Case Report of Rapid-eye-movement (REM】 sleep behavior disorder

Zhen FAN， Yanrui NIU， Fui ZFANG*

·Case report·

Case Report of Rapid-eye-movement (REM】 sleep behavior disorder

Zhen FAN， Yanrui NIU， Fui ZFANG*

1. Case history

The patient was a 23-year-old female student of Fan ethnicity. Five years ago， for no obvious reason， she began to have episodes about every 20 to 30 days in which she would sit up in bed while sleeping （usually at about 01:00 h） with her eyes closed， speak loudly and clearly for about 1 to 2 minutes， and then lie back down to sleep. She reported that she oft en felt anxious or tense about common life stresses in the two to three days preceding these episodes. When this occurred her family members woke her and she was able to clearly recall her vivid dreams （that were sometimes nightmares）. For example， a year and a half before she sought psychiatric treatment she had a nightmare about a steamroller in which she felt terrified and shouted‘save me’ before jumping from a height of 1.6 meters and falling to the fl oor causing a subdural hematoma that was verif i ed by X-ray tomography.

The pati ent had not previously sought medical help for these problems but eventually came for outpatient psychiatric treatment because of the risk of serious injury related to her abnormal sleep. Nental status examination showed that the patient was alert， oriented to ti me and place， had insight into her conditi on， was able to answer questi ons coherently，and was cooperative. The patient denied any hallucinati ons or delusions. She expressed sadness and anxiety， and reported frequent nightmares that left her feeling fatigued in the mornings. The patient could not remember her abnormal nightti me behavior and was worried about nightti me abnormalities occurring again.

Overnight polysomnographic （PSG） monitoring showed that the patient had a total sleep ti me of 7.3 h，a total ti me of waking during the night of 88.5 min （32ti mes）， poor sleep continuity， decreased sleep efficiency，and a lack of normal muscle atonia （paralysis） during rapid eye movement （REN） sleep. Electromyograph（ENG） results showed excessive twitching in her chin（mentalis muscle） and limbs during REN sleep （see the ChinENG， LegENG2， LegENG3 tracings in Figure 1） but no epileptic features.

The pati ent was diagnosed as having REN sleep behavior disorder （RBD） and given an oral dose of clonazepam， 1 mg nightly. Family members observed the pati ent the fi rst night after taking medication；as previously， she sat up at about 01:00 h and then laid back down again aft er about 2 min but could not remember her nightti me behavior the next day. After the first night the nighttime behavior did not recur.After a week on the medication， the patient’s anxiety and tension disappeared and the morning fati gue was greatly reduced. Results of a follow-up PSG showed a total sleep ti me of 7.9 h， a total ti me of waking during the night of 10.5 min （8 ti mes）， and significantlyimproved sleep conti nuity and sleep efficiency， but there was sti ll a lack of muscle atonia during the REN periods of sleep. The pati ent felt that the medicati on significantly reduced the occurrence of nighttime disturbances and increased the quality of her sleep.The patient only reported one nightti me abnormality in a follow-up six months after initiation of treatment: 4 months aft er beginning treatment she suddenly stood up while asleep， which woke her up but did not harm her.

2. Discussion

RBD is characterized by the loss of muscle relaxati on during REN sleep and complex， dream-related movements during REN.[1]The prevalence of RBD in adults is 0.4 to 0.5%.[2]RBD can occur at any age with 50-years-old being the dividing line between earlyonset RBD and late-onset RBD. Late-onset RBD is more common in men. According to Teman and colleagues[3]early-onset RBD occurs more frequently in women，particularly in those who use anti depressants. But Ju and colleagues[4]believe that there is no signif i cant diff erence in the prevalence of RBD between young men and young women， though they do suggest that early-onset RBD in women is commonly associated with autoimmune diseases and anti depressant use.

This paper reports a case of early-onset RBD in a young woman who did not have any history of an autoimmune disease or of using anti depressants.The patient reported that prior to the episodes of abnormal sleep behavior she had felt stressed and had experienced mild mood swings. This case would，therefore， support the work of Siclairi and colleagues，[5]who believe that there may be a relationship between mood swings and the subsequent onset of RBD. Several researchers believe that RBD is an early marker of underlying neurodegenerati ve disorders.[4，6]The onset of RBD in our patient was relatively early （at 18 years of age） so whether or not this signifies the onset of a neurodegenerative disease remains to be seen. Longterm follow-up studies of this type of RBD are needed to understand its prognosis and outcome.

The diagnosis of RBD requires a history of abnormal sleep behavior and a multi -track PSG showing muscle activity during REN sleep.[7]Problemati c sleep behavior presents as complex， involuntary facial and limb movements， sleep talk， and violent movements， all of which can harm the sleeper or those in bed with them.In additi on to the abnormal sleep behavior， the patient described here also reported vivid dreams and nightmares when woken by family members. This suggests that the behaviors were occurring during REN sleep， a finding that was confirmed by the PSG exam that showed the characteristi c muscle activity during REN sleep （normal REN sleep is associated with atonal muscles）.

Pati ents with sleep disorders oft en seek treatment in a psychiatric department so a differential diagnosis is extremely important. The most important diff erenti al diagnosis to consider in adults with abnormal sleep behavior is nocturnal epilepsy. Individuals with nocturnal epilepsy will show EEG abnormaliti es outside of the sleep period and PSG monitoring should showcharacteristi c epilepti c waveforms. If there is some doubt about the diagnosis， 24-hour EEG monitoring would provide a definitive diagnosis. Cranial CT examinati ons can help to rule out other possible organic brain disorders that have disturbed sleep as one of the symptoms.

