Left-Leg Apraxia and Bilateral Incoordination of the Lower Limb After Left Anterior Cerebral Artery Infarction: A Case Report.

Callosal disconnection syndrome is characterized by impaired interhemispheric communication and motor coordination. Although its effects on upper limbs are well documented, reports on lower-limb function are limited, and their pathological mechanisms remain poorly understood. We describe a case involving a right-handed woman in her early 70s who presented with slurred speech and difficulty moving her feet. Magnetic resonance imaging revealed an atherothrombotic cerebral infarction affecting the splenium, body, and genu of the corpus callosum, as well as the medial region of the left frontal lobe. In addition to callosal disconnection symptoms, including impaired transfer of proprioceptive information from the fingers, left-hand apraxia, and intermanual conflict, this patient exhibited asynchrony in lower-limb movements and left lower-limb apraxia. The patient's ability to perform coordinated movements improved with repeated rehabilitation sessions. These findings suggest that corpus callosum injury plays a pivotal role in bilateral lower-limb coordination and motor control. We emphasize the need for further research to elucidate the role of the corpus callosum in lower-limb motor control.