1. The syndrome: It’s a rare, neurological disorder in which you feel as if your hand is possessed. Although you can feel sensation in the affected hand, you think the hand is not part of your body and that you have no control over its movement.

2. Symptoms: The affected hand may be viewed as wayward or disobedient. It may remove clothing or reach for certain objects without the sufferer’s awareness. At times, both hands may appear to be acting in opposition to each other. For example, as one hand tries to answer the phone, the other might grab the receiver and put it down. Extreme cases have involved self-inflicted punching or choking.

3. The cause: It usually occurs following a stroke, brain trauma or surgery in which the hemispheres of the brain have been separated to relieve severe epilepsy.

4. Treatment: There is no known treatment for alien hand syndrome, but symptoms can be eased by occupying the wayward hand with an object at all times or by wearing an oven mitt. Sometimes the disorder goes away after weeks or years.

5. Pop culture: The title character in Stanley Kubrick’s “Dr. Strangelove or: How I Learned to Stop Worrying and Love the Bomb’’ suffers from the syndrome. His hand seems to act in accordance with his subconscious urges. He punches himself and gives a Hitler salute when discussing eugenics.