Research & Current Literature
List compiled by Robin Lindsay, M.D.
Griffin, G. R. and J. C. Kim (2011). "Potential of an Electric Prosthesis for Dynamic Facial Reanimation." Otolaryngol Head Neck Surg.
Chronic facial paralysis is a devastating condition with severe functional and emotional consequences. The current surgical armamentarium permits the predictable reestablishment of a protective blink as well as good resting symmetry. Yet the ultimate goal of symmetric, spontaneous emotional expression remains elusive despite significant progress in the areas of peripheral nerve grafting and free tissue transfer. This commentary explores the possibility of an implantable electrical prosthesis for facial reanimation. It reviews animal studies supporting this concept as well as recent human data suggesting that such an implant could rescue denervated facial musculature, thus overcoming a major hurdle for existing reanimation techniques.
Horta, R., P. Silva, et al. (2011). "Facial reanimation with gracilis muscle transplantation and obturator nerve coaptation to the motor nerve of masseter muscle as a salvage procedure in an unreliable cross-face nerve graft." Microsurgery 31(2): 164-166.
Marre, D. and B. Hontanilla (2011). "Brain Plasticity in Mobius Syndrome After Unilateral Muscle Transfer: Case Report and Review of the Literature." Ann Plast Surg.
BACKGROUND:: Mobius syndrome is mainly characterized by bilateral facial palsy. Facial reanimation of these children is achieved by microsurgical techniques, namely free-gracilis muscle innervated by the masseteric nerve. Notorious commissure excursion and speech improvement are reported with such procedure. Several studies have demonstrated the presence of cortical reorganization after injury and repair of different segments of the body. Intensive training of a behaviorally relevant task is key in this process. CASE REPORT:: A 4-year-old patient with complete bilateral facial palsy secondary to Mobius syndrome was operated with left hemiface free-gracilis muscle transplant innervated by the masseteric nerve and submitted for postoperative physiotherapy. Eight months later, bilateral movement was noted. CONCLUSIONS:: Brain plasticity is likely to play an important role in smile restoration in patients with bilateral facial palsy. Intensive physiotherapy and psychosocial relevance of facial expression might be key in such phenomenon.
Karlidag, T., M. Yildiz, et al. (2011). "Evaluation of the effect of methylprednisolone and N-acetylcystein on anastomotic degeneration and regeneraton of the facial nerve." Auris Nasus Larynx.
OBJECTIVES: This study was aimed to determine the effects of methylprednisolone and N-acetylcystein on nerve healing in facial nerve anastomosis. METHODS: Thirty rabbits were randomly divided into 3 groups: Group I: control group received no medication; Group II: 50mg/kg/day N-acetylcystein administered group; Group III, 1mg/kg/day Methylprednisolone administered group. All rabbits underwent the same standard surgical procedure. A 1mm segment was resected from the facial nerve and the free ends were anastomosed. The drugs were administered for two months twice a day. At the end of the second month, the anastomosed regions were dissected and examined under electron and light microscopy. RESULTS: Best nerve regeneration was observed in the N-acetylcystein and the control groups, respectively, whereas the weakest regeneration was determined in the methylprednisolone group. In the N-acetylcystein group, due to Schwann cell and glial cell proliferation, the increased regeneration rate was significantly higher compared to that of the methylprednisolone group. In the methylprednisolone group, no significant regeneration was observed despite the presence of degenerative signs of significant axonal withdrawal and an increase in the number of myelin debris. CONCLUSION: In the present study, we demonstrated that methylprednisolone had no beneficial effect in nerve regeneration after facial nerve anastomosis. It further caused increased degeneration. On the contrary, N-acetylcystein administration significantly increased the extent of regeneration, whereas it decreased the extent of degeneration compared to the control and the methylprednisolone groups.
Esaki, S., J. Kitoh, et al. (2011). "Hepatocyte growth factor incorporated into herpes simplex virus vector accelerates facial nerve regeneration after crush injury." Gene Ther.
