The Experience of Hospital of Sick Children in Patients with Agenesis of Corpus Callosum: Neuroradiological and Clinical Evailuation (S25.004)

OBJECTIVE: To correlate the clinical findings and neuroradiological features of patients with corpus callosum abnormality. BACKGROUND: The corpus callosum is the largest interhemispheric fiber bundle in the brain. Agenesis of corpus callosum is a heterogeneous condition, which can be observed either as isolated condition or in the context of congenital syndrome. DESIGN/METHODS: A retrospective review to study patients with corpus callosum abnormality. 125 patients were included in the study. The following clinical variables were included: patient demographics, developmental delay, epilepsy, genetic etiology, microarray testing, etc. The neuroradiological variables included a new functional classification for callosal abnormalities: complete agenesis, anterior agenesis (rostrum, genu, body), posterior agenesis (isthmus, splenium), complete hypoplasia (thinning). We studied as well the presence and absence of extra callosal brain abnormalities. We used the SPSS version 17 to calculate proportions between the different variables. RESULTS: There is a significant proportion of patients having developmental delay, 78% had fine motor developmental delay, 76% had speech delay and 50% had behavioral issues. Visual impairment was found in 39%. 22% had microcephaly and 21% had macrocephaly. Final etiological diagnosis was reached in 43% of the patients while positive genetic testing was found in 27% of the patients. Microarray testing was done in 30% and it was positive in 39% of those tested. We found complete agenesis is the commonest type of callosal abnormality and epilepsy diagnosis was commonest among this group. The presence of extra callosal brain abnormality is around 60%, interestingly microarray testing yield was comparable between this group and patients with isolated callosal abnormality. CONCLUSIONS: Corpus callosum abnormality may be a common end phenotype and implicate multiple overlapping pathway in the etiology of corpus callosum abnormality. The functional classification system alone can not predict the functional outcome. The presence of extracallosal brain anomaly is not the only major predictive factor and probably underlying etiology has the major interplay. Disclosure: Dr. Al Hashim has nothing to disclose. Dr. MacGregor has nothing to disclose. Dr. Raybaud has nothing to disclose. Dr. Blaser has nothing to disclose.