Unusual compensatory neural connections following disruption of corpus callosum fibers in a patient with corpus callosum hemorrhage

Abstract

Objective: We report on a patient with hemorrhage of the corpus callosum (CC) in whom unusual compensatory neural connections were observed following disruption of CC fibers. Methods: A 42-year-old female patient presented with callosal alien hand syndrome (AHS) after the onset of the hemorrhage. She showed a rapid recovery and the symptoms of her AHS had almost disappeared at 7 weeks after onset. We performed diffusion tensor tractography (DTT) for the evaluation of CC fibers and performed a comparison with DTT findings acquired from a normal subject (a 47-year-old female). Results: Findings on DTT of the patient revealed extensive disruption of CC fibers passing through the anterior portion of the genu and most of the CC body. We observed that CC fibers in the right and left temporal lobes joined with the right and left inferior fronto-occipital fasciculus, respectively, and these neural fibers were connected to each other through the anterior commissure. These changes of neural connections were not observed in the normal subject. Conclusion: We think that the unusual neural connections in this patient were compensatory phenomena for disruption of CC fibers. In addition, the good recovery from symptoms of AHS in this patient appears to be correlated with these unusual compensatory neural connections. We believe that the results of this study suggest a mechanism for neural recovery following injury of the CC fibers.