Occipital nerve stimulation (ONS) is a neuromodulation technique aimed at the treatment of different types of neuralgia. This minimally invasive adjustable, and reversible approach provides an implantable device composed of a subcutaneous regional electrode and a pulse generator. It was first described by Picaza et al., in 1977, and thus performed on 13 patients by Weiner and Reed in 1999 for the “control of intractable occipital neuralgia.”[1][2] From this first application, possible indications of ONS have expanded to various primary and secondary headache disorders not responsive to other therapies, including drugs for neuropathic pain, infiltrations (e.g., corticosteroids), radiofrequency rhizolysis, acupuncture, psychobehavioral approaches, and different multidisciplinary strategies.[3][4][5][6]
The nerves that innervate the occipital area includes the greater (a branch of C2 spinal root), lesser (a branch of C2 and C3 spinal root), and least occipital nerve (a medial branch of the posterior division of C3). The greater occipital is the largest pure sensory nerve and provides sensory innervation to the skin of the posterior skull, occipital, and temporal area. It is closely associated with the occipital artery at the exit site. The lesser occipital nerve is a cutaneous branch that provides sensory innervation to the skin of the upper and back part of the auricle. The least occipital nerve lies medial to greater occipital nerve and supplies C2-C3 zygapophyseal joint, part of semispinalis capitis, and a small area below the occiput.[7] While the precise mechanism of action of ONS is still unclear, there has been a proposal that the continuous stimulation of the occipital nerves may produce diverse functional and metabolic changes in many brain regions, including pons, midbrain, and periaqueductal gray.[8]
ONS is indicated in primary (without an underlying organic cause) and secondary (caused by an underlying condition, such as neck injuries, infections, or severe high blood pressure) intractable headache disorders including migraine and non-migrainous chronic headaches, and neuropathic pain in the occipital region.[9] Chronic headache is commonly defined as a headache on 15 or more days every month for longer than three months.[10] Patients with refractory headaches usually have failed results with conventional drugs either because of lack of effect, intolerable side effects, or contraindication to using.[10]
Indications for occipital nerve stimulation include:
Recently, this approach has been successful in treating a case of chemotherapy-related headaches.[11]
The contraindication of ONS are as follows[12]:
The equipment required for ONS include[13]:
Preprocedural planning. A trial is necessary before permanent ONS implantation. In the trial period, leads are placed under the skin and connected to an external battery. The leads get inserted into the trailing cable. Stimulation is provided temporarily using a radiofrequency transmitter to different electrode combinations; this helps the patient to report the location, intensity, and sensation of stimulation. The trial period lasts for 4 to 7 days. During this period, the patient must maintain a headache diary. ONS is considered successful if there is more than fifty percent improvement in pain, or there is a decrease in the number of headache days or the patient reports improvement in the quality of life. The patients with successful block qualify for permanent implantation.[14] After the procedure, a complete healing time lasts for approximately six weeks. During that period, the patient is to avoid rigorous activity.
Local anesthesia vs. general anesthesia. Weiner and Reed performed the placement of electrodes under local anesthesia. The advantage with local anesthesia is that it allows the patient to assess the site of paresthesia and thus verify electrode placement. This procedure can also take place under sedation with propofol (i.e., procedural sedation), and the staff can wake the patient to check areas of paresthesia intra-operatively. Recently, physicians have also been performing the procedure under general anesthesia in the prone position, which decreases the risk of lead migration.[15]
Positioning. The procedure is possible in a lateral or prone position, depending on the entry point of incision.
ONS is a minimally invasive technique in which a stimulator is implanted either unilaterally or bilaterally at the level of occipito-cervical junction. The stimulation parameters, like pulse width, amplitude, and frequency, can be adjusted to create paresthesia in the distribution of the occipital nerve. The procedure is performable under a lateral or medial approach.
Lateral approach. Weiner and Reed originally described the lateral approach in which the clinician makes an incision on the mastoid process, and the catheter was then subcutaneously advanced towards midline at the level of C1 with the help of fluoroscopy.[2]
Medial approach. A 2 cm midline incision is made at the level of C1, and then leads are inserted laterally from the midpoint.
The advantages of the medial approach include[16]:
Implant placement. The different positioning sites of the IPG include the upper buttock, abdomen, infrascapular region, and infraclavicular regions.[13] The advantage of placement in the upper buttock is that both electrode and generator can be placed in a prone position, whereas lateral or supine position is necessary for the other sites. It takes place under general anesthesia.
Programming. Specific personnel appointed by the manufacturer do the device programming and maintenance.
