Development and Validation of a Deep Learning Predictive Model Combining Clinical and Radiomic Features for Short-Term Postoperative Facial Nerve Function in Acoustic Neuroma Patients

Objective This study aims to construct and validate a predictable deep learning model associated with clinical data and multi-sequence magnetic resonance imaging(MRI)for short-term postoperative facial nerve function in patients with acoustic neuroma.Methods A total of 110 patients with acoustic neuroma who underwent surgery through the retrosigmoid sinus approach were included.Clinical data and raw features from four MRI sequences(T1-weighted,T2-weighted,T1-weighted contrast enhancement,and T2-weighted-Flair images)were analyzed.Spearman correlation analysis along with least absolute shrinkage and selection operator regression were used to screen combined clinical and radiomic features.Nomogram,machine learning,and convolutional neural network(CNN)models were constructed to predict the prognosis of facial nerve function on the seventh day after surgery.Receiver operating characteristic(ROC)curve and decision curve analysis(DCA)were used to evaluate model performance.A total of 1050 radiomic parameters were extracted,from which 13 radiomic and 3 clinical features were selected.Results The CNN model performed best among all prediction models in the test set with an area under the curve(AUC)of 0.89(95%CI,0.84–0.91).Conclusion CNN modeling that combines clinical and multi-sequence MRI radiomic features provides excellent performance for predicting short-term facial nerve function after surgery in patients with acoustic neuroma.As such,CNN modeling may serve as a potential decision-making tool for neurosurgery.

The Anti-Inflammatory Effects of NaCl with KCl as a Potent Graphene Exfoliator in a Patient with Guillaine-Barré Syndrome and Facial Nerve Palsy

Guillain-Barré syndrome is a rare but fatal autoimmune disease of unknown origin. Infectious disease is the most common etiology of Guillain-Barré syndrome. We had a 75-year-old female patient with Guillain-Barré syndrome and a 90-year-old male patient with facial nerve palsy admitted to our hospital. Both patients experienced recovery from early Guillain-Barré syndrome and peripheral facial nerve palsy after receiving intravenous infusion of NaCl with KCl solution and taking vitamin C.

Muscarinic receptor-mediated calcium changes in a rat model of facial nerve nucleus injury

The muscarinic receptor modulates intracellular free calcium ion levels in the facial nerve nucleus via different channels. In the present study, muscarinic receptor-mediated free calcium ions levels were detected by confocal laser microscopy in the facial nerve nucleus following facial nerve injury in rats. There was no significant difference in muscarinic receptor expression at the affected facial nerve nucleus compared with expression prior to injury, but muscarinic receptor-mediated free calcium ion levels increased in the affected side following facial nerve injury （P 〈 0.01）. At day 30 after facial nerve injury, 50 pmol/L muscarinic-mediated free calcium ion levels were significantly inhibited at the affected facial nerve nucleus in calcium-free artificial cerebrospinal fluid, and the change range was 82% of artificial cerebrospinal fluid （P 〈 0.05）. These results suggest that increased free calcium ion concentrations are achieved by intracellular calcium ion release, and that the transmembrane flow of calcium ions is also involved in this process.

Autogenous inside-out versus standard vein and skeletal muscle-combined grafting for facial nerve repair

