Alien Hand Syndrome

Imagine you wake up and you find your hand clenched against your throat. Your hand has you in a death grip and you struggle to free it from you. You finally pry your hand from your throat. You have feeling in the hand but it doesn't seem like it belongs to you. You might even think it's possessed. This is an extreme example of something called Alien Hand Syndrome.

Alien hand syndrome is a rare and strange problem. Normally when you do something, like pick up a glass of water, your brain sends a signal from the motor area across a bundle of fibers, called the corpus collosum, down your spinal cord and peripheral nerves, to your hand. The corpus collosum enables the two sides of your brain to communicate with each other. You can think of it like an email server. If the corpus collosum is damaged then your email server is down. This is what happens with alien hand syndrome. A stroke or aneurysm causes damage to the corpus callosum so the messages that initiate movement don’t get to your hand.

Like I said, the example of your hand choking you is an extreme one. In most cases, the alien hand will reach or grab an object, touch your face, put food in your mouth, or do something like unbutton your shirt. It is such a weird problem that is has been portrayed in movies, the most famous being Dr. Strangelove. In the movie, Dr. Strangelove’s right hand continually does offensive things and he has to beat it down with his left hand.

Unfortunately, there is no treatment for alien hand syndrome. People will often try to keep the alien hand occupied by having it hold an object. Others will go as far as tying it behind their back. Gradual recovery may occur if the person's brain trauma was not too extensive. For the rest, all they can do is try to adapt to the feeling that their hand does not belong to them and that it has a mind of its own.