A skull X-ray is taken after procedure completion to document the final lead position; this is also useful in the future to assess complications associated with lead migration or fracture.
The procedure-related complications are hardware-related and biological.
Hardware-related complications
Lead migration is by far the most frequent complication reported with ONS. In a retrospective analysis of fifteen patients treated for a medically refractory headache, Schwedt et al. reported the rate as high as 60 to 100%.[17] Moreover, this was also the most frequently reported adverse event (12 of 51 patients) in the ONSTIM randomized controlled trial on cephalgia.[18] The various studies on occipital neuralgia report an 8 to 10% incidence of lead migration.[19][20][2] Of note, the occurrence of the complications is reducible by decreasing mechanical stress on the leads by avoiding excessive neck movement. Moreover, these complications are usually related to severe trauma, such as a major car accident. Other methods described in the literature to prevent lead migration include the use of silicone glue, soft neck collars, and the use of a midline approach.[13] The other hardware-related complications include lead fracture and malfunction and repositioning of the generator.[17][18][2][9]
Biological complications
Patients treated with implanted neuromodulation devices often report pain related to the site of device components.[21] Saper et al. reported two cases of pain, one over the IPG site and other burning pain over the lead site. The other complications reported in retrospective studies include muscle spasms, wound dehiscence, infection (up to 4%), and skin erosion.[18][22] Infection can be prevented by prophylactic antibiotics, maintaining asepsis throughout the procedure, and trimming of occipital region hair using clippers.
Some other complications associated with ONS include device malfunction, compliance issues, ineffective stimulation, and device shock.[21]
Chronic headache affects 3 to 5% of the world population and ranks third highest cause of years lost due to disability.[23] Recent advances in the medical management of headache disorders have led to the effective treatment of the majority of patients. However, a small percentage of these patients do not respond to conventional treatment options. While ONS could be an interesting option in the treatment of this subset of patients, there is only limited scientific evidence regarding its effectiveness as the studies conducted so far have enrolled a small number of patients and are uncontrolled investigations. Furthermore, there is little data on the long-term results. A multicentric, controlled (ONS compared to the optimal medical management), and randomized study organized by the Nantes University Hospital is ongoing. The estimated study completion date is the end of 2022, and its results should clarify many doubts about the actual utility of the technique.
A systemic review on chronic migraine demonstrated that the short term effect of ONS might be modest but still clinically significant in patients with refractory headache.[24] While some patients apparently experienced significant improvement, the data is limited. At the same time, it correlates with the procedure and device-related complications. Currently, ONS seems a valuable option for patients who have failed all conventional treatment, but further studies are needed to evaluate the safety and efficacy. Due to the lack of conclusive data, currently, the use of ONS should be based on individual preference and treatment response.
[1] | Picaza JA,Hunter SE,Cannon BW, Pain suppression by peripheral nerve stimulation. Chronic effects of implanted devices. Applied neurophysiology. 1977-1978 [PubMed PMID: 309314] |
[2] | Weiner RL,Reed KL, Peripheral neurostimulation for control of intractable occipital neuralgia. Neuromodulation : journal of the International Neuromodulation Society. 1999 Jul; [PubMed PMID: 22151211] |
[3] | Keifer OP Jr,Diaz A,Campbell M,Bezchlibnyk YB,Boulis NM, Occipital Nerve Stimulation for the Treatment of Refractory Occipital Neuralgia: A Case Series. World neurosurgery. 2017 Sep; [PubMed PMID: 28634063] |
[4] | Rodrigo D,Acin P,Bermejo P, Occipital Nerve Stimulation for Refractory Chronic Migraine: Results of a Long-Term Prospective Study. Pain physician. 2017 Jan-Feb; [PubMed PMID: 28072807] |
