OBJECTIVETo study the characteristics of spectra on proton magnetic resonance spectroscopy (1H-MRS) and its value in patients with mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS).

METHODSSeven clinically diagnosed patients with MELAS underwent magnetic resonance imaging (MRI) and 1H-MRS examinations. The 1H-MRS techniques, characteristics of the spectra, and its correlation with the laboratory tests were analyzed.

RESULTSCerebral abnormalities were revealed in all 7 patients on conventional MR images, and most abnormal signals were observed in bilateral occipital, parietal, and temporal lobes. We found 4 cases with basal ganglia involvement, 2 cases with mild frontal lobe lesions, and 1 case with involvement of lateral cerebral peduncles and thalami. Additionally, 1 patient was involved with left insular lobe. Spectra from prominent lesions in brain parenchyma showed lactate doublet peak in 6 patients, 3 of whom were also noted lactate peak in ventricular cerebrospinal fluid (CSF).

CONCLUSION1H-MRS may provide more direct information about the metabolism changes, which aids to affirm the diagnosis, and may replace the conventional invasive method of quantifying lactate in CSF.

Adolescent ; Adult ; Basal Ganglia ; pathology ; physiopathology ; Cerebral Cortex ; pathology ; physiopathology ; Child ; Female ; Humans ; Lactic Acid ; metabolism ; MELAS Syndrome ; diagnosis ; physiopathology ; Magnetic Resonance Imaging ; Magnetic Resonance Spectroscopy ; Male ; Parietal Lobe ; pathology ; physiopathology

This study was conducted to investigate the etiology, the clinical characteristics and prognosis of acute necrotizing encephalopathy (ANE) in Korean children. Six children (1 yr to 7 yr) patients with ANE were enrolled. They were diagnosed by clinical and radiological characteristics and their clinical data were retrospectively analyzed. In a search of clinically plausible causes, brain MRI in all patients, mitochondrial DNA studies for mitochondrial encephalomyopathy, lactic acidosis, and strokelike episodes (MELAS) and myoclonus epilepsy and ragged red fibers (MERRF) in four patients, and genomic typing on HLA DRB/HLA DQB genes in three patients were performed. All had precedent illnesses and the main initial symptoms included mental change (83%), seizures (50%), and focal deficits (50%). MRI revealed increased T2 signal density in the bilateral thalami and/or the brainstem in all patients. Mitochodrial DNA studies for MELAS and MERRF were negative in those children and HLA-DRB1*1401, HLA-DRB3*0202, and HLA-DQB1*0502 seemed to be significant. A high dose steroid was given to all patients, which seemed to be partly effective except for 2 patients. In conclusion, ANE is relatively rare, but can result in serious neurological complication in children. Early detection and appropriate treatment may lead to a better neurological outcome.
Child ; Child, Preschool ; Female ; HLA-DQ Antigens/metabolism ; HLA-DQ beta-Chains ; HLA-DR Antigens/metabolism ; HLA-DRB1 Chains ; HLA-DRB3 Chains ; Humans ; Infant ; Korea ; Leukoencephalitis, Acute Hemorrhagic/diagnosis/etiology/*pathology/*physiopathology ; MELAS Syndrome/pathology/physiopathology ; MERRF Syndrome/pathology/physiopathology ; Magnetic Resonance Imaging ; Male ; Prognosis ; Retrospective Studies