Objective The clinical characteristics and prognosis of post traumatic hearing loss were retrospectively evaluated to aid further diagnosis, medical evaluation, early identification, and effective treatment.
Methods We recruited 84 patients (96 ears) and obtained their clinical examination findings, hearing test results, and audiograms from a single-institution otolaryngology service with comparative data generated from their first and follow-up visits.
ResultsAmong all the recruited patients, 34 ears (35.4%) had normal hearing, while 62 ears (64.6%) had hearing loss after trauma, at their first visit. Among 62 ears with hearing loss, 33 ears (53.2%) had conductive hearing loss, 25 ears (40.3%) had sensorineural hearing loss, and four ears (6.5%) had a mixture of conductive and sensorineural hearing loss. At the follow-up visit, the air conduction threshold of ears with conductive hearing loss had significantly decreased from 45.77±4.28 dB HL to 34.48±4.53 dB HL (t=2.906, P < 0.05), while the bone conduction threshold decreased from 23.45±2.31 dB HL to 19.63±2.20 dB HL (t=2.906, P < 0.05). However, no significant differences between the first and follow-up visits were observed in ears with sensorineural hearing loss or ears with mixed hearing loss. Of all the 96 ears, 39 (40.6%) had intact tympanic membrane, while 57 (59.4%) had traumatic tympanic membrane perforation. At follow-up, 40 ears (70.2%) with traumatic tympanic membrane perforation had healed spontaneously, while 12 ears (21.1%) had healed after tympanoplasty. However, five ears (8.8%) did not heal. Among the ears that spontaneously healed, 83.0% had grade Ⅰ and 16.7% had grade Ⅱ tympanic membrane perforation. Ears with grade Ⅲ and grade Ⅳ tympanic membrane perforations did not heal spontaneously.
Conclusions Hearing impairment is a common clinical presentation in patients with traumatic injury. In most patients, this manifests as conductive hearing loss, while severely affected patients may have sensorineural or mixed hearing loss. Patients with conductive hearing loss have a favorable prognosis, while patients with sensorineural or mixed hearing loss have a poor prognosis. Trauma could cause different degrees of tympanic membrane perforation. With gradually aggravated tympanic membrane perforation, the spontaneous healing rate decreases. Therefore, for patients with large tympanic membrane perforations, which rarely heal spontaneously, tympanoplasty is warranted.