CONGENITAL ANOMALIES OF THE HEAD & NECK
Written by Rhiana Devadasan
HEAD
Macrocephaly
Definition = abnormally large head circumference (greater than the 98th percentile)
Types:
- Disproportionate macrocephaly – the head is larger than appropriate for the child's size. It is a clinical indicator of autism spectrum disorders, developmental disabilities and seizures.
- Proportionate macrocephaly – the head appears appropriately sized for the body (large head + large stature). An overgrowth syndrome (e.g. growth hormone excess) should be considered.
Microcephaly
Definition = abnormally small head circumference (less than 2 SD below average)
Normally due the brain not developing properly during pregnancy, or one that has stopped growing after birth.
Causes:
- Prenatal drug, alcohol, toxin or radiation exposure
- Prenatal infections
- Uncontrolled maternal phenylketonuria
Craniosynostosis
Definition = premature fusion of one or more calvarial sutures, causing characteristic skull deformity.
Effects:
- problems with normal brain and skull growth.
- may cause the pressure inside the head to increase & the skull/facial bones to change from a normal, symmetrical appearance.
Types:
- Saggital craniosynostosis - most common type, causes a narrow & long skull (dolichocephaly), learning disability may be present.
- Coronal craniosynostosis - can be bilateral, causing a short & broad skull (brachycephaly), or unilateral, causing a diagonal skull deformity (plagiocephaly)