焦風(fēng)，張磊，趙春維，劉波，王棟梁，梁冶矢，劉獻(xiàn)增

(1北京大學(xué)人民醫(yī)院，北京100044；2烏魯木齊市友誼醫(yī)院)

面肌痙攣患者微血管減壓術(shù)中側(cè)方擴(kuò)散反應(yīng)監(jiān)測(cè)對(duì)療效的預(yù)測(cè)作用

焦風(fēng)1，張磊2，趙春維1，劉波1，王棟梁1，梁冶矢1，劉獻(xiàn)增1

(1北京大學(xué)人民醫(yī)院，北京100044；2烏魯木齊市友誼醫(yī)院)

目的 分析面肌痙攣患者微血管減壓術(shù)(MVD)中側(cè)方擴(kuò)散反應(yīng)(LSR)監(jiān)測(cè)對(duì)療效的預(yù)測(cè)作用。方法 面肌痙攣患者45例，均行MVD術(shù)治療，分別于術(shù)中微血管減壓前后進(jìn)行LSR監(jiān)測(cè)。分別于術(shù)后第1、7天及術(shù)后3個(gè)月采用自我評(píng)價(jià)量表評(píng)估手術(shù)效果。分析減壓后LSR變化與療效的關(guān)系。結(jié)果 40例減壓后LSR即刻消失(LSR消失組)；5例LSR未即刻消失(LSR未消失組)，其中1例下降86%、2例下降幅度不足50%、1例無變化、1例因持續(xù)自發(fā)放電未引出LSR。術(shù)后第1天，LSR消失組治愈31例、好轉(zhuǎn)9例，LSR未消失組治愈1例、好轉(zhuǎn)1例、無效3例；術(shù)后第7天，LSR消失組治愈35例、好轉(zhuǎn)5例，LSR未消失組治愈1例、好轉(zhuǎn)2例、無效2例；術(shù)后3個(gè)月，LSR消失組治愈39例、好轉(zhuǎn)1例，LSR未消失組治愈1例、好轉(zhuǎn)2例、無效2例。隨訪3～88個(gè)月，LSR消失組全部治愈，LSR未消失組好轉(zhuǎn)3例、無效2例。術(shù)后各觀察時(shí)點(diǎn)LSR消失組治愈和好轉(zhuǎn)比例均高于LSR未消失組，減壓后LSR是否消失與療效存在相關(guān)性(P均<0.05)。結(jié)論 面肌痙攣患者M(jìn)VD術(shù)中LSR監(jiān)測(cè)結(jié)果與療效有關(guān)，減壓后LSR消失者治愈及好轉(zhuǎn)率較高。

面肌痙攣；微血管減壓術(shù)；側(cè)方擴(kuò)散反應(yīng)

面肌痙攣是以一側(cè)面神經(jīng)支配肌肉不自主陣發(fā)性抽動(dòng)為主要癥狀的疾病。目前認(rèn)為面肌痙攣是由面神經(jīng)出根區(qū)受血管壓迫導(dǎo)致的[1]。微血管減壓術(shù)(MVD)是惟一能夠治愈面肌痙攣的方法[2]。側(cè)方擴(kuò)散反應(yīng)(LSR)為面肌痙攣患者特征性的電生理表現(xiàn)，表現(xiàn)為在痙攣側(cè)刺激面神經(jīng)一個(gè)分支，可在其他分支支配的肌肉中記錄到誘發(fā)肌電圖。在面神經(jīng)MVD術(shù)中應(yīng)用LSR監(jiān)測(cè)有助于正確判斷責(zé)任血管以保證減壓充分，但學(xué)界對(duì)LSR監(jiān)測(cè)結(jié)果能否作為治療效果的預(yù)測(cè)因素仍存在爭(zhēng)議[3～5]。為此，本研究分析了面肌痙攣患者M(jìn)VD術(shù)中LSR監(jiān)測(cè)結(jié)果對(duì)手術(shù)療效預(yù)測(cè)價(jià)值，現(xiàn)報(bào)告如下。

