Middle ear damages

Middle ear damages. The eardrum and middle ear are often exposed to blunt and penetrating trauma, blasts, thermal or caustic injuries. These injuries may result in tympanic membrane perforation, middle ear haemorrhage, dislocation and fracture of the ossicular chain, perilymphatic fistula and damage to the chorda tympani and/or facial nerve. In case of life-threatening injuries and/or mass casualty incidents, middle ear trauma obviously does not take highest priority. However, middle ear lesions should be suspected and recognized as early as possible. After meticulous history taking, physical examination consists of cranial nerve evaluation, thorough inspection of the outer ear, otoscopy and assessment of hearing and vestibular function. In the majority of cases, traumatic tympanic membrane perforations by penetrating and blunt injuries have a good prognosis with spontaneous resolution. Tympanic membrane perforations from blast trauma, thermal or caustic injuries are less likely to heal spontaneously. Perforations lasting six months after injury warrant surgery. A high resolution CT scan of the temporal bone is required in case of immediate complete facial nerve paralysis and when oval window pathology or perilymphatic fistula is suspected. Early surgical intervention is needed in case of early onset facial nerve paralysis, when there is suspicion of a perilymphatic fistula with persisting or increasing vestibular symptoms or neurosensory hearing loss and in case of vestibular dislocation of the stapes footplate. When ossicular chain damage is suspected, elective tympanoplasty is indicated. As any traumatic tympanic membrane perforation runs the risk of cholesteatoma formation, biannual follow-up during a minimum of two years is recommended.