MELAS

  • Acronym: mitochondrial encephalopathy, lactic acidosis, stroke-like episodes
  • Due to mitochondrial DNA mutation
  • Stroke like symptoms, encephalopathy, seizures, myopathy
  • Lactic acid in CSF
  • Ragged red fibres on muscle biopsy
Imaging
  • MRI
    • Cortico-subcortical T2 hyperintensities in parietal, temporal and occipital lobes
    • Topography does not correspond to single vascular territory
    • Cortical and leptomeningeal contrast enhancement
    • DWI – restriction or increased diffusion depending on phase of lesions
    • Spectroscopy – lactate peak in lesions, in normal appearing brain areas and in CSF of lateral ventricles
  • CT
    • Bilateral basal ganglia calcifications
Read more

Cheon, Jung-Eun, et al. “Leukodystrophy in children: a pictorial review of MR imaging features.” Radiographics 22.3 (2002): 461-476.

Saenz, Rocky C. “The disappearing basal ganglia sign.” Radiology 234.1 (2005): 242-243.