Unilateral prosopometamorphopsia caused by infarction of the splenium of the corpus callosum: 4 case report and review of the literature.

BACKGROUND

Prosopometamorphopsia (PM) is a high-level visual-perceptual disorder characterized by facial distortion. Unilateral PM caused by splenium lesions in the corpus callosum (CC) is rare.

OBJECTIVE

To investigate the role of CC splenium lesions in unilateral PM and explore their implications for facial information processing and rehabilitation.

METHODS

We reported four cases of PM due to splenium lesions in the CC and conducted a retrospective analysis of 17 previously reported cases. A comprehensive evaluation framework was developed to assess primary, intermediate, and advanced visual processing in PM patients. Additionally, individualized rehabilitation strategies incorporating avoidance and compensatory methods were implemented.

RESULTS

CC splenium lesions were identified as the most common cause of unilateral PM, with a tendency toward bottom-up processing. Disconnection syndromes associated with CC splenium lesions were also observed. Patients showed a relatively favorable recovery rate, suggesting dynamic compensatory mechanisms in bilateral facial processing, with stronger compensatory functions in the right hemisphere.

CONCLUSION

The splenium of the corpus callosum plays a crucial role in bilateral facial information processing, exerting a lateralized influence on the right hemisphere. Further studies are needed to confirm these findings and elucidate the underlying pathophysiological mechanisms.