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Updated: May 11, 2026
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Modeling Mitochondrial Disease Using Brain Organoids: A Focus on Mitochondrial Encephalomyopathy, Lactic Acidosis, and Stroke-like Episodes
Published on: October 10, 2025
Transient ischemic attack-like episodes without stroke-like lesions in MELAS.
Tadahiro Mitani1, Noriko Aida, Moyoko Tomiyasu
1Division of Neurology, Kanagawa Children's Medical Center, Mutsukawa 2-138-4, Minami-ku, Yokohama, Kanagawa, 232-8555, Japan.
Pediatric Radiology
|May 17, 2013
Summary
Mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) can cause stroke-like episodes. Proton magnetic resonance spectroscopy (1H-MRS) detected elevated lactate in a child with MELAS, despite normal MRI scans, indicating a mild, transient event.
Area of Science:
- Neurology
- Mitochondrial Diseases
- Neuroimaging
Background:
- Stroke-like episodes are a hallmark symptom of MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes).
- Proton magnetic resonance spectroscopy (1H-MRS) is a valuable diagnostic tool for mitochondrial disorders.
Observation:
- An 8-year-old girl with MELAS experienced a seizure and temporary blindness.
- 1H-MRS revealed a significant lactate elevation in the right occipital lobe.
- Standard MRI sequences (T2-W, diffusion-weighted) showed no abnormalities in the affected region.
Findings:
- The patient exhibited a mild clinical presentation with a transient ischemic attack-like episode.
- Elevated lactate levels on 1H-MRS were observed in normal-appearing gray matter.
- Complete recovery occurred within 24 hours.
Implications:
- This case highlights the utility of 1H-MRS in diagnosing MELAS, even with subtle or absent MRI findings.
- It suggests that transient lactate elevations in normal-appearing brain regions can represent mild stroke-like episodes in MELAS.
- Early detection and understanding of these episodes are crucial for managing mitochondrial diseases.
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