ICD-11

A disease caused by failure of the brain to correctly develop during the antenatal period. This condition is characterised by a rapid increase in head circumference or an unusually large head size due to excessive accumulation of cerebrospinal fluid in the brain. This condition may also present with vomiting, sleepiness, irritability, downward deviation of the eyes, or seizures. Confirmation is through observation of cerebrospinal fluid within cerebral ventricles by imaging.

Hydrocephalus with stenosis of aqueduct of Sylvius (HSAS) or Bickers-Adams syndrome is characterised by the association of hydrocephaly, severe intellectual deficit, spasticity and adducted thumbs, and is part of the L1 syndrome (see this term).