側頭骨骨折と内耳障害の手術的治療

抄録

Temporal bone fractures due to skull trauma often associate with facial palsy and inner ear disorders. For the management of sensorineural hearing loss, tinnitus, vertigo and/or dizziness, medical treatments are usually chosen and continued for long time until the symptoms stabilize as sequelae. In our abundant surgical experiences in the treatments of facial nerve paralysis due to temporal bone fracture we found middle ear pathologies such as ossicular dislocation, ossicular chain interruption and perilymphatic fistula frequently triggered the inner ear disorders.
Successful surgical corrections of the middle ear pathologies brought dramatic improvements of the inner ear disorders. Based on the experiences we have come to the belief that otologists are responsible to treat surgically not only the facial nerve paralysis but also the middle ear pathologies which induce inner ear disorders. Two representative cases were reported. Case 1 was a 55-year-old female with a transverse fracture of the left temporal bone complaining of deafness, tinnitus, persistent dizziness and unsteadiness. From the findings of pure tone audiometry, tympanogram, left sided positional vertigo, loss of caloric nystagmus and coronal CT, ossicular dislocation and perilymphatic fistula were suspected. Transmastoid exploration of the middle ear revealed the incudostapedial dislocation and the perilymphatic fistula due to a fracture of the stapes foot plate. Following the surgical repair low tone hearing and tinnitus improved. Dizziness and unsteadiness disolved significantly. Case 2 was a 41-year-old male complaining of left facial palsy, deafness and tinnitus. He had a vertical temporal bone fracture and a sensorineural hearing loss of 35 dB in average. The coronal CT suggested a dislocation of the incus. Surgical decompression of the facial nerve together with correction of the ossicular dislocation and reconstruction of the ossicular chain brought immediate improvement of facial palsy and tinnitus. One year follow up examination confirmed normal facial nerve function and normal hearing without tinnitus. Based on the review of the cases and the literatures we conclude that the transmastoid middle ear exploration is advisable in the patients with inner ear disorders associated with temporal bone fracture if middle ear damage is suspected to induce the inner ear disorders.