Magnuson, Jared

SHARE @ Advocate Health - Midwest

Imaging of Nontraumatic Temporal Bone EmergenciesAuthor: Jared Magnuson, MDLearning Objectives• Discuss important anatomic landmarks involved in temporal bone pathology • Discuss clinical and imaging findings of various temporal bone emergenciesOutline• Pathology of the External Ear• Pathology of the Middle Ear and Petrous Apex• Pathology of the Inner EarExternal EarAnatomic ApproachAcute External OtitisNecrotizing External OtitisCholesteatoma Infected First Branchial Cleft RemnantsAcute Otitis ExternaAlso known as swimmer’s ear, inflammation of the external auditory canal (EAC) with or without involvement of the pinnaEPIDEMIOLOGY: 98% bacterial (pseudomonas aeruginosa), swimmers, narrow canal PRESENTATION: pain of pinna and otorrhea, EAC edema, erythema and tendernessTREATMENT: topical antibiotics/antifungals +/-corticosteroids IMAGING: thickening of the EAC lining and tympanic membrane with thickening and stranding of the auricle and periauricular soft tissueNecrotizing External OtitisAlso known as malignant otitis externa, severe invasive infection of the EAC which can spread to the surrounding soft tissues, neck spaces and skull  RISK FACTORS: elderly, diabetes, immunocompromised (chemo/radiation) PRESENTATION: pain out of proportion of typical otitis externa IMAGING: EAC swelling +/- underlying osseous erosion +/- soft tissue infectionCOMPLICATIONS: osteomyelitis, subdural empyema, cerebral abscess, meningitis, facial nerve palsy, vascular complications EAC Cholesteatoma Desquamated keratinizing squamous cells, arising from a peripheral shell of inward-facing epithelium. As cells mature, they continue to be shed into the mass, resulting in slow growth.PRESENTATION: chronic, dull otalgia, otorrhea, conductive hearing lossTREATMENT: small lesions can be treated endoscopically under local anesthesia, whereas larger lesions need surgery to remove the cholesteatoma and affected bone areasIMAGING: unilateral EAC soft tissue lesion with osseous erosion, on MRI presents as a nonenhancing lesion with restricted diffusion Infected First Branchial Cleft AnomaliesFirst branchial cleft remnants include cysts, sinuses and fistulae and reflect congenital abnormalities of the lateral neck that can be a nidus for recurrent infectionEPIDEMIOLOGY: 8% of all branchial anomalies, usually near the EAC or parotid glandETIOLOGY: abnormal ectodermal closure of the first cleft, typically around the periauricular regionPRESENTATION: recurrent EAC or periauricular swelling and painIMAGING: circumscribed, rim-enhancing fluid filled lesion in the periauricular regionTREATMENT: antibiotics +/- surgical excisionInfected First Branchial Cleft AnomaliesColoboma auris, also known as preauricular (or more rarely periauricular) sinus or preauricular pit, is a relatively common congenital abnormality. It consists of a blind-ended opening in the EE that is often located at or near the anterior crus of the helix. The diagnosis is made clinically. Most of these sinuses remain asymptomatic, but recurrent infection may cause chronic discharge, repeated abscess formation, and/or scarring.Middle Ear and Petrous ApexAnatomic ApproachAcute Otomastoiditis and Potential Complications- Subperiosteal Abscess- Bezold Abscess- Dural Venous Sinus Thrombosis- Epidural Abscess- Subdural Empyema- Meningitis- Brain Abscess- Petrous ApicitisAcute OtomastoiditisSuppurative infection of the mastoid air cells. It is the most common complication of acute otitis media and is a clinical diagnosis EPIDEMIOLOGY: largely a disease of childhoodETIOLOGY: most commonly bacterial (S. pneumoniae)PRESENTATION: postauricular tenderness, erythema, and swelling causing protrusion of the auricleIMAGING: opacification of middle ear and mastoid +/-fluid level and mucosal enhancement COALESCENT MASTOIDITIS: term given to acute otomastoiditis when mucoperiosteal disease extends to involve the bone with a subsequent increased likelihood of complicationsSubperiosteal and Epidural AbscessesBezold AbscessBezold abscess complication of acute otomastoiditis where the infection erodes through the cortex medial to the attachment of thesternocleidomastoid muscle, at the attachment site of the posterior belly of the digastric muscle, and extends into the infratemporalfossaSubdural Empyema, Meningitis, and VentriculitisSubdural empyema is a rare complication characterized by a purulent collection in the subdural space. It is a serious intracranialcondition with a high mortality rate.Epidural AbscessEpidural abscess typically appears as a biconvex fluid collection that does not cross suture lines.Brain AbscessBrain abscess typically occurs in the temporal lobe and cerebellum.Thrombosis of the Cavernous Sinus and Superior