Hydrocephalus with stenosis of the aqueduct of Sylvius

**Definition:** 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).

**Inclusions:** - Stenosis of the aqueduct of Sylvius