Acta Neurochir (2015) 157:105–108 DOI 10.1007/s00701-014-2281-8

HOW I DO IT - FUNCTIONAL

The surgical technique of occipital nerve stimulation P. J. Slotty & G. Bara & J. Vesper

Received: 26 August 2014 / Accepted: 11 November 2014 / Published online: 26 November 2014 # Springer-Verlag Wien 2014

Abstract Background Occipital nerve stimulation is increasingly used in the treatment of primary headache disorders. We describe a surgical technique applying preoperative fluoroscopy and intraoperative tactile orientation designed to reduce radiation exposure and provide reproducible results. Method Under general anesthesia and in the supine position, the C1-C2 transition is identified fluoroscopically and marked with an electrocardiogram (ECG) electrode prior to surgery. During electrode placement, the ECG electrodes are used for tactile orientation of electrode direction and depth. Conclusions The use of tactile orientation solely during surgery reduces radiation exposure and decreases the duration of surgery. This technique allows reproducible results of final electrode position. Keywords Occipital nerve stimulation . Surgical technique

Introduction During the past 15 years, there has been increased interest in neurostimulation of the occipital nerve (ONS) in

Electronic supplementary material The online version of this article (doi:10.1007/s00701-014-2281-8) contains supplementary material, which is available to authorized users. P. J. Slotty (*) : G. Bara : J. Vesper Department of Stereotactic and Functional Neurosurgery, Neurosurgical Clinic, Heinrich-Heine University, Düsseldorf, Germany e-mail: [email protected] P. J. Slotty Division of Neurosurgery, Department of Surgery, University of British Columbia, Vancouver, BC, Canada

the treatment of primary headache disorders. The main rationale for ONS is the anatomo-functional convergence of cervical (especially C2), somatic trigeminal, and dural trigeminovascular afferent neurons on second-order nociceptors in the trigeminocervical complex [1, 4]. The surgical technique of ONS first described in 1999 is not yet standardized and many different techniques exist, many of them differing to a large extent regarding number, type and placement of the electrodes [7]. The common aim of all ONS techniques is to establish epifascial, subcutaneous stimulation of the greater occipital nerve complex (GON). We do not use trial stimulation as we commonly observe delayed treatment onset and with the adjunct of fluoroscopy the patient does not have to be conversant during the procedure. We therefore designed a simple, all-in-one ONS technique applying a combination of anatomical landmarks and radiological orientation rendering intraoperative trial stimulation unnecessary. This approach reduces the radiation exposure to operating room staff and patients compared with other techniques relying on fluoroscopic guidance during ONS surgery.

Relevant surgical anatomy The greater occipital nerve shows a wide variety ascending between 5 and 28 mm laterally of the midline in the intermastoid line [2]. As its position is related to the spine but not to the mastoid process during movement the C1C2 transition is identified fluoroscopically in our approach. The midline of the head and spine is identified by palpation. The posterior superior iliac spine is identified by palpation and used as the superior border of the stimulator pouch.

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Description of the technique Surgery is performed under general anesthesia in the Concorde position with a headrest supporting the zygoma and forehead. Straight lateral X-ray of the cranio-cervical junction is used to identify the C1-C2 transition. The posterior division of the C1-C2 transition is bilaterally marked with two electrocardiogram (ECG) electrodes bonded to the skin of the neck for intraoperative tactile orientation (Fig. 1). The sterile draping follows the course of the midline incision in the back of the neck and the course of the leads paraspinal down to the IPG (implantable pulse generator) implantation site either on the left or the right lower back. A 4-cm linear incision is made in the midline of the neck with its midpoint at the level of the intermastoid line. A circular epifascial preparation of 5-cm diameter is performed strictly avoiding damage to the fascia preventing accidental subfascial electrode placement. The ipsilateral ECG electrode is palpated below the sterile draping serving as a tactile guidance regarding direction and depth. A slightly bent Touhy needle approximating the curvature of the skin is inserted and advanced in the direction of the ECG electrode in a strict epifascial plane. Cylindrical electrodes (e.g., Octrode; St. Jude Medical, St Paul, MN, USA) are inserted and the needle is carefully pulled back. The electrodes are advanced backwards until the most proximal contact ring becomes visible in the approach. The electrode is then closely anchored in the midline and following placement of the contralateral electrode two loops each are placed in the nuchal area and likewise tightly sutured with non-absorbable suture (Fig. 2). The electrodes are tunneled to the left or right (depending on the patient’s discretion) gluteal region, additional loops are placed halfway in the paraspinal epifascial tissue and extensions are connected. The IPG is placed in a generous pouch and tightly sutured to prevent turning of the device.

Fig. 1 Preoperative fluoroscopic localization of the C1-C2 transition and placement of ECGelectrodes at the C1/C2 transition for intraoperative tactile orientation (note radiographic appearance of ECG markers on left image, skin markings for the primary incision and green interrupted line indicating the planned electrode position and trajectory on the right image)

Acta Neurochir (2015) 157:105–108

Meticulous hemostasis should be applied to reduce the risk of infection. All wounds are closed and draped in a standard manner. Correct electrode placement is verified by lateral and AP fluoroscopy at the end of surgery (Fig. 3). During the first weeks after surgery we expect relevant changes in tissue conductivity due to edema and possibly hematoma. We therefore start programming not before 4 weeks after surgery.

