Late-onset MELAS: a case report of mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes in a 55-year-old patient

Abstract

Mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) are typically presented before the age of 30 years. This case report describes a rare late-onset MELAS in a 55-year-old woman with the m.3243A>G mutation. The patient presented with aphasia, perseveration, and headache. She had diabetes mellitus but did not show common MELAS features like short stature. The diagnosis was confirmed through MRI, elevated lactate and pyruvate levels in the serum and cerebrospinal fluid, and genetic testing. Levetiracetam treatment improved her symptoms and taurine prevented the recurrence of stroke-like attacks. This case highlights the importance of considering MELAS as a differential diagnosis in patients with atypical stroke-like symptoms for appropriate treatment, even in middle-aged patients.