Use of an innervated tongue flap to rehabilitate the tongue after hypoglossal-to-facial nerve transfer.

Facial palsy resulting from loss of the intracranial portion of the facial nerve has been reconstructed traditionally by transferring motor axons from the hypoglossal nerve to the facial nerve.1–4 This approach can reinnervate the facial muscles if it is done before these muscles have undergone irreversible atrophy, eliminating the need for a free-muscle transfer. The two major disadvantages of the hypoglossal-to-facial nerve transfer as an ideal strategy are (1) synkinetic movements of the reinnervated side of the face without volitional control5 and (2) untoward sequelae of hemiglossal denervation. Cross-facial nerve grafting can provide the volitional control of facial animation6,7 and is now the preferred approach.1,8 Transferring half of the hypoglossal nerve is recommended to “babysit” the paralyzed side of the face until the crossfacial nerve graft regenerates.9 There remains a need, however, to rehabilitate those patients in whom a complete hypoglossal-tofacial nerve transfer has resulted in tongue dysfunction. In the patients who have undergone complete hypoglossal-to-facial nerve transfer, moderate hemiglossal atrophy has been reported to occur in 50 percent and severe hemiglossal atrophy in 25 percent, with swallowing problems in 10 percent and speech problems in 16 percent.10 An approach to rehabilitate the tongue with these problems, by transferring an innervated flap from the contralateral tongue, is presented in two patients. CASE REPORTS