According to a 2007 review in the "Journal of Clinical Sleep Medicine," sleep occurs in a progressive series of stages. People typically experience light sleep, deep sleep and then rapid eye movement sleep. This last stage is also known as REM sleep, and it's associated with dreams. During REM sleep, the body is paralyzed, yet the mind remains active. Heart palpitations, body twitches and eye movements are often observed. While these events are normal, they can be excessive or occur in other sleep stages. Such outbursts may be symptoms of an underlying medical condition.
Narcolepsy
Narcolepsy is a sleep disorder associated with extreme fatigue. Common symptoms include sleep-related hallucinations and paralysis as well as emotion-related loss of muscle control. According to a 1997 experiment documented in "Electroencephalography and Clinical Neurophysiology," narcoleptic patients showed more eye movements and muscle twitches during REM sleep than control subjects. The narcoleptics also displayed more twitches early in the night. Although eye movements and muscle twitches were independently controlled, their greater number and earlier density suggests REM sleep dysregulation.
REM Behavior Disorder
Many patients who have narcolepsy also have REM behavior disorder. In this condition, people are not completely paralyzed during REM sleep. This lack of inhibition allows them to act out their dreams, often with dangerous consequences. For example, a 1997 case study in "Age and Ageing" describes an older woman who frequently experienced falls during nighttime REM episodes. Such patients also display excessive palpitations and twitches. A 2010 review in "Journal of Clinical Sleep Medicine" reveals that several medications may contribute to this sleep disorder. Drugs that may be involved in REM behavior disorder include clomipramine, selegiline and phenelzine.
Autoimmune Disease
Morvan's syndrome is an autoimmune disease characterized by incessant palpitations and twitching. These symptoms are so severe that they prevent sleep. This sleep deprivation leads to "sleep attacks," including the spontaneous appearance of REM sleep without atonia. Morvan's syndrome is a rare disorder with less than a hundred known cases. Yet the condition can provide insight into the cause of autonomic nervous system arousal. The autonomic system controls involuntary responses like breathing and sweating.
A 2007 case study in "Neurology India" describes a patient with Morvan's syndrome. This individual displayed autonomic hyperactivity. Prednisolone, a steroidal anti-inflammatory drug, proved effective in treating the patient. This finding reveals that an overreaction of the immune system may contribute to nighttime palpitations and twitches.
Posttraumatic Stress Disorder
Posttraumatic stress disorder is caused by previous exposure to a traumatic event with the threat of perceived harm. This anxiety disorder is common in veterans and refugees. A 1994 report in the journal "Sleep" reveals that Vietnam veterans with posttraumatic stress disorder exhibit an unusually large number of muscular twitches during sleep. Interestingly, the veterans showed these abnormal bursts during both REM and other stages of sleep. These results suggest that psychological conditions may be responsible for palpitations and movements during sleep.
References
- "Journal of Clinical Sleep Medicine"; The Visual Scoring of Sleep and Arousal in Infants and Children; M. Grigg-Damberger et al.; March 15, 2007
- "Electroencephalography and Clinical Neurophysiology"; Rapid Eye Movements, Muscle Twitches and Sawtooth Waves in the Sleep of Narcoleptic Patients and Controls; P. Geisler et al.; December 1987
- "Age and Ageing": REM Sleep Behaviour Disorder: A Treatable Cause of Falls in Elderly People; 1997
- "Journal of Clinical Sleep Medicine"; Pharmacologically Induced/Exacerbated Restless Legs Syndrome, Periodic Limb Movements of Sleep, and REM Behavior Disorder/REM Sleep without Atonia: Literature Review, Qualitative Scoring, and Comparative Analysis; R. Hoque et al.; Feb. 15, 2010
- "Neurology India"; An Interesting Case Report of Morvan's Syndrome from the Indian Subcontinent; B. K. Bajaj et al.; January 2007
