Tetsuka Syuichi, Tagawa Asako, Ogawa Tomoko, Otsuka Mieko, Hashimoto Ritsuo, Kato Hiroyuki
Department of Neurology, Hospital of Yuki, 9629-1, Yuki, Yuki-City, Ibaraki 307-0001, Japan.
Department of Neurology, Hospital of International University of Health and Welfare, 537-3, Iguchi, Nasushiobara, Tochigi 329-2763, Japan.
J Clin Med Res. 2017 Sep;9(9):812-819. doi: 10.14740/jocmr3122w. Epub 2017 Jul 27.
The most common disease-causing mitochondrial DNA (mtDNA) mutation in mitochondrial encephalomyopathy (ME) with lactic acidosis and stroke-like episodes (MELAS) is m.3243A>G. In the future, the incidence of patients with cerebral infarction and diabetes mellitus is expected to increase tremendously. Additionally, the A3243G mutation typical of diabetes is estimated to be present in approximately 2% of all diabetes patients, which suggests that the potential disease population with a mitochondrial disorder is greater than previously thought, and there may have been many cases among the elderly that were misdiagnosed. Considering this background, MELAS with the onset of stroke-like episodes should be considered an important differential diagnosis for elderly patients with cerebral infarction, although it might have been overlooked until now. A 68-year-old Japanese female developed convulsive seizures and was admitted to Hospital of International University of Health and Welfare for epilepsy. She had been hospitalized twice in the previous year for cerebral infarction and seizures. She experienced sensorineural hearing loss at a young age. Thus, although she was elderly, we suspected MELAS and detected elevations of pyruvic and lactic acid. A genetic test revealed a point mutation in the mtDNA (m.3243A>G) that led to a definitive diagnosis of MELAS. To date, MELAS has been regarded as a disease of the relatively young. The incidence of patients with cerebral infarction and diabetes mellitus is expected to greatly increase. Thus, we should evaluate cerebral infarction in the elderly with caution to prevent missed diagnoses of MELAS.
伴有乳酸性酸中毒和卒中样发作的线粒体脑肌病（MELAS）中最常见的致病线粒体DNA（mtDNA）突变是m.3243A>G。未来，脑梗死和糖尿病患者的发病率预计将大幅上升。此外，据估计，所有糖尿病患者中约2%存在典型的糖尿病A3243G突变，这表明线粒体疾病的潜在患病人数比之前认为的更多，而且老年人中可能存在许多误诊病例。考虑到这一背景，尽管直到现在可能一直被忽视，但对于老年脑梗死患者，应将伴有卒中样发作的MELAS视为重要的鉴别诊断。一名68岁的日本女性出现惊厥发作，因癫痫入住国际医疗福祉大学医院。她上一年曾因脑梗死和癫痫发作住院两次。她年轻时就出现了感音神经性听力损失。因此，尽管她年事已高，但我们怀疑是MELAS，并检测到丙酮酸和乳酸水平升高。基因检测显示mtDNA存在点突变（m.3243A>G），从而确诊为MELAS。迄今为止，MELAS一直被认为是一种相对多见于年轻人的疾病。脑梗死和糖尿病患者的发病率预计将大幅上升。因此，我们应谨慎评估老年患者的脑梗死，以防止漏诊MELAS。
