And Primary Headache
Because primary headache often includes pain in the back of the head, anaesthetic blockade of the greater occipital nerve (GON) has become an increasingly common practice,1 despite denunciation of its value on the basis that it supplies only the skin, muscles and vessels of the scalp which are not established sources of pain.2
Whilst some studies support the efficacy of anaesthetizing the GON in acute and chronic migraine,3-18 the great heterogeneity of published studies renders their evaluation difficult. In an extensive review of eleven studies, 4,6,8-17 the authors18 highlight inconsistencies surrounding patient selection, timing of the procedure i.e. inter / ictally, variability of technique (including bilateral / unilateral), inclusion of other nerves and / or the presence of trigger points, local anaesthetic agent alone or combined with different types and dosages of steroids, and variable outcome measures.
Unfortunately, randomized, double-blinded, placebo-controlled studies of GON block in migraine have produced conflicting results.15,16 Supporting the benefit of GON block outcomes in open-label studies or case series3-12 in addition to the perception of benefit among clinicians2,19 was the larger (n=73) of two studies,16 whilst the smaller (n=33)15 found no benefit of GON block in the management of migraine. Thus, the role of GON block in migraine remains uncertain.
Regardless of the ambivalence surrounding GON block in primary headache, GON block provides (albeit temporary) relief for some patients.
Debate continues as to whether the modulatory effect of the GON block on migraine is peripherally driven or activates central inhibitory mechanisms.2,20 However, GON afferent information arises from structures not considered as sources of pain in migraine and in itself the GON is not compromised. Therefore, modulation cannot be interpreted as ‘anaesthetizing’ the source of pain.2
Supporting, the neuro modulation theory is a study demonstrating De sensitisation of the trigemino cervical nucleus (TCN) following a GON anaesthetic block21 ameliorating the underlying disorder in Migraine (and probably primary headache). This same (de sensitisation of the TCN) effect was replicated by research in which upper cervical (C1-3) afferents were modulated by a manual cervical intervention,22 supporting the possibility that noxious C1-3 afferents may play a role in sensitisation of the TCN in migraine.
Conceivably the ongoing relief provided by neurotomy or (to a lesser extent) medial branch blocks, supports the assertion that targeting the GON as the primary source of pain in migraine is sub optimal.2 However, because of the inability to nullify information from the C2-3 disc, a recognised as a source of headache,23-25 and as such, another contributor to sensitisation of the TCN, the full effect of anaesthetic blockade of C1-3 afferents in primary headache remains unknown.
- Ashkenazi A, Young WB. The effects of greater occipital nerve block and trigger point injection on brush allodynia and pain in migraine. Headache. Apr 2005;45(4):350-354.
- Bogduk N. Role of anesthesiologic blockade in headache management. Curr Pain Headache Rep. Oct 2004;8(5):399-403.
- Young W, Cook B, Malik S, Shaw J, Oshinsky M. The first 5 minutes after greater occipital nerve block. Headache. Jul 2008;48(7):1126-1128.
- Caputi CA, Firetto V. Therapeutic blockade of greater occipital and supraorbital nerves in migraine patients. Headache. Mar 1997;37(3):174-179.
- Yi X, Cook AJ, Hamill-Ruth RJ, Rowlingson JC. Cervicogenic headache in patients with presumed migraine: missed diagnosis or misdiagnosis? J Pain. Oct 2005;6(10):700-703.
- Weibelt S, Andress-Rothrock D, King W, Rothrock J. Suboccipital nerve blocks for suppression of chronic migraine: safety, efficacy, and predictors of outcome. Headache. Jun 2010;50(6):1041-1044.
- Tobin J, Flitman S. Treatment of migraine with occipital nerve blocks using only corticosteroids. Headache. Jan 2011;51(1):155-159.
- Saadah HA, Taylor FB. Sustained headache syndrome associated with tender occipital nerve zones. Headache. Apr 1987;27(4):201-205.
- Anthony M. Headache and the greater occipital nerve. Clin Neurol Neurosurg. 1992;94(4):297-301.
- Afridi SK, Shields KG, Bhola R, Goadsby PJ. Greater occipital nerve injection in primary headache syndromes–prolonged effects from a single injection. Pain. May 2006;122(1-2):126-129.
- Takmaz SA, Inan N, Ucler S, Yazar MA, Inan L, Basar H. Greater occipital nevre block in migraine headache: preliminary results of 10 patients. Agri. Jan 2008;20(1):47-50.
- Gawel MJ, Rothbart PJ. Occipital nerve block in the management of headache and cervical pain. Cephalalgia. Feb 1992;12(1):9-13.
- Tobin JA, Flitman SS. Occipital nerve blocks: effect of symptomatic medication: overuse and headache type on failure rate. Headache. Nov-Dec 2009;49(10):1479-1485.
- Gelfand AA, Reider AC, Goadsby PJ. Outcomes of greater occipital nerve injections in pediatric patients with chronic primary headache disorders. Pediatr Neurol. Feb 2014;50(2):135-139.
- Dilli E, Halker R, Vargas B, et al. Occipital nerve block for the short-term preventive treatment of migraine: A randomized, double-blinded, placebo-controlled study. Cephalalgia. Dec 12 2014.
- Inan LE, Inan N, Karadas O, et al. Greater occipital nerve blockade for the treatment of chronic migraine: a randomized, multicenter, double-blind, and placebo-controlled study. Acta Neurol Scand. Mar 13 2015.
- Ashkenazi A, Matro R, Shaw JW, Abbas MA, Silberstein SD. Greater occipital nerve block using local anaesthetics alone or with triamcinolone for transformed migraine: a randomised comparative study. J Neurol Neurosurg Psychiatry. Apr 2008;79(4):415-417.
- Ambrosini A, D’Alessio C, Magis D, Schoenen J. Targeting pericranial nerve branches to treat migraine: Current approaches and perspectives. Cephalalgia. Mar 3 2015.
- Charleston Lt. One occipital nerve block for the short-term prevention of migraine? Cephalalgia. May 6 2015.
- Slotty PJ, Bara G, Kowatz L, et al. Occipital nerve stimulation for chronic migraine: a randomized trial on subthreshold stimulation. Cephalalgia. Jan 2015;35(1):73-78.
- Busch V, Jakob W, Juergens T, Schulte-Mattler W, Kaube H, May A. Functional connectivity between trigeminal and occipital nerves revealed by occipital nerve blockade and nociceptive blink reflexes. Cephalalgia. Jan 2006;26(1):50-55.
- Watson DH, Drummond PD. Cervical referral of head pain in migraineurs: effects on the nociceptive blink reflex. Headache. Jun 2014;54(6):1035-1045.
- Schellhas KP, Smith MD, Gundry CR, Pollei SR. Cervical discogenic pain. Prospective correlation of magnetic resonance imaging and discography in asymptomatic subjects and pain sufferers. Spine (Phila Pa 1976). Feb 1 1996;21(3):300-311; discussion 311-302.
- Grubb SA, Kelly CK. Cervical discography: clinical implications from 12 years of experience. Spine (Phila Pa 1976). Jun 1 2000;25(11):1382-1389.
- Bogduk N. Cervicogenic headache: anatomic basis and pathophysiologic mechanisms. Curr Pain Headache Rep. Aug 2001;5(4):382-386.