 1 of whom was successfully reimplanted. Three patients (21.4%) underwent surgical revision other than for infection.

CONCLUSIONS

We present an improved method for craniofacial PNS surgery which introduces a separate incision for electrode anchoring at the parietal boss. This technique simplifies the procedure and greatly reduces rates of erosion and migration, improving patient comfort and satisfaction.

Upper Cervical Spinal Cord Stimulation as an Alternative Treatment in Trigeminal Neuropathy

OBJECTIVE

To describe the indications and outcomes of upper cervical cord stimulation in trigeminal neuropathy.

METHODS

A consecutive single-center series of patients was retrospectively reviewed. It included 12 patients with trigeminal neuropathy treated with upper cervical spinal cord stimulation. Clinical features, complications, and outcomes were reviewed.

RESULTS

All patients had a successful trial before the definitive implantation of a spinal cord stimulator at the level of the craniocervical junction. The mean follow-up period was 4.4 years (range, 0.3-21.1 years). The average coverage in the pain zone was 72% and the median baseline, trial, and postoperative numeric rating scale (NRS) was 7, 3, and 3, respectively. When compared with the baseline, the mean reduction achieved in the postoperative average numeric rating scale was 4 points, accounting for a 57.1% pain reduction. The long-term failure rate was 25%.

CONCLUSIONS

Despite there being enough evidence to consider upper cervical spinal cord stimulation as an effective treatment for patients with neuropathic trigeminal pain, a randomized controlled trial is needed to fully assess its indications and outcomes and compare it with other therapeutic approaches.

Sandwich technique, peripheral nerve stimulation, peripheral field stimulation and hybrid stimulation for inguinal region and genital pain

OBJECTIVE

Ilioinguinal neuralgia (IG) and genitofemoral (GF) neuralgia following inguinal hernia repair is a chronic and debilitating neuropathic condition. Recently, peripheral nerve stimulation has become an effective and minimally invasive option for the treatment of refractory pain. Here we present a retrospective case series of six patients who underwent placement of peripheral nerve stimulation electrodes using various techniques for treatment of refractory post-intervention inguinal region pain.

METHODS

Six patients with post-intervention inguinal, femoral or GF neuropathic pain were evaluated for surgery. Either octopolar percutaneous electrodes or combination of paddle and percutaneous electrodes were implanted in the area of their pain. Pain visual analog scores (VAS), surgical complication rate, preoperative symptom duration, degree of pain relief, preoperative and postoperative work status, postoperative changes in medication usage, and overall degree of satisfaction with this therapy was assessed.

RESULTS

All six patients had an average improvement of 62% in the immediate post-operative follow-up. Four patients underwent stimulation for IG, one for femoral neuralgia, and another for GF neuralgia. Peripheral nerve stimulation provided at least 50% pain relief in all the six patients with post-intervention inguinal region pain. 85% of patients indicated they were completely satisfied with the therapy overall. There was one treatment failure with an acceptable complication rate.

CONCLUSION

Peripheral nerve or field stimulation for post-intervention inguinal region pain is a safe and effective treatment for this refractory and complex problem for patients who have exhausted other management options.

Trigeminal and sphenopalatine ganglion stimulation for intractable craniofacial pain--case series and literature review

INTRODUCTION

Facial pain is often debilitating and can be characterized by a sharp, stabbing, burning, aching, and dysesthetic sensation. Specifically, trigeminal neuropathic pain (TNP), anesthesia dolorosa, and persistent idiopathic facial pain (PIFP) are difficult diseases to treat, can be quite debilitating and an effective, enduring treatment remains elusive.

METHODS

We retrospectively reviewed our early experience with stimulation involving the trigeminal and sphenopalatine ganglion stimulation for TNP, anesthesia dolorosa, and PIFP between 2010-2014 to assess the feasibility of implanting at these ganglionic sites. Seven patients received either trigeminal and/or sphenopalatine ganglion stimulation with or without peripheral nerve stimulation, having failed multiple alternative modalities of treatment. The treatments were tailored on the physical location of pain to ensure regional coverage with the stimulation.

RESULTS

Fluoroscopy or frameless stereotaxy was utilized to place the sphenopalatine and/or trigeminal ganglion stimulator. All patients were initially trialed before implantation. Trial leads implanted in the pterygopalatine fossa near the sphenopalatine ganglion were implanted via transpterygoid (lateral-medial, infrazygomatic) approach. Trial leads were implanted in the trigeminal ganglion via percutaneous Hartel approach, all of which resulted in masseter contraction. Patients who developed clinically significant pain improvement underwent implantation. The trigeminal ganglion stimulation permanent implants involved placing a grid electrode over Meckel's cave via subtemporal craniotomy, which offered a greater ability to stimulate subdivisions of the trigeminal nerve, without muscular (V3) side effects. Two of the seven overall patients did not respond well to the trial and were not implanted. Five patients reported pain relief with up to 24-month follow-up. Several of the sphenopalatine ganglion stimulation patients had pain relief without any paresthesias. There were no electrode migrations or post-surgical complications.

CONCLUSIONS

Refractory facial pain may respond positively to ganglionic forms of stimulation. It appears safe and durable to implant electrodes in the pterygopalatine fossa via a lateral transpterygoid approach. Also, implantation of an electrode grid overlying Meckel's cave appears to be a feasible alternative to the Hartel approach. Further investigation is needed to evaluate the usefulness of these approaches for various facial pain conditions.