[The management of facial nerve tumor manifested as facial paralysis].

OBJECTIVE

To heighten the awareness of the facial nerve tumors.

METHODS

The clinical data of twenty-three patients complaining of facial paralysis who were diagnosed postoperatively as facial nerve tumors were analyzed. The hearing assessment of all patients was based on pure tone audiometry at the frequency of 0. 5, 1, 2, 4 kHz. Temporal bone high resolution CT scan and temporal bone MRI with gadolinium enhancement were conducted on all patients. Facial nerve function was assessed with the House-Brackmann (HB) grading system. Facial electroneurography (ENoG) was conducted on 20 patients to quantify the degree of nerve degeneration preoperatively. The pathological types of tumor were determined by postoperative pathological reports.

RESULTS

Nineteen out of 23 cases presented hearing loss (82.6%), 10 cases suffered from tinnitus (43.5%), otalgia (17.4%) affected 4 cases, 3 cases manifested otorrhea (13.0%), and 2 cases presented vertigo (8.7%). Geniculate ganglion was the most commonly involved site (20 cases, 87.0%), followed by tympanic segments (18 cases, 78.3%), pyramid segment (16 cases, 69.6%), mastoid segment (10 cases, 43.5%), labyrinthine segment (9 cases, 39.1%), internal auditory canal segment and parotid gland segment (5 cases, 21.7%, respectively). Twenty-one cases (91.3%) of schwannomas, 1 case (4.3%) of neurofibroma and 1 case (4.3%) of hemangiomas were identified with histopathology postoperatively. The tumors were all completely excised, and the facial nerve function could recovered to HB III at the best after facial nerve repairment.

CONCLUSIONS

Facial nerve tumor is a rare and often misdiagnosed disease which was commonly manifested as facial nerve paralysis. Temporal bone CT and MRI can help to clarify the diagnosis preoperatively. Pure tone audiometry and electroneurography also plays a some certain roles in the diagnosis of facial nerve tumors. The tumors should be completely resected and the surgical approaches were determined based on tumor size, facial nerve function and preoperative auditory function.