Sleepwalkers Feel No Pain In Their Nightly Sleepwalking Accidents

Sleepwalkers likely feel no pain if they stub their toe on the corner of a table or suffer from another even more serious injury while they are sleepwalking, new research published in the journal Sleep indicates. Sleep is the joint publication of the Sleep Research Society and the American Academy of Sleep Medicine. Sleepwalking, which an earlier Inquisitr article indicated is likely genetic, also seems to be linked to an increased risk for headaches and migraines during waking hours, but interestingly, when people sleepwalk, they are unlikely to feel pain.

Somnambulism, or sleepwalking, is a sleep disorder that affects up to four percent of adults and is classified, according to Medical News Today, as a "parasomnia," or a sleep disorder involving undesirable physical events or experiences. Sleepwalking happens when people almost, but don't completely, awaken from a deep sleep, or a shortwave sleep (SWS).

Some sleepwalkers injure themselves while they are walking around in their slumber, but when they do, they often won't feel the pain unless it's severe enough to still be there when the sleepwalker actually awakens. Dr. Regis Lopez, a psychiatrist and sleep medicine specialist at Hospital Gui-de-Chauliac in Montpellier, France, led the sleepwalking research. Dr. Lopez speculated that the changes in the build-up of the waves during SWS might decrease the pain perception threshold during sleepwalking.

For the research, the team studied 100 sleepwalkers and 100 control subjects with a median age of 30 years. They were assessed by a clinician and by answering questionnaires for sleep patterns, chronic pain, headache, disease characteristics, migraines, symptoms of depression, and quality of life. Sleepwalkers reported that they had four times the headaches of the control group and 10 times the migraines. Sleepwalkers also reported more chronic pain, exhaustion, depression, and insomnia.

While walking in their sleep, almost half of all sleepwalkers have been injured. Among the sleepwalking group, 47 out of the 100 subjects in the group experienced being injured while sleepwalking, while only 10 of them said that they woke up from that pain. Thirty-seven of them perceived no pain while sleepwalking, but felt the pain from the injury later. One of the subjects even suffered severe fractures after jumping out of a third-floor window while sleepwalking. That sleepwalker didn't feel the pain from the fall until waking up later in the night. Another sleepwalker broke his leg after climbing onto the roof of his house and then falling. He didn't wake up until morning.

"Our most surprising result was the lack of pain perception during the sleepwalking episodes. We report here, for the first time, an analgesia phenomenon associated with sleepwalking," Dr. Lopez explained, adding that even with these findings they aren't sure what the relationship between sleepwalking and pain actually is. The researchers hope that the findings may help explain why people sleepwalk. Sleepwalking might be related to lower nociceptive states, the article states. Nociceptors are sensory neurons that respond to potentially damaging stimuli by sending signals to the brain and spinal cord causing the perception of pain.

"Our results highlight the clinical enigma of pain in sleepwalking patients with complaints of frequent chronic pain, migraine, and headache during wakefulness but who report retrospectively experience of analgesia during severe parasomnia episodes, suggesting a relationship between dissociated brain activity and nociceptive dysregulation."
Dr. Michael Howell, of the Department of Neurology at the University of Minnesota in Minneapolis, claims that there has been a recent surge in sleepwalking. Howell says that sleepwalking might be related to motor restlessness like restless leg syndrome. Johns Hopkins' website claims that in restless leg syndrome, there appear to be three important factors: brain concentrations of iron, brain dopamine concentrations, and genes. Stress, exhaustion and certain medications are also listed as possible causes of sleepwalking.Have you ever been injured while sleepwalking and not felt any pain?

[Image via Pixabay]