Microcephaly

Microcephaly is a term that describes head circumference as equal or more than two standard deviations below the mean for gender and age. In plain words, it can be defined as a head size smaller than average for age and sex. Either due to abnormalities in brain development hindering the brain from reaching its full size or sudden stoppage of brain growth for many reasons. Congenital microcephaly is present at birth, whereas postnatal microcephaly occurs later in life. Genetic abnormalities, syndromes, metabolic disorders, teratogens, infections, prenatal, perinatal, and postnatal injuries can cause both congenital and postnatal microcephaly. If microcephaly is associated with other congenital defects, it is classified as syndromic microcephaly; if not, then it is isolated microcephaly. The approach to the patients with microcephaly starts with a thorough history and physical examination, additionally, further studies and workup should be conducted and directed by the presence of signs or symptoms found by history and exam pointing towards an underlying etiology and are usually used as confirmatory tests for a certain condition. Lately, genetic studies are becoming more commonly used for diagnosis following neuroimaging when there is no specific evidence in the history or physical examination suggesting a diagnosis. The prognosis of microcephaly is usually worse for children who have an intrauterine infection or have a chromosomal or metabolic abnormality. Many complications and problems may be present in children with microcephaly, which are usually life-long, so early diagnosis and interventions might attenuate these sequences and improve the life quality of the affected child.