Prevalence Common complaint (730% general population), 5 > 4, greater in the eld- erly. \200\230Clinically signi \201 cant insomnia \200\231 (causing marked personal distress or interference with social and occupational functioning) 9 \200\22312%. Primary causes (see Table 11.1) \200 Psychophysiological insomnia: with associated somatized tension anxiety: over-concern with inability to sleep, and learned sleep prevention. Paradoxical insomnia: also called \200 \230sleep state misperception \200\231: patient complains of little or no sleep without obj ective evidence of sleep disturbance. Adjustment sleep disorder: stress, con \202 ict, or environmental change, causing emotional arousal. Disorder usually resolves once the stresso r is no longer present. clinically signi \201 cant disruption of the normal Inadequate sle ep hygiene: sleep \200\223wake schedule due to a wide range of daily living activities (e.g . level of coffee consumption, frequent late nights) is inconsistent with the maintenance o f good-quality sleep and full daytime alertness. Understanding the contribution of each fac tor and taking steps to eliminate or minimize their effects usually sorts out the problem. Idiopathic insomnia: Behavioral insomnia of childhood: \200 dif \201 culty initiating and maintaining sleep, sleep disturbance temporally related to \200 Rare, lifelong inability to sleep adequately. includes two common subtypes: \200\224estimated prevalence 5 \200\22310% in children, Limi t-setting sleep disorder characterized by inadequate enforcement of bedtimes by a caregiver , with resultant stalling or refusal to go to bed at an appropriate time. Sleep-onset assoc iation disorder \200\224occurring mainly in children aged 6mths to 3yrs, sleep onset is im paired by the absence of a certain object (e.g. favorite toy) or set of circumstances (spec i \201 c routine, TV, night-light). Less commonly: childhood problem (prevalence 5% in chi ldren aged 6mths to 3yrs), with marked decrease after weaning, characterized by recurrent a wakenings and inability to return to sleep without eating or drinking. nocturnal eating (drinking) syndrome \200\224primarily a Other sleep disorders: \200 Environmental sleep disorder due to disturbing environmental factor(s) (e.g. heat, cold, no ise, \200\224common transient sleep disturbance 11_Semple_Chap11.indd 424 12/10/2012 6:28:57 PM INSOMNIA 1: OVERVIEW 425 light, excessive movement of bed partner, danger, allergens, hospitalization, unfamiliar su rroundings) leading to insomnia or excessive sleepiness. Altitude insomnia \200\224unusual form of acute insomnia, accompanied by headaches, loss of appetite, and fatigue, occuring at high altitudes in the absence of administered oxygen. Seen in 25% of individuals who asc end above 2000m above sea level, and in most individuals above 4000m. Food allergy insomnia sleep due to an allergic response to food allergens. \200\224a rare disorder of initiating and maintaining Secondary or comorbid causes \200 Sleep disorders classi \201 ed elsewhere: (b p. 428); circadian rhythm disorders (b p. 436); sleep-related movement disorders (b p. 450). Insomni a due to medical condition: headache), respiratory disorders (COPD, cystic \201 brosis, a sthma), diabetes, Parkinson \200\231s disease, endocrine disorders (Addison \200\231s disea se, Cushing \200\231s syndrome). Insomnia due to mental disorder Drugs and alcohol SSRIs, v enlafaxine, reboxetine); anti-Parkinsonian medication; bronchodilators (e.g. aminophylline, theophylline, pseudoephedrine); cardiovascular medication (e.g. -blockers, clonidine, hi gh-dose digoxin, verapamil); chemotherapy agents; corticosteroids/anabolic steroids; NSAIDs (high-dose); stimulants (e.g. dexamfetamine methylphenidate, amfetamine cocaine, caffeine, nicotine); levothyroxine withdrawal/ dependency (e.g. hypnotics, opiates, alcohol, or cann abis). sleep-related breathing disorders pain (arthritis, peptic ulcer, \200 (see b pp. 454 \200\2237). (see also b p. 458). Antidepressants (e.g. MAOIs, Table 11.1 Classi \201 cation of insomnia with diagnostic codes ICSD-2 ICD-10 DSM-IV-TR Psychophysiological insomnia F51.04 307.42 Paradoxical insomnia F51.03 307.42 Adjustment insomnia F51.02 307.42 Inadequate sleep hygiene Z72.821 307.42 Idiopathic F51.01 307.42 Insomnia due to mental disorder F51.05 327.02 Behavioral insomnia of childhood Z73.81 307.42 Insomnia due to a medical condition G47.09 327.01 Insomnia due to a drug or substance F11 \200\22319.x 291.85 Insomnia due to alcohol F10.x 291.82 Physiological (organic) insomnia, unspeci \201 ed G47.00 Insomnia not due to a substance or known physiological condition, unspeci \201 ed F51.09 11_Semple_Chap11.indd 425 12/10/2012 6:28:57 PM CHAPTER 11 Sleep disorders 426 Insomnia 2: general management strategies Education about sleep Many myths surround sleep and the clinician should be able to educate