Rasmussen腦炎又稱Rasmussen綜合征（RE），是一種罕見的后天獲得性進(jìn)展性、累及一側(cè)大腦的慢性炎癥疾病，表現(xiàn)為難治性局灶性癲癇、部分性癲癇持續(xù)狀態(tài)(epilepsia partialis continua，EPC)和進(jìn)行性神經(jīng)功能缺損(偏癱、偏盲、智力下降等)，因1958年由Rasmussen首先報(bào)道而命名。
RE臨床特點(diǎn):
· aprogressive disease 逐漸進(jìn)展
· drug-resistant focal epilepsy 難治性局灶性癲癇
· progressive hemiplegia偏癱
· cognitive decline 認(rèn)知功能下降
· with unihemispheric brain atrophy 一側(cè)半球萎縮
流行病學(xué)：
· 主要見于兒童，平均發(fā)病年齡6歲，嬰幼兒到青年均可見
· 性別、地理位置、種族等未見明顯差異
典型RE各期臨床表現(xiàn)：
· 前驅(qū)期：緩慢起病，癲癇多為部分性發(fā)作，伴有輕度偏癱
· 急性期：癲癇發(fā)作頻繁，常伴隨部分性癲癇持續(xù)狀態(tài)（EPC）（約占50%），藥物難以控制。癲癇發(fā)作形式多樣（不同的皮層區(qū)受影響），約1年后出現(xiàn)進(jìn)行性偏癱、偏盲、認(rèn)知功能下降和失語（影響到優(yōu)勢(shì)半球時(shí)）
· 后遺癥期：相對(duì)靜止，遺留永久神經(jīng)功能缺失，包括精神癥狀和智力減退等，大腦半球進(jìn)行性萎縮。難以控制的癲癇發(fā)作
RE其他臨床特點(diǎn)：
· 部分RE有不同表現(xiàn)，青少年或成年期起病的RE約占總發(fā)病率的10%，臨床進(jìn)展更慢，神經(jīng)功能缺失較兒童輕，更傾向于顳葉癲癇的特點(diǎn)
· 絕大部分RE為單側(cè)半球受累表現(xiàn)，有的表現(xiàn)為半側(cè)手足徐動(dòng)癥或半側(cè)肌張力不全；極少表現(xiàn)為雙側(cè)半球受累（目前仍被爭(zhēng)議），只有2例報(bào)告有雙側(cè)半球受累的組織學(xué)依據(jù)
· 目前尚沒有RE半球切除術(shù)后對(duì)側(cè)半球受累的報(bào)道
· 另有少部分RE早期無明顯癲癇發(fā)作
RE影像學(xué)特點(diǎn)：
· 頭顱影像學(xué)檢查早期可正常
· 急性期：MRI顯示單側(cè)半球萎縮，常由顳葉開始，伴外側(cè)裂擴(kuò)大。MRI的特征性表現(xiàn)是一側(cè)半球萎縮，表現(xiàn)為腦回和側(cè)腦室擴(kuò)大，腦白質(zhì)異常高信號(hào)，皮質(zhì)異常高信號(hào)，基底節(jié)尾狀核頭部輕、重度萎縮
· 皮質(zhì)萎縮通常在島葉進(jìn)行性發(fā)展，最先受累的部位常最嚴(yán)重。
Figure 2: Neuroimagingin Rasmussen’s encephalitis
MRI brain scans of children with Rasmussen’s encephalitis, showing contrastingcases of radiological progression. (A) Progressive right hemisphere atrophy,high signal and basal ganglia loss over 1 year (from left to right) in a childwith Rasmussen’s encephalitis. The disease was mostly centred near the rightSylvian fi ssure (arrow). (B) Slowly progressive disease with more subtle righthemisphere atrophy in a child on immunosuppressant treatment at 6 months(left), 18 months (centre), and 30 months (right) of disease course.
