How to do it Pract Neurol: first published as 10.1136/practneurol-2020-002612 on 23 October 2020. Downloaded from Peripheral nerve blocks for headache disorders Linford Fernandes ,1 Marc Randall ,1,2 Luis Idrovo 1,2 ► Supplemental material is ABSTRACT experience obtained from clinical supervi- published online only. To view Headache is a common neurological referral and sion by practised healthcare professionals. please visit the journal online a frequent cause for acute hospital admissions. (http://dx.doi.org/10.1136/ practneurol-2020-002612). Despite peripheral nerve blocks being widely used EVIDENCE BASE FOR PERIPHERAL NERVE BLOCKS 1 in headache and pain services to treat patients Neurology, Leeds Teaching Headache practitioners frequently target Hospitals NHS Trust, Leeds, UK with headache disorders, there is no readily 2Headache Service, Leeds accessible resource with instructions for the the greater occipital nerve (GON), but Teaching Hospitals NHS Trust, delivery of peripheral nerve blocks. Here we the treatment of both primary and second- Leeds, UK provide a practical approach for administering ary headaches might target other cervical and cranial nerves. Despite headache spe- Correspondence to peripheral nerve blocks and cover the current Luis Idrovo, Consultant evidence base for such procedures in different cialists seeing positive results in clinical Neurologist, Department of headache disorders. We provide instructions and practice, there is little high-quality infor- 4 Adult Neurology, Leeds Teaching an audiovisual guide for administering greater and mation to support their widespread use. Hospitals NHS Trust, Leeds LS1 lesser occipital, supratrochlear, supraorbital and Several recent randomised controlled 3EX, UK; luis. idrovo@ nhs. net auriculotemporal nerves blocks, and give trials and cohort studies have studied the Accepted 26 August 2020 information on their adverse effects and potential efficacy of peripheral nerve blocks, parti- Published Online First complications. This information will provide cularly GON blocks. The level of evidence 23 October 2020 a reference for headache practitioners when for the effectiveness of peripheral nerve giving peripheral nerve blocks safely to people blocks for managing different headache with headache. disorders varies depending on the pericra- nial nerve targeted and the outcome mea- sure used (table 1). GON blocks for the INTRODUCTION acute and preventative treatment of Headache is one of the most prevalent, dis- migraine and cluster headaches reduce abling and undertreated conditions in neu- headache days and give high levels of rological clinical practice.1 Headache patient-reported efficacy.56Furthermore, http://pn.bmj.com/ practitioners commonly administer periph- peripheral nerve blocks have been effec- eral nerve blocks to treat various headache tive in managing acute or prolonged disorders both in the acute and outpatient migrainous episodes that commonly pre- setting, often with rewarding results.2 There sent to the emergency department.78The is no current national consensus on the tech- rapid onset of pain relief provided by nical aspects of delivering peripheral nerve anaesthetic nerve blocks makes them on September 25, 2021 by guest. Protected copyright. blocks. However, a recent survey among ideal for acute headache presentations, UK headache practitioners showed that where timely management is essential, blocks have become relatively popular tran- reducing the need for opiate-based sitional treatments for cluster headache and therapies. chronic migraine.3 Here we aim to provide Although it is difficult to predict which practical instructions for effective and safe patients will benefit significantly from per- delivery of the most common peripheral ipheral nerve blocks, headache practitioners nerve blocks used in headache medicine. have developed a wealth of clinical experi- We briefly outline the evidence base for ence in maximising their efficacy. In the common indications and describe the per- trigeminal autonomic cephalalgias—predo- © Author(s) (or their ipheral nerve block method, including injec- minantly unilateral headaches including employer(s)) 2021. No commercial re-use . See rights tion location, technique, drug constituents cluster headache and hemicrania continua and permissions. Published and potential pitfalls. This, together with —ipsilateral greater and lesser occipital by BMJ. the supplementary illustrative videos, nerve (LON) blocks as first-line treatments To cite: Fernandes L, should provide a comprehensive guide on may avoid the need for corticosteroids or Randall M, Idrovo L. nerve block delivery. This guide should be indometacin. Patients with headache who Pract Neurol 2021;21:30–35. used to support, but not to replace, the