PICTORIAL INTERLUDE

Colpocephaly

Nicky Wieselthaler
MB chá FCRad (D) FCRC (Lond)

Savvas Andronikou
MB ChB, FCRad(D), FRCR (Lond)

Department of Paediatric Radiology
Red Cross War Memorial Childrens Hospital

University of Cape Town and Institute of Child
Health

Colpocephaly was first described
by Benda in 1940 and termed vesicu-
locephaly but was renamed
colpocephaly by Yakovlev and
Wadsworth in 1946.

Colpocephaly is a congenital
enlargement of the occipital horns of
the lateral ventricles. This is caused by
a global impairment in brain develop-
ment with aberrant migration of neu-
roblasts resulting in a decreased thick-
ness of cerebral white matter in the
posterior part of the sentrum semio-

vale. Hence the secondary dilatation
of the occipital horns. This abnormal-
ity is thought to occur at 1 - 4 months'
gestation. I

Associated CNS abnormalities
include corpus callosum agenesis,
neuronal migration disorders
(lissencephaly, pachygyria), schizen-
cephaly, microcephaly, meningomye-
locoele and hydrocephalus. In corpus
callosum agenesis often associated
with Chiari II malformation the ven-
tricles are also widely spaced, parallel
and pointed anteriorly.

The clinical features may include
learning disability, seizures, spasticity,
hypotonia and visual abnormalities.

It has been postulated that certain
aetiologies may predispose to
colpocephaly. These are intra-uterine
infection, IUGR, perinatal anoxic
ischaemie encephalopathy, maternal
drug ingestion and trisomy 8 and 9.2

Fig. 1. Axial non-contrast CT scan of a chI/d's brain
with corpus cal/osum agenesis shows the di/ated
occipital horns of colpocephaly. The ventricles are
also widely spaced and pointed anteriorly.

The diagnosis of colpocephaly is
made on cr,MRI or ultrasound (Fig.l).

References
l. Cerullo A, Marini C, Ceroli S, Carelli V,

Montagna P, Tinuper P. Colpocephaly in two
siblings: Further evidence of a genetic transmis-
sion. Dev Med Child NeuroI2000; 42: 280-282.

2. Noorani P, Bodensteiner J, Barnes P.
Colpocephaly: Frequency and associated find-
ings. J Child Ne!lroI1988; 3: 100-104.

49 SA JOURNAL OF RADIOLOGY • March 2002