BACKGROUND： In the repair of nerve defects, collapse of the venous wall, as a result of vein grafting alone, could impede nerve regeneration. Therefore, vein lumens filled with muscle and nerve segments have been used to bridge nerve defects. OBJECTIVE： To compare the effects of autogenous, inside-out, vein-skeletal, muscle-combined grafting versus standard, vein-skeletal, muscle-combined grafting for the repair of facial nerve defects. DESIGN, TIME AND SETTING： A randomized, controlled, neuroanatomical, animal study was performed at the Animal Experimental Center and Laboratories of the Capital Medical University Xuanwu Hospital and the Peking Union Medical College Hospital from September 2007 to October 2008.MATERIALS： A total of 10 healthy, male, New Zealand rabbits, aged 6 months, were randomly assigned to inside-out, vein-skeletal, muscle-combined grafting and standard, vein-skeletal, muscle-combined grafting groups, with 5 rabbits in each group. METHODS： A 20-mm gap in the buccal branch of the right facial nerve was made in each animal, which was respectively repaired with inside-out, vein-skeletal, muscle-combined grafts or standard vein-skeletal muscle-combined grafts.MAIN OUTCOME MEASURES： At 6 months after implantation, evoked maximal compound muscle action potentials were recorded on bilateral facial nerves using electromyogram. Myelinated nerve fibers of the regenerating nerves were quantified using myelin sheath osmic acid staining. RESULTS： There was no significant difference between the groups in terms of ratios of bilateral amplitude and latency of compound muscle action potential （P 〉 0.05）. Moreover, morphology of regenerating nerves and quantity of myelinated nerve fibers were similar between the groups （P 〉 0.05）. CONCLUTION： Compared with standard vein grafting, the inside-out vein grafting did not significantly improve nerve regeneration. Therefore, it is not necessary to utilize inside-out vein grafting for the repair of nerve defects, in particular with the combined use of autogenous vein and skeletal muscle grafts.

Artificial facial nerve reflex restores eyelid closure following orbicularis oculi muscle denervation

To date, treatment of peripheral facial paralysis has focused on preservation of facial nerve integrity. However, with seriously damaged facial nerve cases, it is difficult to recover anatomical and functional integrity using present therapies. Therefore, the present study utilized artificial facial nerve reflex to obtain orbicularis oculi muscle （OOM） electromyography signals on the uninjured side through the use of implanted recording electrodes. The implanted electrical chips analyzed facial muscle motion on the uninjured side and triggered an electrical stimulator to emit current pulses, which resulted in stimulation of injured OOM contraction and maintained bilateral symmetry and consistency. Following signal recognition, extraction, and computer analysis, electromyography signals in the uninjured OOM resulted in complete eyelid closure, which was consistent with the voltage threshold for eye closure. These findings suggested that artificial facial nerve reflex through the use of implanted microelectronics in unilateral peripheral facial paralysis could restore eyelid closure following orbicularis oculi muscle denervation.

Scala tympani drill-out technique for oval window atresia with malformed facial nerve: A report of three cases

Objective: To report a scala tympani drill-out technique for managing malformed facial nerve covering the entire oval window(OW).Methods: Data from three cases with OW atresia, malformed stapes and abnormal facial nerve courses were reported, in which a scala tympani drill-out technique was employed with a TORP between the tympanic membrane and scala tympani fenestration for hearing reconstruction.Results: Air conduction hearing improved in two of the three cases following surgery. In the third case, there was no improvement in air conduction hearing following a canal wall up mastoidectomy and tympanoplasty. There were no vertigo, tinnitus or sensorineural hearing loss in the three cases.Conclusion: The scala tympani drill-out technique, which is basically fenestration at the initial part of the basal turn, provides a choice in hearing reconstruction when the OW is completely covered by abarrently coursed facial nerve.

Transcriptome analysis of molecular mechanisms underlying facial nerve injury repair in rats

Although the transcriptional alterations inside the facial nucleus after facial nerve injury have been well studied,the gene expression changes in the facial nerve trunk after injury are still unknown.In this study,we established an adult rat model of facial nerve crush injury by compressing the right lateral extracranial nerve trunk.Transcriptome sequencing,differential gene expression analysis,and cluster analysis of the injured facial nerve trunk were performed,and 39 intersecting genes with significant variance in expression were identified.Gene Ontology annotation and Kyoto Encyclopedia of Genes and Genomes pathway analyses of the 39 intersecting genes revealed that these genes are mostly involved in leukocyte cell-cell adhesion and phagocytosis and have essential roles in regulating nerve repair.Quantitative real-time polymerase chain reaction assays were used to validate the expression of pivotal genes.Finally,nine pivotal genes that contribute to facial nerve recovery were identified,including Arhgap30,Akr1b8,C5ar1,Csf2ra,Dock2,Hcls1,Inpp5d,Sla,and Spi1.Primary Schwann cells were isolated from the sciatic nerve of neonatal rats.After knocking down Akr1b8 in Schwann cells with an Akr1b8-specific small interfering RNA plasmid,expression levels of monocyte chemoattractant protein-1 and interleukin-6 were decreased,while cell proliferation and migration were not obviously altered.These findings suggest that Akr1b8 likely regulates the interaction between Schwann cells and macrophages through regulation of cytokine expression to promote facial nerve regeneration.This study is the first to reveal a transcriptome change in the facial nerve trunk after facial nerve injury,thereby revealing the potential mechanism underlying repair of facial nerve injury.This study was approved by the Animal Ethics Committee of Nantong University,China in 2018(approval No.S20180923-007).