Hepatocyte growth factor (HGF) promotes regeneration of the central nervous system, but its effects on the peripheral nervous system remain unclear. This study was conducted to elucidate the effect of HGF on regeneration of the murine facial nerve after crush injury. To do so, a replication-defective herpes simplex virus vector that incorporated HGF was prepared (HSV-HGF). The main trunk of the facial nerve was compressed by mosquito hemostats, and HSV-HGF, control vector or medium was then applied to the compressed nerve. We found that mice in the HGF group required significantly fewer days for complete recovery from nerve compression. Furthermore, the amplitude of the evoked buccinator muscle compound action potential increased following HSV-HGF application. HGF expression in and around the compressed nerve was demonstrated by enzyme-linked immunoassay and immunohistochemistry. In addition, HSV-HGF introduction around the damaged nerve significantly accelerated recovery of function of the facial nerve. These data suggest a possible role of HGF in promoting facial nerve regeneration after nerve damage. Furthermore, this viral delivery method may be applied clinically for many types of severe facial palsy during facial nerve decompression surgery.Gene Therapy advance online publication, 12 May 2011; doi:10.1038/gt.2011.57.
Siemionow, M., B. B. Gharb, et al. (2011). "Pathways of sensory recovery after face transplantation." Plast Reconstr Surg 127(5): 1875-1889.
BACKGROUND: : Severely disfiguring facial injuries have a devastating impact on the patient's quality of life. The advent of facial allotransplantation has allowed optimal anatomical reconstruction to be achieved; however, the need for lifelong immunosuppression and unpredictable functional outcomes preclude it from routine acceptance in clinical practice. Evidence from published reports on the first four face transplant recipients indicates improved and accelerated return of sensation to the facial allograft despite suboptimal repair of the sensory nerves. METHODS: : The authors performed a comparative analysis of the sensory outcomes following face transplantation with the sensory recovery achieved after conventional nerve repair, autologous face and scalp replantation, and vascularized free tissue transfer. RESULTS: : Sensory recovery following face transplantation, even when the sensory nerves were not repaired, was comparable to the outcome of microsurgical repair of the peripheral branches of the trigeminal nerve and innervated free flaps. CONCLUSIONS: : Nearly normal sensory recovery can be expected following facial allotransplantation with or without repair of the sensory nerves. The mechanisms responsible for this surprising outcome include preservation of normal density of the receptors within the facial allograft, regeneration from the recipient bed and allograft margins, transmission of the sensory inputs through afferent fibers contained in the facial nerve, nervi nervorum of the facial nerve, or trigeminofacial communicating rami. Furthermore, immunosuppressive therapy with tacrolimus contributes to the accelerated nerve regeneration. The minimum requirements for quantitative sensory testing and timing of the follow-up assessments are outlined to facilitate comparison of sensory outcomes after face transplantation.
Hadlock, T. A., J. S. Malo, et al. (2011). "Free Gracilis Transfer for Smile in Children: The Massachusetts Eye and Ear Infirmary Experience in Excursion and Quality-of-Life Changes." Arch Facial Plast Surg 13(3): 190-194.
Background Free muscle transfer for facial reanimation has become the standard of care in recent decades and is now the cornerstone intervention for dynamic smile reanimation. We sought to quantify smile excursion and quality-of-life (QOL) changes in our pediatric free gracilis recipients following reanimation. Methods We quantified gracilis muscle excursion in 17 pediatric patients undergoing 19 consecutive pediatric free gracilis transplantation operations, using our validated SMILE program, as an objective measure of functional outcome. These were compared against excursion measured the same way in a cohort of 17 adults with 19 free gracilis operations. In addition, we prospectively evaluated QOL outcomes in these children using the Facial Clinimetric Evaluation (FaCE) instrument. Results The mean gracilis excursion in our pediatric free gracilis recipients was 8.8 mm +/- 5.0 mm, which matched adult results, but with fewer complete failures of less than 2-mm excursion, with 2 (11%) and 4 (21%), respectively. Quality-of-life measures indicated statistically significant improvements following dynamic smile reanimation (P = .01). Conclusions Dynamic facial reanimation using free gracilis transfer in children has an acceptable success rate, yields improved commissure excursion, and improves QOL in the pediatric population. It should be considered first-line therapy for children with lack of a meaningful smile secondary to facial paralysis.
Ishii, L. E., A. Godoy, et al. (2011). "What faces reveal: Impaired affect display in facial paralysis." Laryngoscope 121(6): 1138-1143.
