Inner-Ear Disorders Presenting with Air-Bone Gaps: A Review.

Air-bone gaps (ABGs) are commonly found in patients with conductive or mixed hearing loss generally due to outer- and/or middle-ear diseases such as otitis externa, tympanic membrane perforation, interruption or fixation of the ossicular chain, and chronic suppurative otitis media. ABGs can also be found in correlation with inner-ear disorders, such as endolymphatic hydrops, enlarged vestibular aqueduct syndrome, semicircular canal dehiscence, gusher syndrome, cochlear dehiscence, and Paget disease's as well cerebral vascular anomalies including dural arteriovenous fistula. The typical clinical presentation of inner-ear conditions or cerebral vascular anomalies causing ABGs includes audiological and vestibular symptoms like vertigo, oscillopsia, dizziness, imbalance, spinning sensation, pulsatile or continuous tinnitus, hyperacusis, autophony, auricular fullness, Tullio's phenomenon, and Hennebert's sign. Establishing a definitive diagnosis of the underlying condition in patients presenting with an ABG is often challenging to do and, in many patients, the condition may remain undefined. Results from an accurate clinical, audiological, and vestibular evaluation can be suggestive for the underlying condition; however, radiological assessment by computed tomography and/or magnetic resonance imaging is mandatory to confirm any diagnostic suspicion. In this review, we describe and discuss the most recent updates available regarding the clinical presentation and diagnostic workup of inner-ear conditions that may present together with ABGs.

FGF23 deficiency leads to mixed hearing loss and middle ear malformation in mice.

Fibroblast growth factor 23 (FGF23) is a circulating hormone important in phosphate homeostasis. Abnormal serum levels of FGF23 result in systemic pathologies in humans and mice, including renal phosphate wasting diseases and hyperphosphatemia. We sought to uncover the role FGF23 plays in the auditory system due to shared molecular mechanisms and genetic pathways between ear and kidney development, the critical roles multiple FGFs play in auditory development and the known hearing phenotype in mice deficient in klotho (KL), a critical co-factor for FGF23 signaling. Using functional assessments of hearing, we demonstrate that Fgf[Formula: see text] mice are profoundly deaf. Fgf[Formula: see text] mice have moderate hearing loss above 20 kHz, consistent with mixed conductive and sensorineural pathology of both middle and inner ear origin. Histology and high-voltage X-ray computed tomography of Fgf[Formula: see text] mice demonstrate dysplastic bulla and ossicles; Fgf[Formula: see text] mice have near-normal morphology. The cochleae of mutant mice appear nearly normal on gross and microscopic inspection. In wild type mice, FGF23 is ubiquitously expressed throughout the cochlea. Measurements from Fgf[Formula: see text] mice do not match the auditory phenotype of Kl-/- mice, suggesting that loss of FGF23 activity impacts the auditory system via mechanisms at least partially independent of KL. Given the extensive middle ear malformations and the overlap of initiation of FGF23 activity and Eustachian tube development, this work suggests a possible role for FGF23 in otitis media.

Temporal bone changes in patients with Goldenhar syndrome with special emphasis on inner ear abnormalities.

OBJECTIVE: Goldenhar syndrome is a developmental disorder presenting with orofacial and vertebral anomalies, which are also accompanied by abnormalities in other organs. We examined temporal bone changes with special emphasis on inner ear abnormalities in these patients. STUDY DESIGN: A retrospective review of 7 new cases in addition to a previously published series of 14 cases with clinically diagnosed Goldenhar syndrome was carried out to search for inner ear anomalies. In addition, temporal bone imaging studies from the literature were summarized and compared with our results. SETTING: Departments of Neuroradiology and Otorhinolaryngology at a university hospital. PATIENTS: In addition to the previous series of 14 patients, 7 new patients with Goldenhar syndrome were identified. INTERVENTIONS: Patients underwent otologic examination, audiometric studies, and high-resolution computed tomography (CT) or magnetic resonance imaging (MRI) of the temporal bone. MAIN OUTCOME MEASURE: Temporal bone changes and specifically inner ear malformations. RESULTS: Nineteen of 21 patients showed changes of the external and middle ear correlating with the literature. Seven of 21 patients showed inner ear abnormalities constituting one-third of all patients. These ranged from mild such as vestibular enlargement to severe defects such as cochlear hypoplasia and common cavity. CONCLUSION: Inner ear abnormalities were present in one-third of patients. Although in some cases, these might not be of clinical significance, some patients show severe defects of the inner ear requiring more complex hearing loss therapy. Therefore, imaging of the temporal bone structures is important in the care of these patients.

