线粒体脑病.ppt
北大医院医学影像科,神经影像病例汇报,朱颖2009-10-20,北大医院医学影像科,Case 1 2090748,男，31岁主因“发作性视力下降，听力下降伴癫痫5年，复发表达异常、听理解异常3天”入院入院查体：发育差，身材偏瘦，言语欠流利，听理解力障碍，命名障碍，查体欠合作。高级皮层功能查体不配合。四肢腱反射未引出。左侧Babinski（+），右侧（）乳酸 13.8（0.5-2 mmol/l）（May-04，天坛）血mtDNA A3243突变阳性,北大医院医学影像科,Case2 631976,女，11岁“间断抽搐伴视力下降2年，右侧肢体活动障碍1周”09-4入院2年来2此频繁抽搐、类卒中样发作，伴视力下降，头痛、生长发育缓慢，智力落后、倒退。查体：身材矮小，头围小，计算力差，背部多毛，右眼内斜，拖曳步态；肌力右侧上下肢IV，腱反射弱。脑电图：异常肌电图未见异常。乳酸高,北大医院医学影像科,线粒体病,定义由于遗传缺损引起线粒体代谢缺陷，导致ATP合成障碍，能量产生不足而出现的一组多系统疾病。分类,北大医院医学影像科,北大医院医学影像科,MELAS发病机制,血管病学说异常的线粒体沉积于软脑膜和脑内小动脉的平滑肌细胞和内皮细胞，导致脑组织缺血而致病细胞病学说线粒体功能障碍导致脑神经细胞能量供应不足，无氧代谢增加，乳酸酸中毒，当能量需求增高时，即诱发卒中样发作线粒体的氧化磷酸化异常最容易损伤枕叶非缺血性神经血管细胞学说神经元过度兴奋、神经元脆弱、毛细血管通透性增加和充血,北大医院医学影像科,MR表现,游走皮质受累为主顶枕颞多见不按脑血管分布钙质沉积基底节等脑内神经核团不同时期发作期慢性期,北大医院医学影像科,钙化,北大医院医学影像科,MRA少见异常DWIADC血管源性水肿ADC细胞毒性水肿MRSNAALac,北大医院医学影像科,1.266,0.826,1.172,0.765,北大医院医学影像科,1.082,0.831,0.851,北大医院医学影像科,北大医院医学影像科,北大医院医学影像科,Fig.1 MRI exams were realized at admission(D0),at 15 days(D15)of evolution,and for control 6(M6)and 12 months later.Conventional FLAIR and DWI data arerepresented in Fig.1.FLAIR and DWI sequences are represented at two levels;the first 2 left columns corresponding to a view at the temporal level,and the 2 right columnsto the occipital level.Rows represent successively MRI exams realized at D0,D15,and M6(MRIs at M12 were not represented as they were similar to images obtained 6months earlier).At admission,recent left temporal lesion appeared with a hyper intensity on FLAIR sequence(1a),and ADCs were heterogeneous;elevated in anterior localization,anddiminished in posterior region(1b).There were no signal abnormalities on FLAIR or DWI views in the occipital regions(2a and 2b).At D15,bilateral occipital FLAIR hyperintensities appeared(2c).ADCs increased in these regions(2d),and became homogeneously elevated in the left temporal lesion(1d).At M6,FLAIR hyperintensities diminished in the temporal lesion,replaced with gliosis(1e),and disappeared in the occipital region(2e).Lesion regression was more markedin those regions of the temporal lobe in which ADCs were previously the most elevated(white arrow).FLAIR abnormalities disappeared completely in occipital regions(2e),and ADCs reached normal values(2f).,北大医院医学影像科,a mild energy failure resulting in moderate cellular dysfunction,responsible for vasogenic edema(high ADCs)a severe energy failure resulting in an irreversible cellular failure,with cytotoxic edema(low ADCs).,北大医院医学影像科,36岁，女，急性听觉失认,北大医院医学影像科,急性期CBF,北大医院医学影像科,(a)MRA on day 9.(b)ce T1WI on day 23.,男，8岁，卒中样发作，累及血管,北大医院医学影像科,脑病理,脑组织海绵状变性,病变区神经元变性或脱失、星形胶质细胞增生及继发性脱髓鞘改变,同时可见灶状坏死或软化、小血管异常增多、增生血管的管腔大小不等与管壁厚薄不均钙的沉积底节区苍白球最易发生,丘脑、小脑齿状核,