Immunobiology of Facial Nerve Repair and Regeneration

Immunobiological study is a key to revealing the important basis of facial nerve repair and regeneration for both research and development of clinic treatments. The microenvironmental changes around an injuried facial motoneuron, i.e., the aggregation and expression of various types of immune cells and molecules in a dynamic equilibrium, impenetrate from the start to the end of the repair of an injured facial nerve. The concept of 'immune microenvironment for facial nerve repair and regeneration', mainly concerns with the dynamic exchange between expression and regulation networks and a variaty of immune cells and immune molecules in the process of facial nerve repair and regeneration for the maintenance of a immune microenvironment favorable for nerve repair. Investigation on microglial activation and recruitment, T cell behavior, cytokine networks, and immunological cellular and molecular signaling pathways in facial nerve repair and regeneration are the current hot spots in the research on immunobiology of facial nerve injury. The current paper provides a comprehensive review of the above mentioned issues. Research of these issues will eventually make immunological interventions practicable treatments for facial nerve injury in the clinic.

Classification of facial nerve aberration in congenital malformation of middle ear:Implications for surgery of hearing restoration

Objectives: Facial nerve aberration is the most troublesome situation in congenital malformations of middle ear.The aim of our study is to investigate its imaging and clinical features as well as relevant choice of surgical techniques for hearing improvement.Methods: A retrospective study involving review of clinical data of 227 patients(256 ears) with congenital middle ear anomaly was undertaken, including preoperative computed tomography(CT) data, surgical records and videos.Results: Aberration involving intratemporal facial nerve was found in 82/256 ears(32.03%) with congenital middle ear anomaly. The most common forms of aberration included overhanging over the oval window(50/82 ears, 60.98%), bifurcation(3/82 ears, 3.66%) and transverse over the promontory(3/82 ears, 3.66%), counting for 68.29%(56/82) of the cases with facial nerve aberration. Concomitant stapes malformation was found in 76/82 ears(92.68%) and atresia or stenosis of the oval window in 27/82 ears(32.93%). In 9/82 ears(10.98%) both stapes and oval window was absent. Elective surgeries for the purpose of hearing improvement included stapodotomy + piston implantation, labyrinthotomy, labyrinthotomy + total ossicular replacement prosthesis(TORP) implantation and Vibrant Soundbridge(VSB) implantation.Conclusion: The majority of facial nerve aberration in congenital malformation of middle ear involves displacement of facial nerve, in addition to concomitant malformations of the stapes and/or oval window, which may influence the choice of surgery for hearing improvement. VSB implantation may be considered as a useful option.

Repairing whole facial nerve defects with xenogeneic acellular nerve grafts in rhesus monkeys