Incus necrosis after irradiation.

OBJECTIVES: Osteoradionecrosis (ORN) of the temporal bone is a rare, late complication of radiotherapy to the temporal bone region for head and neck or skull base tumours. ORN can occur as a localized or a diffuse type, according to the extension of the affected temporal bone. It can lead to otitis externa, otitis media, aseptic labyrinthitis and may lead to serious intracranial complications. Hearing loss may be conductive, sensorineural, or mixed. A few case studies report of previously irradiated patients presenting with conductive hearing loss presumably caused by ORN of the ossicular chain. In only one case report of diffuse ORN, ORN of the ossicles was histologically proven, leading to the conclusion that ossicular chain involvement as the sole entity of ORN would not exist. However, the presented case report disputes this. PATIENTS: A 13-year-old boy presenting with a unilateral mixed hearing loss as the sole otological complaint, 10 years after radiotherapy for an anaplastic ependymoma. RESULTS: Middle ear inspection revealed ORN of the incus which was confirmed by histological investigation. CONCLUSION: ORN of the ossicular chain as a late complication can occur as an isolated entity and may present as conductive hearing loss predominantly in the low frequencies. Middle ear inspection and ossicular chain reconstruction should be attempted, bearing in mind the risk of iatrogenic lacerations of a thin tympanic membrane and possibly a delayed wound healing.

Challenges in fitting a hearing aid to a severely collapsed ear canal and mixed hearing loss.

BACKGROUND: Collapsed ear canals typically occur when an outside force, such as a headset for audiometric testing, is present. However, when a collapsed ear canal occurs without external pressure, this creates a challenge not only for performing audiometric testing but also for coupling a hearing aid to the ear canal. PURPOSE: This case report highlights the challenges associated with fitting a hearing aid on a patient with a severe anterior-posterior collapsed ear canal with a mixed hearing loss. RESEARCH DESIGN: A 67-yr-old female originally presented to Washington University in St. Louis School of Medicine in 1996 with a long-standing history of bilateral otosclerosis. She had chronic ear infections in the right ear and a severely collapsed ear canal in the left ear and was fit with a bone anchored hearing aid (BAHA®) on the right side in 2003. However, benefit from the BAHA started to decrease due to changes in hearing, and a different hearing solution was needed. It was proposed that a hearing aid be fit to her collapsed left ear canal; however, trying to couple a hearing aid to the collapsed ear canal required unique noncustom earmold solutions. CONCLUSIONS: This case study highlights some of the obstacles and potential solutions for coupling a hearing aid to a severely collapsed ear canal.

Clinical analysis of intratympanic tympanosclerosis: etiology, ossicular chain findings, and hearing results of surgery.

CONCLUSION: The success rate (57.5%) in this study is not high for surgical treatment of tympanosclerosis, and therefore lends further evidence that intratympanic tympanosclerosis has been considered intractable for reconstructive surgery. OBJECTIVE: To investigate the clinical findings and surgical results of intratympanic tympanosclerosis. METHODS: From January 1989 to December 2006, a total of 1523 tympanoplasties were performed. Of these, 84 tailored tympanomastoidectomies were performed for tympanosclerosis in 80 patients. RESULTS: The incidence of intratympanic tympanosclerosis with chronic ear disease was 5.5%. Chronic otitis media was the most common etiologic factor for the tympanosclerosis (79 ears, 94.1%). Tympanosclerosis in the middle ear cavity was most often found around the malleus handle (67 ears, 79.8%), and more than half of the cases of tympanosclerosis (43 ears, 51.2%) had multiple areas affected by the sclerotic tissue. Tympanosclerotic fixation of the stapes was found in 31 ears (36.9%), and an intact ossicular chain was seen in 57 ears (67.9%). There was a postoperative improvement in hearing in 42 ears (57.5%).

