Abstract
The aim of this study is to present a patient who developed a pneumolabyrinth following intratympanic steroid injection performed one year after stapes surgery. The patient started a medical treatment but since no improvement of his symptoms occurred, 10 days after the intratympanic injection a surgical treatment was proposed. An exploratory tympanotomy showed a displacement of the stapes prosthesis from the platinotomy, a dislocation of the incus long process, a fracture of the footplate and a depression into the vestibule. The fragment of the broken footplate was removed, a new prosthesis was located. Nausea, vertigo and nystagmus resolved immediately following surgery with a hearing threshold unchanged. In the present case report, the pathogenesis of pneumolabyrinth may be connected to an IT steroid injection proposed to the patient for the onset of sudden sensorineural hearing loss. To our knowledge, no case of a pneumolabyrinth provoked by intratympanic steroid injection has been previously described.
1
Introduction
Pneumolabyrinth is a condition in which air is in the vestibule (pneumovestibule) or in the cochlea (pneumocochlea). In 1984 Mafee et al. described for the first time pneumolabyrinth as the presence of air in the labyrinth subsequent to the fracture of the footplate of the stapes. Nowadays vestibular pneumolabyrinth is still a relatively uncommon diagnosis. As written by Hidaka et al. there are only 51 cases overall described in literature.
Currently the main causes of pneumolabyrinth are congenital malformations, traumatic petrous bone fractures, barotraumas, perilymphatic fistula between the middle ear and the inner ear, chronic ear disease or iatrogenic complication such as dislocation or fracture of the footplate during stapedectomy, displacement of stapes prosthesis into the vestibule and in some rare cases after cochleostomy for cochlear implantation . Yanagihara N et al. described also a case of pneumolabyrinth induced by Eustachian Tube air inflation. The symptoms of pneumolabyrinth occur immediately after the damage and include sensorineural hearing loss, tinnitus, fullness, dizziness, nystagmus and vertigo with nausea or vomiting; fistula test results positive in case of abnormal opening between the inner ear and the labyrinth capsule. The prognosis of hearing function is worse than the one of the vestibular symptoms. The aim of this study is to present a patient who developed a pneumolabyrinth following intratympanic (IT) steroid injection performed one year after stapes surgery.
2
Case report
On April 2011 a 64-year-old man affected by bilateral otosclerosis underwent a stapedotomy on his left ear with satisfactory results ( Fig. 1 A ).
One year later, on July 2012, the patient suffered a sudden sensorineural hearing loss (SSNHL) with high-pitch tinnitus in the same ear of the previous stapedotomy ( Fig. 1 B). Patient did not report symptoms or present signs suggesting traumatic events or vestibular disease before the onset of symptoms.
He accepted to start a cycle of IT steroid injections in the same hospital where he underwent stapes surgery. Immediately after the first IT injection the patient presented severe vertigo, nystagmus, vomiting lasting several hours, he did not respond to medical therapy and developed further deterioration of the hearing threshold on his left ear ( Fig. 1 C). The patient decided to interrupt the IT treatment and four days later he came to our attention reporting his recent clinical history and his symptoms that did not subside with bed rest and medical therapy (steroids, antiemetics and thiethylperazine). Clinical examination showed spontaneous horizontal, left-beating nystagmus. The swallowing and the deep inhalation exacerbated his vestibular symptoms. The general neurological examination was normal and also the Fistula test was negative. Vestibular examination including caloric test, vestibular myogenic potentials (ocular VEMPS – cervical VEMPS) and video head impulse test (VHIT) revealed a left hyporeflexia.
High resolution computed tomography (HRCT) of the ear detected air bubbles in the basal turn of the left cochlea leading to the diagnosis of pneumolabyrinth as suggested by several authors ( Fig. 2 ).
