Long-Term Clinical Outcome of Peripheral Nerve Stimulation for Chronic Headache and Complication Prevention

Neuromodulation for Craniofacial Pain and Headaches

Headaches and facial pain are highly prevalent diseases but are often difficult to treat. Though there have been significant advances in medical management, many continue to suffer from refractory pain. Neuromodulation has been gaining interest for its therapeutic purposes in many chronic pain conditions, including headaches and facial pain. There are many potential targets of neuromodulation for headache and facial pain, and some have more robust evidence in favor of their use than others. Despite the need for more high-quality research, the available evidence for the use of neuromodulation in treating headaches and facial pain is promising. Considering the suffering that afflicts patients with intractable headache, neuromodulation may be an appropriate tool to improve not only pain but also disability and quality of life.

Peripheral Nerve Stimulation: Two Cases of Intractable Neuropathic Pain

Introduction

Neuropathic pain can be caused by several pathologies affecting the nervous system. Peripheral neuralgias may be related to nerve entrapment, traumatic or iatrogenic events, and may also accompany many other diseases. Peripheral nerve stimulation is effective in treating many of these neuralgic syndromes.

Case Presentation

We treated two patients suffering from chronic neuropathic pain of peripheral origin with the implantation of a Bioness (Valencia CA, USA) StimRouter® peripheral nerve stimulation system with follow-up visits at 1 - 3 - 6 - 12 months.

Conclusions

PNS performed with the StimRouter® system, implanted percutaneously under ultrasound guidance, is safe and effective for patients.

Short-Term Peripheral Nerve Stimulation Relieve Pain for Elder Herpes Zoster Ophthalmicus Patients: A Retrospective Study

OBJECTIVE

Ophthalmic postherpetic neuralgia (PHN) is the final stage of herpes zoster (HZ) ophthalmicus and a severe refractory neuropathic pain, thus there is no curative treatment that could alleviate pain and reduce the incidence of ophthalmic PHN now. The purpose of this study is to evaluate therapeutic efficacy of short-term peripheral nerve stimulation (PNS) for elder patients with HZ ophthalmicus.

MATERIALS AND METHODS

We performed a retrospective study from March 2015 to August 2019 in our pain department. All the HZ ophthalmicus patients underwent supraorbital nerve short-term PNS were included. The patients' data, including numeric rating scale (NRS), 36-Item short form health survey (SF-36), and analgesic consumptions, were retrospectively analyzed. Severe side effects also were recorded.

RESULTS

A total of 68 patients were enrolled in this study. The NRS scores were significantly decreased at different time points after short-term PNS compared to baseline (p < 0.001). The SF-36 scores, including general health, social function, emotional role, mental health, bodily pain, physical functioning, physical role, and vitality, were significantly improved at different time points after treatment (p < 0.001). The average dosages of tramadol and pregabalin administered (mg/d) were both significantly reduced compared to baseline (p < 0.001). There was no bleeding, infection, pain increase, and other side effects after treatment.

CONCLUSIONS

Short-term PNS is an effective and safe therapeutic alternative for elder patients with HZ ophthalmicus and could reduce the incidence of ophthalmic PHN.

Peripheral Neuromodulation for the Management of Headache

Context

Neuromodulation is an expanding field of study for headache treatment to reduce pain by targeting structures within the nervous system that are commonly involved in headache pathophysiology, such as the vagus nerve (VNS), occipital nerves, or sphenopalatine ganglion (SPG) for stimulation. Pharmaceutical medical therapies for abortive and prophylactic treatment, such as triptans, NSAIDs, beta-blockers, TCAs, and antiepileptics, are effective for some individuals, but the role that technology plays in investigating other therapeutic modalities is essential. Peripheral neuromodulation has gained popularity and FDA approval for use in treating certain headaches and migraine headache conditions, particularly in those who are refractory to treatment. Early trials found FDA approved neurostimulatory implant devices, including Cephaly and SpringTMS, improved patient-oriented outcomes with reductions in headaches per month (frequency) and severity.

Evidence Acquisition

This was a narrative review. The sources for this review are as follows: Searching on PubMed, Google Scholar, Medline, and ScienceDirect from 1990 - 2019 using keywords: Peripheral Neuromodulation, Headache, vagus nerve, occipital nerves, sphenopalatine ganglion.

Results

The first noninvasive neurostimulator device approved for migraine treatment was the Cefaly device, an external trigeminal nerve stimulation device (e-TNS) that transcutaneously excites the supratrochlear and supraorbital branches of the ophthalmic nerve. The second noninvasive neurostimulation device receiving FDA approval was the single-pulse transcranial magnetic stimulator, SpringTMS, positioned at the occiput to treat migraine with aura. GammaCore is a handheld transcutaneous vagal nerve stimulator applied directly to the neck at home by the patient for treatment of cluster headache (CH) and migraine. Several other devices are in development for the treatment of headaches and target headache evolution at different levels and inputs. The Scion device is a caloric vestibular stimulator (CVS) which interfaces with the user through a set of small cones resting in the ear canal on either side and held in place by modified over-ear headphones. The pulsante SPG Microstimulator is a patient-controlled device implanted in the patient’s upper jaw via an hour-long oral procedure to target the sphenopalatine ganglion. The occipital nerve stimulator (ONS) is an invasive neuromodulation device for headache treatment that consists of an implanted pulse generator on the chest wall connected to a subcutaneous lead with 4 - 8 electrodes that is tunneled the occiput.

Conclusions

The aim of this review is to provide a comprehensive overview of the efficacy, preliminary outcomes, and limitations of neurostimulatory implants available for use in the US and those pending further development.

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.

Increased mechanosensivity of the greater occipital nerve in subjects with side-dominant head and neck pain - a diagnostic case-control study

Objectives: To investigate differences in pressure pain thresholds (PPTs) and longitudinal mechanosensitivity of the greater occipital nerve (GON) between patients with side-dominant head and neck pain (SDHNP) and healthy controls. Evaluation of neural sensitivity is not a standard procedure in the physical examination of headache patients but may influence treatment decisions. Methods: Two blinded investigators evaluated PPTs on two different locations bilaterally over the GON as well as the occipitalis longsitting-slump (OLSS) in subjects with SDHNP (n = 38)) and healthy controls (n = 38). Results: Pressure pain sensitivity of the GON was lower at the occiput in patients compared to controls (p = 0.001). Differences in pressure sensitivity of the GON at the nucheal line, or between the dominant headache side and the non-dominant side were not found (p > 0.05). The OLSS showed significant higher pain intensity in SDHNP (p < 0.001). In comparison to the non-dominant side, the dominant side was significantly more sensitive (p = 0.004). Discussion: Palpation of the GON at the occiput and the OLSS may be potentially relevant tests in SDHNP. One explanation for an increased bilateral sensitivity may be sensitization mechanisms. Future research should investigate the efficacy of neurodynamic techniques directed at the GON. Level of Evidence: 3b.