Objective: To determine if the degree of congenital, idiopathic microcephaly in a female infant was congruent with the degree of developmental motor delay she exhibited.
Methods: A 6.5-month-old female infant with idiopathic microcephaly was referred for evaluation due to parental concerns about possible cerebral palsy. She was assessed with two standardized tests: the Motor Scale of the Bayley-II Scales of Infant Development and the Harris Infant Neuromotor Test.
Results: The infant scored 2.3-2.6 SD (standard deviation) from the mean on both tests, a degree of developmental delay that was reasonably consistent with the degree of microcephaly (2.0 SD below the mean).
Conclusion: These findings highlight the importance of head circumference measurements, even in infants with no known risks for microcephaly, and the need to conduct standardized developmental assessments in infants with head sizes ≥2 SD below the mean.