Our purpose is to detect the metabolic alterations in acute stroke-like lesions (SLLs) and further investigate the correlations between metabolic concentrations and focal cerebral blood flow in patients with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) using proton MR spectroscopy (¹H-MRS) and arterial spin labeling (ASL). A total of 23 patients with MELAS at acute stage of stroke-like episodes (SLEs) and 20 normal controls (NC) were recruited in this study, respectively. All subjects underwent conventional MRI and¹H-MRS. In addition, ASL was performed in each patient. The measurements of creatine (Cr), choline (Cho), N-acetyl aspartate (NAA), lactate (Lac), glutamine/glutamate (Glx) levels and the ratios of Cho/Cr, NAA/Cr, Lac/Cr and Glx/Cr in acute SLLs for MELAS patients and left parietal and occipital lobes for NC were measured using LC-model software. Furthermore, in MELAS group, the associations between relative cerebral blood flow (rCBF) and metabolite concentrations in acute SLLs were also assessed. In MELAS group, acute SLLs were identified with metabolic abnormalities and increased rCBF. Specifically, compared with controls, MELAS patients exhibited significantly higher Lac, Cho levels and Lac/Cr, Cho/Cr ratios, and lower NAA, Glx levels and NAA/Cr and Glx/Cr ratios. Moreover, for MELAS patients, Lac concentration in acute SLLs was positively correlated with focal rCBF. This study exhibited the neural injury with increasing lactate and cerebral blood flow in the acute SLEs. It might shed light on the underlying biochemical mechanism of mitochondrial cytopathy and angiopathy in MELAS.

我们的目的是检测急性中风样病变 (SLL) 的代谢变化，并进一步研究使用质子的线粒体肌病、脑病、乳酸性酸中毒和中风样发作 (MELAS) 患者的代谢浓度与局灶性脑血流之间的相关性MR 光谱 ( ^1H -MRS) 和动脉自旋标记 (ASL)。本研究分别招募了 23 名处于卒中样发作 (SLE) 急性期的 MELAS 患者和 20 名正常对照 (NC)。所有受试者均接受常规 MRI 和¹H-MRS。此外，对每位患者进行了 ASL。测量肌酸 (Cr)、胆碱 (Cho)、N-乙酰天冬氨酸 (NAA)、乳酸 (Lac)、谷氨酰胺/谷氨酸 (Glx) 水平以及 Cho/Cr、NAA/Cr、Lac/Cr 和 Glx 的比率使用 LC 模型软件测量 MELAS 患者的急性 SLL 和 NC 的左顶叶和枕叶中的 /Cr。此外，在 MELAS 组中，还评估了急性 SLL 中相对脑血流量 (rCBF) 和代谢物浓度之间的关联。在 MELAS 组中，急性 SLL 被鉴定为代谢异常和 rCBF 增加。具体而言，与对照组相比，MELAS 患者的 Lac、Cho 水平和 Lac/Cr、Cho/Cr 比值显着升高，而 NAA、Glx 水平和 NAA/Cr 和 Glx/Cr 比值显着降低。此外，对于 MELAS 患者，急性 SLL 中的 Lac 浓度与局灶性 rCBF 呈正相关。本研究表明，急性 SLE 中伴随着乳酸和脑血流量增加的神经损伤。它可能揭示 MELAS 中线粒体细胞病变和血管病变的潜在生化机制。