Dear Doctors: I have frequent nightmares about being chased where I wake up flailing my arms and legs and crying out. It’s manageable at home but problematic for sleep on long-distance flights. I’ve woken up to find myself grabbing a stranger in the seat next to me. I’m reluctant to take medication -- will it even help? -- and I wonder if you have any advice, other than staying awake.
Dear Reader: Performing movements while you are dreaming is known as dream enactment behavior. During a vivid dream or nightmare, the sleeping person may toss and turn, flinch, move their limbs and even laugh, speak or cry out. Because this physical activity is not normal behavior in this stage of sleep, it alerts the brain that something is wrong. The brain, always guarding against possible harm, then nudges you awake.
Dream enactment behavior is common enough that most people experience it every now and then, but when these episodes become recurrent, it edges into sleep disorder territory. It can be a malfunction of the REM sleep system that's known as REM sleep behavior disorder (RSBD). The acronym REM refers to rapid eye movement, the stage of sleep when dreams occur. Its name comes from the fast eye movements behind the sleeping person's closed eyelids as they dream.
Brain activity is high during normal REM sleep, mirroring brain activity when you’re awake. However, the body remains deeply relaxed. This is called muscle atonia. It’s caused by a reset of certain mechanisms within the brain stem. In RSBD, these protective mechanisms fail. Rather than the limited twitches and jerks common to REM sleep, the dreamer performs specific actions. These can include reaching, grabbing, hitting, pushing, clawing, and even walking or running. This is all clearly a risk to others nearby, and to the sleeper as well.
We understand that your goal is to safely sleep during a long flight. The starting point would be to work with your doctor to determine whether your episodes qualify as RSBD. This involves reviewing medical history, observing you in a sleep lab, and exploring and excluding other possible causes of this sleep behavior. Other possible causes include side effects from medications, an undiagnosed neurodegenerative condition and other types of sleep disorders.
The stress, sleep deprivation and close quarters of a long flight can worsen all forms of sleep disorders. These trips often increase insomnia, circadian rhythm disturbances and RSBD. For people diagnosed with RSBD, certain medications to limit movement during sleep may be prescribed. When flying, you can choose the window seat to reduce contact with others. Bundling in a shawl or blanket can also limit movement during sleep. Sleep scientists agree with your instinct to avoid the deep sleep that occurs with sleep medications. Without a diagnosis that provides access to an appropriate medication, the only way to eliminate the risk of acting out dream behavior is to stay awake during the flight.
(Send your questions to [email protected], or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)
