Temporal bone imaging in osteogenesis imperfecta patients with hearing loss

Abstract

Objectives/Hypothesis Osteogenesis imperfecta (OI) is an autosomal‐dominant connective‐tissue disorder, predominantly characterized by bone fragility. Conductive hearing loss develops in half of the OI patients and often progresses to mixed loss. Findings of computed tomography (CT) and magnetic resonance (MR) imaging of the temporal bone in the largest series of OI patients to date are presented and correlated with the audiograms. Study Design Retrospective case series. Methods CT images and audiograms of 17 hearing‐impaired OI patients, aged 9 to 67 years, were analyzed retrospectively. In four patients, MR imaging was performed as well. Imaging abnormalities were correlated with type and severity of hearing loss deduced from the audiograms. Results CT revealed fenestral hypodense foci in the fissula ante fenestram (25 of 33 ears), oval window (23 of 33 ears), and round window (20 of 33 ears). Retrofenestral hypodensities were observed, affecting the cochlear turns (16 of 33 ears), facial nerve canal (10 of 33 ears), or semicircular canals (6 of 33 ears), or appearing like the fourth turn of the cochlea (11 of 33 ears). The site of hypodensities corresponded to the type of hearing loss in 72.2% of the OI ears. The air‐bone gap and bone‐conduction thresholds showed significant positive associations with the number of affected fenestral (P < .05) and retrofenestral structures (P < .01), respectively. Gadolinium‐enhanced MR images demonstrated active lesions in three patients with mixed hearing loss or deafness. Conclusions The site of hypodensities on temporal bone CT images in OI corresponds to presence and type of hearing loss determined by audiometry. The more severe the hearing loss, the more affected temporal bone structures in OI. Level of Evidence 4. Laryngoscope, 123:1988–1995, 2013

The Size of Internal Auditory Canal Diverticula Is Unrelated to Degree of Hearing Loss

“…Perhaps these diverticula reflect an anatomic variant that is susceptible to cavitation when subjected to a specific set of circumstances, for example, otosclerosis or osteogenesis imperfecta. In these conditions, the rates of IAC diverticula may be as high as 31% and 49%, respectively. Small diverticula may be incidental findings or harbingers of susceptibility to future otologic disease.…”

“…A diverticulum was noted on computed tomography (CT) scan in 49% of patients in a series of hearing-impaired patients with osteogenesis imperfecta. 9 In a recent study from our institution, we described a 5% prevalence (unilateral or bilateral) of IAC diverticula in a series of 807 patients who underwent high-resolution CT of the temporal bone. 10 We discovered a preponderance of IAC diverticula that occurred without radiographic findings of fenestral or retrofenestral otosclerosis.…”

“…In each of these descriptions, the IAC diverticulum is described in the context of otosclerosis. A diverticulum was noted on computed tomography (CT) scan in 49% of patients in a series of hearing‐impaired patients with osteogenesis imperfecta …”

Kraniofaziale Manifestationen von systemischen Erkrankungen: CT- und MRT-Befunde

“…Eine Schallleitungsschwerhörigkeit kann das Ergebnis eines übermäßigen Wachstums von untermineralisiertem Knochen, einer Fixierung der Steigbügelfußplatte, einer Fraktur oder Dehiszenz des Steigbügelbogens oder einer Atrophie des langen Ambossschenkels sein (▶ Abb. 20) [69,71].…”

Craniofacial Manifestations of Systemic Disorders: CT and MR Imaging Findings and Imaging Approach

“…These changes may result in mixed or sensorineural hearing loss (69). Conductive hearing loss may occur as a result of overgrowth of undermineralized bone, fixation of the stapedial footplate, fracture or dehiscence of the stapedial arch, or atrophy of the long process of the incus (69,71) (Fig 20).…”