have reproducible pain with palpation over 1 of 7 Fernandes L, et al. Pract Neurol 2021;21:30–35. doi:10.1136/practneurol-2020-002612 How to do it Pract Neurol: first published as 10.1136/practneurol-2020-002612 on 23 October 2020. Downloaded from corticosteroid, reducing the need for medications. The Table 1 Evidence base for the efficacy of peripheral nerve block in frequency of the nerve blocks can be tailored to the treating different headache disorders individual’s response duration but is usually 3 months Type of nerve Evidence or more. If the benefit lasts less than 2 months, then Headache disorder block studied level* clinicians might consider other headache medications or Acute migraine GON 2B8 interventions. Chronic migraine GON 2A910 Some headache practitioners inject only the occipital Cluster headache GON, suboccipital 1B11 12 nerves during the first session, which reduces the num- Occipital neuralgia GON 2B13 ber of injections and allows for an assessment of initial Chronic daily headache GON 2B14 response. If the patient reports some benefit but has Other trigeminal autonomic residual facial pain, then at a subsequent session, the cephalalgias trigeminal nerves can be blocked as well as the occipital SUNCT/SUNA Supraorbital, 45 nerves. Consensus recommendations by the American supratrochlear Headache Society and the Spanish Headache Study Paroxysmal hemicrania/ Supraorbital, 415 Group have used this evidence base to provide gui- hemicrania continua supratrochlear dance on the administration of peripheral nerve blocks Other painful cranial neuralgias Supraorbital, 416 17 for different headache disorders.21 22 auriculotemporal *Based on the Oxford Centre for Evidence-based Medicine Levels of GENERAL CONSIDERATIONS Evidence. Knowledge of the anatomical landmarks of the occipital GON, greater occipital nerve; SUNCT, short-lasting unilateral neuralgiform and superficial branches of the trigeminal nerve is headache attacks with conjunctival injection and tearing; SUNA, short- lasting unilateral neuralgiform headache attacks with cranial autonomic important for effective nerve blockade, and to avoid features. possible complications such as nerve trauma, bleeding or inadvertent arterial injection of anaesthetic drug. thepericranialnerveareainthescalp,andthosewith People with headache disorders often describe pain localised cutaneous allodynia, are also likely to respond over the forehead, behind their eyes, temples, occipital to nerve blocks.718Peripheral nerve blocks are also and upper cervical areas. The forehead and upper perio- demonstrably effective in the older population with cular areas are innervated by peripheral branches of the headache disorders, whose comorbidities might pre- first division of the trigeminal nerve (V1), mainly the clude the use of first-line preventative medications.6 supraorbital and the supratrochlear nerves. The temples There are conflicting results about adding corticosteroid are largely innervated by the auriculotemporal nerve to nerve blocks in people with migraine, but evidence to branch from the mandibular division of the trigeminal support its efficacy in cluster headache.11 14 19 Greater nerve (V3). The upper cervical and occipital region is occipital neuralgia with or without another coexisting innervated by C2/C3 posterior cervical branches, mainly 20 23 headache disorder is not uncommon. Giving a GON the greater, lesser and third occipital nerves. http://pn.bmj.com/ block to a patient with suspected GON neuralgia can be Having identified someone as suitable for both diagnostic and therapeutic, usually conferring pro- a peripheral nerve block, we find it helps to show longed relief. The evidence base for using peripheral them an illustration of the peripheral cranial nerve to nerve blocks in other cranial neuralgias, such as auricu- be injected (figure 1). The written consent should lotemporal and supraorbital neuralgias, is predomi- include the known complications of any invasive pro- 15 16 nantly anecdotal, from published case series. cedure, such as bleeding or infection at the injection on September 25, 2021 by guest. Protected copyright. Pregnant women with troublesome headaches can site, and some may find the procedure painful. often be managed throughout pregnancy and the post- Peripheral nerve blocks are contraindicated at any pre- partum period with anaesthetic nerve blocks without vious surgical site, for example, previous burr hole or Figure 1 Illustrative drawings of the anatomical course of the peripheral cranial nerves. These are used during the consent process to demonstrate the location of the nerves to be injected. Adapted with permission from Blumenfeld et al.21 Fernandes L, et al. Pract Neurol 2021;21:30–35. doi:10.1136/practneurol-2020-002612