The convergence of facial nerve branches providing whisker pad motor supply in rats: implications for facial reanimation study.

INTRODUCTION: Rodent whisking behavior is supported by the buccal and mandibular branches of the facial nerve, but a description of how these branches converge and contribute to whisker movement is lacking. METHODS: Eight rats underwent isolated transection of either the buccal or mandibular branch and subsequent opposite branch transection. Whisking function was analyzed after both transections. Anatomical measurements, and video recording of stimulation to individual branches, were taken from both facial nerves in 10 rats. RESULTS: Normal to near-normal whisking was demonstrated after isolated branch transection. Whisking was eliminated after transection of both branches. The buccal and mandibular branches form a convergence just proximal to the whisker pad, herein called "distal pes." Distal to this convergence, we identified consistent anatomy that demonstrated cross-innervation. CONCLUSION: The overlap of efferent supply to the whisker pad must be considered when studying facial nerve regeneration in the rat facial nerve model.

Facial reanimation of patients with neurofibromatosis type 2.

BACKGROUND: Neurofibromatosis type 2 (NF2) is a tumor suppressor syndrome defined by bilateral vestibular schwannomas. Facial paralysis, from either tumor growth or surgical intervention, is a devastating complication of this disorder and can contribute to disfigurement and corneal keratopathy. Historically, physicians have not attempted to treat facial paralysis in these patients. OBJECTIVE: To review our clinical experience with free gracilis muscle transfer for the purpose of facial reanimation in patients with NF2. METHODS: Five patients with NF2 and complete unilateral facial paralysis were referred to the facial nerve center at our institution. Charts and operative reports were reviewed; treatment details and functional outcomes are reported. RESULTS: Patients were treated between 2006 and 2009. Three patients were men and 2 were women. The age of presentation of debilitating facial paralysis ranged from 12 to 50 years. All patients were treated with a single-stage free gracilis muscle transfer for smile reanimation. Each obturator nerve of the gracilis was coapted to the masseteric branch of the trigeminal nerve. Measurement of oral commissure excursions at rest and with smile preoperatively and postoperatively revealed an improved and nearly symmetric smile in all cases. CONCLUSION: Management of facial paralysis is often times overlooked when defining a care plan for NF2 patients who typically have multiple brain and spine tumors. The paralyzed smile may be treated successfully with single-stage free gracilis muscle transfer in the motivated patient.

The effects of potential neuroprotective agents on rat facial function recovery following facial nerve injury.

OBJECTIVE: To evaluate whether a series of pharmacologic agents with potential neuroprotective effects accelerate and/or improve facial function recovery after facial nerve crush injury. STUDY DESIGN: Randomized animal study. SETTING: Tertiary care facility. METHODS: Eighty female Wistar-Hannover rats underwent head restraint implantation and daily conditioning. Animals then underwent unilateral crush injury to the main trunk of the facial nerve and were randomized to receive treatment with atorvastatin (n = 10), sildenafil (n = 10), darbepoetin (n = 20), or a corresponding control agent (n = 40). The return of whisking function was tracked throughout the recovery period. RESULTS: All rats initiated the return of whisking function from nerve crush by day 12. Darbepoetin-treated rats (n = 20) showed significantly improved whisking amplitude and velocity across the recovery period, with several days of significant pairwise differences vs comparable control rats (n = 16) across the first 2 weeks of whisking function return. In contrast, rats treated with sildenafil (n = 10) and atorvastatin (n = 10) did not show significant improvement in whisking function recovery after facial nerve crush compared to controls. By week 8, all darbepoetin-treated animals and comparable nerve crush control animals fully recovered whisking function and were statistically indistinguishable. CONCLUSION: Among the 3 potentially neuroprotective agents evaluated, only darbepoetin administration resulted in accelerated recovery of whisking parameters after facial nerve crush injury. Further efforts to define the mechanism of action and translate these findings to the use of darbepoetin in the care of patients with traumatic facial paralysis are needed.

Transoral resection of tonsillar squamous cell carcinoma.

OBJECTIVES: The tonsillar fossa is the most common subsite of the oropharynx to be afflicted with squamous cell carcinoma (SCCA). Accepted treatments include any combination of surgery, radiotherapy, and chemotherapy. We review the oncologic and functional outcomes of patients with tonsillar carcinoma who underwent transoral tumor resection and neck dissection with or without postoperative radiotherapy or chemoradiotherapy. STUDY DESIGN: Retrospective chart review. METHODS: From 1996 through January 2005, 102 patients with tonsillar SCCA underwent transoral resection. Overall survival, disease-specific survival, local control, and locoregional control rates were analyzed using the Kaplan-Meier method. Immediate and long-term speech and swallowing function and treatment-related morbidity were analyzed. RESULTS: Twenty-six patients had surgery only, 71 had surgery and radiotherapy, and five had surgery and chemoradiotherapy. Twenty patients had stage III disease, 63 had stage IVA disease, and two had stage IVB disease. The Kaplan-Meier overall survival estimate was 92.2% at 2 years and 85.0% at 5 years. The 5-year local control estimate was 91.8%, and the 5-year Kaplan-Meier disease-specific survival estimate was 93.9%. The median hospital stay was 3 days. Tracheostomy was required for 14 patients, and 13 of these patients had decannulation. Temporary feeding tubes were placed in 35 patients. Sixteen patients received a percutaneous endoscopic gastrostomy tube; of these, 12 had the tubes removed. CONCLUSIONS: Transoral resection of tonsillar SCCA with or without postoperative adjuvant therapy provided excellent locoregional control and minimized treatment-related morbidity. We believe that transoral resection is the optimal treatment for patients with oropharyngeal SCCA.