Ophthalmic VeinCavernous sinus and superior ophthalmic vein thrombosis are very rare complications of acute mastoiditis. Clinical manifestation isvariable, including ipsilateral headache, proptosis, ophthalmoplegia, vision loss, and papilledema.Petrous ApicitisInfection with involvement of bone at the very apex (petrous apex) of the petrous temporal bonePRESENTATION: classically presents with Gradenigo syndrome:• suppurative otitis media with persistent otorrhea and ear pain• abducens nerve palsy, secondary to involvement of the nerve as it passes through Dorello canal• retro-orbital pain, or pain in the cutaneous distribution of the frontal and maxillary divisions of the trigeminal nerve, due to extension of inflammation into Meckel caveTREATMENT: antibiotics +/- surgical drainageInner EarAnatomic ApproachIdiopathic Peripheral Facial Paralysis (Bell Palsy)Ramsay Hunt SyndromeLabyrinthitis Labyrinthine HemorrhageIdiopathic Peripheral Facial Paralysis (Bell Palsy)EPIDEMIOLOGY: peak age of presentation is between 15-50 years with ~25 cases per 100,000 per year. There is no gender predominanceRISK FACTORS: older age, diabetes, pregnancyPRESENTATION: rapid onset unilateral facial paralysis in a lower motor neuron pattern whereby both upper and lower facial muscles are affectedIMAGING: enhancement of the facial nerveTREATMENT: steroids within 72 hours of presentation Idiopathic Peripheral Facial Paralysis (Bell Palsy)Ramsay Hunt SyndromeLatent infection of the geniculate ganglion with varicella zoster virus (VZV) and subsequent reactivationPRESENTATION: classic triad of otalgia, facial nerve palsy and vesicle eruptionIMAGING: linear to nodule enhancement of CN VII +/ VIII in the IAC, thickening and enhancement of the EAC and auricleTREATMENT: antiviral medications (valaciclovir) and corticosteroidsRamsay Hunt SyndromeLabyrinthitisLabyrinthitis is a potential complication of acute otomastoiditis with the spread of infection or of toxins from the middle ear to the inner ear via either the round window or oval window, unilateralPRESENTATION: sensorineural hearing loss and vertigoIMAGING: increased FLAIR, decreased T2 signal with enhancement COMPLICATIONS: labyrinthitis ossificans Labyrinthine HemorrhageBleeding within the labyrinth of the inner earEPIDEMIOLOGY: associated with hematological disorders and patient's on anticoagulation, secondary causesPRESENTATION: sudden onset of unilateral sensorineural hearing loss, vertigo, dizziness, tinnitus IMAGING: increased T1 signal with varying T2 depending on age of hemorrhageTREATMENT: management of the underlying conditionReferencesAcute mastoiditis | radiology reference article | radiopaedia.org. (n.d.-a). https://radiopaedia.org/articles/acute-mastoiditis?lang=us Bell Palsy | Radiology Reference Article | radiopaedia.org. (n.d.-b). https://radiopaedia.org/articles/bell-palsy?lang=us Gaillard, F. (2021, September 18).Loureiro, R. M., Carneiro, R. M., Sumi, D. V., Gomes, R. L., Agarwal, M., Moonis, G., & Soares, C. R. (2024). Imaging of Nontraumatic Temporal Bone Emergencies: Keys to diagnosis. RadioGraphics, 44(4). https://doi.org/10.1148/rg.230120 Labyrinthitis: Radiology Reference Article. Radiopaedia. https://radiopaedia.org/articles/labyrinthitis?lang=us Imaging of Nontraumatic Temporal Bone Emergencies: Keys to diagnosis. (2024). RadioGraphics. https://doi.org/10.1148/rg.230120.pres Juliano, A. F., Ginat, D. T., & Moonis, G. (2013). Imaging Review of the temporal bone: Part I. anatomy and inflammatory and neoplastic processes. Radiology, 269(1), 17–33. https://doi.org/10.1148/radiol.13120733 Kloth, C., Beck, A., Sollmann, N., Beer, M., Horger, M., & Thaiss, W. M. (2023). Imaging of pathologies of the temporal bone and middle ear: Inflammatory diseases, their mimics and potential complications—Pictorial Review. Tomography, 9(6), 2190–2210. https://doi.org/10.3390/tomography9060170 Necrotizing otitis externa | radiology reference article | radiopaedia.org. (n.d.-c). https://radiopaedia.org/articles/necrotizing-otitis-externa-1?lang=us Otitis media | radiology reference article | radiopaedia.org. (n.d.-d). https://radiopaedia.org/articles/otitis-media?lang=us Ramsay Hunt Syndrome | radiology reference article | radiopaedia.org. (n.d.-e). https://radiopaedia.org/articles/ramsay-hunt-syndrome?lang=us Rich, J. (2021, April 11). Intralabyrinthine hemorrhage: Radiology reference article. Radiopaedia. https://radiopaedia.org/articles/intralabyrinthine-haemorrhage?lang=us 

Imaging of nontraumatic temporal bone emergencies

https://institutionalrepository.aah.org/cgi/viewcontent.cgi?article=1646&context=auroragme

Imaging of nontraumatic temporal bone emergencies

Abstract

Similar works

Full text

Available Versions

SHARE @ Advocate Health - Midwest