Hypnic jerk
| Hypnic jerk | |
|---|---|
| Other names | Myoclonic jerk, hypnagogic jerk, sleep start, sleep twitch, night start |
| Specialty | Sleep medicine |
| Causes | Unknown |
| Risk factors | Irregular sleep schedule, anxiety, excessive stimulant consumption, stress, smoking |
| Diagnostic method | Based on symptoms |
| Treatment | Medication, reducing stimulant consumption, consuming magnesium |
| Medication | Clonazepam |
A hypnic jerk, hypnagogic jerk, sleep start, sleep twitch, myoclonic jerk, or night start is a brief and sudden involuntary contraction of the muscles of the body which occurs when a person is beginning to fall asleep, often causing the person to jump and awaken suddenly for a moment. Hypnic jerks are one form of involuntary muscle twitches called myoclonus.
Physically, hypnic jerks resemble the "jump" experienced by a person when startled, sometimes accompanied by a falling sensation.[1] Hypnic jerks are associated with a rapid heartbeat, quickened breathing, sweat, and sometimes "a peculiar sensory feeling of 'shock' or 'falling into the void'".[2] It can also be accompanied by a vivid dream experience or hallucination.[3] A higher occurrence is reported in people with irregular sleep schedules.[4] When they are particularly frequent and severe, hypnic jerks have been reported as a cause of sleep-onset insomnia.[3]
Hypnic jerks are common physiological phenomena.[5] Around 70% of people experience them at least once in their lives with 10% experiencing them daily.[6][7] They are benign and do not cause any neurological sequelae.[7]
- ^ "Brain Basics: Understanding Sleep" (PDF). National Institute of Neurological Disorders and Stroke. National Institutes of Health. 2006. Archived from the original (PDF) on 2019-07-03. Retrieved 2019-07-03.
Many also experience sudden muscle contractions called hypnic myoclonia, often preceded by a sensation of starting to fall. These sudden movements are similar to the "jump" we make when startled.
- ^ Friedman, Lauren F. (2014-05-21). "Why You Sometimes Feel Like You're Falling And Jerk Awake When Trying To Fall Asleep". Business Insider. Retrieved 2016-07-17.
- ^ a b Oswald, Ian (1959-03-01). "Sudden Bodily Jerks on Falling Asleep". Brain. 82 (1): 92–103. doi:10.1093/brain/82.1.92. ISSN 0006-8950. PMID 13651496.
- ^ "Basics of Sleep Behavior: NREM and REM Sleep". Sleep Syllabus. Archived from the original on 2011-07-18. Retrieved 2019-07-03.
These muscular contractions, called sleep related myoclonias are not pathological events, although they tend to occur more frequently with stress or unusual or irregular sleep schedules.
- ^ Sander, Howard; Geisse, Hildegarde; Quinto, Christine; Sachdeo, Rajesh; Chokroverty, Sudhansu (1998). "Sensory sleep starts". Journal of Neurology, Neurosurgery & Psychiatry. 64 (5): 690. doi:10.1136/jnnp.64.5.690. PMC 2170079. PMID 9598699.
- ^ Chokroverty, Sudhansu; Bhat, Sushanth; Gupta, Divya (2013). "Intensified Hypnic Jerks: A Polysomnographic and Polymyographic Analysis". Journal of Clinical Neurophysiology. 30 (4): 403–410. doi:10.1097/WNP.0b013e31829dde98. PMID 23912581. S2CID 38840788.
- ^ a b Vetrugno, Roberto; Montagna, Pasquale (2011). "Sleep-to-wake transition movement disorders". Sleep Medicine. 12: S11 – S16. doi:10.1016/j.sleep.2011.10.005. PMID 22136891.