OBJECTIVETo investigate the morphological changes after chemically extracted acellular nerve allografts transplant.

METHODSSeventy-two rabbits were divided into four groups. Acellular allografts of facial nerve were used in experimental group, and facial nerve autografts, acellular peroneal nerve allografts and peroneal nerve autografts respectively used in three control groups. The morphological changes after transplant were evaluated by modified trichrome staining, immunohistological staining and transmission electron microscope.

RESULTSThe two facial nerve grafts showed numerous regenerated nerve fibers, vessels and as well as a spindle schwann cells arranged longitudinally. No significant difference was observed in the fiber number and myelin thickness between the two groups,while the two peroneal nerve groups showed poor regeneration 6 months after operation.

CONCLUSIONSThe facial nerve allografts showed more neurite regeneration six months after transplant, and the regenerated axons passed through the distal stoma and there were well revascularized and proliferated schwann cells in the grafts.

Animals ; Disease Models, Animal ; Facial Nerve ; pathology ; transplantation ; Facial Nerve Injuries ; pathology ; surgery ; Nerve Regeneration ; Rabbits ; Transplantation, Homologous

Neurilemmomas are benign tumors that arise from the nerve sheath. Facial nerve neurilemmomas are uncommon, slow-growing neoplasms that occur anywhere along the course of the facial nerve. The majority of facial nerve neurilemmomas are intratemporal, with a few cases arising from the intraparotid portion. The clinical presentations are generally insidious and the nature of the disease depends on the location and extent of the tumor. They are difficult to diagnose preoperatively and are frequently misdiagnosed because of the variety of their clinical manifestations. Therefore, early and correct diagnosis and evaluation are necessary. Recently, we experienced two cases of facial nerve neurilemmoma with relatively good surgical result, involving the mastoid segment of the facial nerve and the main trunk of the facial nerve in the parotid gland. We reviewed the diagnosis, pathology, and treatement of this case, and report the cases with reviews of literature.
Diagnosis ; Facial Nerve* ; Mastoid ; Neurilemmoma* ; Parotid Gland ; Pathology

OBJECTIVE: To study the changes in facial nerve function, morphology and neurotrophic factor III (NT-3) expression following three types of facial nerve injury. METHOD: Changes in facial nerve function (in terms of blink reflex (BF), vibrissae movement (VM) and position of nasal tip) were assessed in 45 rats in response to three types of facial nerve injury: partial section of the extratemporal segment (group one), partial section of the facial canal segment (group two) and complete transection of the facial canal segment lesion (group three). All facial nerves specimen were then cut into two parts at the site of the lesion after being taken from the lesion site on 1st, 7th, 21st post-surgery-days (PSD). Changes of morphology and NT-3 expression were evaluated using the improved trichrome stain and immunohistochemistry techniques ,respectively. RESULT: Changes in facial nerve function: In group 1, all animals had no blink reflex (BF) and weak vibrissae movement (VM) at the 1st PSD; The blink reflex in 80% of the rats recovered partly and the vibrissae movement in 40% of the rats returned to normal at the 7th PSD; The facial nerve function in 600 of the rats was almost normal at the 21st PSD. In group 2, all left facial nerve paralyzed at the 1st PSD; The blink reflex partly recovered in 40% of the rats and the vibrissae movement was weak in 80% of the rats at the 7th PSD; 8000 of the rats'BF were almost normal and 40% of the rats' VM completely recovered at the 21st PSD. In group 3, The recovery couldn't happen at anytime. Changes in morphology: In group 1, the size of nerve fiber differed in facial canal segment and some of myelin sheath and axons degenerated at the 7th PSD; The fibres' degeneration turned into regeneration at the 21st PSD; In group 2, the morphologic changes in this group were familiar with the group 1 while the degenerated fibers were more and dispersed in transection at the 7th PSD; Regeneration of nerve fibers happened at the 21st PSD. In group 3, most of the fibers crumbled at the 7th PSD and no regeneration was seen at the 21st PSD. Changes in NT-3: Positive staining of NT-3 was largely observed in axons at the 7th PSD, although little NT-3 was seen in the normal fibers. CONCLUSION Facial palsy of the rats in group 2 was more extensive than that in group 1 and their function partly recovers at the 21st PSD. The fibres' degeneration occurs not only dispersed throughout the injury site but also occurred throught the length of the nerve. NT-3 immunoreactivity increased in activated fibers after partial transection.
Animals ; Facial Nerve ; metabolism ; pathology ; physiopathology ; Facial Nerve Injuries ; classification ; metabolism ; pathology ; physiopathology ; Neurotrophin 3 ; metabolism ; Rats ; Rats, Wistar

