PICTORIAL INTERLUDE Colpocephaly vale. Hence the secondary dilatation Nicky Wieselthaler MB chá FCRad (D) FCRC (Lond) of the occipital horns. This abnormal- ity is thought to occur at 1 - 4 months' Savvas Andronikou gestation. I MB ChB, FCRad(D), FRCR (Lond) Associated CNS abnormalities Department of Paediatric Radiology Red Cross War Memorial Childrens Hospital include corpus callosum agenesis, University of Cape Town and Institute of Child neuronal migration disorders Health (lissencephaly, pachygyria), schizen- cephaly, microcephaly, meningomye- locoele and hydrocephalus. In corpus Fig. 1. Axial non-contrast CT scan of a chI/d's brain Colpocephaly was first described callosum agenesis often associated with corpus cal/osum agenesis shows the di/ated occipital horns of colpocephaly. The ventricles are by Benda in 1940 and termed vesicu- with Chiari II malformation the ven- also widely spaced and pointed anteriorly. locephaly but was renamed tricles are also widely spaced, parallel colpocephaly by Yakovlev and and pointed anteriorly. Wadsworth in 1946. The clinical features may include The diagnosis of colpocephaly is Colpocephaly is a congenital learning disability, seizures, spasticity, made on cr,MRI or ultrasound (Fig.l). enlargement of the occipital horns of hypotonia and visual abnormalities. the lateral ventricles. This is caused by It has been postulated that certain References a global impairment in brain develop- aetiologies may predispose to l. Cerullo A, Marini C, Ceroli S, Carelli V, ment with aberrant migration of neu- Montagna P, Tinuper P. Colpocephaly in two colpocephaly. These are intra-uterine siblings: Further evidence of a genetic transmis- roblasts resulting in a decreased thick- infection, IUGR, perinatal anoxic sion. Dev Med Child NeuroI2000; 42: 280-282. ness of cerebral white matter in the 2. Noorani P, Bodensteiner J, Barnes P. ischaemie encephalopathy, maternal Colpocephaly: Frequency and associated find- posterior part of the sentrum semio- drug ingestion and trisomy 8 and 9.2 ings. J Child Ne!lroI1988; 3: 100-104. 49 SA JOURNAL OF RADIOLOGY • March 2002.