Imaging the Future: Diagnosing Treatable Neurometabolic Disorders in Children

Inborn errors of metabolism are a prevalent cause of pediatric neurological abnormalities, often resulting from enzyme deficiencies that disrupt metabolic pathways. Understanding the radiological manifestations of these disorders is critical for timely diagnosis and therapy. This study aimed to elucidate the magnetic resonance imaging (MRI) brain characteristics and magnetic resonance spectroscopy (MRS) findings of specific treatable pediatric neurometabolic disorders through clinical vignettes, thereby enhancing diagnostic accuracy and informing therapeutic approaches. The study includes four cases with varying presentations, all confirmed by genetic testing, and utilized magnetic resonance imaging and spectroscopy to identify characteristic features. The first case, diagnosed as thiamine metabolism dysfunction syndrome type 4, exhibits bilateral corpus striatum T2 hyperintensities with diffusion restriction on MRI brain, increased lactate peak, and reduced N-acetylaspartate (NAA) on magnetic resonance spectroscopy (MRS), and SLC25A19 gene mutation on genetic analysis - features consistent with biotin-thiamine-responsive basal ganglia disease. The second case, identified as thiamine metabolism dysfunction syndrome type 2, reveals T2 hyperintensities in the bilateral corpus striatum, medial thalami, and cerebellar white matter, along with restricted diffusion, reduced NAA, and an inverted lactate doublet on MRS, with genetic analysis confirming an SLC19A3 mutation, also falling under the spectrum of biotin-thiamine-responsive basal ganglia disease. The third case, representing cerebral creatine deficiency syndrome type 2, demonstrates bilateral symmetric T2 hyperintensities in the globus pallidus and central tegmental tracts, a characteristic absence of a creatine peak on MRS, and a confirmed guanidomethyl transferase (GAMT) deficiency gene mutation. The fourth case, diagnosed as hypermanganesemia with dystonia type 2, is characterized by T1 hyperintensity and T2 hypointensity involving the bilateral globus pallidi, substantia nigra, and dentate nuclei, with genetic testing revealing an SLC39A14 mutation. The study emphasizes the importance of MR imaging and spectroscopy in identifying pediatric neurometabolic diseases that can be treated.