儿童Leigh综合征的脑MRI影像学特征及诊断

Leigh syndrome in children: brain MR imaging characters and diagnosis

目的探讨儿童亚急性坏死性脑脊髓综合征(Leigh综合征)的脑MRI表现特点。方法回顾性分析15例经基因检测证实为Leigh综合征患儿的临床资料及脑MRI表现。结果 15例患儿脑内病变均表现为双侧大致对称性病变,形态不规则,大小不等,呈斑块状分布。病变累及部位包括脑干(14例)、基底节(10例)及丘脑(8例,背侧丘脑内侧近第三脑室),累及单一部位(4例)或多个部位(11例)。基底节受累好发顺序依次为壳核(9例)、苍白球(8例)和尾状核(5例)。脑干受累好发顺序依次为大脑脚(13例)、延髓(10例)、中脑背侧(9例)、导水管周围(8例)、桥脑(5例)。T_1WI呈低信号或稍低信号,T_2WI呈高信号,T_2FLAIR多数病变信号不均匀(12例),高信号内可见斑片状及点状低信号。15例患儿中11例可见DWI弥散受限,且弥散像信号不均匀,病变内可见点片状无弥散受限区。5例行质子磁共振波谱(~1H-MRS)检查的患儿中3例可见NAA降低,乳酸增高。结论儿童Leigh综合征的脑MRI表现具有一定的特征性。当脑内病变呈基本对称性分布,单独或同时累及脑干、基底节时,尤其是T_2FLAIR和DWI信号不均匀时,病变同时具有弥散受限和不受限区域时,应怀疑Leigh综合征。如~1H-MRS同时显示病变区乳酸增高,则高度提示该病的诊断。

Objective To investigate the brain MRI features of children with subacute necrotic cerebrospinal cord syndrome (Leigh syndrome). Methods The clinical data and MRI findings of 15 children with Leigh syndrome confirmed by genetic testing were retrospectively analyzed. Results In the 15 cases, lesions in the brain showed as symmetrical patchy or irregular shape. The brainstem (14 cases), basal ganglia (10 cases) and thalamus (8 cases), dorsal thalamus medial third ventricle were involved. Four of 15 cases involved only single site and 11 of 15 cases involved multiple sites. The involvement propensity of basal ganglia was as follows: putamen (9 cases), globus pallidus (8 cases), and caudate nucleus (5 cases). The involvement propensity of brain stem was as follows: cerebellar peduncle (13 cases), medulla oblongata (10 cases), midbrain dorsal (9 cases), aqueduct (8 cases) and pontine (5 cases). Lesions showed hypointensity or slightly hypointensity on T 1 weighted imaging and hyperintensity on T 2 weighted imaging. Most of the lesions showed inhomogeneous on T 2FLAIR (12 cases), which showed hyperintensity patchy with hypointensity punctates in it. Lesions showed heterogenous diffusion restriction on DWI in 11 of 15 cases, in which high signal pathchy with diffusion restriction intermixed with low signal areas with no diffuse restriction. Three of 5 cases underwent MRS spectroscopy examination showed decreased NAA and elevated lactate. Conclusion Brain MR imaging features of Leigh syndrome in children appeared certain characteristics. Leigh syndrome should be considered when a symmetric lesions involved the brainstem, basal ganglia and the thalamus isolately or simultaneously,especially when the lesions with heterogenous diffusivity and inhomogenous intensity on T 2FLAIR. If the lesions combined with elevated lactate on proton MR spectrum, Leigh syndrome should be highly suggested.