Abnormalities in Head Size

Online Mendelian Inheritance in Man, OMIM™. McKusick-Nathans Institute for Genetic Medicine, Johns Hopkins University (Baltimore, Md) and National Center for Biotechnology Information, National Library of Medicine (Bethesda, Md), 2000. Available at: http://www.ncbi.nlm.nih.gov/omim/CDC Growth Charts: United States. Kuczmarski RJ, Ogden CL, Grummer-Strawn LM, et al. Advance Data from Vital and Health Statistics. No. 314. Hyattsville, Md: National Center for Health Statistics; 2000. Available at: http://www.cdc.gov/growthchartsDisorders of Cranial Volume and Shape. In: Fenichel GM. Clinical Pediatric Neurology: A Signs and Symptoms Approach. Philadelphia, Pa: Elsevier Saunders; 2005: 353–369Perspectives on Craniosynostosis. Cohen M. Am J Med Genet. 2005; 136A:313– 326OpenUrlMolecular Genetics of Human Microcephaly. Mochida GH, Walsh CA. Curr Opin Neurol. 2001;14 :151– 156OpenUrlCrossRefPubMedThe Infant Skull: A Vault of Information. Glass RBJ, Fernbach SK, Norton KI, Choi PS, Naidich TP. Radiographics. 2004;24 :507– 522OpenUrlCrossRefPubMedSmith’s Recognizable Patterns of Human Malformation. Jones KL. 6th ed. Philadelphia, Pa: Elsevier Saunders; 2006

Measuring the head circumference is an important element of the pediatric physical examination, especially in the first 3 years after birth, when brain growth is maximal. A series of measurements over time is more instructive than a single measurement, which can, however, still provide useful information. For example, an abnormal head circumference at birth is a clue to an early prenatal effect. A head circumference more than 3 standard deviations below or above the mean almost always is associated with some degree of neurologic impairment. Measurements are plotted on standardized charts. The latest Centers for Disease Control and Prevention growth charts feature curves for 3rd and 97th percentiles, which are important cut-offs in the measurement of head circumference. Special charts are available for children who have conditions associated …