Imaging of hearing loss.

In this article, we review the common entities causing the hearing loss and divide these pathologies into conductive hearing loss, sensorineural hearing loss, and mixed hearing loss. With this format, congenital pathologies are addressed first followed by the acquired entities. We review the common pathologies and the imaging findings affecting the hearing pathways from outside to inside, starting at the external auditory canal and moving inward toward the midbrain.

Posibilidades de tratamiento quirúrgico de la hipoacusia en pacientes afectados de osteogénesis imperfecta / Surgical options for hearing loss in patients with osteogenesis imperfecta

El objetivo del estudio es presentar las extensas y severas lesiones óticas que acontecen en la forma más leve de osteogénesis imperfecta, correlacionarlas con las alteraciones audiométricas y discutir las posibilidades quirúrgicas disponibles. Se presenta a 3 pacientes afectados de osteogénesis imperfecta tipo 1 con hipoacusia en distintos estadios funcionales. Se realizó a cada paciente estudio audiológico, médico y radiológico, y se sometieron a distintos tratamientos quirúrgicos. Los pacientes presentaron hipoacusias mixtas de carácter moderado, severo y profundo, imágenes radiológicas con extensas áreas de desmineralización que afectaban la cadena osicular y con desprotección de las estructuras vitales alojadas en el peñasco temporal, desmineralización de la cápsula ótica, dehiscencias, distorsiones y destrucciones cocleares. Los tratamientos quirúrgicos realizados, e indicados según los criterios actualmente aceptados, obtuvieron escasos resultados funcionales. El presente estudio plantea la necesidad de evaluar los criterios quirúrgicos específicos para esta enfermedad(AU)

The aim of the study is to present the severe, extensive lesions in the temporal bone appearing in the mildest forms of osteogenesis imperfecta, correlate these with audiometric results and discuss the possible surgical treatments available. We present three patients suffering hearing loss due to osteogenesis imperfecta type 1 to various functional degrees. All patients underwent an audiological, medical and radiological evaluation and were then treated with different surgical procedures. The patients presented mild, severe and profound mixed hearing losses and the radiological images showed extensive areas of demineralization affecting the ossicular chain and removal of protection for the vital structures inside the temporal bone. Also, the cochlea showed otic capsule demineralization, dehiscence, distortions and even destructions. The various surgical treatments, indicated under current international criteria, obtained limited functional results. This study reviews the need to evaluate the current surgical criteria for this specific condition(AU)

Benign vascular lesions involving the external ear canal.

Benign vascular lesions include various forms whose classification has created some controversies in the literature. The observation of two rare cases of vascular bulge of the external ear canal prompted us to analyze the essential features of these lesions. One case was observed during an episode of otitis media, the other one was an incidental finding, and both are still on follow-up without treatment. The lesions are unmodified after 4 and 10 years, respectively. Vascular malformations can be differentiated from vascular tumors since they are present at birth, are generally stable, and do not involute. An attending strategy is justified unless symptoms occur.

A new syndrome of microtia with mixed type hearing loss, renal agenesis, and multiple skeletal anomalies.

We report on a 17-year-old man who presented with unreported combination of right sided microtia and preauricular skin tag with conductive hearing loss, unilateral renal agenesis, partial syndactyly of forth and fifth metacarpals, multiple tarsal coalitions, absent toe, and hypoplastic tibia and fibula. Radiological and clinical findings did not match with the previously described syndromes with the type of anomalies seen in the case. We propose that this represents a new syndrome.