Brain Magnetic Resonance Imaging in Organic Acidemias: A Single Center Experience

Abstract

Background: Organic acidemias (OAs) are a group of inherited diseases with a defect of amino acid metabolism, unless treatment is initiated early in life, they cause serious central nervous system (CNS) complications as seizures, encephalopathy and others. Pre-symptomatic diagnosis is achieved within neonatal screening programs, otherwise the diagnosis is delayed and challenging. Aim of work:To search for a specific magnetic resonance imaging (MRI) diagnostic finding common to OAs. Material and Methods: This cross-sectional descriptive study included 42 children with confirmed organic acidemias following up at the Neurometabolic Clinic at Center for Social and Preventive Medicine, Pediatric Hospitals, Cairo University, Egypt. MRI brain scans were performed on a (1.5 T Aera machine). Results:The study included 42 children with a median age of 36 months. Of them 29 (69%) were males and 13 (31%) were females, with male to female ratio of 2.23:1. Glutaric academia type 1 was confirmed in 26 (61.9%) followed by methylmalonic academia in 7 (16.67%), isovaleric academia in 3 (7.14%), propionic academia in 3 (7.14%), pyroglutamic academia in 2 (4.76%) and D2 hydroxy glutaric acidemia in 1 (2.38%). Abnormal signal in basal ganglion was encountered in 20 (47.6%), followed by cortical atrophy in 11 (26.2%), white matter changes in 11 (26.2%), temporal lobe hypovolemia in 10 (23.8%), ventricular dilatation in 6 (16.7%), arachnoid cyst in 4 (9.5%), normal MRI brain in 3 (7.1%) and encephalomalacia in 2 (4.8%). No specific imaging finding was associated with OAs or its type. Conclusion: MRI findings of brain are common but not unique in organic acidemias or its types, but is not sensitive or specific. Normal MRI brain does not exclude the diagnosis of OAs.