Polysomnographic And Clinical Features In Narcoleptic Patients With Rapid Eye Movement Sleep Behaviour Disorder

Narcolepsy is a kind of sleep disorders with longlife. The main clinical features aresleep-wake rhythm instability (daytime hypersomnia and nighttime insomnia), episodescataplexy (emotion evoked reduction or loss of muscular tonus not accompanied by loss ofconsciousness and common in emotional situations), sleep paralysis (inability to move atfalling asleep or waking up) and hypnagogic or hypnopompic hallucinations (vivid imagesthat pervade the state of wakefulness) before falling asleep or at waking up. In recent years,we have found that narcolepsy also has features with dysthymic disorder（anxiety，depression），memory failure,failure in the attentional capacity and increased incidenceof REM sleep behaviour disorder.85-95%reduction in the number of hypocretin(orexin)neurons has been observed in brains obtained from narcoleptic donors. Hypocretin neurons are exclusively located in the hypothalamus but project widely over the cerebralcortex, thalamus, hypothalamus, brainstem, locus ceruleus, olfactory bulb,tubermammillary nucleus, raphae nuclei medianae and formatio reticularis medullaeoblongatae, especially dense in locus ceruleus. Therewith, Narcolepsy is defined as adisease of the nervous system eventually. It is speculated that may be presence of damageabout neural structure. In China, the peak incidence of narcolepsy center on teenager. Thesymptomatology of the disease affects the patients’ quality of life very considerably. Thisdisease also brings some economic burden to family and society.RBD is deep sleep behavior disorder. The neurodegenerative diseases associated withRBD are synucleinopathies such as Parkinson’s disease, Lewy body disease, and multiplesystems atrophy. Any age can occur the neurodegenerative diseases associated with RBD,but the old men had higher rates, and young people are relatively rare. RBD ischaracterized by abnormal REM sleep during which control of muscle tonus is lacking(REM sleep without atonia), with dream-enacting relevant simple or complex movementsbehaviors,including talk, shout, making hand gestures, boxing, split kick, out-of-bedactivity, presenting a risk for harm to others and self-injury.According to study, RBD symptoms of narcoleptic patients could occurconcomitantly or appear before or after the onset of narcolepsy. In young patients, thepresence of RBD can increase the possibility of narcolepsy diagnosis,although RBD is nota typical symptoms of narcoleptic patients. The RBD event does not appear every night.So the video-PSG records can well prove this clinical diagnosis. Meantime, thevideo-PSG records can well display action distribution characteristics and forms ofexercise during the REM sleep,which is about narcoleptic patients with RBD.Objective: To describe clinical features, polysomnography (PSG) alterations andcharacteristics of motor and distribution during rapid eye movement (REM) sleep innarcoleptic patients with REM sleep behavior disorder (RBD).Methods: We gathered narcoleptic patients who have been diagnosed in our sleepcenter for in2008December to2011November. This study included three groups:narcoleptic patients with RBD (N+RBD)(n=22), narcoleptic patients without RBD (N-RBD)(n=96), healthy subjects as controls (n=21). We respectively summarizedgeneral features and compared their PSG parameter and the related indexes in three groups.Then we analyzed a full-night video-PSG recording in a continuous series about (N+RBD)group to identify their motor behavior and distribution features.Results There was18.6percentage of（N+RBD） patients in narcoleptic patients.Male to female ratio was about1∶1.There was no significant difference in PSGparameter and correlation index between the（N+RBD）group and (N-RBD) group.However, compared with normal control group, the（N+RBD）group and (N-RBD) groupshowed increased the body mass index(BMI)(F=4.869，P=0.009),shortened NREM sleepand REM sleep (min) latency at night(4.41±7.01,3.55±3.98and14.69±9.62，2=31.697，P=0.000；69.39±81.39,71.04±74.45and115.31±45.13，2=11.485， P=0.003),increased percentage of sleep stage1, decreased percentage of slow wave sleep, delayedthe arousal time and increased number of arousal episode longer than5minutes. In the（N+RBD）group, RBD episodes occurred frequently at any stage of REM sleep throughwhole night and the frequency of vocalizations did not signifcantly differ between the twohalves of the night. Pantomimes were signifcantly more frequent in RBD episodes of thesecond half of the night. Only one patient had aggressive-violent movements.Conclusions The prevalence of RBD is high in narcoleptic patients. Sleeparchitecture didn’t differ between the（N+RBD）group and (N-RBD) group. There was nocorrelation between the occurrence of RBD and narcoleptic duration. In（N+RBD）patients,vocalizations and pantomimes accounted for major proportion of RBD episodes whileaggressive-violent movements are rare.