We used voxel-based morphometry (VBM) with magnetic resonance imaging to investigate gray matter (GM) and white matter (WM) volume reductions in four MELAS patients and in five A3243G carriers compared to 16 healthy controls. In addition, we investigated the regions of previous SEs using conventional MRI.
All four MELAS patients showed significant GM volume reductions in the left superior parietal lobule (SPL), right precuneus, right middle temporal gyrus (MTG), and bilateral posterior lobes of the cerebellum. These areas of GM volume reduction were beyond the regions of previous SEs. As for A3243G carriers, GM volume reductions in the left SPL, right precuneus, right MTG, and bilateral posterior lobes of the cerebellum were detected in three, one, two, and five subjects, respectively. All four MELAS patients showed significant WM volume reductions in the bilateral or unilateral temporal sub-gyral regions, which were included in the regions of previous SEs. No A3243G carriers showed WM volume reductions.
The distribution patterns of GM volume reductions in VBM may reflect a common vulnerability of the brains among MELAS patients and A3243G carriers.