Temporal Bone Fractures
Temporal bone fractures can occur after severe blunt trauma to the head and sometimes involve structures of the ear, causing hearing loss, vertigo, balance disturbance, or facial paralysis.
Temporal bone fractures are suggested by
Bleeding may come from the middle ear (hemotympanum) through a ruptured tympanic membrane or from a fracture line in the ear canal (see Traumatic Perforation of the Tympanic Membrane). A hemotympanum makes the tympanic membrane appear blue-black. CSF otorrhea indicates a communication between the middle ear and the subarachnoid space.
Temporal bone fractures have been classified by orientation with respect to the long axis of the petrous portion of the temporal bone. Longitudinal fractures make up 70 to 90% of temporal bone fractures, and transverse fractures make up 10 to 30%. Some fractures may have characteristics of both patterns.
Longitudinal fractures can extend through the middle ear and rupture the tympanic membrane; they cause facial paralysis in 20% of cases and may cause hearing loss (usually conductive).
Transverse fractures cross the fallopian canal and otic capsule, causing facial paralysis in about 40% of patients and sometimes hearing loss (usually sensorineural) and vestibular dysfunction (eg, vertigo, balance disturbance).
Rarely, fluctuating sensorineural hearing loss and vestibular dysfunction occur with temporal bone fracture and may be due to a perilymph fistula. Immediate complete facial paralysis may indicate a severed or crushed facial nerve, whereas delayed-onset complete facial paralysis usually indicates edema within an intact nerve.
If a temporal bone fracture is suspected, immediate CT of the head with special attention to the temporal bone is recommended. The Weber and Rinne tuning fork tests can be done during the initial physical examination in conscious patients to help differentiate between conductive and sensorineural hearing loss. However, formal audiometric examination is required for all patients with temporal bone fractures. If facial paralysis is present, electrical testing of the facial nerve is warranted.
Treatment is based on managing facial nerve injury, hearing loss, vestibular dysfunction, and CSF leakage. If immediate facial nerve paralysis occurs with loss of electrical response, surgical exploration may be warranted. Delayed-onset or incomplete facial paralysis almost always resolves with conservative management, including use of corticosteroids, which are gradually tapered.
Conductive hearing loss requires ossicular chain reconstruction several weeks to months after the injury. Good results can be expected. When sensorineural hearing loss occurs, it is typically permanent, and there are no medical or surgical therapies available to improve hearing. However, in the rare case of fluctuating sensorineural hearing loss, an exploratory tympanotomy to search for a perilymph fistula may be indicated.
When vestibular dysfunction results from perilymph fistula, repair may reduce severity and frequency of vertiginous episodes. When dysfunction results from injury to the vestibular nerve or vestibular labyrinth, few interventions can improve outcome. Symptoms may subside when benzodiazepines are used. More lasting improvement may occur with vestibular rehabilitation.
Patients who have a temporal bone fracture and CSF otorrhea should be hospitalized because meningitis is a risk. The leak usually stops spontaneously within a few days, although a lumbar drain or surgical closure of the defect is occasionally required. The ear canal is not irrigated or manipulated. Prophylactic antibiotics are used in some institutions.
Temporal bone fracture can cause blood coming from the ear, blood behind the tympanic membrane, hearing loss, vestibular dysfunction, and/or facial nerve paralysis.
Do CT with attention to the temporal bone, refer patients for audiometry, and, if facial nerve paralysis is suspected, arrange electrical testing of the facial nerve.
Direct treatment toward management of facial nerve injury, hearing loss, vestibular dysfunction, and CSF leakage.