A 67-year-old right-handed woman had a 2-year history of progressive abnormal right grip and uncontrollable fisting attitude of her right hand.

The most common lesions in the corpus callosum are gliomas, lymphomas, and demyelinating diseases. Our patient had a striking syndrome secondary to an infarction of the midportion of the corpus callosum and medial aspect of left frontal lobe regions supplied by the anterior cerebral artery (ACA). Infarction of the corpus callosum may be more common than previously thought and is often the result of cerebral embolism. Cardiac embolism due to atrial fibrillation was identified as the cause of our patient’s ischemic stroke.