: 1H-MR spectroscopic and SPECT findings in a patient with MELAS syndrome confirmed by molecular genetic analysis

ABSTRACT

An eighteen-year-old girl presented recurrent partial and generalized seizures associated with the T-2 high signal intensities of MR brain imaging. Serum and CSF lactate levels were elevated. Muscle biopsy revealed "ragged red fiber" . The diagnosis of MELAS was confirmed by molecular genetic analysis showing 3,243 mtDNA point mutation. Localized proton MR spectroscopy was performed on a GE 1.5 T SIGNA MRI/MRS system and analyzed by STEAM (Stimulated Echo Acquisition Method). 1H-MR spectrocopy demonstrated elevation of lactate contents and decrease of N-acetyl aspartate contents in the involed area. The Tc99m-ECD SPECT revealed multifocal decrease of perfusion in bilateral parietal, temporal and occipital lobe, especially right temporal and left occipital lobe. These features suggest that the pathology of brain lesions of MELAS syndrome may be sub-necrotic incomplete ischemic changes caused by metabolic derangement.