Introduction
Temporal bone fractures (TBFs) present complex diagnostic and management challenges. Due to the large amount of force required to fracture the temporal bone, several other injuries may also be present. The severity and number injuries may result in incomplete or evaluation of the temporal bone, which may delay diagnosis and proper follow-up care. The management of TBF overall focuses on restoring functional deficits and reducing regional and intracranial complications due to injury to structures within the TB. This chapter will provide an overview of the diagnosis and medical and surgical management of TBF.
Diagnosis
History
In the conscious patient, hearing loss is often the most immediately reported symptom following head and temporal bone injury. Tinnitus may also be present and does not alter prognosis. Vestibular symptoms such as imbalance and dizziness often are exacerbated following ambulation. Symptoms of facial weakness, paralysis, and asymmetry suggest facial nerve injury, which warrant early surgical intervention. Determining the temporality and onset of facial symptoms is critical as this will help guide treatment planning. ,
In the unconscious patient, eliciting a detailed history is not possible and therefore relies on obtaining information from individuals who may have arrived with the patient and may help characterize the mechanism of injury. The nature and etiology of TBF may help dictate the urgency of interventions; TBF from penetrating trauma due to gunshot wounds may cause neurologic and vascular injury requiring more immediate attention than TBF from blunt trauma, such as motor vehicle accidents.
Physical examination and evaluation
Initial survey
Patients with suspected temporal bone trauma will be evaluated by the trauma team and assessed for life-threatening issues often before a complete temporal bone examination takes place. This consists of a full-body trauma assessment, including securing an airway, controlling hemorrhage and maintaining circulation, and examining neurologic status. The cervical spine should also be evaluated and stabilized.
Isolated TBFs are rare, which necessitates evaluation of the entire facial skeleton. Facial nerve function should be evaluated as soon as possible, particularly before muscle relaxants are administered, as this will affect examination accuracy and lose valuable prognostic information. An otologic exam should then be performed systematically, which focuses on the external and middle ear.
Otologic exam
The auricles and soft tissue are first inspected for exposed cartilage, hematomas, and lacerations. Hematomas should be incised and drained, and pressure bolsters are sutured to prevent “cauliflower ear” or auricular chondropathy. Lacerations are cleaned and closed. Retroauricular hematoma, also known as the “Battle sign,” may be present over the mastoid prominences, which is an arch-shaped bruising behind the auricle. This may point to a basilar skull fracture.
Next, the ear canal is inspected. Irrigation should not be used to remove cerumen or blood to avoid inadvertently introducing pathogens. The presence of brain herniation, fracture of the roof of the external auditory canal, middle ear effusions (e.g., hemotympanum), scutum fracture, and color of otorrhea should be noted. Otorrhea may be bloody or clear, which suggests a cerebrospinal fluid (CSF) leak.
The tympanic membrane should also be assessed for perforations. Typically, traumatic tympanic membrane perforations heal spontaneously, and no immediate intervention is needed. Pneumatic otoscopy should be used judiciously and not be used in the early period following injury as this may introduce air or bacteria into the intracranial space or inner ear via a CSF fistula or otic capsule disrupting fracture.
An operating microscope may be used following stabilization to further evaluate the ear canal, tympanic membrane, or middle ear and may be required to remove a foreign body, if present. Packing of the ear canal is not generally initially needed unless significant hemorrhage is present. If profuse hemorrhage is present, management via balloon occlusion or carotid ligation may be used.
Hearing assessment
An early bedside evaluation with a 512-Hertz tuning fork allows for documenting baseline hearing function and potential hearing loss. The Weber test is performed by placing the base of a struck tuning fork on the forehead, nose, or teeth. The patient is then asked if the sound is louder on either side. Typically, a patient with unilateral sensorineural hearing loss (SNHL) will lateralize sound toward the unaffected side, whereas a patient with unilateral conductive hearing loss (CHL) will lateralize sound toward the affected side. There is no sound lateralization in a normal test.
The Rinne test is a follow-up test performed for each side by placing the base of a struck tuning fork on the mastoid and then held near the meatus. The patient is then asked if the tuning fork is louder near the meatus (evaluating air conduction) or when applied to the mastoid (evaluating bone conduction). A patient with a moderate CHL will report louder bone conduction than air conduction on the affected side. A patient with normal hearing will report louder air conduction than bone conduction (i.e., considered to be a positive Rinne) but does not exclude sensorineural hearing loss in the tested ear.
Combined results from the Weber and Rinne tests will help characterize the underlying nature of hearing loss. A patient may have CHL if the Weber test lateralizes to the affected ear and a negative Rinne is present. Patients with SNHL may have variable tuning fork findings. A Weber test that is louder on the affected side suggests SNHL and the Rinne test will generally be positive, unless if there is significant hearing loss. Audiograms are generally not obtained until the patient’s condition is stabilized, unless if urgent complications such as CSF leak or facial paralysis are noted, which guides treatment approach in cases with residual hearing.
