The Investigation Of Pathogenesis On The Hemifacial Spasm

objection: To establish the animal model of domestic rabbit in which theAMR wave could be detected after the facial nerve compressed with offending arteryand studying the relation between the AMR and the neurovascular compression.Methods:14rabbits were randomly divided into3groups,5rabbits of group A inwhich the facial nerve was bind with the line of chromium and tightly stick thesuperficial temporal artery，all the5rabbit’s of group B, the facial nerve was attachedthe artery only and the other2rabbits were used to control. After20weeks the AMRwave was detected and the pathological examination of facial nerve was performed.Results: the AMR was collected in4(66.67%) rabbits of group and3(60%) rabbitsof group B and the difference was insignificance (p>0.05), the demyelination of facialnerve were occurred in5(66.67%) animals in group A and1(16.67%) in group, thedifference of them was significance (p<0.05). Conclusions: the AMR wave could bedetected when the facial nerve of the rabbit was compressed with offending artery andwhich was closely related with the neurovascular compression but the dymyelinationof facial nerve. The animal model was scientific, efficient and credible, it may bebeneficial to study the pathogenesis of hemifacial spasm. Objection: to investigate the effect of the factors such as arterial pulse、mechanical compression and the neurovascular contact in HFS. Methods:21therabbits of HFS model were divided into3experimental group of A、B、C, in theanimals of group A, the tefflon inserted between the vessel and the facial nerve, ingroup B the arterial pulse was removed when the artery was ligated but the vesselcontact with the facial nerve closely,in group C the artery was wrapped with Celluloseacetate film and the normal animals in group D was regarded as controller. TheAMR、Z-L wave were measured and the facial nerve biopsied. Results: there was noAMR、Z-L wave found in all animals of group A, the AMR found in3(50%）rabbitsand Z-L of2(33.33%) animals in group B and no AMR measured in group C.Demyelination of facial nerve occurred on all the animals. Conclusions: the directcontact of the demyelinated facial nerve and offending vessels may act on a key roleon the pathogeny of HFS but the arterial pulse and mechanical compression of bloodstream. Objection: To investigate the effect of Sympathetic nerve andEpinephrine in the pathogeny of Hemifacial spasm. Methods:16rabbits of HFSmodel animal were divided into4groups, in group A0.5ml Swine PseudorabiesVaccine was injected into Cervical sympathetic ganglion and the Antigen antibodycomplex was tested with the method of the fluorescence immunity; in group B thecervical sympathetic trunk was cut after injecting the SPV; in group C the AMR waveof facial nerve was measured after the cervical sympathetic trunk was cut and ingroup D a small film of Gelatin sponge infiltrated Epinephrine was inserted betweenthe superficial temporal artery and the facial nerve and the AMR wave was measured.Results: Antigen antibody complex of the Swine Pseudorabies Vaccine were tested in3animals of group A and there were none in the animals of group B, the AMR wavewas disappeared in3rabbits of group C and2of group D. Conclusions: the facialnerve and neuron could be infected by SPV through the joint of ending of Cervicalsympathetic and facial nerve, so we speculated that the short circuit may existbetween the facial nerve and the ending of sympathetic nerve which result to thenerval conduction passing through the neuro-vascular joint, and the abnormal nervalconduction may the etiology of HFS, at the same time the Neurotransmitter ofEpinephrine may act on no effect. objection: to investigate the mechanism of facial nerve conduction inHemifacial spasm. Methods: animals including6HFS model rabbits of experimentalgroup and4normal rabbits of control group. In experimental group, we recorded theincubation period and amplitude of the evoked potential in lower jaw after electricalstimulating the orbicularis oculi muscle, also recording the incubation period andamplitude of the evoked potential in frontal after electrical stimulating the orbicularisoris muscle；the facial nerve conduction in the longitudinal and horizontal axis wasmeasured; the facial nerve tracts were obtained after the epineurium incised inintracranial and the incubation period and amplitude of the evoked potential inlower jaw and frontal were recorded after the facial tract stimulated. The sameexperiments were also performed in4animals of control group. Results: the motorevoked potentials were acquired in lower jaw after electrical stimulating theorbicularis oculi muscle and the means incubation period was2.85ms in experimentalgroup and3.41ms in control group, the difference of which was remarkable(p<0.05),and the means incubation period was1.96ms in experimental group and2.55ms in control group which were obtained in frontal after the orbicularis orismuscle stimulated and the difference was remarkable(p<0.05); in experimentalgroup,the nerval conduction of horizontal axis among the facial nerval tracts was found, the mean Nerve conduction velocity were3.45±0.52m/s、8.01±0.15m/s、7.41±0.11m/s、6.44±0.16m/s and the mean amplitude were2.6±0.11mm、3.4±0.14mm、3.5mm、3.6±0.10mm，the Point stimulation intensity were0、0.1、0.3、0.5mA, there was no naval conduction in horizontal axis among facial nervaltracts in the animals of control group; the Facial nerve evoked potentials could becollected in the frontal and in the lower jaw at the same time in the animals ofexperimental group but which was obtained only in the Innervation of muscle whenthe single facial nerval tract was stimulated. Conclusions: the conduction in horizontalaxis among facial nerval tracts occurred when the facial nerve compressed byoffending vessels, further the short circuit of nerval conduction happened and chichmaybe the nerval conduction mechanism of HFS. objection:to investigate the difference of the surgical method and curativeeffect between the conventional decompression and the4district decompression.Methods: the clinic data of offending vessels,the results of Electrophysiologicalmonitoring and the curative effect were compared between the patients of group Awho were undergone conventional decompression of MVD and the patients treated by4district decompression in group B. Results: the offending vessels of group A werePICA：1020cases（56.67%），AICA：360（20%），VA：108（6%），mixed：309（17%），none vessels：3（0.2%）; in group B PICA：1320（55%），AICA：（18%），VA：168（7%），mixed：384（16%），Innominate arteries：96（4%）, none vessels：2（0.1%）；the distribution of vessels on4district were:1district:1区：420cases（17.5%）、2district：460（19%）、3district：1300（54%）、4district：220（9%）;in group B the positive of AMR2280（95%）and disappeared2212cases（97%）afteroperation, and positive of Z-L wave was289cases (85%) and disappeared270(93%) cases; in group A the complete remission of symptom was1638cases(91%),partial remission72(4%),invalid90(5%); in group B the complete remission ofsymptom was2280cases (95%),partial remission96(4%),invalid24(1%).Re-operation in group A80cases and symptom remission74cases, in group re-operation16cases and remission11cases.Conclusions: with the help ofmonitoring AMR and Z-L the method of4district decompression can improve thecurative effect of HFS for which can help surgeon distinguishing the offendingvessels.