A-36Case Study

Objective: This is a neuropsychological case study involving an 88-year-old right-handed man with recent onset of intermittent left-hand apraxia that he noted while driving and dressing himself, occurring approximately twice per week over the past year. He has lifelong corpus callosum agenesis (CCA) and other associated structural brain abnormalities. Method: The patient underwent a variety of neurodiagnostic procedures, including MRI, EEG, neurological, and comprehensive neuropsychological examination. Results: A brain MRI evidenced mild generalized parenchymal volume loss and complete agenesis of the corpus callosum, with marked dilatation of the occipital horns of the lateral ventricles (colpocephaly), as well as moderate dilatation of the temporal horns. EEG findings suggested bitemporal slowing with a left temporal focus. In contrast with the highly abnormal MRI, the results of his neuropsychological examination reflected wide-ranging normal neurobehavioral functioning and only mild compromise of speech perception, verbal learning ability, and bilateral proprioception. Conclusion: This case underscores the plasticity of the developing brain and, in specific, compensatory mechanisms for interhemispheric connectivity in the absence of a corpus callosum and in the presence of several congenitally based structural abnormalities.