Subcutaneous Trigeminal Nerve Field Stimulation for Refractory Facial Pain

Summary

Treating chronic or neuropathic facial pain can be challenging when medical or standard treatment fails. Subcutaneous nerve field stimulation is the least invasive form of neuromodulation and is used for chronic back pain. We applied this technology to treat chronic and neuropathic trigeminal facial pain.

Abstract

Chronic or neuropathic trigeminal facial pain can be challenging to treat. Neurosurgical procedures should be applied when conservative treatment fails. Neuromodulation techniques for chronic facial pain include deep brain stimulation and motor cortex stimulation, which are complex to perform. Subcutaneous nerve field stimulation is certified for chronic back pain and is the least invasive form of neuromodulation. We applied this technique to treat chronic and neuropathic trigeminal pain as an individual therapy concept. First, trial stimulation is performed. Subcutaneous leads are placed in the painful trigeminal dermatome under local anesthesia. The leads are connected to an external neurostimulator that applies constant stimulation. Patients undergo a 12 day outpatient trial to assess the effect of the stimulation. Electrodes are removed after the trial. If the patient reports pain reduction of at least 50% in intensity and/or attack frequency, a reduction in medication or increase in quality of life, permanent implantation is scheduled. New electrodes are implanted under general anesthesia and are subcutaneously tunneled to an infraclavicular internal pulse generator. Patients are able to turn stimulation on and off and to increase or decrease the stimulation amplitude as needed.

This technique represents a minimal invasive alternative to other more invasive means of neuromodulation for trigeminal pain such as motor cortex stimulation or deep brain stimulation.

Introduction

The neurosurgical armamentarium to treat trigeminal pain is as large and diverse as the underlying etiologies. In cases of classical trigeminal neuralgia (TN) caused by arterial compression at the brainstem root entry zone of the trigeminal nerve microvascular decompression (MVD)¹ is highly effective. Percutaneous destructive techniques at the Gasserian Ganglion (such as radiofrequency thermocoagulation, glycerol injection or balloon compression²) and stereotactic radiosurgery for trigeminal neuralgia³ can be applied in cases without neurovascular conflict or whenever there are contrain....

Protocol

NOTE: All procedures are performed as individual healing attempts ("Individueller Heilversuch"). And comply with the local ethics board (Ethikkommission Heidelberg) as well as national laws regarding individual healing attempts. Patients are extensively informed by the treating physician about the nature of the therapy, the procedures, the risks and benefits. All patients give written informed consent before beginning with the procedure. Individual healing attempts need the approval for reimbursement by the patient's health care service. This has to be obtained by the treating physician before scheduling the procedures.

1. Indicat....

Results

As subcutaneous trigeminal nerve field stimulation (sTNFS) is not a standard treatment and the number of patients that can potentially benefit from it is rather small compared to other diseases, there are only smaller case series that present results of sTNFS. In one series, 10 patients underwent test stimulation for sTNFS. Eight of the patients responded to the therapy and received permanent implantation of electrodes and an IPG¹¹. The patients suffered from trige.......

Discussion

With subcutaneous trigeminal nerve field stimulation (sTNFS), we present a surgical technique to perform minimally invasive neuromodulation for chronic refractory pain of the trigeminal nerve of different etiologies.

To reduce complications thorough disinfection of the entire surgical field is vital. Any unnecessary skin perforation can increase the risk of device infection with the consecutive loss of the system. Physicians should always pay attention to the implantation depth of the electrod.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
myStim Patient Programmer	Medtronic	97740	enables the patient to turn off and on stimulation
Prime Advanced	Medtronic	97702	non-rechargeable IPG as powersource for stimulation
Restore Ultra	Medtronic	97712	rechargeable IPG as powersource for stimulation
Charging System	Medtronic	97754	used by the patient to recharge the Restore Ultra IPG
N'Vision Programmer	Medtronic	8840	used by the physician to program the IPG and define stimulation parameters
External Neurostimulator	Medtronic	37022	external IPG as powersource for trial stimulation with externalized electrodes
Advanced Screening Cable	Medtronic	355531	connects externalized electrodes to the external neurostimulator during trial stimulation
Tunnelling Spear 60 cm	Medtronic	3655-60	used to subcutaneously tunnel the permanent electrodes to an infraclavicular pocket that houses the IPG
Tunnelling Spear 38 cm	Medtronic	3655-38	used to subcutaneously tunnel the permanent electrodes to an infraclavicular pocket that houses the IPG
Tuhoy Cannula	Medtronic	3550-32	14 G Epidural Tuhoy cannula (length 9 cm) to subcutaneously implant the electrodes
InjexFixation Device	Medtronic	97791 / 97792	used to fixate the electrodes on the skin or on the muscle fascia
Octad Compact	Medtronic	3878-60	permanent electrode (length 60 cm) implanted in the subcutaneous tissue with 8 contacts
Vectris Trial Lead	Medtronic	977D260	externalized electrode (length 60 cm) used during the stimulation trial
Ethilon*II 3-0	Ethicon	EH7933H	non-absorbable suture for skin closure
Seide 2-0	Resorba	40221	non-absorbable silk suture to fixate electrodes and IPG
Resolon DS21	Resorba	881413	absorbable suture for subcutaneous wound closure
Feather disposable scalpel	Feather	5205052	single use scalpel for skin incision and suture cutting
Scandicain 1%	Astra Zeneca	23186	1% Mepivacain solution for local anesthesia
Cosmopor E steril 10 x 6	Hartmann	900871	Sterile draping for IPG wound
Cosmopor E steril 7, 2 x 5	Hartmann	900870	Sterile draping for skin punctures and small incisions
Foliodrape Comfort 50 x 50	Hartmann	252302	Sterile draping for the surgical field
Cephazolin	Fresenius	6062403.00.00	Single shot perioperative antibiotic
Kepinol forte 800 mg/160 mg	Dr. R. Pfleger Chemische Fabrik	2485177	Postoperative prophylactic oral antibiotic
Poly-Alcohol	Antiseptica	UN1219	Coloured skin disinfectant used during the permanent implantation
Cutasept F	Bode	976800	Un-colored skin disinfectant used during the trial implantation