1 資料與方法

1.1 臨床資料 2009年5月～2016年7月北京大學(xué)人民醫(yī)院收治的面肌痙攣患者45例，男13例、女32例，年齡28～81歲，病程6個(gè)月～20年，左側(cè)27例、右側(cè)28例。所有患者均通過3.0 T MRI掃描除外腫瘤及血管畸形等繼發(fā)原因并采用3D-FIETSTA序列預(yù)測(cè)面神經(jīng)出根區(qū)有無壓迫、預(yù)測(cè)責(zé)任血管[6]。所有患者均采用MVD術(shù)治療。患者取健側(cè)臥位，頭向健側(cè)旋轉(zhuǎn)10°、下垂15°，使乳突根部位于最高點(diǎn)；枕下乙狀竇后縱形切口，氣鉆顱骨鉆孔后擴(kuò)大骨窗直徑約1.5 cm；顯微鏡下釋放腦脊液，仔細(xì)分離蛛網(wǎng)膜并輕輕牽拉小腦絨球，顯露面神經(jīng)出根區(qū)；判斷責(zé)任血管，小腦前下動(dòng)脈(AICA)20例、小腦后下動(dòng)脈(PICA)9例、椎動(dòng)脈(VA)3例、AICA+PICA 4例、VA+AICA 2例、VA+PICA 6例、靜脈1例，之后充分解剖責(zé)任血管與面神經(jīng)的粘連，以Teflon棉墊開；術(shù)中根據(jù)LSR監(jiān)測(cè)結(jié)果確定減壓是否充分，必要時(shí)探查蛛網(wǎng)膜下腔的面神經(jīng)全長(zhǎng)。

1.2 LSR監(jiān)測(cè)方法 于術(shù)中微血管減壓前后進(jìn)行LSR監(jiān)測(cè)。監(jiān)測(cè)LSR時(shí)，應(yīng)用去極化型肌松藥進(jìn)行麻醉插管后不再應(yīng)用肌松類藥物，以異丙酚和芬太尼維持麻醉[7]。監(jiān)測(cè)設(shè)備為CADWELL 32通道術(shù)中神經(jīng)電生理監(jiān)測(cè)儀。記錄電極位置包括患側(cè)面神經(jīng)支配的額肌、眼輪匝肌、口輪匝肌、頦肌及三叉神經(jīng)支配的咬肌，有一支插入肌腹并與另一支距離0.5 cm。刺激電極位于面神經(jīng)分支的顳支，陰極位于患側(cè)耳屏與外眥連線中點(diǎn)、陽(yáng)極位于距陰極1 cm處。地線位于FPz點(diǎn)(根據(jù)國(guó)際10-20系統(tǒng)電極定位)。刺激顳支，額肌及眼輪匝肌有肌電圖表現(xiàn)為直接刺激反應(yīng)；觀察患側(cè)口輪匝肌及頦肌有無肌電圖反應(yīng)。初始刺激強(qiáng)度從5 mA開始，逐漸增加至20 mA，若仍未引出LSR則認(rèn)為其消失；若初始刺激強(qiáng)度未引出LSR，但隨著刺激強(qiáng)度增加、LSR重現(xiàn)，則認(rèn)為L(zhǎng)SR未消失，需重新探查面神經(jīng)全程以保證充分減壓[8]。

1.3 療效評(píng)估方法 分別于術(shù)后第1、7天及術(shù)后3個(gè)月評(píng)估手術(shù)效果?；颊咭宰晕以u(píng)價(jià)量表描述面肌痙攣癥狀改善的程度，改善100%為治愈，改善50%～90%為好轉(zhuǎn)，0～50%無效。

1.4 統(tǒng)計(jì)學(xué)方法 采用SPSS16.0軟件進(jìn)行統(tǒng)計(jì)學(xué)分析。計(jì)數(shù)資料以頻數(shù)表示，組間比較采用Fisher確切概率法。P<0.05為差異有統(tǒng)計(jì)學(xué)意義。