Acellular nerve allografts conducted via chemical extraction have achieved satisfactory results in bridging whole facial nerve defects clinically,both in terms of branching a single trunk and in connecting multiple branches of an extratemporal segment.However,in the clinical treatment of facial nerve defects,allogeneic donors are limited.In this experiment,we exposed the left trunk and multiple branches of the extratemporal segment in six rhesus monkeys and dissected a gap of 25 mm to construct a monkey model of a whole left nerve defect.Six monkeys were randomly assigned to an autograft group or a xenogeneic acellular nerve graft group.In the autograft group,the 25-mm whole facial nerve defect was immediately bridged using an autogenous ipsilateral great auricular nerve,and in the xenogeneic acellular nerve graft group,this was done using a xenogeneic acellular nerve graft with trunk-branches.Examinations of facial symmetry,nerve-muscle electrophysiology,retrograde transport of labeled neuronal tracers,and morphology of the regenerated nerve and target muscle at 8 months postoperatively showed that the faces of the monkey appeared to be symmetrical in the static state and slightly asymmetrical during facial movement,and that they could actively close their eyelids completely.The degree of recovery from facial paralysis reached House-Brackmann grade II in both groups.Compound muscle action potentials were recorded and orbicularis oris muscles responded to electro-stimuli on the surgical side in each monkey.Fluoro Gold-labeled neurons could be detected in the facial nuclei on the injured side.Immunohistochemical staining showed abundant neurofilament-200-positive axons and soluble protein-100-positive Schwann cells in the regenerated nerves.A large number of mid-graft myelinated axons were observed via methylene blue staining and a transmission electron microscope.Taken together,our data indicate that xenogeneic acellular nerve grafts from minipigs are safe and effective for repairing whole facial nerve defects in rhesus monkeys,with an effect similar to that of autologous nerve transplantation.Thus,a xenogeneic acellular nerve graft may be a suitable choice for bridging a whole facial nerve defect if no other method is available.The study was approved by the Laboratory Animal Management Committee and the Ethics Review Committee of the Affiliated Wuxi No.2 People's Hospital of Nanjing Medical University,China(approval No.2018-D-1)on March 15,2018.

Negative regulation of gamma-aminobutyric acid type A receptor on free calcium ion levels following facial nerve injury

Previous studies have demonstrated that muscarinic, and nicotinic receptors increase free Ca2＋ levels in the facial nerve nucleus via various channels following facial nerve injury. However, intracellular Ca2＋ overload can trigger either necrotic or apoptotic cell death. Gamma-aminobutyric acid （GABA）, an important inhibitory neurotransmitter in the central nervous system, exists in the facial nerve nucleus. It is assumed that GABA negatively regulates free Ca2＋ levels in the facial nerve nucleus. The present study investigated GABA type A （GABAA） receptor expression in the facial nerve nucleus in a rat model of facial nerve injury using immunohistochemistry and laser confocal microscopy, as well as the regulatory effects of GABAA receptor on nicotinic receptor response following facial nerve injury. Subunits α1, α3, α5, β1, β2, δ, and γ3 of GABAA receptors were expressed in the facial nerve nucleus following facial nerve injury. In addition, GABAA receptor expression significantly inhibited the increase in nicotinic receptor-mediated free Ca2＋ levels in the facial nerve nucleus following facial nerve injury in a concentration-dependent fashion. These results suggest that GABAA receptors exhibit negative effects on nicotinic receptor responses following facial nerve injury.

Traumatic facial nerve paralysis dilemma. Decision making and the novel role of endoscope

Objective: The management of traumatic facial nerve paralysis(FNP) has remained a controversial issue with conflicting findings arguing between surgical decompression and conservative management.However, recent advances in endoscopic surgery may consolidate the management plan for this condition.Methods: This prospective clinical study included patients with posttraumatic FNP at a tertiary referral center. Patients were categorized in two main groups: surgical and conservative. Indications for surgery included patients with immediate and complete FNP, no improvement in facial function on medical treatment, with electroneurography showing >90% degeneration or electromyography showing fibrillation potential. Patients who did not satisfy this criterion received the conservative approach. The transcanal endoscopic approach(TEA) or endoscopic assisted transmastoid approach was performed for facial nerve decompression in the surgical group.Outcome: The main outcome was facial function improvement, assessed using the House Brackmann grading scale(HBGS) 6 months after surgery, and hearing state assessed using the air bone gap(ABG).Results: The study included 38 patients, of whom 15 underwent had surgical decompression and 23underwent conservative therapy. A significant improvement in facial nerve function from a mean of4.66 ± 0.97 to 1.71 ± 0.69(P = 0.001) and ABG from a median of 30(10-40) to 20(10-25)(P = 0.002)was observed.Conclusion: Decision-making in cases of traumatic FNP is critical. The geniculate ganglion and tympanic segment were the most commonly affected areas in FNP cases. The TEA represents the most direct and least invasive approach for this area.

