Mitochondrial Encephalomyopathies in Children. Part I: Conventional MR Imaging Findings

Background and Purpose: Mitochondrial encephalomyopathies (ME) may promote many brain abnormalities that can be detected with advanced neuroradiologic tools. The aim of this first of two reports is to evaluate if there are representative neuroradiological patterns of the most common ME disorders affecting children. Methods: Non-selected longitudinal study in 55 patients over 15 years. All of them underwent one or more MR imaging studies. Five different patterns of imaging involvement were proposed: 1-Myelinization delay and atrophy, 2-Gray nuclei involvement, 3-Leukodystrophyc pattern, 4-Menke's pattern, and 5-Others. Results: Leigh's disease (LD): 19 (34.5%), Alper's disease (AD):12 (22.18%), Kearns-Sayre syndrome (KSS): 3 (5.4%); Menkes and Menkes-like diseases and variants: 4 (9%), others: 17 (30.9%). On imaging grounds, there were statistical association between the main syndromes and the patterns proposed. Conclusion: MRI imaging shows non-specific features in about one third of the patients, whereas the other two third are associated with some few characteristic neuroradiologic-phenotypes proposed. Although these findings are not pathognomonic they provide a guide in imaging approach for children suspected of ME.