Pain in Sleepwalking: A Clinical Enigma

Study Objectives: Sleepwalking is a disorder characterized by arousal specifically from slow wave sleep with dissociated brain activity that may be related to lower nociceptive state. Our objectives were to assess the frequency of chronic pain, headache, and migraine in sleepwalkers compared to controls, examine the impact and determinants of pain in sleepwalkers, and report analgesia frequency during injurious parasomnia episodes. Design: Cross-sectional case-control study. Setting: Data were collected at the Sleep Disorders Center, Montpellier, France. Participants: One hundred patients with sleepwalking were assessed for disease characteristics, sleep (polysomnography, sleepiness, and insomnia), pain (chronic pain, multidimensional pain inventory, headache, and migraine), depressive symptoms, and quality of life compared to 100 adult controls. Pain perception was retrospectively assessed during injurious parasomnia episodes. Measurements and Results: Raw association data showed that lifetime headache, migraine, and chronic pain at time of study were significantly associated with sleepwalking (also called somnambulism). Compared to controls, sleepwalkers reported more frequent daytime sleepiness, and depressive and insomnia symptoms. After adjustments, sleepwalking was associated with increased risk for headache and migraine only. Compared to pain-free sleepwalkers, sleepwalkers with chronic pain were more likely to be older and to have greater daytime sleepiness, insomnia, and depressive symptoms, with no difference in polysomnography assessment. Of the 47 sleepwalkers with at least one previous violent parasomnia episode, 78.7% perceived no pain during episodes, allowing them to remain asleep despite injury. Conclusion: 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.