RE腦電圖特點(diǎn)：
· EEG改變?yōu)榉翘禺愋?，廣泛異常
· 背景活動(dòng)多為不規(guī)則慢波及低電壓不對(duì)稱波，占89％～90％，可見多灶或孤立性棘波，睡眠期呈非對(duì)稱分布；
· 早期EEG可正常，癲癇發(fā)作幾個(gè)月后患側(cè)半球可出現(xiàn)持續(xù)存在高幅δ波；
· 健側(cè)半球可出現(xiàn)孤立的發(fā)作間期異常放電，25%的病人在癲癇發(fā)作開始6個(gè)月后出現(xiàn)，62%的病人在3-5年后出現(xiàn)；健側(cè)異常放電可認(rèn)為是認(rèn)知功能下降的標(biāo)志，但并不提示雙側(cè)病變
RE診斷：
《A European consensus panel proposed formal diagnostic criteria for Rasmussen’s encephalitis in2005》
· 隨著免疫抑制治療的開展，自然病程進(jìn)展減慢，尤其是MRI大腦半球萎縮進(jìn)展減緩，帶來臨床診斷困難
Figure 1: Naturalclinical course and expected eff ect of immunotherapy
The natural clinical course of Rasmussen’s encephalitis was characterised inthe past century. The disease might have a preceding prodromal stage withinfrequent seizures, and presents with an acute stage of drug-resistant epilepsy.The epilepsy is characterised by very frequent seizures of diff erent semiologiesin the same patient, often epilepsia partialis continua, with the emergence ofa fluctuating then permanent hemiplegia (motor function) and concurrentprogressive hemispheric volume loss on neuroimaging. With the advent ofimmunotherapy, the natural clinical course seems to be changing. The rate ofmotor function and hemispheric volume loss is slowed, and seizures decrease infrequency and plateau. Cognitive deterioration is not shown because it is morevariable, although usually becomes manifest during the acute phase.EPC=epilepsia partialis continua.
Diagnostic criteria- Part A
· 需同時(shí)滿足如下3點(diǎn)：
· 1.臨床特點(diǎn)：局灶性癲癇（伴或不伴EPC），一側(cè)皮層損害
· 2.腦電圖：?jiǎn)蝹?cè)半球慢波，伴或不伴癇樣放電
· 3.MRI：?jiǎn)蝹?cè)半球局灶性皮層萎縮伴至少具備下列之一：（1）灰質(zhì)或白質(zhì)T2/FLAIR高信號(hào)（2）同側(cè)尾狀核頭高信號(hào)或萎縮
Diagnostic criteria- Part B
· 至少滿足下列條件2條：
· 1.臨床特點(diǎn)：EPC或進(jìn)展性一側(cè)皮質(zhì)損害
· 2.MRI：進(jìn)展性單側(cè)局灶皮層萎縮
· 3.組織病理：小膠質(zhì)細(xì)胞、活化T細(xì)胞浸潤或反應(yīng)性星型膠質(zhì)增生（非必須）；如有大量的巨噬細(xì)胞、B細(xì)胞、漿細(xì)胞或病毒包涵體形成作為排 Rasmussen腦炎診斷的依據(jù)
具備A部分3項(xiàng)指標(biāo)或者B部分2項(xiàng)指標(biāo)，則可診斷。
RE病理
· 一側(cè)半球多灶炎癥，進(jìn)行性小膠質(zhì)細(xì)胞增生和淋巴細(xì)胞浸潤在血管周形成血管套, 神經(jīng)元死亡和嗜神經(jīng)現(xiàn)象是最常見的病理特征
· 晚期主要表現(xiàn)為皮層空洞形成，大量星型膠質(zhì)增生及神經(jīng)元的丟失
· 大腦所有部位均可累及，最常見為額-島葉，枕葉皮層相對(duì)累及較少
(A–E)Cortical degeneration in Rasmussen’s encephalitis. (A) Staining for MAP2 showsintact cortical neurons on the left side while loss of MAP2 neurons is found onthe right side. (B) Cortical degeneration in a later stage of the disease; mostneurons are already lost. (C) The same areas stained for glial fibrillaryacidic protein, showing strong activated astrocytes. (D) An almost completeloss of cortical neurons. (E) In this area, nearly complete fibrillary astrogliosisis present.
參考文獻(xiàn)：
Rasmussen’sencephalitis: clinical features, pathobiology, and treatment advances. Lancet Neurol 2014; 13: 195–205
聯(lián)系客服
