Objective: To investigate the facial nerve contralateral innervation of patients with facial nerve injury.
Methods: Electroneuronography (ENoG) of 22 university student volunteers (US) without any injury and systemic diseases and 108 patients with facial nerve injury were measured. The patients were divided into three groups: iatrogenic, traumatic, and Bell's palsy groups. When stimulating the facial nerve at the site below the lobule and behind the ramus, ENoGs of each branch of the facial nerve on ipsilateral and contralateral sides were recorded. A total of 76 branch I, 81 branch II, 88 branch III, and 66 branch IV were measured.
Results: (1) There were no significant differences among three patient groups (P > 0.05). (2) The ratios of contralateral innervation of the branch I and II of the patients were significantly. greater than those of the US group (P < 0.001). (3) The ratio of contralateral innervation of the branch I was greater than that of the branch II in the patients (P < 0.001).
Conclusion: The contralateral innervation of the facial nerve increases after facial nerve injured.