A disturbing case of abnormal behavior during slow-wave sleep raises questions about the incidence of violence during sleep.

It has been 10 years since Moldofsky and his coworkers summarized parasomnias that occurred as a result of partial arousals during non-rapid eye movement (NREM) sleep.¹ They reported 65 adult patients (mean age of 30 years) who had sleep walking and sleep terrors. Group 1 was associated with serious violence during sleep. Group 2 developed harmful but not destructive behavior. Group 3 developed nonviolent behavior.

We report a case of NREM parasomnia with disturbing behavior during sleep. For the patient, the disorder led to a divorce requested by his wife. He had a history of somnambulance and somniloquy since childhood. He did not abuse drugs, and while the divorce had created anxiety depression, he had no other psychopathology. The disturbing episodes were sometimes precipitated by vigorous exercise during the daytime and stress.

Readers are recommended to review several excellent articles in Sleep, 1995.^1-5 They provide guidelines on how to handle these difficult but interesting patients in the sleep center.

Case Report
A 32-year-old man was seen in the sleep center due to sleep talking and abnormal behavior during sleep. The patient was known to have been sleep walking and sleep talking especially after strenuous exercise in the evening. The patient stated that he was totally amnesic to those events during sleep.

He had two daughters aged 8 years and 4 years. Sometimes, unknowingly, he took down their underwear during sleep. He was totally amnesic to this too. During the daytime, he performed his job well and apparently had not been treated for sleep walking and sleep talking. He had occasional nightmares but no history of sleep terrors. His wife told him that he snored during sleep. He considered this problem very upsetting.

The patient was a nonsmoker and nondrinker. He played basketball and did some weight training and running. He denied the use of recreational drugs. His normal bedtime was between 10:30 and 11:00 pm His normal wake time was 6:30 to 7:00 am.

The family history was negative for sleep disorders. The patient rated his own health as excellent. Because of his peculiar behavior during sleep, he was going through a divorce.

He had been treated for some seasonal allergies and depression, with medications including the anti-inflammatory naproxen, the selective serotonin reuptake inhibitor sertraline, the antihistamine fexofenadine, and the decongestant pseudoephedrine hydrochloride.

There were no symptoms to suggest the presence of narcolepsy. The patient had some anxiety and had occasional racing thoughts. He frequently remembered his dreams.

He denied any stress in his workplace. The patient usually could get 8 hours of sleep at night. After he was awake in the morning, he got out of bed within 5 minutes. He said that he only slept with his children because they were afraid of the dark. Then, after they fell asleep, he would leave them. He had regular working hours. He might exercise before bedtime. He seldom took naps in the afternoon or in the evening. Physical and neurological examinations were completely normal.

An overnight polysomnogram was done according to a standard protocol. In the morning the patient estimated his sleep latency of 5 minutes and the total sleep time of 7 hours. He did recall some dreams but did not recall any nocturnal awakenings. His sleep was less refreshing because of the strange environment of the sleep laboratory, but he said he felt fine in the morning. The total recording time was 443.5 minutes. Total sleep time was 420 minutes. The sleep efficiency measure was 86%. Sleep onset was within 8 minutes. REM onset was at 98 minutes. Three REM periods were obtained. The patient spent 4.8% of the time awake in bed. Stage I sleep was 9%, stage II was 48%, stage III/IV was 13.5%, and REM sleep was 24%. The patient’s sleep architecture was relatively intact with a slight increase in waking and stage I.

Respiratory measurements: Total apneas and hypopneas were 18, and the apnea/hypopnea index (AHI) was 2.6/h. The total arousal was 10. The arousal index was 1.4/h. Obstructive and mixed apneas was 4. Hypopneas was 14. The REM respiratory disturbance index (RDI) was 3.4/h. The lowest SpO² was 87%. Moderately loud snoring was heard in all sleep positions. However, nocturnal myoclonus or other parasomnia was not noted. His diagnoses were primary snoring and parasomnias with somnambulism and somniloquy. The patient was advised to seek care from an ears, nose, and throat surgeon for snoring.

The patient refused medications or treatments for somnambulance and somniloquy. The patient, however, was advised to sleep in a separate bedroom from his children.