Indications The indications for this technique include but are not limited to primary headache disorders as chronic migraine and cluster headache. Additional and future indications include occipital neuralgia, short-lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT), trigeminal neuralgia and postherpetic pain.

Limitations General limitations of ONS are prior major surgery in the posterior neck or occipital region. Severe psychiatric disorders and the inability to operate the IPG have been stated as a contraindication in recent publications on neuromodulation devices in general.

How to avoid complications Compared with other neuromodulation techniques, and especially peripheral nerve stimulation, ONS seems to bear a higher rate of complications, especially infections and dislocations. Numerous idiosyncrasies might contribute to this: (1) the long run of the extensions from the back of the head to the IPG, (2) the rather thin subcutaneous tissue in the back of the

Acta Neurochir (2015) 157:105–108

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Specific information for the patient Lead migrations and infections are still a major concern in ONS surgery and rates for both events are higher in ONS compared with other neuromodulation techniques. The patients should be well aware of the limited number of responders and the commonly observed delayed treatment onset of this technique. Individual information regarding this must be given depending on the condition treated.

Summary (ten key points) Fig. 2 Intraoperative view at the dorsal cervical region straight from the midline, technique of electrode fixation: two loops for each electrode placed in epifascial pouch, amply fixated with non-resorbable sutures

neck, (3) the high amount of movement in the course of the extension and (4) the high amount of movement by head rotation and flexion/extension in the area of the electrodes [3]. These have to be anticipated and confronted by meticulous sterility, implant placement and wound closure. Especially choosing the right plane of electrode and lead placement is crucial to avoid skin erosion at the electrode tip, therefore ultrasound guidance has been investigated by some groups [5, 6]. Multiple tight anchors at the fascia have to be placed to avoid lead migration and electrode displacement.

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Specific perioperative considerations – Patients should refrain from sports and strenuous activities for at least 14 days to prevent early lead migration and dislocation. As the leads are likely to move during the early postoperative phase, programming might be postponed 2-4 weeks from surgery. Fig. 3 Postoperative radiographic verification of electrode position (AP and lateral, note placement and harmonic turns of the nuchal loops to prevent electrode displacement)



Occipital nerve stimulation is increasingly being used in the treatment of primary headache disorders, such as chronic migraine, cluster headache and fibromyalgia As the target structure, the greater occipital nerve, is not anatomically identified during surgery, anatomical knowledge of the most common variations is required Anatomical landmarks leading to correct final electrode placement must be clearly identified, marked and kept accessible during surgery Preoperative marking reduces radiation exposure to the patient and the operating room staff Tactile orientation during electrode placement allows a two hand technique decreasing the risk of skin perforation during needle placement Bending the Touhy needle to resemble the curvature of the skin further decreases the risk of perforation of the skin The technique described is easily reproducible and allows for consistent surgical results regarding electrode position, thereby improving comparability of treatment results Preoperative marking of the final electrode position does not only reduce radiation exposure but most likely also

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duration of surgery, with infectiological and financial implications Conflicts of interest JV is a consultant for St Jude Medical (SJM), receiving payment for preparing and giving educational presentations as well as reimbursement for travel expenses. PJS received payments for preparing and giving educational presentations as well as reimbursement for travel expenses from SJM. GB received reimbursement for travel expenses from SJM.

References 1. Bartsch T, Goadsby PJ (2002) Stimulation of the greater occipital nerve induces increased central excitability of dural afferent input. Brain 125:1496–1509

2. Becser N, Bovim G, Sjaastad O (1998) Extracranial nerves in the posterior part of the head. Anatomic variations and their possible clinical significance. Spine (Phila Pa 1976) 23:1435–1441 3. Brewer AC, Trentman TL, Ivancic MG, Vargas BB, Rebecca AM, Zimmerman RS, Rosenfeld DM, Dodick DW (2013) Long-term outcome in occipital nerve stimulation patients with medically intractable primary headache disorders. Neuromodulation 16:557–562, discussion 563–554 4. Le Doare K, Akerman S, Holland PR, Lasalandra MP, Bergerot A, Classey JD, Knight YE, Goadsby PJ (2006) Occipital afferent activation of second order neurons in the trigeminocervical complex in rat. Neurosci Lett 403:73–77 5. Skaribas I, Alo K (2010) Ultrasound imaging and occipital nerve stimulation. Neuromodulation 13:126–130 6. Trentman TL, Dodick DW, Zimmerman RS, Birch BD (2008) Percutaneous occipital stimulator lead tip erosion: report of 2 cases. Pain Physician 11:253–256 7. Weiner RL, Reed KL (1999) Peripheral neurostimulation for control of intractable occipital neuralgia. Neuromodulation 2:217–221

The surgical technique of occipital nerve stimulation.

Occipital nerve stimulation is increasingly used in the treatment of primary headache disorders. We describe a surgical technique applying preoperativ...
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