2 結(jié)果

40例減壓后LSR即刻消失(LSR消失組)；5例LSR未即刻消失(LSR未消失組)，1例下降86%、2例下降幅度不足50%、1例無變化、1例因持續(xù)自發(fā)放電未引出LSR。術(shù)后第1天，LSR消失組治愈31例、好轉(zhuǎn)9例，LSR未消失組治愈1例、好轉(zhuǎn)1例、無效3例；術(shù)后第7天，LSR消失組治愈35例、好轉(zhuǎn)5例，LSR未消失組治愈1例、好轉(zhuǎn)2例、無效2例；術(shù)后3個(gè)月，LSR消失組治愈39例、好轉(zhuǎn)1例，LSR未消失組治愈1例、好轉(zhuǎn)2例、無效2例。隨訪3～88個(gè)月，LSR消失組全部治愈，LSR未消失組好轉(zhuǎn)3例、無效2例。術(shù)后各觀察時(shí)點(diǎn)LSR消失組治愈和好轉(zhuǎn)比例均高于LSR未消失組，減壓后LSR是否消失與療效存在相關(guān)性(P均<0.05)。

3 討論

面肌痙攣發(fā)病機(jī)制有兩種學(xué)說：外周性學(xué)說認(rèn)為面神經(jīng)出腦干區(qū)覆蓋的中樞性髓鞘受損，導(dǎo)致暴露的神經(jīng)軸突互相接觸，進(jìn)而引發(fā)神經(jīng)纖維之間跨突觸傳遞的異位沖動(dòng);中樞性學(xué)說則認(rèn)為各種原因引起面神經(jīng)運(yùn)動(dòng)核興奮性異常增高，進(jìn)而導(dǎo)致面肌痙攣[9]。目前MVD已成為治療面肌痙攣的最有效方法。術(shù)中準(zhǔn)確找到責(zé)任血管并將面神經(jīng)根出根區(qū)與責(zé)任血管充分墊開是手術(shù)成功的關(guān)鍵。LSR為面肌痙攣患者特征性的電生理表現(xiàn)[10]。

在臨床實(shí)踐中我們發(fā)現(xiàn)，當(dāng)將責(zé)任血管從面神經(jīng)根出根區(qū)分離開后，多數(shù)病例(40例)LSR即刻消失，部分病例反應(yīng)幅度明顯降低。究其原因我們考慮在解除血管對(duì)神經(jīng)的壓迫后，運(yùn)動(dòng)神經(jīng)元的興奮性隨之降低并逐漸恢復(fù)正常。LSR可反映面神經(jīng)傳導(dǎo)通路的興奮性，排除干擾后，LSR消失表明興奮性恢復(fù)正常[11～13]。通過本組病例研究我們體會(huì)，術(shù)中應(yīng)用LSR監(jiān)測(cè)對(duì)正確判斷責(zé)任血管和保證減壓效果有很大幫助。部分病例在初步判定責(zé)任血管并減壓后，LSR并未消失，其主要原因?yàn)樾g(shù)中對(duì)責(zé)任血管判斷不正確或遺漏、對(duì)神經(jīng)減壓不充分、墊入Teflon棉位置不正確、遠(yuǎn)端血管壓迫等。本組3例患者存在上述情況，經(jīng)過調(diào)整顯微鏡角度重新探查發(fā)現(xiàn)另有其他壓迫血管[14]。另外，有些責(zé)任血管游離不徹底，致使墊入的Telfon棉與面神經(jīng)仍有緊密接觸，調(diào)整墊棉后LSR消失。因此，通過術(shù)中LSR監(jiān)測(cè)，可保障充分游離責(zé)任血管，并將Telfon棉墊入責(zé)任血管與腦干之間以改變責(zé)任血管的行程，完全解除其對(duì)面神經(jīng)的壓迫。

