Brain Magnetic Resonance Imaging of Children With Molybdenum Cofactor Deficiency

Molybdenum cofactor deficiency (MoCD) is a rare differential diagnosis of neonatal hypoxic ischemic encephalopathy (HIE) with considerable variation in presentation and treatment outcomes. The temporospatial evolution of brain MRI appearances has not been well described. We systematically evaluated 35 MRI brain scans of 13 patients with neonatal MoCD (7 type A, 6 type B) to characterize brain abnormalities arising from exposure to toxicity related to sulfite accumulation and to evaluate changes in response to cPMP treatment in 6 children with MoCD type A. All cases showed evidence of chronic toxicity with developmental disruption. We identified a disease-specific pattern of acute and chronic brain injury, distinct from HIE. White matter edema, as the earliest sign of sulfite-related toxicity, indicates a reversible disease stage. The presence of restricted diffusion in the context of MoCD signifies irreversible brain injury and a poor neurological prognosis, irrespective of subsequent biochemical correction upon cPMP treatment. This is the largest neuroimaging study of children with MoCD and the first longitudinal study to examine MR imaging changes in MoCD type A under cPMP substitution. Neuroimaging can identify diagnostic and prognostic features with relevance for treatment decisions and for the evaluation of the effectiveness of treatment attempts.