Application of a venous conduit as a stent for repairing rabbit facial nerve injury

BACKGROUND： Recently, many investigators have tried to use natural biomaterials, such as, artery, vein, decalcified bone, etc., as conduits for nerve repair. However, immunological rejection of conduits made of natural biomaterials limits their application. Therefore, it is essential to identify more suitable types of biomaterials. OBJECTIVE： To observe the characteristics of a bioengineering processing method using venous conduit as a stent for repairing facial nerve injury. DESIGN： A controlled observational experiment. SETTING： Animal Laboratories of the Third Hospital Affiliated to Sun Yat-sen University and the 157 Hospital. MATERIALS： Thirty-three male New Zealand rabbits of pure breed, weighing 1.5 to 2.0 kg, were provided by Medical Experimental Animal Room of Sun Yat-sen University. The protocol was carried out in accordance with animal ethics guidelines for the use and care of animals. Venous conduits and autogenous nerves were transplanted into the left and right cheeks, respectively. Eleven animals were chosen for anatomical observations at 5, 10 and 15 weeks after surgery. METHODS： This experiment was carried out in the Animal Laboratories of the Third Hospital Affdiated to Sun Yat-sen University and the 157 Hospital between May and November 2006. After animals were anesthetized, 15 mm of retromandibular vein was harvested for preparing a venous conduit. Approximately 3 cm of low buccal branch of facial nerve was exposed. A segment of 1.2 cm nerve was resected from the middle, and a gap of 1.5 cm formed due to bilateral retraction. The prepared venous conduit of 1.5 cm was sutured to the outer membrane of the severed ends of the nerve. Muscle and skin were sutured layer by layer. Using the same above-mentioned method, the low buccal branch of right autogenous facial nerve was resected, and the left facial nerve segment from the same animal was transplanted using end-to-end neurorrhaphy for control. MAIN OUTCOME MEASURES： （1）Post-operatively, food intake, vibrissae activity and wound healing of each animal were observed daily. （2） Animals were anesthetized at 5, 10 and 15 weeks after operation for observing the structural change of the venous conduit, the appearance of regenerated nerve, and the relationship between conduit and peripheral muscle tissue. （3） The action potential and latency of bilateral nerves of animals were measured by electrophysiologic examination, and nerve conduction velocity was calculated. （4）Neural myelination and neurite growth were observed by histological staining using an optical microscope. RESULTS： Thirty-three New Zealand rabbits were involved in the final analysis. （1）Immediately following the operation, vibrissae activity and orbicularis otis muscle activity of the upper lip on venous conduit side were more prominent, and their amplitudes of movement were larger as compared with autogenous nerve side. （2） At postoperative 10 weeks, by visual inspection, we found that on the venous conduit side, the venous conduit exhibited membrane structure which encased regenerated nerve. Regenerated nerve adhered to the muscle edge of orbicularis oris muscle. Muscle and nerve could be separated with a forceps. The muscle of musculus orbicularis oris of rabbit was darker and thicker as compared with autogenous nerve side. After the venous conduit was longitudinally split, the regenerated nerve and nerves at two the severed ends were connected together. When compared with postoperative 5 weeks, the connected nerve was thickened, texture was tough and its middle part was thicker than its two ends. On the autogenous nerve side, the regenerated nerve stem was enwrapped by scar tissue. It was bulky and adhered to peripheral muscle. Its neural profile structure was unclear. The two stomas were obviously enlarged. （3）At postoperative 10 weeks and 15 weeks, nerve action potentials could be elicited from both the venous conduit and autologous nerve side. The mean nerve conduction velocity on the venous conduit side was greater than that of the autologous nerve side. （4）At postoperative 10 weeks, using histochemical staining, it was found that in the venous conduit, regenerated medullated nerve fibers were densely distributed, with well split facial nerve structure, while on the autologous nerve side, nerve fibers were sparsely scattered, with immature medullated nerve structure. CONCLUSION： Biological natural venous conduit processed by bioengineering technology overcomes the tissue inflammatory reactions and connective tissue reactions caused by natural biomaterials. It is more conducive to promote neural regeneration and functional recovery than autologous nerve transplantation.