OBJECTIVES/HYPOTHESIS: To evaluate affect display in patients with facial paralysis as compared with normal subjects. We hypothesized that patients with facial paralysis would have impaired affect display and be perceived as displaying a negative affect as compared with normal subjects. STUDY DESIGN: Randomized controlled experiment. METHODS: Forty naive observers viewed pictures of patients with facial paralysis and normal faces. Observers classified the affect display of the patients and normal subjects by using a survey containing choices regarding primary emotions and personal attributes. RESULTS: An exploratory latent class analysis was performed on the survey results, and the faces were categorized into three types: positive, negative, and neutral. The probability of interpreting normal smiling faces as positive was 98%; the probability of interpreting those in repose as neutral or positive was 60%. The faces with facial paralysis were much more likely to be regarded as negative or neutral. The probability for classification into the negative class was 73% for the paralyzed faces in repose and 69% for the paralyzed smiling faces. In the latent class regression, smiling normal faces were six times more likely to be classified as positive, and smiling paralyzed faces were three times less likely to be in that class. CONCLUSIONS: Patients with facial paralysis were classified as having a negative affect display the vast majority of the time. Antithetically, normal faces in repose were classified as neutral the majority of the time; they were classified as positive the majority of the time when smiling. These novel results demonstrate the impact of the facial paralysis defect on perception by observers. Laryngoscope, 2011.
Chu, E. A., T. Y. Farrag, et al. (2011). "Threshold of visual perception of facial asymmetry in a facial paralysis model." Arch Facial Plast Surg 13(1): 14-19.
OBJECTIVE: To determine the degree of facial asymmetry required to trigger conscious perception in the observer in a simulated model of facial paralysis. METHODS: A model of unilateral facial paralysis was created using the face of a participant without facial paralysis. Digital morphing software was used to create progressive asymmetry of the brow, oral commissure, and combined brow and oral commissure based on the typical sequelae seen in facial paralysis. Volunteers naive to the goals of the study repeatedly were shown a series of photographs of faces without facial paralysis, with the manipulated image interspersed within the series. RESULTS: At least 3 mm of facial asymmetry of the oral commissure, brow, or both was required before participants detected the asymmetry. With longer display intervals, participants tended to detect a smaller degree of asymmetry. CONCLUSIONS: To our knowledge, this is the first study directed at determining the amount of facial asymmetry required to trigger conscious perception of patients' facial paralysis in the naive observer. The pilot data and the discussion herein provide insight into the processes of visual perception of facial asymmetry and may be useful to surgeons for patient counseling and in setting surgical goals.
Klebuc, M. J. (2011). "Facial Reanimation Using the Masseter-to-Facial Nerve Transfer." Plast Reconstr Surg 127(5): 1909-1915.
BACKGROUND: : This article describes facial reanimation using the transfer of the trigeminal motor nerve branch of the masseter muscle (masseter nerve) to the facial nerve (masseter-to-facial nerve transfer). METHODS: : A retrospective review was performed of 10 consecutive facial paralysis patients treated with a masseter-to-facial nerve transfer for reanimation of the midface and perioral region over a 7-year period. Patients were evaluated with physical examination, direct measurement of commissure excursion, and video analysis. RESULTS: : All patients regained oral competence, good resting tone, and a smile, with a vector and strength comparable to those of the normal side. Motion developed an average of 5.6 months after masseter-to-facial nerve transfer, with 40 percent of patients developing an effortless smile by postoperative month 19. CONCLUSIONS: : The masseter-to-facial nerve transfer is an effective method for reanimation of the midface and perioral region in a select group of facial paralysis patients. The technique is advocated for its limited donor-site morbidity, avoidance of interposition nerve grafts, and potential for cerebral adaptation, producing a strong, potentially effortless smile.
de Ru, J. A. and P. P. van Benthem (2011). "Combination Therapy Is Preferable for Patients With Ramsay Hunt Syndrome." Otol Neurotol.
OBJECTIVE:: To critically appraise the topic, questioning whether administering antiviral medication in case of Ramsay Hunt syndrome improves the restoration of facial nerve function. METHODS:: We reviewed the literature on this subject and calculated the odds ratios for the different treatment modalities. RESULTS:: Our study clearly shows that antiviral medication in combination with corticosteroids improves the outcome for patients with Ramsay Hunt syndrome. CONCLUSION:: Contrary to a recent Cochrane Library review, we conclude that patients with Ramsay Hunt syndrome should be treated with combination therapy including antivirals.