OBJECTIVE: To heighten the awareness of the facial nerve tumors. METHOD: The clinical data of twenty-three patients complaining of facial paralysis who were diagnosed postoperatively as facial nerve tumors were analyzed. The hearing assessment of all patients was based on pure tone audiometry at the frequency of 0. 5, 1, 2, 4 kHz. Temporal bone high resolution CT scan and temporal bone MRI with gadolinium enhancement were conducted on all patients. Facial nerve function was assessed with the House-Brackmann (HB) grading system. Facial electroneurography (ENoG) was conducted on 20 patients to quantify the degree of nerve degeneration preoperatively. The pathological types of tumor were determined by postoperative pathological reports. RESULT: Nineteen out of 23 cases presented hearing loss (82.6%), 10 cases suffered from tinnitus (43.5%), otalgia (17.4%) affected 4 cases, 3 cases manifested otorrhea (13.0%), and 2 cases presented vertigo (8.7%). Geniculate ganglion was the most commonly involved site (20 cases, 87.0%), followed by tympanic segments (18 cases, 78.3%), pyramid segment (16 cases, 69.6%), mastoid segment (10 cases, 43.5%), labyrinthine segment (9 cases, 39.1%), internal auditory canal segment and parotid gland segment (5 cases, 21.7%, respectively). Twenty-one cases (91.3%) of schwannomas, 1 case (4.3%) of neurofibroma and 1 case (4.3%) of hemangiomas were identified with histopathology postoperatively. The tumors were all completely excised, and the facial nerve function could recovered to HB III at the best after facial nerve repairment. CONCLUSION Facial nerve tumor is a rare and often misdiagnosed disease which was commonly manifested as facial nerve paralysis. Temporal bone CT and MRI can help to clarify the diagnosis preoperatively. Pure tone audiometry and electroneurography also plays a some certain roles in the diagnosis of facial nerve tumors. The tumors should be completely resected and the surgical approaches were determined based on tumor size, facial nerve function and preoperative auditory function.
Cranial Nerve Neoplasms ; complications ; Facial Nerve ; pathology ; Facial Nerve Diseases ; complications ; Facial Paralysis ; etiology ; Hearing Loss ; Hemangioma ; Humans ; Neurilemmoma ; Temporal Bone

Adult ; Cranial Nerve Neoplasms ; diagnosis ; Facial Nerve ; pathology ; Female ; Glomus Jugulare Tumor ; diagnosis ; Humans ; Neurilemmoma ; diagnosis

Adolescent ; Cranial Nerve Neoplasms ; Facial Nerve ; Humans ; Male ; Neurilemmoma ; Parotid Region ; pathology

Adult ; Cranial Nerve Neoplasms ; diagnosis ; Diagnostic Errors ; Facial Nerve ; pathology ; Hemangioma ; diagnosis ; Humans ; Male

OBJECTIVETo observe the change of the muscular fiber phynotype at different condition of nerve injury.

METHODSRabbits were used as an animal model in this study. The trigeminus and facial nerves of the animal were simultaneously severed (group 1) or only the latter was severed (group 2). The morphologic change of the muscular fibers was observed with histochemical methods; the tension of contraction and the threshold value of electrical stimulation were observed with electrical physiological methods.

RESULTSTrigeminus nerve play an important role in delaying muscular atrophy after facial nerve was severed. The atrophy degree of type II a and II b muscular fibers was less in group 2 than that in group 1. The change of type 1 muscular fibers was not affected by trigeminus nerve. New muscular fibers emerged in group 2. The tension of contraction and the threshold value of electrical stimulation were better in group 2 than that of in group 1.

CONCLUSIONSSensory nerve could delay muscle atrophy after denervation. Sensory nerve should be repaired simultaneously when the motor nerve was sutured. The results of this study would facilitate clinical treatment for facial palsy.

Animals ; Denervation ; Disease Models, Animal ; Facial Nerve ; Facial Nerve Diseases ; pathology ; Female ; Muscle Fibers, Skeletal ; pathology ; Muscle Fibers, Slow-Twitch ; pathology ; Rabbits

OBJECTIVEThis study was to establish an animal model to imitate facial nerves injury by explosion.

METHODSThe impact was simulated by detonator blast in the distance of 5 cm, 10 cm and 15 cm over the face of dogs under anesthesia and the edge injury of masseters were made by rifle-shot steel ball to imitate segment injury in real explosion. The dogs were killed after different time of injury and the heart, lung, brain and facial nerve were taken to observe the pathological changes in order to evaluating the wound effect in different distances.

RESULTSThe animal was injured severely in the distance of 5 cm and could not survive for a long time because of severe damage to brain, heart and lung. The dogs injured at 10 cm could survive after emergency treatment, and there was diffusing hemorrhage in edematous nerve trunk. In the distance of 15 cm, the dogs were injured slightly and, as the distance to the explosive source increased, the local wound became slighter. Under light microscope, the breakage and necrosis of facial nerve fibers could be widely observed, degenerative and necrotic neurons with infiltrating inflammatory cells could be found in the facial nerve nuclei as well.

CONCLUSIONThe dog's traumatic model established by impact wave and segment in this experiment is an appropriate animal model for the research of explosive effect on facial nerves because of its controllable and repeatable injuring conditions.

Animals ; Blast Injuries ; complications ; pathology ; Disease Models, Animal ; Dogs ; Facial Nerve Injuries ; etiology ; pathology ; Female ; Male

In the present study we made out an animal model on rabbit whose trigeminus and facialis nerves were simultaneously or only the latter one was severed. The pathological changes in facial muscle atrophy under different nerve injuries were investigated. The degeneration of contractile proteins of upper lip muscle -- myosin and actin was observed. In addition, we also examined the ultrastructural changes in the muscle atrophy in the two above-mentioned nerve injury cases. We observed that the intact trigeminus nerve could delay and lighten the atrophy of facialis-denervated facial muscle and attenuate the degeneration of myosin and actin, as well as decrease the increment of collagen and maintain the ultrastructure of the thick and thin muscle filaments. These results may provide the possibility of improvement of clinical treatment for facial muscle palsy.
Animals ; Denervation ; Facial Muscles ; innervation ; pathology ; Facial Nerve ; physiology ; surgery ; Female ; Muscle Fibers, Skeletal ; diagnostic imaging ; Muscular Atrophy ; pathology ; Rabbits ; Trigeminal Nerve ; physiology ; surgery ; Ultrasonography