Case report: neuroimaging analysis of pediatric ADHD-related symptoms secondary to hypoxic brain injury.

A 2-year-old male pediatric patient experienced a partial occlusion of the internal carotid and subsequent asphyxiation resulting in hypoxic brain injury that was later misdiagnosed as primary attention deficient hyperactivity disorder (ADHD). Imaging analyses using diffusion tensor imaging (DTI), positron emission tomography (PET), and magnetic resonance imaging (MRI) quantitative volumetrics (QV) were used nine years following the incident to identify whether his development of ADHD is of a primary heritability or secondary hypoxic brain injury sequelae. The patient's DTI analysis generated decreases in fractional anisotropy (FA) values in the anterior corpus callosum, bilateral internal capsule, and hippocampus. Decreases in FA are seen in ADHD patients, but the degree of FA decrease in the patient under study is several orders of magnitude greater than in ADHD patients. Also, not normally observed in ADHD patients were decreases in the metabolism of the orbitofrontal cortex, anterior cingulate, left anterior insular cortex, and left striatum. Additionally, QV showed enlargements of various regions of the brain including the amygdala which is often cited in the literature to be reduced in ADHD patients. The diagnosis of this patient despite having non-characteristic neuroimaging data suggests a unique specificity of the hypoxic injury to the development of a secondary hypoxic brain injury caused ADHD.