Secondary Otalgia: Referred Pain Pathways and Pathologies

Facial nerve, associated nuclei, and major branches. Axial graphic (A) shows the segments of the facial nerve (CN VII), including the cisternal (black solid arrow), canalicular (black arrowhead), labyrinthine (white solid arrow), tympanic (white arrowhead), and proximal descending mastoid (black solid curved arrow) segments. Note additionally the geniculate ganglion (white solid curved arrow) and greater superficial petrosal nerve (white dashed curved arrow). The 3 brain stem nuclei of CN VII are seen at the level of the pons, including the motor (orange shading, white dashed straight arrow), superior salivatory (pink shading, black dashed curved arrow), and solitary tract nuclei (blue shading, black dashed straight arrow). Sagittal graphic (B) shows the motor, sensory, and parasympathetic fibers of the facial nerve and its major branches. Motor fibers (orange shading) give off the small stapedius motor nerve (white dashed curved arrow) before exiting the skull base at the stylomastoid foramen as the extracranial CN VII (white solid arrow), which is purely motor. Parasympathetic fibers (shaded pink) give off the greater superficial petrosal nerve (black dashed straight arrow) that innervates the lacrimal gland and contribute to the chorda tympani nerve (black solid arrow). The chorda tympani nerve also receives special sensory fibers, providing taste to the anterior two-thirds of the tongue in addition to providing parasympathetic innervation of the submandibular and sublingual glands. Sagittal graphic (C) shows the extracranial motor branches of CN VII, including the temporal (black solid arrow), zygomatic (black arrowhead), buccal (white solid arrow), mandibular (white arrowhead), cervical (black dashed straight arrow), and posterior auricular (white dashed straight arrow) branches. Graphics are reproduced with permission from Imaging Anatomy: Brain and Spine. Copyright Elsevier.

Glossopharyngeal nerve, associated nuclei, and major branches. Coronal graphic (A) shows the glossopharyngeal nerves (black solid arrows, CN IX) exiting the skull base at the jugular foramina. CN IX is a mixed nerve, including afferent sensory fibers to the spinal nucleus of CN V (purple shading, black arrowhead), afferent special sensory fibers (taste from posterior two-thirds of the tongue) to the solitary tract nucleus (blue shading, white solid arrow), efferent motor fibers from the nucleus ambiguus (green shading, white dashed straight arrow), and efferent parasympathetic fibers from the inferior salivatory nucleus (lavender shading, black dashed curved arrow). Axial graphic (B) shows CN IX (black solid arrows) departing the medulla laterally at the postolivary sulcus and exiting the skull base at the pars nervosa segment of the jugular foramina. Note the brain stem nuclei of CN IX, including the spinal nucleus of CN V (purple shading, black arrowheads), solitary tract nucleus (blue shading, white solid arrows), inferior salivatory nucleus (pink shading, black dashed curved arrows), and nucleus ambiguus (green shading, white dashed straight arrows). Sagittal graphic (C) demonstrates the complex extracranial innervation provided by CN IX, including motor innervation of the stylopharyngeus muscle (black solid arrow, magnified inset), sensory innervation from the middle ear and parasympathetic innervation to the parotid gland via the tympanic (Jacobson) nerve (white solid arrow, magnified inset), sensory and taste from the posterior two-thirds of the tongue (black arrowhead), sensory from the soft palate and oropharynx (white arrowhead), and viscerosensory to the carotid sinus and body (white dashed straight arrow). Graphics are reproduced with permission from Imaging Anatomy: Brain and Spine. Copyright Elsevier.

Vagus nerve, associated nuclei, and major branches. Coronal graphic (A) shows the vagus nerves (black solid arrows, CN X) exiting the skull base at the jugular foramina. CN X is a mixed nerve, including afferent sensory fibers to the spinal nucleus of CN V (purple shading, black arrowhead), afferent special sensory fibers (taste from epiglottis and valleculae) to the solitary tract nucleus (blue shading, white solid arrow), efferent motor fibers from the nucleus ambiguus (green shading, white dashed straight arrow), and both efferent parasympathetic fibers from and afferent viscerosensory fibers to the dorsal vagal nucleus (rose shading, black dashed curved arrow). Axial graphic (B) shows CN X (black solid arrows) departing the medulla laterally at the postolivary sulcus and exiting the skull base at the pars vascularis segment of the jugular foramina. Note the brain stem nuclei of CN X, including the spinal nucleus of CN V (purple shading, black arrowheads), solitary tract nucleus (blue shading, white solid arrows), dorsal vagal nuclei (rose shading, black dashed curved arrows), and nucleus ambiguus (green shading, white dashed straight arrows). Sagittal graphic (C) demonstrates the complex extracranial innervation provided by CN X, including motor innervation of the soft palate and constrictors via the pharyngeal plexus (black solid arrow); motor innervation of the muscles of the larynx (except cricothyroid) via the recurrent laryngeal nerve (black arrowhead); special sensory (taste) from the epiglottis and valleculae (white solid arrow); afferent sensory from the external ear and skull base; parasympathetic innervation of the cervical, thoracic, and abdominal viscera; and viscerosensory afferents (white arrowhead) from the larynx, visceral space, chest, and abdomen. Graphics are reproduced with permission from Imaging Anatomy: Brain and Spine. Copyright Elsevier.

