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Diffuse posterior leukoencephalopathy in MELAS without stroke-like episodes: A case report
Peng Bai1,2, Yinling Feng1, Jin Chen1
1Department of Neurology, Inner Mongolia People's Hospital, Hohhot, People's Republic of China.
Rationale:
Mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) is the most common subtype of mitochondrial encephalopathy. In the past, it was believed that most hereditary white matter lesions were lysosome storage disorders or peroxisome diseases. However, in recent years, white matter lesions have been increasingly regarded as a common feature of patients with mitochondrial diseases. In addition to stroke-like lesions, about half of the patients with MELAS reported white matter lesions in the brain.
Patient Concerns:
Herein, we provide a case of A 48-year-old female who presented with episodic loss of consciousness with twitching of extremities. Previous medical history revealed 10 years of history of epilepsy, 10 years of history of diabetes, a history of hearing loss, and unknown etiology. Ancillary findings included brain magnetic fluid-attenuated inversion recovery showed symmetrical lesions in the bilateral parietal lobe with high signal intensity at the edge, and high signal intensity in the bilateral occipital lobe, paraventricular white matter, corona radiata, and the center of semiovale.
Diagnoses:
Mitochondrial deoxyribonucleic acid gene sequencing returned A3243G point mutation and it supports the diagnosis of intracranial hypertension.
Interventions:
Considered the diagnosis of symptomatic epilepsy, the patient was treated with mechanical ventilation, midazolam, and levetiracetam, and the limb twitching symptoms were controlled. The patient was comatose, chronically bedridden, with gastrointestinal dysfunction, and was treated prophylactically with antibiotics against infection, parenteral nutrition, and other supportive measures. B vitamins, vitamin C, vitamin E, coenzyme Q10, and idebenone were given, and mechanical ventilation and midazolam were stopped after 8 days. He was discharged from the hospital on 30 days and continued symptomatic treatment with B-vitamins, vitamin C, vitamin E, coenzyme Q10, and idebenone, and antiepileptic treatment with levetiracetam, with outpatient follow-up.
Outcomes:
No further seizures were recorded and the patient recovered well.
Lessons:
MELAS syndrome without stroke-like episodes of diffuse posterior cerebral white matter lesions is rare in clinical practice, and the possibility of MELAS syndrome should be considered in symmetric posterior cerebral white matter lesions.
Insights
Mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) can present with white matter lesions without typical stroke-like episodes. This case highlights MELAS syndrome in a patient with diffuse posterior cerebral white matter lesions, emphasizing diagnostic considerations.
Area of Science:
- Neurology
- Genetics
- Neuroimaging
Background:
- Mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) is a common mitochondrial disease.
- White matter lesions are increasingly recognized in mitochondrial diseases, not solely in lysosome or peroxisome disorders.
- Approximately 50% of MELAS patients exhibit white matter lesions, alongside stroke-like episodes.
Observation:
- A 48-year-old female presented with loss of consciousness and extremity twitching, with a history of epilepsy and diabetes.
- Brain MRI revealed symmetrical high-intensity lesions in the bilateral parietal and occipital lobes, consistent with white matter abnormalities.
- Genetic analysis identified the A3243G point mutation in mitochondrial DNA, confirming MELAS syndrome.
Findings:
- The patient received symptomatic treatment including mechanical ventilation, antiepileptics, and supportive care with vitamins and coenzyme Q10.
- Following treatment, seizure activity ceased, and the patient showed clinical improvement.
- The case demonstrated MELAS syndrome presenting with diffuse posterior cerebral white matter lesions without overt stroke-like episodes.
Implications:
- This case underscores the importance of considering MELAS syndrome in patients with unexplained symmetric posterior cerebral white matter lesions.
- Early diagnosis and appropriate management, including antioxidant therapy, can lead to improved patient outcomes.
- Further research into the diverse clinical manifestations of MELAS syndrome is warranted.
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