Advertisement

Auriculotemporal and Zygomaticotemporal Nerve Block

  • Siddharth Chavali
  • Girija Prasad Rath
Chapter

Abstract

Entrapment of the auriculotemporal nerve (ATN) could possibly be the most frequent of all the trigeminal headaches. Classically, the patient presents with complaints of headache in the area of temple. There are two main presentations when the ATN is involved: auriculotemporal neuralgia and auriculotemporal syndrome.

Key Points

  • Most common variant of trigeminal neuralgia (TGN) present with pain in the temple region

  • There are two distinct presentations such as Auriculo-temporal neuralgia and Zygomatico-temporal syndrome

  • Zygomatico-temporal neuralgia may mimic the features of Auriculo-temporal neuralgia

Introduction

Entrapment of the auriculotemporal nerve (ATN) could possibly be the most frequent of all the trigeminal headaches. Classically, the patient presents with complaints of headache in the area of temple. There are two main presentations when the ATN is involved: auriculotemporal neuralgia and auriculotemporal syndrome.

The auriculotemporal neuralgia usually presents with:
  • Attacks of paroxysmal pain in preauricular/temple/retro-orbital regions, usually presenting at dawn [1]. The early morning headache seems to be associated with bruxism/jaw clenching during sleep.

  • The patient may complain of auricular headache which may radiate to the temple.

  • Unilateral or bilateral headache may be associated with ear/parotid/jaw pain or numbness [2].

  • The headache is throbbing type due to the close proximity of ATN to the temporal artery.

  • Pain may be increased by talking/chewing/menses/palpation over the preauricular area, and it is a disorder which mainly affects middle-aged females [3].

The auriculotemporal syndrome, also called the Frey syndrome [4] is a complex of symptoms that includes flushing and unilateral hyperhidrosis over the ear and cheek. It occurs while eating or drinking anything that may stimulate saliva secretion from the parotid gland. These symptoms normally occur following parotid surgery or trauma to the gland [5] and there may be a concomitant trigeminal neuralgia (TGN). A possible mechanism could be improper regeneration of autonomic innervation of the parotid gland.

Anatomy

The mandibular division of the trigeminal nerve (V3) gives off three branches near the lateral pterygoid muscle: the auriculotemporal nerve (ATN), the inferior alveolar nerve and the lingual nerve. The ATN has a tortuous course, putting it at an increased risk of entrapment along its course. It is made up of two roots, which course around the middle meningeal artery, and then fuse to form a short trunk. The ATN runs to the medial side of the mandibular neck, then turns superiorly together with the superficial temporal artery, between the pinna and the mandibular condyle, under the parotid gland. After it exits the parotid gland, it arches over the zygomatic arch, and travels in front of the temporomandibular joint, till it pierces the temporalis muscle. It divides into five smaller branches: nerve to external auditory meatus, parotid branch nerve, anterior auricular nerve, auricular branch nerves, superficial temporal nerve which innervate the temporal region, temporomandibular joint, and the ear.

Etiopathogenesis of Auiculotemporal Neuralgia

Entrapment of the ATN may be due to spasm of the lateral pterygoid muscle or due to compression along its course between the medial and lateral pterygoid muscles; it causes facial numbness, mandibular pain or headaches [6]. It may also be trapped between the TMJ and muscles of mastication [7], or by the superficial temporal artery itself, possibly caused by intertwining of the nerve and artery.

Indications

  • Pain relief for TGN in auriculotemporal distribution

  • Pain relief for facial pain caused by TMJ anomalies

  • Anesthesia for the external ear

  • Pain relief for acute herpes zoster involving the external ear

Contraindications

  • Any allergy or sensitivity to anesthetic agent

  • Evidence of infection at the injection site

  • Distortion of normal anatomical landmarks

  • Uncooperative patient

Techniques of Auriculotemporal Nerve Block

Landmark Guided (Classical Approach)

  • The patient lies supine with the head turned to opposite side from the side of block

  • The temporal artery may be identified just above the origin of the zygoma

  • A 25 G needle is inserted perpendicular to the skin just behind the superficial temporal artery until bony resistance is encountered

  • Paraesthesia may be elicited, and after aspiration, 3 mL of anesthetic agent may be injected

  • The needle may be then directed cephalad, and a further 2 mL of anesthetic is injected

Ultrasound Guided

  • A high frequency linear probe may be placed transversely over the TMJ, and the superficial temporal artery is identified using colour Doppler

  • The nerve looks like a small hyperlucent bundle adjacent to the artery

  • The probe is then rotated to obtain a long-axis view tracking the nerve cephalad

  • A 25 G needle is introduced using an out-of-plane approach to deliver the anesthetic solution

Zygomaticotemporal Neuralgia

The zygomaticotemporal nerve is a purely sensory branch of the maxillary division. It originates in the pterygopalatine fossa, enters the orbit through the inferior orbital fissure, and divides into zygomaticotemporal and zygomaticofacial branches. Then it passes along the inferolateral angle of the orbit, and enters into the temporal fossa through a bony canal in the zygomatic bone. This branch then ascends between the bone and the temporalis muscle. It pierces the deep temporal fascia approximately 2 cm above the zygomatic arch to innervate a small triangular area of skin in the temporal area.