Agmatine promotes expression of brain-derived neurotrophic factor in brainstem facial nucleus in the rat facial nerve injury model

BACKGROUND： Studies have shown that agmatine can reduce inhibition of neuronal regeneration by increasing cyclic adenosine monophosphate and brain-derived neurotrophic factor （BDNF） in the hippocampus of morphine-dependent rats. The hypothesis that agmatine exerts similar effects on facial nerve injury deserves further analysis. OBJECTIVE： To study the effects of peritoneal agmatine injection on BDNF levels in the rat brainstem after facial nerve injury. DESIGN, TIME AND SETTING： A controlled animal experiment was performed at the Department of Otolaryngology-Head and Neck Surgery at the Second Affiliated Hospital, Chongqing University of Medical Sciences （Chongqing, China）, between October and December in 2007. MATERIALS： Twenty-four male Sprague-Dawley rats were randomly divided into a control, a lesion, and an agmatine treatment group, with eight rats in each group. Bilateral facial nerve anastomosis was induced in the lesion and agmatine treatment groups, while the control group remained untreated. A rat BDNF Enzyme-linked immunosorbent assay kit was used to measure BDNF levels in the brainstem facial nucleus. METHODS： Starting on the day of lesion, the agmatine group received a peritoneal injection of 100 mg/kg agmatine, once per day, for a week, whereas rats in the lesion group received saline injections. MAIN OUTCOME MEASURES： BDNF levels in the brainstem containing facial nucleus were measured by ELISA. RESULTS： Twenty-four rats were included in the final analysis without any loss. Two weeks after lesion, BDNF levels were significantly higher in the lesion group than in the control group （P 〈 0.01）. A significant increase was noted in the agmatine group compared to the lesion group （P 〈 0.01）. CONCLUSION： Agmatine can substantially increase BDNF levels in the rat brainstem after facial nerve injury.

Assessment of T Cell Activation in a Mouse Model of Traumatic Facial Nerve Injury

Objective To investigate T cell activation following facial nerve axotomization and latent neuroimmunologic mechanisms in traumatic facial paralysis.Methods A murine model of facial nerve transaction was used.Lymphocytes from cervical and mesenteric lymph nodes in BABL/c mice at specific times were collected and expression rates of CD69 on T cells were assessed by flow cytometry.Results Infiltrating T cells were detected around the facial neurons in the facial nerve nucleus in mice whose facial nerve was transected.Immunofluorescent staining showed recruitment of activated T cells.Three days post-facial nerve transection,the expression rate of CD69 on T cells from cervical draining lymphoid nodes(CDLNs) was significantly different from that on T cells from mesenteric lymph nodes(MLNs)(P =0.0457),whereas the latter was similar to that in animals undergoing sham surgeries and that in blank control animals(p= 0.2817 and 0.2724,respectively).Two weeks post-nerve transection,the T cell CD69 expression rate from CDLNs remained at a higher level and than that in the sham-operation animals(p= 0.0007).At two weeks,CD69 expression rate on T cells from MLNs was also up-regulated and different compared with the sham-operation animals and with itself at three days post-operation(p= 0.0082 and 0.0133,respectively).Conclusion T cells appear to be activated and up-regulated in CDLNs following facial nerve transection.There is even evidence of T cell activation in MLNs at 2 weeks post-nerve transection.This suggestes an alteration of immune response from local to general immunity in the acute stage of facial nerve trauma,which may help coordinating and controlling the scales and orientation of the neuroimmune response during the pathogenesis and progression of facial nerve trauma.