A 55-year-old man with secondary otalgia due to cervical spondylosis. Axial bone algorithm CT shows marked left-sided facet arthropathy (white arrow), which along with uncovertebral hypertrophy (black arrow) results in narrowing of the C II to C III neural foramen (white arrowhead). Impingement of the C III nerve root can lead to otalgia via referred pain along the great auricular or lesser occipital nerves.

A 64-year-old man with secondary otalgia caused by palatine tonsil squamous cell carcinoma. Axial contrast-enhanced CT shows a right palatine tonsil mass (white arrow) with deep invasion through the superior constrictor (white arrowhead) into the parapharyngeal space. Conglomerate right level II cervical adenopathy (black arrows) with extracapsular spread displaces the carotid space and invades the parotid tail (black arrowhead). In this case, the patient’s referred otalgia may be caused by involvement of CN IX, CN X, and/or upper cervical nerve branches (great auricular or lesser occipital).

A 35-year-old man with secondary otalgia caused by perineural tumor spread from parotid adenoid cystic carcinoma. Axial T1-weighted postcontrast fat-saturated MR imaging shows cordlike enhancement (white arrow) along the course of the auriculotemporal nerve, which serves as an extracranial bridge linking the intraparotid facial nerve to CN V3 (black arrow) in the infrazygomatic masticator space. Note hyperenhancement along the descending mastoid segment of CN VII (white arrowhead) from additional perineural tumor spread. In this case, referred otalgia may occur along the auriculotemporal nerve, CN V3, and/or CN VII.

A 58-year-old woman with secondary otalgia caused by TMJ derangement. Oblique sagittal T1-weighted image in open-mouth position demonstrates irregularity and loss of normal biconcave morphology of the articular disk (white arrow), which has been displaced anteriorly. The disk does not recapture upon mouth opening, which prevents normal anterior translation of the mandibular condyle (white arrowhead) with respect to the articular eminence (black arrow). TMJ degeneration is a very common etiology of secondary otalgia with pain likely referred along CN V3.

Benign parotid pathology presenting with secondary otalgia. Axial contrast-enhanced CT in a 75-year-old man with right-sided ear pain shows obstructive calculous parotitis and sialodochitis with marked intraparotid ductal dilation (white arrow) and wall enhancement upstream of an obstructing sialolith (white arrowhead). Referred otalgia from intraparotid pathologies is thought to occur via the auriculotemporal nerve, a branch of CN V3.

A 42-year-old woman with secondary otalgia due to odontogenic infection. Axial T1-weighted postcontrast fat-saturated MR imaging shows a rim-enhancing subperiosteal abscess (white arrowhead). Note the corresponding hyperenhancing marrow (white arrow) from osteitis and hyperenhancing medial pterygoid (black arrow) and masseter (black arrowhead) muscles from myositis. Odontogenic infection is a common source of referred otalgia via CN V3 and its branches.

A 64-year-old woman with secondary otalgia caused by sinus mucosal disease. Axial bone algorithm CT shows a partially opacified right sphenoid sinus with marked hyperostosis and sclerosis of the sinus walls from long-standing mucoperiosteal reaction (white arrow) related to sinus mucosal disease. Note an air-fluid level (white arrowhead), which is a nonspecific finding that can be seen in the setting of acute inflammation related to the sinus mucosal disease. Sinus disease is a common source of secondary otalgia, thought to yield referred pain via CN VII parasympathetic branches or via CN V1 sensory branches.

A 52-year-old man with secondary otalgia caused by nasopharyngeal carcinoma (NPC). Axial T2-weighted fat-saturated MR imaging shows an intermediate signal intensity nasopharyngeal mass (white arrow) consistent with a cellular tumor, which extends laterally into the parapharyngeal space. Note the additional metastatic retropharyngeal adenopathy (white arrowhead) and left mastoid effusion. NPC may present with primary and secondary otalgia caused by mastoid–middle ear effusion (primary otalgia) and referred pain along CN IX (secondary otalgia).

Transient perivascular inflammation of the carotid artery (TIPIC) syndrome presenting as otalgia. Axial contrast-enhanced CT in a 44-year-old woman with TIPIC syndrome shows characteristic segmental, eccentric soft tissue thickening (white arrow) around the wall of the common carotid artery. Note the lack of associated arterial stenosis (white arrowhead). TIPIC syndrome may yield referred otalgia via CN IX and/or CN X branches, depending on which segments of the carotid artery are involved.