Abstract
Laminar cortical necrosis has been described in many conditions of cellular energy
depletion, such as hypoxia and hypoglycemia. In MELAS, a genetic defect in mitochondrial
protein synthesis leads to impairment of oxidative phosphorylation, with subsequent
insufficient energy production within the cell. Neurons are more vulnerable to energy
depletion than glial cells and vascular elements, and among the layers of the cerebral
cortex the lower laminae are more vulnerable than the superficial layers.
We studied a child with severe MELAS syndrome two months before death with MR and
compared the images to autopsy findings, including macroscopic specimens and light
and electron microscopy. The MR images showed an excellent correlation with the neuropathological
results and displayed the various degrees of damage to the brain tissue caused by
deficient energy production. Acute laminar cortical necrosis was seen as swelling
of the cortex with intracortical hyperintense bands in T2-weighted images. The subacute stage with focal cortical hemorrhage was displayed
as hyperintensity of the gyral surface in T1-weighted and hypointensity in T2-weighted images, with T2-hyperintensity and swelling of the rest of the cortex and underlying white matter.
Severe cortical atrophy represented the chronic stage.
Key words
Laminar cortical necrosis - MELAS - Mitochondrial disorders