the patient about the stages of sleep, sleep cycles, changes in sleep patterns with age, a nd the nature of the particular sleep problem or disorder the patient presents with. Sleep hygiene Establishing good sleep habits Control environmental factors (noise, light, t emperature); \200\230wind down \200\231 time (71hr) before going to bed: distract from the day \200\231s stresses (reading, watching television, listening to music, having a warm ba th); avoidance of caffeine-containing drinks after about 16.00hr; not smoking for at least 1 hr before bed; regular exercise (not late at night); late \200\230tryptophan \200\231 sn ack (warm milk or other milky drink); avoid naps during the day (or con \201 ne naps to th e early afternoon, not longer than 740min); set aside time during the day to re \202 ect o n problems and stresses. Stimulus control Go to bed only when sleepy; avoid other activities (with the exception of sex) whilst in bed; if sleep does not occur, do not remain in bed for more than 10 \200\223 20min, get up and go to another room (without turning on all the lights), returning to bed only when sleepy; establish a regular time to get up, with no more than 1hr variation (even at weekends and during holidays). Relaxation training The regular practice of relaxation t echniques during the day (particularly progressive relaxation) may help to provide patients with the means to reduce general arousal, which can be used if necessary whilst in bed. Sleep restriction When sleep is fragmented, a sleep restriction strategy may help to reduce total time spent in bed and improve quality of sleep by \200\230consolidation \200\231. T here are a number of steps to sleep restriction, and to complete the program does require m otivation and encouragement (see Box 11.2). Medication Despite prevailing public perception that insomnia is best treated by use of a s leeping tablet \200\224prescribing should be last option, rather than \201 rst. Before a hypnotic is prescribed, cause of insomnia should be estab- lished, possible underlying fact ors addressed, and any primary medical or psychiatric disorder effectively treated. Should only be used to treat insomnia when it is severe, disabling, or subjects individual to extr eme distress. Ideally, hypnotics should be short-term adjuncts to other forms of therapy an d avoid prolonged administration. Interrupted courses (i.e. 5 nights with medication, 2 wit hout) for no more than 4wks may help avoid tolerance and reduce \200\230rebound insomnia \200\231 often accompanying ces- sation. Choices (see Table 11.2) include: benzodiazepines, the \200\230Z-drugs \200\231 11_Semple_Chap11.indd 426 12/10/2012 6:28:57 PM INSOMNIA 2: GENERAL MANAGEMENT STRATEGIES 427 (zopiclone, zolpidem, zapeplon \200\224usually \201 rst line), chloral hydrate, sedat- in g antidepressants (e.g. trazodone, mirtazapine), sedating antipsychotic, and possibly melat onin agonists. Box 11.2 Sleep restriction \200 Keep a sleep diary for 5 \200\22314 days to allow the calculation of total sleep time (TST) and sleep ef \201 ciency (SE). TST = (total time spent in bed) \200\223 (time spent awak e during night). SE = (TST \227 100)/total time spent in bed. For \201 rst few nights of a sleep restriction program spend only the same number of hours in bed as the average TST for the past week. No naps allowed during the day (despite initial tiredness). Continue to keep sleep diary. When the calculated mean SE for 5 nights reaches 85% or better, go to bed 15min earlier. Repeat procedure with increases of 15min if mean SE remains 85% or better, or decreases of 15min if the mean SE falls below 85%, until a satisfactory amount of night- time sleep is achieved. \200 \200 Table 11.2 Pharmacokinetic data for drugs used as hypnotics (in order of decreasing Thalf)1 Drug Availability (%) Plasma Time to Tmax (hr) Thalf (hr) bound (%) Mirtazapine 50 85 0.25 \200\2232 16.3 \200\22340 Nitrazepam 78 85 \200\22387 0.5 \200\2235 15 \200\22340 Olanzapine 60 93 5 \200\2236 24 \200\22330 Temazepam 91 96 \200\22398 0.75 \200\2233 2 \200\22325 Promethazine 12.3 \200\22325 \200\224 4.39 18.6 Trazodone 60 \200\22380 89 \200\22395 1 \200\2232 6 \200\22315 Lormetazepam 70 \200\22380 92 2 7.9 \200\22312 Chloral hydrate2 \200\224 35 0.76 \200\2238.2 9.3 \200\22310.9 Quetiapine \200\224 83 1 \200\2232 5.3 \200\2237 Zopiclone 70 \200\22380 45 \200\22380 0.25 \200\2231.5 3.5 \200\2236.5 Zolpidem 70 90 \200\22392 0.5 \200\2232.6 1.5 \200\2234.5 Agomelatine3 <5 95 1 \200\2232 1 \200\2232 Zaleplon 30 60 0.25 \200\2231.5 0.9 \200\2231.1 1 BAP Consensus Guidelines (2010) M http://www.bap.org.uk/pdfs/BAP_Sleep_Guidelines.pdf 2 T half is so short, values are for the primary active metabolite trichloroethanol 3 Source: M http://www.servier.co.uk/products/valdoxan/ 11_Semple_Chap11.indd 427 12/10/2012 6:28:58 PM CHAPTER 11 Sleep disorders 428 Sleep-related