Neuropsychological functioning in dysgenesis of the corpus callosum with colpocephaly

Dysgenesis of the corpus callosum is a rare developmental abnormality in brain structure that is associated with changes in physical appearance, as well as behavioral and cognitive consequences. A relatively commonly co-occurring structural abnormality with callosal dysgenesis is colpocephaly, characterized by enlargement of the posterior lateral ventricles and reductions in posterior brain volume. Although some case studies of individuals with this combination of structural malformations exist, they do not often report results of neuropsychological evaluation. Furthermore, those that do contain neuropsychological data may be of limited generalizability due to unique patient characteristics. The current manuscript overcomes these limitations by presenting the case of a 55-year-old male with callosal dysgenesis and colpocephaly identified in adulthood. The paper includes a full profile of his performance on a comprehensive neuropsychological test battery with discussion of differential diagnosis and treatment planning. Findings indicated low average intellectual abilities with deficits in processing speed, executive functions, and social cognition, consistent with expectations based on callosal dysgenesis. One surprising finding was that despite the significant posterior involvement of colpocephaly, visuospatial skills were a relative strength. The manuscript provides a clear characterization of callosal dysgenesis with colpocephaly to facilitate future clinical comparisons and set the stage for future research on this rare neuromorphological presentation.