Background <p>Alien hand syndrome is a rare condition characterized by involuntary movements of a limb that the patient perceives as alien and is usually associated with anterior or posterior brain lesions. This case involved a unique posterior alien hand syndrome overlapping with the anterior form.</p> Case presentation <p>A 76-year-old Caucasian male patient presented to the emergency department with acute confusional state associated with involuntary movement of the right arm subsequent to a fall. His medical history included recurrent pulmonary embolism treated with edoxaban, diabetes, and hypertension. Initial computed tomography imaging indicated chronic changes; nevertheless, within 24 h, his symptoms intensified, and subsequent imaging demonstrated a left posterior circulation infarct. His uncontrollable arm movements resulted in a diagnosis of posterior alien hand syndrome.</p> Management and outcome <p>Management involved the use of aspirin, temporary cessation of edoxaban, and agitation management with quetiapine. After confirming the stability of the infarction, edoxaban was reintroduced. This case underscores the difficulties in treating alien hand syndrome and anticoagulation in a complicated stroke scenario.</p> Conclusion <p>This case underscores the varied manifestations of alien hand syndrome variations, indicating a complicated interaction among anatomical regions. A multidisciplinary approach is crucial for the management of alien hand syndrome, especially in instances with overlapping features.</p>