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Vascular involvement in the pathogenesis of mitochondrial encephalomyopathies

Zai-Qiang Zhang1, Song-Tao Niu, Xian-Hong Liang

  • 1Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing 100050, China.

Neurological Research
|May 21, 2010
PubMed
Abstract

Insights

This study reveals that individuals with myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) exhibit reduced cerebral blood flow and volume. Muscle vessel pathology also indicates a role for vasculopathy in MELAS pathogenesis.

Area of Science:

  • Neurology
  • Mitochondrial Diseases
  • Neuroimaging

Background:

  • Mitochondrial encephalomyopathies, such as MELAS, are characterized by stroke-like episodes.
  • The underlying pathogenesis involving cerebral perfusion and vascular pathology requires further elucidation.

Purpose of the Study:

  • To investigate cerebral perfusion abnormalities using CT perfusion imaging in acute MELAS.
  • To examine muscle vessel pathology to understand the role of vasculopathy in MELAS.

Main Methods:

  • Computed tomography perfusion (CTP) imaging was used to assess brain perfusion during symptomatic MELAS episodes.
  • Muscle biopsy samples were analyzed using light and electron microscopy to evaluate blood vessel wall mitochondria.

Main Results:

  • MELAS patients showed hypo-perfusion in affected brain regions (occipital, temporal-parietal lobes) with decreased cerebral blood flow and volume.
  • Prolonged mean transit time and time to peak were observed in both lesional and non-lesional brain areas.
  • Muscle vessel pathology revealed mitochondrial proliferation and granular deposits on the vessel wall.

Conclusions:

  • Reduced cerebral perfusion and vascular reserve, coupled with metabolic dysfunction, are significant factors in MELAS stroke-like episodes.
  • Vasculopathy and ischemic events are implicated in the pathogenesis of mitochondrial encephalomyopathies.

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