The common site of entrapment along its course is when it crosses the zygomatic arch. The coronoid process usually moves cephalad in edentulous patients; it catches the nerve in the arch. The pain mimics the pattern of either observed in the ATN or maxillary nerve. The headache may become worse in the early morning after the dentures are removed the night before.

Technique of Zygomaticotemporal Nerve Block

  • The patient is asked to lie supine, with the head turned away from affected side.

  • The lateral orbital rim may be palpated at the level of the frontozygomatic suture.

  • The index finger of the physician should be placed in the depression of the posterolateral aspect of the lateral orbital rim, inferior to the suture.

  • The needle may be inserted just behind the palpating finger, and then ‘walked down’ the lateral orbital margin to the level of the lateral canthus.

  • After confirming negative aspiration, 1–2 mL of anesthetic agent may be injected.

Drugs

  • Commonly used local anesthetic agents are lidocaine 1% or bupivacaine 0.25–0.5%

  • Alcohol, phenol or botulinum toxin have been used for the treatment of neuropathic pain, however, these agents are being used less frequently

  • Injection of a depot steroid may provide a longer duration of analgesia for neuropathic conditions

Complications

  • Hematoma due to close proximity of the superficial temporal artery

  • Vascular injection of anesthetic agent

  • Temporary facial nerve palsy may occur when the drug is injected at the level of the tragus, as the facial nerve courses along this point

Clinical Pearl

To avoid accidental facial nerve injury, an alternate approach may be considered during ATN block [8]. It utilizes a small volume of local anesthetic agent, and involves blockade of the nerve 1 cm above the tragus which is even further away from the route of facial nerve.

References

  1. 1.
    Murayama RA, Stuginski-Barbosa J, Moraes NP, Speciali JG. Toothache referred from auriculotemporal neuralgia: case report. Int Endod J. 2009;42:845–51.CrossRefGoogle Scholar
  2. 2.
    Speciali JG, Gonçalves DAG. Auriculotemporal neuralgia. Curr Pain Headache Rep. 2005;9:277–80.CrossRefGoogle Scholar
  3. 3.
    Trescot A. Headache: is it a migraine? Think again. Technol Reg Anesth Pain. 2005;9:68–72.CrossRefGoogle Scholar
  4. 4.
    Motz KM, Kim YJ. Auriculotemporal syndrome (Frey syndrome). Otolaryngol Clin N Am. 2016;49:501–9.CrossRefGoogle Scholar
  5. 5.
    Kamath RAD, Bharani S, Prabhakar S. Frey’s syndrome consequent to an unusual pattern of temporomandibular joint dislocation: case report with review of its incidence and etiology. Craniomaxillofac Trauma Reconstr. 2013;6:1–8.CrossRefGoogle Scholar
  6. 6.
    Komarnitki I, Andrzejczak-Sobocińska A, Tomczyk J, Deszczyńska K, Ciszek B. Clinical anatomy of the auriculotemporal nerve in the area of the infratemporal fossa. Folia Morphol (Warsz). 2012;71:187–93.Google Scholar
  7. 7.
    Schmidt BL, Pogrel MA, Necoechea M, Kearns G. The distribution of the auriculotemporal nerve around the temporomandibular joint. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 1998;86:165–8.CrossRefGoogle Scholar
  8. 8.
    Bebawy JF, Bilotta F, Koht A. A modified technique for auriculotemporal nerve blockade when performing selective scalp nerve block for craniotomy. J Neurosurg Anesthesiol. 2014;26:271–2.CrossRefGoogle Scholar

Copyright information

© Springer Nature Singapore Pte Ltd. 2019

Authors and Affiliations

  • Siddharth Chavali
    • 1
  • Girija Prasad Rath
    • 1
  1. 1.Department of Neuroanaesthesiology and Critical Care Neurosciences CentreAll India Institute of Medical SciencesNew DelhiIndia

Personalised recommendations