有研究表明MVD術(shù)中LSR消失或幅度較減壓前明顯下降預(yù)示著比較樂觀的手術(shù)效果，極有可能完全緩解或大部分緩解面肌痙攣癥狀。本研究結(jié)果顯示，術(shù)后第1、7天及術(shù)后術(shù)后3個(gè)月LSR消失組治愈和好轉(zhuǎn)比例均高于LSR未消失組，且隨訪3～88個(gè)月也得到相同結(jié)果，認(rèn)為減壓后LSR是否消失與療效存在相關(guān)性。這表明在充分減壓后面神經(jīng)核的興奮性逐漸降至正常，進(jìn)而面肌痙攣癥狀緩解。影響MVD術(shù)后緩解率的因素多種多樣且比較復(fù)雜，術(shù)者經(jīng)驗(yàn)也是影響手術(shù)效果的重要因素。LSR監(jiān)測(cè)可幫助準(zhǔn)確判斷責(zé)任血管及減壓是否充分，這對(duì)于經(jīng)驗(yàn)不足的年輕神經(jīng)外科醫(yī)生或剛剛開展此類手術(shù)的神經(jīng)外科單位有重要參考價(jià)值。LSR監(jiān)測(cè)不但能減少尋找責(zé)任血管的時(shí)間，減少不必要的過分牽拉，起到保護(hù)面神經(jīng)、聽神經(jīng)功能的作用；而且能夠幫助判斷減壓是否充分，尤其是有多根責(zé)任血管時(shí)，可防止發(fā)生遺漏[15，16]。

由于術(shù)中LSR消失與否和術(shù)后療效之間存在明顯相關(guān)，因此，根據(jù)LSR監(jiān)測(cè)結(jié)果制定不同的減壓策略，盡可能減少責(zé)任血管遺漏，做到對(duì)面神經(jīng)進(jìn)行充分減壓，有助于提高術(shù)后療效。

[1] Kameyama S, Masuda H, Shirozu H, et al. Ephaptic transmission is the origin of the abnormal muscle response seen in hemifacial spasm[J]. Clin Neurophysiol, 2016,127(5):2240-2245.

[2] Sun H, Li ST, Zhong J, et al. The strategy of microvascular decompression for hemifacial spasm: how to decide the endpoint of an MVD surgery[J]. Acta Neurochir(Wien), 2014,156(6):1155-1159.

[3] von Eckardstein K, Harper C, Castner M, et al. The significance of intraoperative electromyographic "lateral spread" in predicting outcome of microvascualr decompression for hemifacial spasm[J]. J Neurol Surg B Skull Base, 2014,75(3):198-203.

[4] Tobishima H, Hatayama T, Ohkuma H. Relation between the persistence of an abnormal muscle response and the long-term clinical course after microvascular decompression for hemifacial spasm[J]. Neurol Med Chir(Tokyo), 2014,54(6):474-482.

[5] Hirono S, Yamakami L, Sato M, et al. Continuous intraoperative monitoring of abnormal muscle response in microvascular decompression for hemifacial spasm; a real-time navigator for complete relief[J]. Neurosurg Rev, 2014,37(2):311-320.

[6] Jia JM, Guo H, Huo WJ, et al. Preoperative evaluation of patients with hemifacial spasm by three-dimensional time-of-flight (3D-TOF) and three dimensional constructive interference in steady state (3D-CISS) sequence[J]. Clin Neuroradiol, 2016,26(4):431-438.

[7] Wilkinson MF, Chowdhury T, Mutch WA, et al. Is hemifacial spasm a phenomenon of the central nervous system?-The role of desflurane on the lateral spread response[J]. Clin Neurophysiol, 2015,126(7):1354-1359.

[8] Jia G, Zhang L, Ren H, et al. What range of stimulus intensities should we apply to elicit abnormal muscle response in microvascular decompression for hemifacial spasm[J]. Acta Neurochir(Wien), 2017,159(2):251-257.

[9] Wilkinson MF, Chowdhury T, Mutch WA, et al. Analysis of facial motor evoked potentials for assessing a central mechanism in hemifacial spasm[J]. J Neurosurg, 2017,126(2):379-385.

[10] Fukuda M, Takao T, Hiraishi T, et al. Free-running EMG monitoring during microvascular decompression for hemifacial spasm[J]. Acta Neurochir(Wien), 2015,157(9):1505-1512.