Klingner, C. M., G. F. Volk, et al. (2011). "Cortical reorganization in Bell's palsy." Restor Neurol Neurosci 29(3): 203-214.
Purpose: Bell's palsy, a unilateral, idiopathic facial nerve palsy, is a common disorder that is generally followed by a good recovery of function. The aim of this study was to investigate the impact of such a transiently decreased motor control (without deafferentation) on the functional reorganization of the brain. Methods: To address this issue, functional MRI was applied to 10 patients in the acute state of Bell's palsy and after their complete clinical recovery. The functional paradigm consisted of unilateral facial movements with the affected as well as the non-affected side. Results: We found an overactivity of several brain areas contralateral to the palsy that are related to error detection and sensory-motor integration in the acute stage and motor integration and control in the follow-up. Functional connectivity was disrupted in the affected cortical motor system during the acute stage of Bell's palsy compared to the follow-up. This altered connectivity was found mostly between motor areas in the hemisphere contralateral to the paretic side, whereas the interhemispherical connectivity remained largely stable. Conclusion: Our results indicate that a transient peripheral deefferentation causes functional reorganization in the brain that partly persists even after an apparently complete clinical recovery.
Hontanilla, B. and G. Rodriguez-Losada (2011). "Bilateral reconstruction of smile through muscular transplants neurotized to masseter nerves." J Craniofac Surg 22(3): 1099-1100.
In recent years, microsurgical transplant of the gracilis muscle has been the most widely used technique in the dynamic rehabilitation of the smile. The most frequently used donor nerve is the seventh cranial nerve, as it allows for the most physiological rehabilitation, including the rehabilitation of spontaneous smile. An exception to this is the case of bilateral facial paralyses, in which there is no contralateral nerve to be used as a donor. In these cases, it is necessary to use other nerves such as the hypoglossal, the accessory nerve, or the masseter branch of the trigeminal nerve. In this article, we describe a case of dynamic bilateral facial rehabilitation with a bilateral transplant of the gracilis muscle neurotized to the masseter nerve to achieve a strong, symmetrical smile, which is properly controlled by the patient.
Hontanilla, B. and C. Auba (2011). "Smile reconstruction through bilateral muscular transplants neurotized by hypoglossal nerves." J Craniofac Surg 22(3): 845-847.
Fattah, A., G. H. Borschel, et al. (2011). "Reconstruction of facial nerve injuries in children." J Craniofac Surg 22(3): 782-788.
Free transplant of gracilis muscle is the criterion-standard technique in dynamic rehabilitation of long-standing facial paralysis in which the facial musculature is atrophied. When the facial nerve is not available because of a bilateral lesion, other sources are the masseteric, hypoglossal, or accessory nerves. Although the use of hypoglossal nerve has been relegated to the background because of the morbidity caused by its loss, there are special situations in which the hypoglossal nerve should be considered the first option as donor motor nerve. The present article discusses the case of a patient with dynamic reanimation of bilateral facial paralysis with free-muscle transfer neurotized to the hypoglossal nerve. End-to-side coaptation of gracilis motor nerve and hypoglossal motor nerve allows neurotization of the transplanted muscle with minimum repercussion in speech or swallowing and can provide an adequate spontaneous smile with time.
Facial nerve trauma is uncommon in children, and many spontaneously recover some function; nonetheless, loss of facial nerve activity leads to functional impairment of ocular and oral sphincters and nasal orifice. In many cases, the impediment posed by facial asymmetry and reduced mimetic function more significantly affects the child's psychosocial interactions. As such, reconstruction of the facial nerve affords great benefits in quality of life. The therapeutic strategy is dependent on numerous factors, including the cause of facial nerve injury, the deficit, the prognosis for recovery, and the time elapsed since the injury. The options for treatment include a diverse range of surgical techniques including static lifts and slings, nerve repairs, nerve grafts and nerve transfers, regional, and microvascular free muscle transfer. We review our strategies for addressing facial nerve injuries in children.