Mitochondrial metabolic stroke: Phenotype and genetics of stroke-like episodes

Area of Science:

• Neurology
• Mitochondrial Diseases
• Neuroimaging

Background:

• Stroke-like episodes (SLEs) are characteristic of MELAS syndrome but occur in other mitochondrial disorders.
• Pathophysiology involves blood-brain barrier disruption due to metabolic defects, seizures, or medications.
• Clinical presentation includes stroke-like symptoms, headache, epilepsy, ataxia, and visual disturbances.

Purpose of the Study:

• To describe the clinical and imaging features of stroke-like lesions (SLLs) in mitochondrial disorders.
• To discuss the pathophysiology and diagnostic challenges of SLEs/SLLs.
• To review current symptomatic treatments and identify research gaps.

Main Methods:

• Multimodal MRI is crucial for visualizing stroke-like lesions (SLLs).
• Acute SLLs show vasogenic edema, potentially with cytotoxic components and hyperperfusion.
• Chronic SLLs evolve into various abnormalities, including white matter lesions, cysts, or atrophy.

Main Results:

• SLEs manifest with diverse neurological symptoms beyond typical stroke features.
• MRI findings differentiate acute (edema, hyperperfusion) and chronic (lesion evolution) stages of SLLs.
• Symptomatic treatments like nitric-oxide precursors, antiepileptics, antioxidants, ketogenic diet, and steroids show potential benefits.

Conclusions:

• SLEs/SLLs are complex manifestations of mitochondrial disorders with distinct imaging characteristics.
• Effective management is symptomatic, guided by expert recommendations.
• Further research is essential to fully understand and treat SLEs/SLLs.