(Arthur Earl Walker, 20th century, American surgeon; Mette Warburg, 20th century, Danish ophthalmologist), a syndrome in which there is an association of eye malformation, lissencephaly and cerebellar dysgenesis, particularly vermian, hypoplasia or agenesis. The eye anomalies are microphthalmic, and oculomotor apraxia. There is hydrocephalus and a posterioir cephalocele. Affected children may not have complete expression. On MR imaging the sulci are shallow, the ventricles are enlarged, there is callosal dysgenesis and vermian hypoplasia.