Alien hand syndrome, a rare presentation of corpus callosum and cingulate infarction.

Alien hand syndrome (AHS) is a rare apraxia syndrome, characterized by involuntary and uncontrollable movements of one upper limb, often accompanied by intermanual conflict. Damage to the corpus callosum, acute infarction and neurodegenerative disease may result in AHS. Based on the presentation and impairment region, AHS has three variants: frontal, callosal and posterior. Each type may have a different clinical presentation. A total of 157 patients admitted to hospital with corpus callosum infarction between 2012 and 2022 were included for this study, of whom a number of 5 presented with AHS. 4 of them had significant symptoms of intermanual conflict and 1 had strong grip symptoms in the affected upper limb. Moreover, new infarcts involving the corpus callosum and cingulate gyrus were found on MRI in all five patients. We simultaneously performed a retrospective study on all reported AHS cases caused by infarction of the corpus callosum. Case reports and literature reviews were conducted in order to provide clinicians with a better understanding of AHS, its etiology, clinical presentation, diagnosis, and treatment.