Which nerve causes sharp left ear pain intermittently after trauma?

Sharp Left Ear Pain After Trauma: Great Auricular Nerve Neuralgia

Sharp, intermittent left ear pain following trauma to the nerve is most likely caused by damage to the great auricular nerve (GAN), a sensory branch of the cervical plexus originating from C2-C3 nerve roots. 1

Anatomical Basis

The great auricular nerve provides sensory innervation to:

• Pre-auricular region
• Jaw angle
• Posteroinferior portion of the ear pinna
• Mastoid area

This nerve is distinct from other cranial nerves that can cause facial or ear pain:

• Great Auricular Nerve (GAN): Sensory branch from C2-C3 cervical plexus 1, 2
• Trigeminal Nerve (CN V): Provides sensation to face and motor function to muscles of mastication 3
• Facial Nerve (CN VII): Controls facial expression muscles and taste to anterior 2/3 of tongue 3
• Glossopharyngeal Nerve (CN IX): Can cause ear pain (glossopharyngeal neuralgia) but typically involves the posterior tongue and throat 3

Clinical Presentation of Great Auricular Neuralgia

Patients with great auricular neuralgia typically present with:

• Pain characteristics: Sharp, paroxysmal, stabbing pain in the ear region 1
• Triggers: Pain provoked by turning the head, touching the neck, neck position during sleep, or jaw movement 1
• Distribution: Pain localized to the periauricular region and lateral head 4

Diagnostic Approach

1. Clinical examination:

   • Map the exact distribution of pain
   • Identify triggers that provoke the pain
   • Look for tenderness along the course of the great auricular nerve

2. Diagnostic nerve block:

   • A diagnostic GAN block with local anesthetic can confirm the diagnosis if it provides immediate pain relief 4
   • The block is performed by injecting superficially along the wing of the atlas with the needle pointing towards the jugular groove 5

3. Electrophysiologic examination:

   • Can help differentiate GAN neuralgia from other facial neuralgias when diagnosis is unclear 4
   • Particularly useful when symptoms overlap with trigeminal or occipital neuralgia

4. Imaging studies:

   • MRI of the cervical region and skull base to rule out compressive lesions
   • CT may be useful if bony pathology is suspected

Treatment Algorithm

1. First-line treatment:

   • Neuropathic pain medications (gabapentin, pregabalin, or tricyclic antidepressants) 3
   • Avoidance of identified triggers

2. Interventional approaches:

   • GAN blocks with local anesthetics and steroids provide dramatic improvement in most patients 1, 4
   • Serial blocks may provide long-term relief (2-5 years in some cases) 1

3. Advanced interventions:

   • GAN stimulation for patients who respond to blocks but need ongoing treatment 1
   • Auricular vagus nerve stimulation has shown efficacy for various chronic pain conditions 6

4. Surgical options (for refractory cases):

   • GAN resection may be considered in cases of persistent pain unresponsive to other treatments 1

Differential Diagnosis

• Trigeminal neuralgia: Sharp, electric-like pain in the distribution of the trigeminal nerve; typically triggered by light touch to the face 3
• Glossopharyngeal neuralgia: Pain in the ear, posterior tongue, and throat; can be confused with TMD 3
• Post-traumatic trigeminal neuropathic pain: Often follows dental procedures or facial trauma 3
• Auriculotemporal neuralgia: Pain in the temporal region and anterior ear 5

Pitfalls and Caveats

• GAN neuralgia is often misdiagnosed as trigeminal neuralgia or occipital neuralgia due to overlapping pain distributions 4
• Failure to recognize GAN neuralgia can lead to inappropriate treatments and prolonged suffering
• When performing GAN blocks, care must be taken to avoid inadvertent blockade of the facial nerve, which could cause temporary facial weakness 5
• If both facial paralysis and ear pain occur simultaneously, consider more complex neurological pathology requiring additional evaluation 7

Great auricular neuralgia should be considered in any patient presenting with sharp, intermittent ear pain following trauma, especially when the pain is triggered by head or neck movement.