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.A significantsubgroup of people diagnosed with hypersomnia previously were exposed to a viralinfection such as mononucleosis, hepatitis, and viral pneumonia, which suggests theremay be more than one cause (Guilleminault & Pelayo, 2000).rebound insomnia In a person with insomnia, the worsened sleep problems thatcan occur when medications are used to treat insomnia and then withdrawn.hypersomnia Abnormally excessive sleep; a person with this condition will fallasleep several times a day.sleep apnea Disorder involving brief periods when breathing ceases during sleep.NarcolepsyDurand 8-84Ann described her father as having narcolepsy, a different form of the sleepingproblem she and her brother shared (Mukai, Uchid, Miyazaki, Nishihara, & Honda,2003).In addition to daytime sleepiness, people with narcolepsy experiencecataplexy, a sudden loss of muscle tone.Cataplexy occurs while the person is awakeand can range from slight weakness in the facial muscles to complete physicalcollapse.Cataplexy lasts from several seconds to several minutes; it is usuallypreceded by strong emotion such as anger or happiness.Imagine that while cheeringfor your favorite team, you suddenly fall asleep; while arguing with a friend, youcollapse to the floor in a sound sleep.You can imagine how disruptive this disordercan be!Cataplexy appears to result from a sudden onset of REM sleep.Instead of fallingasleep normally and going through the four non-REM stages that typically precedeREM sleep, people with narcolepsy periodically progress right to this dream sleepstage almost directly from the state of being awake.One outcome of REM sleep is theinhibition of input to the muscles, and this seems to be the process that leads tocataplexy.Two other characteristics distinguish people who have narcolepsy (Mukai et al.,2003).They commonly report sleep paralysis, a brief period after awakening whenthey can t move or speak that is often frightening to those who go through it.The lastcharacteristic of narcolepsy is hypnagogic hallucinations, vivid and often terrifyingexperiences that begin at the start of sleep and are said to be unbelievably realisticbecause they include not only visual aspects but also touch, hearing, and even thesensation of body movement.Examples of hypnagogic hallucinations, which, likesleep paralysis, can be terrifying, include the vivid illusion of being caught in a fire orflying through the air.Durand 8-85Narcolepsy is relatively rare, occurring in 0.03% to 0.16% of the population, withthe numbers approximately equal among males and females.Although some caseshave been reported in young children, the problems associated with narcolepsyusually are first seen during the teenage years.Excessive sleepiness usually occursfirst, with cataplexy appearing either at the same time or with a delay of up to 30years.Fortunately, the cataplexy, hypnagogic hallucinations, and sleep paralysis oftendecrease in frequency over time, although sleepiness during the day does not seem todiminish with age.Sleep paralysis and hypnagogic hallucinations may serve a role in explaining amost unusual phenomenon UFO experiences.Each year numerous people reportsighting unidentified flying objects UFOs and some even tell of visiting withinhabitants of other planets (Sheaffer, 1986).A group of scientists examined peoplewho had had such experiences, separating them into those who had nonintenseexperiences (seeing only lights and shapes in the sky) and those with intenseexperiences (seeing and communicating with aliens) (Spanos, Cross, Dickson, &DuBreuil, 1993).They found that a majority of the reported UFO incidents occurredat night and that 60% of the intense UFO stories were associated with sleep episodes.Specifically, the reports of these intense accounts were often described in ways thatresembled accounts of people experiencing a frightening episode of sleep paralysisand hypnagogic hallucination, as illustrated by the following account:I was lying in bed facing the wall, and suddenly my heart started to race.I couldfeel the presence of three entities standing beside me.I was unable to move mybody but could move my eyes.One of the entities, a male, was laughing at me, notverbally but with his mind.He made me feel stupid.He told me telepathically,Durand 8-86 Don t you know by now that you can t do anything unless we let you? (Spanos,Cross, Dickson, & DuBreuil, 1993, p.627)The realistic and frightening stories of people who have had UFO sightings maynot be the products of an active imagination or the results of a hoax, but at least insome cases they may be a disturbance of sleep.Sleep paralysis and hypnagogichallucinations do occur in a portion of people without narcolepsy, a phenomenon thatmay help explain why not everyone with these  otherworldly experiences hasnarcolepsy.Specific genetic models of narcolepsy are now being articulated (Wieczorek et al.,2003).Previous research with Doberman pinschers and Labrador retrievers, who alsoinherit this disorder, suggests that narcolepsy is associated with a cluster of genes onchromosome 6, and it may be an autosomal recessive trait.Advances in understandingthe etiology and treatment of such disorders can be credited to the help of  man s bestfriend.Breathing-Related Sleep DisordersFor some people, sleepiness during the day or disrupted sleep at night has a physicalorigin, namely, problems with breathing while asleep.In DSM-IV-TR these problemsare diagnosed as breathing-related sleep disorders.People whose breathing isinterrupted during their sleep experience numerous brief arousals throughout the nightand do not feel rested even after 8 or 9 hours asleep (Bootzin, Manber, Perlis, Salvio,& Wyatt, 1993).For all of us, the muscles in the upper airway relax during sleep,constricting the passageway somewhat and making breathing a little more difficult.For some, unfortunately, breathing is constricted a great deal and may be labored(hypoventilation); in the extreme, there may be short periods (10 to 30 seconds) whenDurand 8-87they stop breathing altogether, called sleep apnea.Often the affected person is onlyminimally aware of breathing difficulties and doesn t attribute the sleep problems tothe breathing.However, a bed partner usually notices loud snoring (which is one signof this problem) or will have noticed frightening episodes of interrupted breathing.Other signs that a person has breathing difficulties are heavy sweating during thenight, morning headaches, and episodes of falling asleep during the day (sleepattacks) with no resulting feeling of being rested(Neylan et al., 2003).There are three types of apnea, each with different causes, daytime complaints,and treatment: obstructive, central, and mixed sleep apnea.Obstructive sleep apnea(OSA) occurs when airflow stops despite continued activity by the respiratory system(Bassiri & Guilleminault, 2000).In some people, the airway is too narrow; in others,some abnormality or damage interferes with the ongoing effort to breathe.Onehundred percent of a group of people with OSA reported snoring at night(Guilleminault, 1989) [ Pobierz całość w formacie PDF ]