Neuroprotective effects of recombinant human erythropoietin on facial motoneurons after facial nerve injury in rats

BACKGROUND： Erythropoietin and recombinant human erythropoietin （rhEPO） inhibit apoptosis of motor neurons caused by spinal cord injury and brain damage in rats. However, it still remains to be shown whether rhEPO can protect facial motoneurons （FMNs） as Well. OBJECTIVE： To test the neuroprotective effects of rhEPO on injured VMNs, as well as the influence on Caspase-3 expression. DESIGN, TIME AND SETTING： Randomized, controlled, animal experiment. This study was performed at the Central Laboratory of Basic Medical College, Chongqing Medical University from January to October 2007. MATERIALS： Seventy-five female SD rats, weighing 210-230 g. rhEPO injection was provided by Sansheng pharmaceuticals company, Shenyang City, Liaoning Province, China, and the License number was HMLN S20010001. METHODS： A total of 75 female rats were randomly divided into rhEPO treatment, control, and sham operation groups, with 25 rats in each group. Rat models of facial nerve injury were established in the rhEPO treatment group and the control group by crushing the main trunk of the left facial nerve. Surgical microscopic observation of the facial nerve damage displayed perineurial disruption. The left stylomastoid foramen of the sham operation group were only exposed, but without nerve injury. The rhEPO treatment group was treated with rhEPO （5 000 U/kg, i.p.） once following injury and once a day for two weeks. The control and sham operation groups were treated with the same dose of normal saline （i.p.）, once following injury and once a day for two weeks. MAIN OUTCOME MEASURES： Rats were sacrificed 3, 7, 14, 21, and 28 days after injury, FMN survival after facial nerve injury was analyzed by Toluidine blue staining, and then survival ratios （L/R） were calculated. The number of apoptotic profiles in the injured FMNs were evaluated by TUNEL staining. Expression of Caspase-3 in the facial nucleus was detected by immunohistochemistry methods. RESULTS： A total of 75 rats were included in the final analysis. FMN survival ratios, both in rhEPO treatment group and control group, decreased gradually between seven and 28 days; however, FMN survival ratios were significantly greater in the rhEPO treatment group compared to the control group （P 〈 0.05）. No TUNEL-positive cells were observed three days after injury in the rhEPO treatment and control groups; however, by seven days after injury, apoptotic cells were observed and peaked by 14 days in the control group. Between seven and 21 days, apoptotic cell numbers were significantly lower in the rhEPO treatment group compared to the control group （P 〈 0.05）. The expression of Caspase-3 increased three days after injury and peaked at 14 days in the control group. Nevertheless, Caspase-3 expression was significantly lower in the rhEPO treatment group compared to the control group at each time point （P 〈 0.05）. CONCLUSION： Treatment with rhEPO can effectively protect facial motoneurons by reducing expression of Caspase-3 and inhibiting apoptosis.

Effects of gamma-aminobutyric acid receptors on muscarinic receptor-mediated free calcium ion levels in the facial nucleus following facial nerve injury

Muscarinic receptors and nicotine receptors can increase free calcium ion levels in the facial nucleus via different channels following facial nerve injury. In addition, γ-aminobutyric acid A （GABAA） receptors have been shown to negatively regulate free calcium ion levels in the facial nucleus by inhibiting nicotine receptors. The present study investigated the influence of GABAA, γ-aminobutyric acid B （GABAB） and C （GABAc） receptors on muscarinic receptors in rats with facial nerve injury by confocal laser microscopy. GABAA and GABAB receptors exhibited significant dose-dependent inhibitory effects on increased muscarinic receptor-mediated free calcium ion levels following facial nerve injury. Results showed that GABAA and GABAB receptors negatively regulate muscarinic receptor effects and interplay with cholinergic receptors to regulate free calcium ion levels for facial neural regeneration.

Acute pathological changes of facial nucleus and expressions of postsynaptic density protein-95 following facial nerve injury of varying severity A semi-quantitative analysis

