MRI IN PAEDIATRIC INHERITED METABOLIC BRAIN DISORDERS

AIMS AND OBJECTIVES To emphasize the role of MRI in paediatric inherited metabolic brain disorders and to study the varied spectrum of imaging findings in these disease entities and to highlight the importance of image based classification. MATERIALS AND METHODS In this study, we reviewed MRI of the brain of 26 paediatric patients (17 male, 9 female; mean age: 7 years, range: 1 month - 15 years) with neurological complaints and had clinical suspicion of inherited metabolic brain disorder on MRI. MRI sequences reviewed included axial T1-, T2-weighted, FLAIR, diffusion weighted and sagittal and coronal T2 weighted images. Post-gadolinium T1-weighted and MR Spectroscopy images were also reviewed when available. MRI findings were interpreted in conjunction with clinical and laboratory findings wherever necessary. The varied spectrum of imaging appearances of paediatric inherited metabolic brain disorders noted by methodological and practical image based approach. RESULTS The distribution of the various inherited metabolic disorders was as follows: 13 cases of Leigh's disease, 4 cases of Metachromatic Leukodystrophy, 2 cases of Pantothenate Kinase Deficiency, 2 cases of Gangliosidosis, 2 cases of Wilson's disease, one case of Alexander's disease, one case of Canavan's disease, one case of Glutaric aciduria diagnosed from the image based pattern in conjunction with the clinical data. Based on the pattern of brain involvement on MRI, these disorders were classified into three categories: disorders with predominant white matter involvement, disorders with predominant gray matter involvement and disorders with involvement of both gray and white matter. There were characteristic metabolic peaks on MRS in cases of Leigh's disease and Canavan's disease. CONCLUSION An image based approach to paediatric inherited metabolic brain disorders helps in diagnosis of varied presentation and knowledge of this practical approach is very useful to the radiologist.