Mitochondrial Myopathy, Lactic Acidosis, and Stroke-Like Episodes Combined with Diabetes: A Case Report

Mitochondrial diseases refer to a group of hereditary disorders involving damage to high-energy-consuming tissues, such as muscles, nerves, and the heart. Mitochondrial DNA (mtDNA) mutations account for most cases, but the timely identification and treatment of these conditions remain challenging.

This report describes a case of a 36-year-old male patient who was diagnosed with diabetes in 2017 and subsequently experienced recurrent diabetic ketoacidosis and seizures. On May 20, 2022, he presented with cognitive impairment, unsteady gait, and an elevated blood lactate level. Brain MRI and mitochondrial gene sequencing on peripheral blood cells revealed destructive neuronal lesions and a mutation of m.3243A>G in the MT-TL1 gene with a ratio of 6.04%, which supported the diagnosis of mitochondrial encephalomyopathy associated with lactic acidosis and stroke-like episodes (MELAS) and mitochondrial diabetes mellitus (MDM). Treatment with insulin, fluid replacement, ketoacidosis correction, diazepam, and phenobarbital relieved most symptoms. However, his blood glucose was poorly controlled. Four months after discharge, the patient suffered a relapse. Although therapies to combat infection, reduce blood glucose, and correct ketoacidosis improved his condition, the patient died in 2023 due to cerebral infarction.

This case embodies the typical manifestations of mitochondrial diseases, emphasizing the urgency of prompt diagnosis and symptom management, which largely depends on effective genetic screening.