Detection of pneumolabyrinth after temporal bone trauma using computed tomography

Abstract

Conclusion: Pneumolabyrinth is a very rare condition, even in otic capsule disrupting (OCD) fracture. Hearing was not always impaired, even in cases with OCD fracture. The co-existence of pneumocochlea, regarded as a risk factor for total hearing loss, was extremely rare in cases of pneumolabyrinth. Objectives: The purposes of this study were to analyze the radiological and clinical features in patients with pneumolabyrinth and to overcome the diagnostic pitfalls encountered during pneumocochlea detection. Materials and methods: The temporal bone computed tomographies (TBCT) of 402 patients diagnosed with temporal bone fracture along with their clinical records were retrospectively reviewed. Results: Only six patients (7% of those with OCD fractures or 1.5% of those with temporal bone fracture) were found to have pneumolabyrinth. Locations of the pneumolabyrinth were in the vestibule in all six cases and three of them showed air densities both in the cochlea and semicircular canal. The size of the air density in the vestibule was 5.38 ± 4.56 mm² at the axial view and 6.57 ± 5.67 mm² at the coronal view. The mean minimal Hounsfield unit (HU) of air density area in the vestibule was −968.1 ± 22.94 at the axial view and −941 ± 16.88 at the coronal view. Patients with pneumocochlea eventually developed total hearing loss.

Keywords:

• Temporal bone
• trauma
• pneumolabyrinth

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.

Funding information

This work was supported by a research fund from 2015 Chungnam National University (2015-1362-01).