RESUMO
Regional anatomical structures of the brain are intimately connected to functions corresponding to specific regions and the temporospatial pattern of genetic expression and their functions from the fetal period to old age. Therefore, quantitative brain morphometry has often been employed in neuroscience investigations, while controlling for the scanner effect of the scanner is a critical issue for ensuring accuracy in brain morphometric studies of rare orphan diseases due to the lack of normal reference values available for multicenter studies. This study aimed to provide across-site normal reference values of global and regional brain volumes for each sex and age group in children and adolescents. We collected magnetic resonance imaging (MRI) examinations of 846 neurotypical participants aged 6.0-17.9 years (339 male and 507 female participants) from 5 institutions comprising healthy volunteers or neurotypical patients without neurological disorders, neuropsychological disorders, or epilepsy. Regional-based analysis using the CIVET 2.1.0. pipeline provided regional brain volumes, and the measurements were across-site combined using ComBat-GAM harmonization. The normal reference values of global and regional brain volumes and lateral indices in our study could be helpful for evaluating the characteristics of the brain morphology of each individual in a clinical setting and investigating the brain morphology of ultra-rare diseases.
RESUMO
PURPOSE: Acute excitotoxic encephalopathy is the most common encephalopathy syndrome in Japan, and consists of acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) and mild encephalopathy associated with excitotoxicity (MEEX). Neurological sequelae remain in approximately 70% of patients with AESD, however, it is difficult to predict the prognosis early in the course. We evaluated the brain metabolites observed on MRS as to whether they can predict the neurological outcome. METHODS: 16 previously healthy Japanese patients with excitotoxic encephalopathy (8 with AESD and 8 with MEEX) were included in this study. MR spectroscopy (MRS) was acquired from the fronto-parietal white matter (TR/TE = 5000/30 msec) with a 3.0 T scanner. Quantification of metabolites was performed using an LCModel. Neurological outcome was assessed with the Pediatric Cerebral Performance Category score, score 1 being classified as G1 (normal), scores 2 and 3 as G2 (mild to moderate), and scores 4-6 as G3 (severe). RESULTS: MRS data which predict a poor neurological outcome (G2 and 3) include the following: decreased N-acetyl aspartate (NAA) (sensitivity 88%, specificity 100%), decreased creatine (47%, 100%), increased lactate (47%, 100%), and decreased glutamate (sensitivity 35%, specificity 100%). Limited to the acute stage within seven days of onset, those for a poor prognosis are as follows, decreased NAA (88%, 100%), decreased creatine (38%, 100%), and increased lactate (38%, 100%). CONCLUSION: MRS is useful for prognosis prediction of acute excitotoxic encephalopathy. Decreased NAA will be the most effective metabolite for neurological prognosis prediction.