Alien Hand Syndrome and Strokes

Written by Aditi Avunuri

Alien hand syndrome (AHS) is a peculiar neurological disease where one’s hand ceases to maintain voluntary control, and starts making voluntary movements of its own. The owner of the hand either feels that their hand is a foreign body, or feels it but is unable to control it. AHS is most commonly associated with tumors of the brain, aneurysm, neurodegenerative disease, and neurosurgery like corpus callosotomy, but it is extremely rare aer stroke. 

In the past, there was a case of a 77-year-old female diagnosed with chronic atrial fibrillation who had AHS part of her cardioembolic stroke presentation. She had her anticoagulation therapy temporarily held off for her operation on spine, without bridging her on low-molecular-weight heparin. Two days aer that, while watching TV, she noticed herself involuntarily stroking her hair and face with her le hand. Despite her attempts to control it, her movements continued on for nearly 30 minutes. Aer regaining control of her hand, noticed the le extremity of her top half was weak and numb. 

Hospital CT scan and MRI confirmed acute parietal lobe infarcts on her two sides suggestive of cardioembolic stroke.The rest of the tests, including her transthoracic and transesophageal echocardiograms, were not showing thrombosis in her heart or its orifices. Fortunately, she managed to gain control of her le side as he regained consciousness within those six hours. She restarted her therapy of her anticoagulation, discharged home on very clear instructions to continue it to preclude recurrence of a stroke.

Alien hand syndrome aer experiencing a stroke is extremely unusual but can occur typically through lesions of the parietal cortex, corpus callosum, or supplementary motor regions; the locations of coordination of movement and control of body movement. The brain’s planning of movement is disrupted, leading to the involuntary movement of one’s hand. AHS can occur on its presentations of intermanual conflict (when movement of a hand is opposite of what is wanted by opposing hand), anarchic hand syndrome (when one’s hand make voluntary movements automatically), supernumerary hand illusion (feeling like there is one hand too much), levitating hand syndrome (when there is involuntary elevation of hand. 

Though AHS is frightening, it is usually temporary aer a stroke and can improve within hours to days as the brain recovers. Even though there is no effective therapy for AHS, rehabilitation can be done to control it. The case serves as a reminder of how nervous system disorders can reflect early signs of underlying stroke of cerebrovascular origin.

Sources: 

https://www.mdsabstracts.org/abstract/the-alien-hand-syndrome/ 

https://my.clevelandclinic.org/health/diseases/alien-hand-syndrome https://pmc.ncbi.nlm.nih.gov/articles/PMC4261226/ 

https://pubmed.ncbi.nlm.nih.gov/24982566/#:~:text=A%2077%2Dyear%2Dold%20woman,r ecovery%2C%20she%20had%20le%20hemiparesis.

Written by Aditi Avunuri from MEDILOQUY