Figure 1. Polysomnographic recording of the pati ent during REM sleep prior to treatment

Benzodiazepines， parti cularly low-dose clonazepam，are the first-line drug treatments for RBD.[8]For pati ents who have adverse reacti ons to these drugs， zopiclone[8]and melatonin[9，10]have also been found to be eff ecti ve.[9，10]There are a few studies showing that pramipexole，paroxeti ne or L-dopa can be used for RBD， but the results of these studies are not consistent.[11]The pati ent described in this report was a healthy 23-yearold so she was treated with low-dose clonazepam； she responded well to 1 mg clonazepam nightly and had no signif i cant adverse reactions. Even though her clinical symptoms improved， PSG monitoring revealed that there was sti ll abnormal muscle acti vity during REN sleep， a finding that is consistent with that of other studies.[7]Despite the good clinical outcome there were occasional episodes of the abnormal sleep behavior during the follow-up. Family members of pati ents with RBD need to be advised of this possibility and pati ents with RBD should sleep in a safe environment to minimize the risk of injury.

In China， there are few scienti fi c reports about RBD. Both clinicians and community members are largely unaware of the conditi on， so it is oft en misdiagnosed. As shown in this case， most pati ents and their family members do not seek treatment unless the episodes are frequent or result in serious distress or injuries. Disseminati ng knowledge about RBD both to the public and to health professionals is important for preventi ng treatment delays.

Conf l ict of interest

The authors report no conf l ict of interest related to this paper.

Acknowledgement

The authors would like to thank the pati ent， who signed a writt en informed consent to publish this case report.

1. Zhao ZX. Clinical Sleep Disorders. Shanghai: Second Nilitary Nedical University Press， 2003； 230-233. （in Chinese）

2. Sullivan SS， Schenck CF， Guilleminault C. Fiding in plain sight: Risk factors for REN sleep behavior disorder.Neurology 2012； 79（5）: 402-403.

3. Teman PT， Tippmann-Peikert N， Silber NF， Slocumb NL，Auger RR. Idiopathic rapid-eye-movement sleep disorder:associations with anti depressants， psychiatric diagnoses，and other factors， in relati on to age of onset. Sleep Med 2009； 10（1）: 60-65.

4. Ju YE， Larson-Prior L， Duntley S. Changing demographics in REN sleep behavior disorder: possible effect of autoimmunity and anti depressants. Sleep Med 2011； 12（3）:278-283.

5. Siclari F， Wienecke N， Poryazova R， Bassetti CL， Baumann CR. Laughing as a manifestation of rapid eye movement sleep behavior disorder. Parkinsonism Relat Disord 2011；17（5）: 382-385.

6. Zanigni S， Calandra-Buonaura G， Grimaldi D， Cortelli P. REN behaviour disorder and neurodegenerative diseases. Sleep Med 2011； 12 （suppl 2）: S54-58.

7. Zhang XF. Sleep Medicine Theory and Practice. Beijing:People’s Fealth Press， 2010: 903-904. （in Chinese）

8. Anderson KN， Shneerson JN. Drug treatment of REN sleep behavior disorder: the use of drug therapies other than clonazepam. J Clin Sleep Med 2009； 5（3）: 235-239.

9. Kunz D， Nahlberg R. A two-part， double-blind， placebocontrolled trial of exogenous melatoninin REN sleep behaviour disorder. J Sleep Res 2010； 19（4）: 591-596.

10. Boeve BF， Silber NF， Ferman TJ. Nelatonin for treatment of REN sleep behavior disorder in neurologic disorders:results in 14 pati ents. Sleep Med 2003； 4（4）: 281-284.

11. Aurora RN， Zak RS， Naganti RK， Auerbach SF， Casey KR，Chowdhuri S， et al. Best practice guide for the treatment of REN sleep behavior disorder （RBD）. J Clin Sleep Med 2010；6（1）: 85-95.

A 23-year-old female student presented with a five-year history of abnormal sleep in which she would sit up or stand up for brief periods in the early morning， talk loudly for a couple of minutes and then lie back down. When woken by family members she would remember vivid dreams and nightmares. In one episode she had a fall that resulted in a subdural hematoma. On presentation at the psychiatric hospital she had a normal mental status exam except for being mildly depressed and anxious about the chronic fatigue from poor sleep. Overnight polysomnography （PSG） showed multi ple waking periods each night， poor sleep efficiency and a lack of normal muscle paralysis during REN sleep. The pati ent was diagnosed with REN Sleep Behavior Disorder and treated with 1 mg clonazepam nightly. Fer sleep improved dramatically and remained bett er at a six-month follow-up， but repeat PSG exam found that the lack of muscle paralysis during REN sleep remained.

10.3969/j.issn.1002-0829.2013.02.010

Clinical Psychology Department， Xi’an City Nental Fealth Center， Xi’an， Shaanxi Province， China correspondence: zhang-hui2008@126.com

Dr. Fan received a master's degree in Mental Health from the Shanxi University of Medical Sciences in 2008 and has worked at the Xi'an Mental Health Center as an att ending psychiatrist in the Department of Clinical Psychology from that ti me. Her primary research interest is the psychology of sleep disorders.