Discussion
During the NREM abnormal behavior, the individual may demonstrate complex behavior, such as playing a musical instrument, eating, drinking, talking on the telephone, and even driving an automobile.³ There may be some mild vocal uttering, but there was usually not any extreme screaming or evidence of intense autonomic discharge, such as pupil dilatation and flushing of the face. The individual may even be able to respond to environmental stimuli; when such patients are interfered with or restrained, they may attempt to resist due to confusion. Physical injuries were common, and dangerous activities, such as opening windows, walking into glass doors, or climbing onto fire escapes, can occur. More violent behavior during NREM parasomnia might include attempted strangling of a spouse or repeated stabbing of a child. During the daytime, the subjects did not have any hostility or motive to do such acts. These have been called confusional arousal states, and the patient is totally amnesic about it. We had another patient whose wife accused him of raping her while he was asleep. Again the husband stated that he was totally amnesic about it in the morning.

Such episodes can be too embarrassing for the bed partners of these types of patients to report. Eventually, they may move to a locked separate bedroom in the house.

In these patients’ medical histories, most have sleep walked and sleep talked since childhood. However, there were some patients who had adult-onset somnambulance and somniloquy. Adult onset NREM parasomnias sometimes may be associated with psychopathology such as schizophrenia, mania, and depression. When a crime is committed during sleep, the patient may prove innocent of the act by lack of motive, is totally amnesic about the event, and has other NREM parasomnias, such as sleep talking and sleep walking.

Mahowald and Schenck had considered that REM behavior disorder and NREM parasomnias may represent opposite ends of a broad spectrum.⁴ The variables of psychologic distress, substance abuse (including caffeine and alcohol), and sleep wake schedule disturbances are very common in the general population. Psychological stressors may or may not be related to complex abnormal sleep behaviors.

Guilleminault and his coworkers found that dysfunctional families, physical and sexual abuse, and drug use are very frequent historical events in many individuals with sleep-related complex behaviors.² The male predominance of sleep-related violence in both REM behavior disorder and sleep walking and sleep talking might reflect the male predominance in violence across many species, including humans.⁴ But affected individuals were often from dysfunctional families, had a history of physical and sexual abuse, and had used drugs. When the behavior was the cause of a lawsuit, the expert witness must have credentials as a sleep expert as outlined by Mahowald and Schenck.⁴

Schenck and Mahowald reported a case of childhood-onset sleep walking with violent nocturnal activity. The activities included running, throwing punches, and wielding knives. The patient also had driven a car for a long distance.⁴ Polysomnography documented many episodes of complex and violent behaviors arising exclusively from stage III and IV sleep.

In the Schenck and Mahowald case, the patient responded promptly to treatment with bedtime doses of the anti-anxiety medication clonazepam and was well for 5 years of follow-up.

In one other patient, we also obtained a history of rape repeatedly by the husband at night. The wife was initially too embarrassed to report it. Violence during sleep is probably often underreported. We have not found the peculiar behavior similar to this case in the other literature.

Lawrence T. Chien, MD, FAAP, FAAN, ABSM, is a clinical associate professor at the University of Tennessee Medical Unit in Chattanooga and practices at Memorial Regional Sleep Center, also in Chattanooga. Anne P.Y. Chien, MSN, APN, NP-C, is a clinical associate professor at the University of Tennessee School of Nursing in Chattanooga.

References
1. Moldofsky H, Gilbert R, Lue FA, Maclean AW. Forensic sleep medicine: violence, sleep, nocturnal wandering, sleep-related violence. Sleep. 1995;18: 731-739.
2. Guilleminault C, Kushida C, Leger D. Forensic sleep medicine and nocturnal wandering. Sleep. 1995;18:721-723.
3. Schenck CH, Mahowald MW. A polysomnographically documented case of adult somnambulism with long-distance automobile driving and frequent nocturnal violence: parasomnia with continuing danger as a noninsane automatism? Sleep. 1995;18:765-772.
4. Mahowald MW, Schenck CH. Complex motor behavior arising during the sleep period: forensic science implications. Sleep. 1995;18:724-727.
5. Alves R, Flavio A, Tavares S. Sexual behavior in sleep, sleepwalking, and possible REM behavior disorder: a case report. Sleep Research Online. 1999;2:71-72.