Improvement in callosal disconnection syndrome with recovery of callosal connectivity

ABSTRACT

Recent advancements in radiological techniques have enabled the observation of the topographic distribution of the human corpus callosum. However, its functional connectivity remains to be elucidated. The symptoms of callosal disconnection syndrome (CDS) can potentially reveal the functional connections between the cerebral hemispheres. Herein, we report a patient with CDS, whose callosal lesion was restricted to the posterior midbody, isthmus, and an anterior part of the dorsal splenium. A 53-year-old right-handed woman demonstrated CDS following cerebral infarction associated with subarachnoid hemorrhage. She exhibited CDS including ideomotor apraxia, and tactile anomia with the left hand, cross-replication of hand postures, cross-localization of the fingers, and constructional impairment with the right hand. Six months after onset, the left-handed ideomotor apraxia on imitation improved, but that to command did not, which indicated the difference in the nature of the transcallosal connections between ideomotor apraxia on imitation and ideomotor apraxia to command. Longitudinal CDS observation and corpus callosum tractography will prove useful in expanding our understanding of the nature of the organization of interhemispheric information transference.

KEYWORDS:

• Corpus callosum
• callosal disconnection syndrome
• callosal topography
• diffusion tensor tractography
• ideomotor apraxia

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by Health Labor Sciences Research [grants no. 20GB1002 and 20GC1008], Grant-in-Aid for Transformative Research Areas [grant no. 20H05956], and Grant-in-Aid for Scientific Research (B) [grant no. 21H03779] to KS.