[5] | Miller S,Watkins L,Matharu M, Treatment of intractable chronic cluster headache by occipital nerve stimulation: a cohort of 51 patients. European journal of neurology. 2017 Feb; [PubMed PMID: 27995704] |
[6] | Liu A,Jiao Y,Ji H,Zhang Z, Unilateral occipital nerve stimulation for bilateral occipital neuralgia: a case report and literature review. Journal of pain research. 2017; [PubMed PMID: 28176938] |
[7] | Choi I,Jeon SR, Neuralgias of the Head: Occipital Neuralgia. Journal of Korean medical science. 2016 Apr; [PubMed PMID: 27051229] |
[8] | Bari AA,Pouratian N, Brain imaging correlates of peripheral nerve stimulation. Surgical neurology international. 2012 [PubMed PMID: 23230531] |
[9] | Palmisani S,Al-Kaisy A,Arcioni R,Smith T,Negro A,Lambru G,Bandikatla V,Carson E,Martelletti P, A six year retrospective review of occipital nerve stimulation practice--controversies and challenges of an emerging technique for treating refractory headache syndromes. The journal of headache and pain. 2013 Aug 6; [PubMed PMID: 23919570] |
[10] | Goadsby PJ,Schoenen J,Ferrari MD,Silberstein SD,Dodick D, Towards a definition of intractable headache for use in clinical practice and trials. Cephalalgia : an international journal of headache. 2006 Sep; [PubMed PMID: 16919073] |
[11] | Abd-Elsayed A,Raphaeil N, Successful Treatment of Chemotherapy-Induced Headaches With Occipital Nerve Stimulation: A Case Report. Neuromodulation : journal of the International Neuromodulation Society. 2019 Nov 22 [PubMed PMID: 31755627] |
[12] | Dodick DW,Silberstein SD,Reed KL,Deer TR,Slavin KV,Huh B,Sharan AD,Narouze S,Mogilner AY,Trentman TL,Ordia J,Vaisman J,Goldstein J,Mekhail N, Safety and efficacy of peripheral nerve stimulation of the occipital nerves for the management of chronic migraine: long-term results from a randomized, multicenter, double-blinded, controlled study. Cephalalgia : an international journal of headache. 2015 Apr; [PubMed PMID: 25078718] |
[13] | Trentman TL,Zimmerman RS, Occipital nerve stimulation: technical and surgical aspects of implantation. Headache. 2008 Feb; [PubMed PMID: 18234049] |
[14] | Lambru G,Matharu MS, Occipital nerve stimulation in primary headache syndromes. Therapeutic advances in neurological disorders. 2012 Jan; [PubMed PMID: 22276076] |
[15] | Trentman TL,Zimmerman RS,Dodick DW,Dormer CL,Vargas BB, Occipital nerve stimulator placement under general anesthesia: initial experience with 5 cases and review of the literature. Journal of neurosurgical anesthesiology. 2010 Apr; [PubMed PMID: 19816202] |
[16] | Paemeleire K,Bartsch T, Occipital nerve stimulation for headache disorders. Neurotherapeutics : the journal of the American Society for Experimental NeuroTherapeutics. 2010 Apr; [PubMed PMID: 20430321] |
[17] | Schwedt TJ,Dodick DW,Hentz J,Trentman TL,Zimmerman RS, Occipital nerve stimulation for chronic headache--long-term safety and efficacy. Cephalalgia : an international journal of headache. 2007 Feb; [PubMed PMID: 17257236] |
[18] | Saper JR,Dodick DW,Silberstein SD,McCarville S,Sun M,Goadsby PJ, Occipital nerve stimulation for the treatment of intractable chronic migraine headache: ONSTIM feasibility study. Cephalalgia : an international journal of headache. 2011 Feb; [PubMed PMID: 20861241] |
[19] | Johnstone CS,Sundaraj R, Occipital nerve stimulation for the treatment of occipital neuralgia-eight case studies. Neuromodulation : journal of the International Neuromodulation Society. 2006 Jan; [PubMed PMID: 22151592] |
[20] | Melvin EA Jr,Jordan FR,Weiner RL,Primm D, Using peripheral stimulation to reduce the pain of C2-mediated occipital headaches: a preliminary report. Pain physician. 2007 May; [PubMed PMID: 17525779] |
[21] | Doran J,Ward M,Ward B,Paskhover B,Umanoff M,Mammis A, Investigating Complications Associated With Occipital Nerve Stimulation: A MAUDE Study. Neuromodulation : journal of the International Neuromodulation Society. 2018 Apr; [PubMed PMID: 29345415] |
[22] | Paemeleire K,Van Buyten JP,Van Buynder M,Alicino D,Van Maele G,Smet I,Goadsby PJ, Phenotype of patients responsive to occipital nerve stimulation for refractory head pain. Cephalalgia : an international journal of headache. 2010 Jun; [PubMed PMID: 20511204] |
[23] | Rizzoli P,Mullally WJ, Headache. The American journal of medicine. 2018 Jan; [PubMed PMID: 28939471] |
[24] | Chen YF,Bramley G,Unwin G,Hanu-Cernat D,Dretzke J,Moore D,Bayliss S,Cummins C,Lilford R, Occipital nerve stimulation for chronic migraine--a systematic review and meta-analysis. PloS one. 2015; [PubMed PMID: 25793740] |