What Causes Microcephaly?

Discussion Microcephaly is usually defined as an occipitofrontal head circumference (OFC) more than 2 standard deviations (SD) below the mean for sex, age and ethnicity. Severe microcephaly is used for OFC < 3 standard deviations. Rates of microcephaly range from 0.5-12 patients/10,000 live births. The OFC should be measured at every well child visit and at other opportunities and plotted on standard growth charts. The OFC is measured using a nonelastic tape measure around the largest part of the head with the tape measure held above the eyebrows and ears. It is a highly reproducible measurement. There are several different international standard growth charts that can be used and those used should reflect the population the patient is drawn from the best. For example, the World Health Organization has growth charts taken from the children in the countries of Brazil, Ghana, India, Oman and the USA (www.who.int/childgrowth/en). In industrialized countries the OFC is larger and may not be as accurately reflected using the WHO chart. Some researchers prefer the Centers for Disease Control growth charts as an industrialized country standard (www.cdc.gov/growthcharts/) While the OFC reflects the skull size and growth over time, the main determinant of normal growth of the skull is the brain and therefore, the OFC is considered a marker of brain growth. However, the extent of the microcephaly does not significantly correlate with the degree of developmental delay. There are d...
Source: PediatricEducation.org - Category: Pediatrics Authors: Tags: Uncategorized Source Type: news