Do not Forget to Measure the Head: Hydrocephalus Can Phenotypically Mimic Developmental Coordination Disorder.

Developmental Coordination Disorder (DCD) is a neurodevelopmental condition presenting with poor motor skill development and impaired coordination at a young age. To diagnose DCD, neurologic conditions explanatory for the phenotype, including structural brain abnormalities like hydrocephalus, must be first ruled out. However, these neurologic conditions may phenotypically mimic DCD, which can hamper their distinction. In this article, we report a patient in whom the initial diagnosis of DCD was withdrawn after the identification of acquired hydrocephalus. An important cue in this case was secondary macrocephaly (from +0.00 to +2.25 standard deviations over approximately 6 years' time). This case illustrates that, in children whose phenotypes seemingly fulfill the DCD criteria, it is important to rule out an underlying, treatable etiology before making the diagnosis of DCD. Since few structural brain abnormalities mimicking DCD may present with macrocephaly, including hydrocephalus, performing longitudinal head circumference measurements can be useful to timely identify these neurologic conditions.