[11] EI Damaty A, Rosenstengel C, Matthes M, et al. The value of lateral spread response monitoring in predicting the clinical outcome after microvascular decompression in hemifacial spasm: a prospective study on 100 patients[J]. Neurosurg Rev, 2016,39(3):455-466.

[12] Lee SH, Park BJ, Shin HS, et al. Prognostic ability of intraoperative electromyographic monitoring during microvascular decompression for hemifacial spasm to predict lateral spread response outcome[J]. J Neurosurg, 2016,126(2):391-396.

[13] Li S, Feng B, Xie C, et al. Good surgical outcomes of hemifacial spasm patients with obvious facial nerve indentation and color change[J]. World Neurosurg, 2016,92:218-222.

[14] Ishikawa M, Tanaka Y, Watanabe E. Microvascular decompression under neuroendoscopic view in hemifacial spasm: rostral-type compression and perforator-type compression[J]. Acta Neurochir(Wien), 2015,157(2):329-332.

[15] Kim HJ, Park YS, Ryu JS, et al. Intraoperative facial electromyography and brainstem auditory evoked potential findings in microvascular decompression for hemifacial spasm: correlation with postoperative delayed facial palsy[J]. Stereotact Funct Neurosurg, 2012,90(4):260-265.

[16] Thirumala PD, Wang X, Shah A, et al. Clinical impact of residual lateral spread response after adequate microvascular decompression for hemifacial spasm: A retrospective analysis[J]. Br J Neurosurg, 2015,29(6):818-822.

Prognostic value of intraoperative lateral spread response monitoring during microvascular decompression in patients with hemifacial spasm

JIAOFeng1,ZHANGLei,ZHAOChunwei,LIUBo,WANGDongliang,LIANGYeshi,LIUXianzeng

(1People'sHospitalofPekingUniversity,Beijing100044,China)

Objective To investigate the prognostic value of intraoperative lateral spread response (LSR) monitoring in the treatment of hemifacial spasm (HFS) by microvascular decompression (MVD). Methods Forty-five patients with primary HFS treated by MVD. During operations, we performed LSR monitoring before and after MVD respectively. All patients were assessed after operation on day 1 and 7, and at 3 month after surgery by self-assessment scale. We analyzed the relationship between the change of LSR and prognosis. Results In 40 patients, the LSR disappeared immediately after decompression (LSR disappeared group). In the remaining 5 patients, the LSR did not vanish immediately after decompression (LSR non vanishing group), one patient's LSR decreased 86%, 2 patients' LSR decreased above 50%, 1 patient had no change, and in 1 patient, LSR was not detected from the start. On day 1 after operation, in the LSR disappeared group, HFS was relieved totally in 31 patients, 9 patients described improvement; in the LSR non vanishing group, 1 patient totally relieved, 1 patient improved, and 3 patients failed. On day 7, in the LSR disappeared group, HFS was relieved totally in 35 patients, 5 patients described improvement; in the LSR non vanishing group, 1 patient totally relieved, 2 patient improved, and 2 patients failed. After 3 month, in the LSR disappeared group, HFS was relieved totally in 39 patients, 1 patients described improvement; in the LSR non vanishing group, 3 patient improved, and 2 patients failed. After 3-month to 88-month follow-up, in the LSR disappeared group, all the 40 patients cured, in the LSR non vanishing group, 3 patients improved and 2 patients failed. At all the postoperative observing time, the proportion of cure and improvement of the LSR disappeared group was higher than that of the LSR non vanishing group. Statistical analysis found a significant correlation between the relief of LSR and clinical outcome (allP<0.05). Conclusion LSR monitoring of HFS patients in MVD is correlated with the curative effect, and the rate of cure and improvement is higher in patients with disappeared LSR after decompression.

hemifacial spasm; microvascular decompression; lateral spread response

10.3969/j.issn.1002-266X.2017.15.021

R745.1

B

1002-266X(2017)15-0071-03

2016-12-08)