Vestibular assessment
Patients may report dizziness or imbalance following temporal bone trauma due to inner ear injury or neurologic injury. In addition to a detailed neurological evaluation, bedside vestibular testing should be performed. Patients who present in the setting of trauma should have cervical spine injuries ruled out before undergoing vestibular testing.
During the physical exam, the presence and type of nystagmus should be noted. Central causes of vertigo can present with purely vertical, horizontal, torsional, or direction-changing nystagmus. Peripheral causes of vertigo may present with horizontal and/or torsional nystagmus. Unlike central vertigo, nystagmus associated with peripheral vertigo is inhibited by eye fixation and is fatigable. Peripheral vertigo is also generally more severe. The Dix-Hallpike maneuver can be used to assess for benign paroxysmal positional vertigo (BPPV), a common etiology of vertigo following traumatic brain injury, which will reveal transient torsional nystagmus. ,
In most cases, posttraumatic vertigo will resolve spontaneously. If vertigo persists, additional testing can be performed in the outpatient setting. The fistula test checks for abnormal communication between the middle and inner ear. Using a pneumatic otoscope, positive and negative pressure is applied in the ear canal. Presence of vertigo and nystagmus suggests evidence of a perilymphatic fistula. Importantly, this test should never be performed if there is evidence of middle ear infection or CSF fistula, or in the acute setting to prevent introduction of air or infection in the inner ear.
Facial nerve
The complex anatomy of the facial nerve increases risk of injury following TBF. Notable anatomical features include tethering of the nerve at various points, such as the perigeniculate region and extremely narrow portions of the canal at the meatal foramen, which may lead to damage of the facial nerve via shearing, compression, and disruption. Trauma leading to otic capsule or transverse TBF also increases risk of facial nerve injury due to the perpendicular direction of the fracture relative to the facial nerve.
Evaluating facial nerve function
Asymmetrical facial movement in the setting of temporal bone trauma is likely due to facial nerve injury. Generally, more diffuse hemifacial weakness will be a result of injury to the intratemporal segments of the facial nerve compared with extratemporal segments. Patient should be instructed to perform several movements with their face, and asymmetries between sides should be noted: elevate their eyebrows to wrinkle their forehead, close their eyes tightly, smile, and puff out their cheeks. In patients who are unable to voluntarily complete these movements (e.g., altered mental status), a painful stimulus (e.g., sternal rub) may be used to assess facial movements. Significant edema may give the appearance of decreased facial function. It is important to note that a high degree of expression on the unaffected side may cause movement on the affected side near the midline. Physically limiting movement by pressing on the unaffected side and reassessing for movement on the suspected affected side can help ascertain if injury has occurred.
Characterizing facial nerve paralysis is important to determine future prognosis and treatment decision-making. Several scales for recording facial nerve function are available. , Regardless of which scale is used, it is important to determine if there is weakness (paresis) or no movement (paralysis) of the facial nerve. The House–Brackmann (HB) 6-point scale is the most commonly used scale ( Table 7.1 ). , A limitation of the HB scale is describing the distribution of which facial nerve branch is affected. As such, recording individual function of the facial nerve’s extratemporal branches (temporal—forehead, zygomatic—eye closure, buccal—midface, marginal mandibular—mouth, and cervical—neck) can help localize the injury and dysfunction. Any patient with partial residual motor function is likely to have a good long-term outcome with conservative management.
| Grade | Defined by | |
|---|---|---|
| 1 | Normal | Normal facial function in all areas. |
| 2 | Mild dysfunction | Slight weakness noticeable only on close inspection. At rest: normal symmetry of forehead, ability to close eye with minimal effort and slight asymmetry, ability to move corners of mouth with maximal effort and slight asymmetry. No synkinesis, contracture, or hemifacial spasm. |
| 3 | Moderate dysfunction | Obvious but not disfiguring difference between two sides, no functional impairment; noticeable but not severe synkinesis, contracture, and/or hemifacial spasm. At rest: normal symmetry and tone. Motion: Slight to no movement of forehead, ability to close eye with maximal effort and obvious asymmetry, ability to move corners of mouth with maximal effort and obvious asymmetry. Patients who have obvious but no disfiguring synkinesis, contracture, and/or hemifacial spasm are grade III regardless of degree of motor activity. |
| 4 | Moderately severe dysfunction | Obvious weakness and/or disfiguring asymmetry. At rest: normal symmetry and tone. Motion: No movement of forehead; inability to close eye completely with maximal effort. Patients with synkinesis, mass action, and/or hemifacial spasm severe enough to interfere with function are grade IV regardless of motor activity. |
| 5 | Severe dysfunction | Only barely perceptible motion. At rest: possible asymmetry with droop of corner of mouth and decreased or absence of nasal labial fold. Motion: No movement of forehead, incomplete closure of eye and only slight movement of lid with maximal effort, slight movement of corner of mouth. Synkinesis, contracture, and hemifacial spasm usually absent. |
| 6 | Total paralysis | Loss of tone; asymmetry; no motion; no synkinesis, contracture, or hemifacial spasm. |
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
