青少年肌陣攣癲及其網絡連接研究進展

孫 偉

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專家論壇

孫 偉

青少年肌陣攣性癲；腦結構網絡；功能網絡

大腦是生物體內結構和功能最復雜的器官，同時它也是極為精巧和完善的信息處理系統。10年前，學者們提出了“腦網絡”的概念。“腦網絡”主要基于實驗測量的反映大腦結構性連接的數據，或大腦功能性連接的數據，計算預先定義的腦區或節點的連接關系，然后構建網絡進行分析，這是目前應用最多的一類“腦網絡”研究方法。

近年來，越來越多的研究證實，JME患者的腦結構網絡和功能網絡(包括靜息態網絡和認知網絡等)連接均受到了影響。下面筆者通過對JME相關網絡的結構連接及功能連接方面的研究做進一步的綜述，以期對近年來JME網絡連接進展有更深入的了解。

1 JME患者腦結構及結構網絡連接改變

常規磁共振成像(magnetic resonance imaging,MRI)和CT(computered tomography,CT)檢查通常不能發現JME患者大腦結構上微小的變化。近年來，隨著影像學技術的發展，許多學者通過基于體素形態學分析(voxel-based morphometry,VBM)和彌散張量成像(diffusion tensor imaging,DTI)等技術發現了JME患者大腦的局部結構異常,且異常部位主要集中在額葉結構。VBM是一種基于體素的針對腦組織結構的形態學測量方法，它通過計算磁共振成像(主要是高分辨率的結構掃描圖像)中腦的灰質/白質的變化，以定量分析不同群體腦結構的特征和腦組織成分的差異，從而替代了傳統上人工勾畫感興趣區域的方法，提高了測量的準確性和可重復性，能夠準確、全面評價不同群體腦的神經解剖變化。1999年, Woermann等[12]應用VBM方法首先發現額中回灰質密度發生變化，為JME患者腦局部結構變化提供了依據。Pulsipher等[13]發現，JME患者的丘腦和額葉體積變小。Tae和Betting等[14,15]應用VBM證實了JME患者額葉灰質密度的減少。Kim等[16]發現，JME患者丘腦灰質密度與病程呈負相關關系，并提出JME患者可能有丘腦進行性神經元缺失。

2 JME患者腦功能及功能網絡連接改變

除了上述提到的應用較多的VBM、DTI及fMRI手段外，學者們還通過磁共振波譜成像(magnetic resonance spectroscopy, MRS)，正電子發射斷層顯像(positron emission tomography, PET)及經顱磁刺激(transcranial magnetic stimulation，TMS)等技術研究JME患者的腦網絡連接變化。Lin等[30]通過MRS發現額中前皮質、初級運動區以及丘腦N-乙酰天門冬氨酸與肌酐的比值(神經元受損的標志)下降；額中前皮層、初級運動區及后扣帶回皮質谷氨酸/谷氨酰胺與肌酐的比值減低，說明了廣泛的大腦皮質興奮性降低。Swartz等[31]通過PET發現背外側前額皮質、運動前區的氟代脫氧葡萄糖減少。同樣，利用PET技術，Meschaks等[32]發現JME患者中縫核、海馬、背外側前額皮質的5-羥色胺受體減少。Akgun等[33]通過TMS證實JME患者的運動區皮質興奮性增加。國內侯文生等[34]也運用同樣的方法證實了該結論。

3 小結與展望

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(2017-04-10收稿 2017-05-05修回)

(責任編輯 梁秋野)

國家自然科學基金(81571267)

孫 偉，博士，主任醫師，教授，博士生導師。

100053 北京，首都醫科大學宣武醫院神經內科

R742.1