Traumatic Facial Paralysis Infratemporal Injury Closed Head Trauma

Closed-head trauma is a very common etiology of traumatic facial paralysis. These patients can have numerous life-threatening injuries with other systemic problems. Often the management of these patients is shifted to rehabilitation facilities, so that otolaryngologists must coordinate serial evaluation of these patients with such facilities. In general, a patient who has a partial paralysis, House-Brackmann, grade II-V, is managed with observation. The only medical intervention available for post-traumatic facial paralysis is steroid therapy. Prednisone 1 mg/kg/day, equally divided doses over 10 days, is recommended in the absence of medical contraindications. The patient with the minimal grade function, House grade V, must be viewed with circumspection. This is a setting in which contralateral function or nearby muscle groups such as masseter motion may mislead the clinician. Accordingly, EMG is helpful for confirming voluntary motor action potentials if there is any doubt of residual function.

For the patient with complete facial paralysis, grade VI, medical therapy with steroids can be combined with surgical treatment as an option for either facial nerve decompression or grafting. Table 42-1 shows an algorithm for managing complete facial paralysis in the patient who has closed head trauma. Although it is generally assumed that delayed paralysis has a better prognosis than immediate paralysis, reliable information concerning the timing of facial paralysis is often difficult to obtain.10 The typical scenario is generally one in which the timing of the development of facial paralysis is unknown. Both CT imaging and electrical facial nerve testing are used to guide the management of these patients. Significant CT findings include a temporal bone fracture through the course of the facial nerve with diastasis of > 1 mm or an apparent bone spicule along the course of the facial nerve. Electrical testing includes volitional EMG beginning after the first 3 days of injury if there is any question of retained motion. Hilger nerve excitability testing is also helpful if there was a suggestion that the paralysis was delayed in onset or if there is no evidence of fracture or bone spicule on CT scan. ENOG testing is also helpful in the face of a significant fracture on CT and loss of Hilger excitability. Surgical exploration of the course of the facial nerve is advocated in patients who have a complete facial paralysis with evidence of significant diastasis along the course of the facial nerve or bone spicule along the course of the facial nerve on CT scan, and electrical degeneration within 3 weeks of their injury to less than 10% of the normal side. In contrast, patients who have temporal bone fractures on CT, but without significant findings along the facial nerve, or with electrical degeneration within the 3-week period, are encouraged to await spontaneous recovery for 6 months. In addition, steroid therapy is implemented. The possible value of a facial nerve exploration and decompression is mentioned because there is some evidence to support decompression and exploration in this setting.11

Patients who develop any motion during this time are observed and are not candidates for temporal bone facial nerve

TABLE 42-2

Closed Head Trauma—Complete Paralysis: 6-Month Decisions

Motion S Observe

No motion s EMG

Fibrillations Polyphasic

EMG, electromyography.

surgery. Patients in whom spontaneous activity does not develop during this time are restudied with EMG for spontaneous muscle fibrillation or polyphasic potentials. Patients who demonstrate fibrillation potentials have not experienced reinnervation of their facial muscle so surgical exploration of the temporal course of the nerve should be considered. Patients who develop polyphasic potentials are undergoing reinnervation of their facial muscule and should be managed with additional observation12 (Table 42-2).

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