breathing disorders Essence Sleep-related breathing disorders (see Table 11.3 ) commonly lead to chronic insomnia and daytime tiredness. Caused by CNS dysfunction, path- ological processes affecting normal lung function, and environmental fac- tors. Obstructiv e sleep apnoea often missed in psychiatric patients despite obvious risk factors (see Centr al sleep apnoea syndromes. Associated with signi \201 cant comorbidity including: hyperten sion, arrhythmias and con- duction disturbances, cardiac or cerebral ischaemia, functional cognitive impairment, and depression. Central sleep apnoea syndromes \200 Primary central sleep apnoea: characterized by recurrent episodes of breathing cessation du ring sleep without associated respiratory effort. Usually leads to EDS, insomnia, or breath ing dif \201 culties during sleep. PSG shows no evidence of hypercapnia and 5+ episodes of apnoea per hour of sleep. Central sleep apnoea including Cheyne \200\223Stokes breathing p attern: recurrent apnoeas and/or hypopnoeas alternating with prolonged hyperpnoea in a cres cendo \200\223decrescendo pattern. Seen in NREM sleep; associated with heart or renal failu re, and cerebrovascular disorders. Central sleep apnoea due to a drug or substance: associa ted with long-term opioid use, due to suppression of respiration through -receptors in th e ventral medulla. Other causes of central sleep apnoea: high-altitude breathing pattern \200 >2600m; characterized by 12 \200\22334s cycles of apnoea or hyperpnoea; other medical conditions demyelinating or traumatic condition involving the brain stem; primary sleep ap noea of infancy other medical problems \200\224includes \200\230apnoea of prematurity \200 \231 and \200\230apnoea of infancy \200\231). disorder of unknown etiology most commonly \200\224seen in most people at elevations of \200\224vascular, neoplastic, degenerative, \200\224developmental or secondary to Obstructive sleep apnoea1,2 (Pickwickian syndrome) Repeated episodes of upper airway obstru ction (hypopnoeas) or cessa- tion of breathing (apnoeas) during sleep, usually associated w ith reduced blood O2 saturation, daytime somnolence, loud snoring, and dry mouth. Usually m iddle-aged, overweight males. Prevalence 1 \200\2232%. PSG showing 5+ respiratory events: a pnoeas, hyponoeas, or respiratory effort-related arousals, makes the diagnosis. In children , cortical arousals less likely pos- sibly due to a higher arousal threshold. Management \200 General: weight loss, avoidance of sedative drugs, reduction of alcohol c onsumption/smoking, alternative sleeping position (not lying on back). Speci \201 c: oral appliances (for mild cases, e.g. sleep and nocturnal obstructive apnoea redactor [SNOAR]); continuous positive airway pressure (CPAP);3 bi-level positive airways pressure (BiPAP). Su rgical uvulopalatopharyngoplasty (UPPP), bimalleolar advancement, and rarely tracheostomy. (for severe cases): nasal reconstruction, tonsillectomy, 11_Semple_Chap11.indd 428 12/10/2012 6:28:58 PM SLEEP-RELATED BREATHING DISORDERS 429 Other causes Sleep-related hypoventilation/hypoxaemic syndromes are caused by a variety of disorders including: idiopathic, congenital central alveolar hypo- ventilation ( \200\230On dine \200\231s curse \200\231: the extremely rare failure of automatic central control of b reathing in infants who do not breathe spontaneously, or only shallowly and erratically). M edical conditions (speci \201 c pulmonary disease: COPD, cystic \201 brosis, and interst itial lung disease; other causes of abnor- mality in lung or vascular pathology, lower airw ays obstruction, neuromus- cular or chest wall disorders.) Table 11.3 Classi \201 cation of sleep-related breathing disorders with diagnostic codes ICSD-2 ICD-10 DSM-IV-TR Primary central sleep apnoea G47.31 780.57 Central sleep apnoea including Cheyne \200\223Stokes breathing pattern G47.39 780.57 or 327.xx Central sleep apnoea including high-altitude periodic breathing G47.37 780.57 or 327.xx Central sleep apnoea due to a medical condition not Cheyne \200\223Stokes breathing pattern 327.xx Central sleep apnoea due to a drug or substance F10 \200\22319.x Primary sleep apnoea of infancy P28.3 Obstructive sleep apnoea, adult G47.33 780.57 Obstructive sleep apnoea, pediatric G47.33 780.57 Sleep-related non-obstructive alveolar hypoventilation, idiopathic G47.34 780.57 Sleep-related hypoventilation/hypoxaemia due to lower airways obstruction G47.36 Sleep-related hypoventilation/hypoxaemia due to neuromuscular and chest wall disorders G47.36 Sleep-related hypoventilation/hypoxaemia due to pulmonary parenchymal or vascular pathology G47.36 Congenital central alveolar hypoventilation syndrome G47.35 Sleep apnoea/sleep-related breathing disorder, unspeci \201 ed G47.30 780.57 1 SIGN Guideline 73 (Jun 2003). M http://www.sign.ac.uk/pdf/sign73.pdf 2 Morgenthaler TI, K apen S, