Traumatic pneumolabyrinth is a relatively rare entity. We report the case of a unilaterally deaf woman with pneumolabyrinth who had suffered penetrating injury 15 years ago. This past history indicated that the case was late pneumolabyrinth occurring from undiagnosed old posttraumatic perilymphatic fistula. In Japan, most cases of traumatic pneumolabyrinth are caused by penetrating injury with an ear pick. Dizziness often improves within several months. Immediate surgical intervention is recommended for hearing loss, but the hearing outcome is not satisfactory. An appropriate strategy should be selected based on the interval to surgery, bone conduction hearing level at disease onset, stapes lesions, and location of air.
Pneumolabyrinth is a condition caused by air in the labyrinth, which indicates that a perilymphatic fistula (PLF) is present in the affected ear. However, patients with traumatic PLF seldom develop pneumolabyrinth. Here, we report a case of pneumolabyrinth that may have been caused by a penetrating injury of the tympanic membrane that occurred 15 years before presentation. This interesting case suggests that pneumolabyrinth may be among the differential diagnoses for recurrent dizziness.
A 25-year-old woman was admitted to hospital with a complaint of longstanding right-sided profound hearing loss. Her hearing impairment had begun 15 years ago. At that time, she suffered traumatic tympanic membrane perforation due to penetration by an ear pick. She had sudden profound hearing loss at the onset of injury and it was unclear that she had felt vertigo after injury. Conservative therapy was performed at ENT clinic nearby. Although perforation of tympanic membrane was healed completely, profound hearing loss had remained. She mentioned the degree of hearing loss had not changed. She had felt lightheadedness about 7 years ago.
An otoscopic examination revealed no perforation in her right ear, but pure tone audiometry showed right profound hearing loss (Figure
Audiogram on hospital on day 1. The right ear showed profound sensorineural hearing loss.
Axial views of the right ear on cone-beam computed tomography on hospital on day 1, showing a round low density area (a) and intrusion of stapes (b) (black arrows).
Two years later, she was admitted again for follow-up of hearing loss. She sometimes had dizziness or lightheadedness. Pure tone audiometry showed right profound hearing loss similar to before (Figure
Follow-up audiogram performed 2 years later. Profound sensorineural hearing loss in her right ear had not changed.
Axial view of the right ear on cone-beam computed tomography obtained 2 years after initial presentation. The air bubble apparent in Figure
The number of reports on pneumolabyrinth is smaller than those on PLF but has shown a slight increase due to improved accuracy of imaging modalities. Hidaka et al. [
According to medical interview, profound hearing loss occurred immediately after injury and was supposed to be permanent. Intrusion of stapes found in CBCT image indicated the possibility of old posttraumatic PLF. Symptoms associated with PLF tend to appear rapidly and the degree of hearing loss varies from mild to profound. Subacute deterioration of hearing level has been documented in several reports [
The unique aspect of this case is the long interval between injury and diagnosis of pneumolabyrinth by CBCT. It was impossible to make sure that pneumolabyrinth had occurred soon after injury. Intrusion of stapes suggested that there had been posttraumatic PLF. There was no causative event other than penetrating injury by ear pick 15 years ago. Air that enters the inner ear usually disappears within several weeks. Pneumolabyrinth detected by CBCT suggested that air was trapped recently and that PLF did not heal completely. In the patient with PLF, elevated atmospheric pressure in the middle ear cavity may induce fainting and dizziness. If excessive elevation of the middle ear pressure happens, entrapment of air in the vestibule may occur. Nurre et al. [
Treatment of dizziness has a good prognosis, but treatment of hearing loss is difficult and often unsuccessful. Most reports have shown unsatisfactory hearing outcomes regardless of the treatment strategy. Hidaka et al. [
Tsubota et al. [
Hidaka et al. [
Prevention from worsening of hearing loss is important. Achache et al. [
Pneumolabyrinth may occur in case PLF is present, even if the interval between diagnosis and causative event is very long. An appropriate decision on the treatment strategy requires consideration of the timing of surgery, the bone conduction level at onset of disease, stapes lesions, and location of air in the inner ear.
The authors declare that there is no conflict of interests regarding the publication of this paper.