Agenesis of the corpus callosum

Abstract

Agenesis of the corpus callosum is an uncommon congenital anomaly which causes dilatation of the posterior horns of the lateral ventricles and a falsely high ventricular/hemispheric ratio on antenatal ultrasound scans with an incidence on studies of air encephalograms of 0.7% (Grogono, 1968). It may be confused with hydrocephalus and lead to unnecessary intervention. The characteristic features on both ante- and postnatal ultrasound are: (1) Absence of the corpus callosum. (2) Marked separation of the slit-like anterior horns of the lateral ventricles and dilatation of the posterior and inferior horns creating the typical “rabbit's ear” or “devil's horn” appearance. (3) Visualization of both medial and lateral walls of the anterior horns of the lateral ventricles which are displaced from the midline. (4) Variable dorsal and superior displacement of the third ventricle. (5) Loss of the normal parallel sulcal pattern above the third ventricle. A case of congenital absence of the corpus callosum is described and the ante-natal ultrasound, post-natal ultrasound and computed tomography (CT) appearances are demonstrated.

Assessment and management of fetal agenesis of the corpus callosum

“…The prognosis of cases with associated anomalies is very poor. Secondly, it is important to recognize that the sonographic appearance of ACC may be very similar to that of uncomplicated ventriculomegaly, as the most striking finding is the enlargement of the occipital horns and atria resulting in the 'tear-drop' configuration (Pilu et al, 1993;Warren and Cook, 1993). Approximately 3 per cent of all fetuses with ventriculomegaly (Filly et al, 1988) and almost 10 per cent of those with mild ventriculomegaly (Goldstein et al, 1990) are noted to have ACC.…”

Tomografia computadorizada na agenesia do corpo caloso: achados em 27 casos

“…O significado clínico da agenesia isolada do corpo caloso é de menor importância, porque sua ausência é compensada por conexões não-calosas, desenvolvimento bilateral de funções específicas e pela utilização de vias sensoriais somáticas ipsilaterais 11,16 . A condição é usualmente identificada incidentalmente durante a investigação de outras anomalias e são estas que, quando presentes, darão os sintomas de epilepsia, problemas neurológicos e atraso do desenvolvimento 16,10 .…”

“…A condição é usualmente identificada incidentalmente durante a investigação de outras anomalias e são estas que, quando presentes, darão os sintomas de epilepsia, problemas neurológicos e atraso do desenvolvimento 16,10 . A idade do diagnóstico em nossos pacientes variou de 23 dias a 33 anos, demonstrando a variabilidade das manifestações clínicas e suas intensidades.…”

Agenesis of the corpus callosum: female monozygotic triplets

“…11,22 The formation of the corpus callosum begins approximately the 12th week of gestation and is complete at 20 weeks of gestation. 11,23 Four main theories have been proposed to explain the etiology of agenesis of the corpus callosum. Classic agenesis of the corpus callosum is thought to occur because of failure of the callosal fibers to cross the midline.…”