Ischemic and Metabolic Stroke Can Co-occur in m.3243A>G Carriers: A Case Report

Stroke-like episodes (SLEs) and their morphological equivalent, stroke-like lesions (SLLs), also termed metabolic stroke, are the hallmark of MELAS. Despite increasing knowledge of the properties of SLEs/SLLs, they are often misinterpreted as ischemic stroke, particularly if both ischemic and metabolic stroke occur in the same patient. The patient is a 56 years-old male with MELAS due to the mtDNA variant m.3243A>G in MT-TL1 and three previous strokes at ages 43 years, 49 years, and 50 years being interpreted as ischemic, focal seizures, depression, right amblyopia, hypoacusis, hyperuricemia, hepatic steatosis, hyperlipidemia, pre-diabetes, and arterial hypertension. He was admitted due to successive worsening of a pre-existing gait disturbance and confusion. Clinical exam revealed dysarthria, word-finding difficulties, right-left confusion disorder, left visual neglect, ataxia, and pyramidal signs. Cerebral MRI showed T2- and DWI hyperintense lesions in a right occipitotemporal location not confined to a vascular territory and in the left posterior border zone. The right occipitotemporal lesion was initially interpreted as subacute ischemia, which is why acetyl-salicylic acid was replaced by clopidogrel. However, after revision of the MRI images, the right occipitotemporal lesion was re-classified as SLL. Arguments for an SLL (metabolic stroke) were the successive onset and the distribution of the lesion. The patient recovered partially from his initial deficits within eight weeks. In summary, SLLs can co-occur with ischemic stroke in the same MELAS patient. Further efforts are needed to clearly differentiate metabolic from ischemic stroke in MELAS patients.