BACKGROUND： Previous studies have demonstrated that postsynaptic density protein-95 （PSD-95） is widely distributed in the central nervous system and is related to the development of the CNS and sensory signal transmission as well as acute or chronic nerve cell death following ischemic brain injury. OBJECTIVE： To semi-quantitatively determine the pathological changes of apoptotic facial neurons and the expression of PSD-95 in the facial nucleus following facial nerve injury of varying extents using immunohistochemical staining methods. DESIGN, TIME AND SETTING： Randomized, controlled animal experiments were performed in the Ultrasonic Institute of the Second Affiliated Hospital of Chongqing University of Medical Sciences from September to December 2007. MATERIALS： Sixty-five healthy, adult, Sprague-Dawley （SD） rats, both male and female, were used for this study. Rabbit anti-rat PSD-95 polyclonal antibody was purchased from Beijing Biosynthesis Biotechnology Co., Ltd. METHODS： SD rats were randomly assigned into a control group with five rats and three injured groups with 20 rats per group. Exposure, clamp and cut for bilateral facial nerve trunks were performed in the rats of the injury groups, and no injury was inflicted on the rats of the control group. MAIN OUTCOME MEASURES; The brainstems of all the rats were excised on days 1, 3, 7, and 14 post injury, and then the facial nuclei were stained with hematoxylin-eosin to observe any pathological changes due to apoptosis in facial neurons. PSD-95 expression in facial nuclei was detected by immunohistochemistry and the number of PSD-95 positive cells was counted under a light microscope. RESULTS： The expression of PSD-95 in the facial nucleus and morphology of the facial neuron within the exposure group had no obvious changes at various points in time tested （P 〉 0.05）. However, the expressions of PSD-95 in the facial nucleus of the clamp group and cut group increased on day 1 post injury （P 〈 0.05）, and showed further increase on day 7 post injury （P 〈 0.01 ）. This did not decrease until day 14 post injury. Facial neuron apoptosis was detected on day 3 post injury and this was even more obvious on day 7 and was maintained to day 14 post injury. The number of cells expressing PSD-95 and displaying severe degrees of facial neuron apoptosis were as follows： cut group 〉 clamp group 〉 exposure group. CONCLUSION： The apoptotic extent of facial neurons and the expression of PSD-95 in apoptotic facial neurons increased with the degree of aggravation of injured severity of facial nerve.

Role of stem cells-based in facial nerve reanimation:A meta-analysis of histological and neurophysiological outcomes

BACKGROUND Treatments involving stem cell(SC)usage represent novel and potentially interesting alternatives in facial nerve reanimation.Current literature includes the use of SC in animal model studies to promote graft survival by enhancing nerve fiber growth,spreading,myelinization,in addition to limiting fibrotic degeneration after surgery.However,the effectiveness of the clinical use of SC in facial nerve reanimation has not been clarified yet.AIM To investigate the histological,neurophysiological,and functional outcomes in facial reanimation using SC,compared to autograft.METHODS Our study is a systematic review of the literature,consistently conducted according to the preferred reporting items for systematic reviews and meta-analyses statement guidelines.The review question was:In facial nerve reanimation on rats,has the use of stem cells revealed as effective when compared to autograft,in terms of histological,neurophysiological,and functional outcomes?Random-effect meta-analysis was conducted on histological and neurophysiological data from the included comparative studies.RESULTS After screening 148 manuscript,five papers were included in our study.43 subjects were included in the SC group,while 40 in the autograft group.The meta-analysis showed no significative differences between the two groups in terms of myelin thickness[CI:-0.10(-0.20,0.00);I^(2)=29%;P=0.06],nerve fibers diameter[CI:0.72(-0.93,3.36);I^(2)=72%;P=0.6],compound muscle action potential amplitude[CI:1.59(0.59,3.77);I^(2)=89%;P=0.15]and latency[CI:0.66(-1.01,2.32);I^(2)=67%;P=0.44].The mean axonal diameter was higher in the autograft group[CI:0.94(0.60,1.27);I^(2)=0%;P≤0.001].CONCLUSION The role of stem cells in facial reanimation is still relatively poorly studied,in animal models,and available results should not discourage their use in future studies on human subjects.

Acquired ptosis associated with oculomotor and contralateral facial nerve synkinesis： the first reported case

Dear Editor,Evidence of oculomotor nerve（ON）synkinesis is a common occurrence following both acquired and congenital III nerve palsy[1].It is generally accepted that aberrant regeneration is the likely aetiology of synkinesis in acquired III nerve palsy,following intracranial aneurysm,trauma,