How to interpret stroke-like attacks in the context of mitochondrial disease

Introduction : Stroke-like attacks are defined as events characterized by the sudden onset of neurological symptoms with clinical manifestations similar to those of a stroke. However, they are distinguished by the presence of radiological lesions that are incompatible with the vascular territory. MELAS syndrome, which is characterized by metabolic encephalopathy, lactic acidosis, and stroke-like attacks, has been identified as the first genetically defined and most widely known mitochondrial cause of stroke-like attacks. It has been demonstrated that stroke-like attacks may occur in the course of a variety of mitochondrial diseases, including those that are the result of nuclear DNA mutations. Objective : In this retrospective, multicenter, observational cohort study, we sought to determine the clinical, radiological, EEG, and genetic characteristics of patients with mitochondrial gene mutations presenting with stroke-like attacks and the frequency and treatment of stroke-like attacks. Methods : Thirty-six patients with mitochondrial disease with stroke-like episodes, all diagnosed by molecular analysis from nine pediatric metabolic disease centers in the Marmara Region of Turkey, were included in the study. Demographic characteristics, symptoms, clinical features, cranial MRI, EEG findings, and genetic characteristics were evaluated. Conclusion : The present study demonstrated that stroke-like attacks in genetically diagnosed mitochondrial diseases are most commonly observed in MELAS and POLG mutations. However, they may also develop in rare subtypes such as CoQ10 deficiency, beta-ketothiolase deficiency ( ACAT1 mutation), and Leigh syndrome. During attacks, cranial MRI showed bilateral cortical lesions incompatible with vascular distribution, often located frontotemporally, and EEG shows focal epileptiform activity. In MELAS, clinical improvement was observed withiv L-arginine treatment initiated in the acute period, and it was determined that long-tMEerm oral arginine may be effective in reducing the frequency of attacks. The findings emphasize that stroke-like episodes should be considered in the differential diagnosis of mitochondrial diseases in the presence of sudden onset neurological findings.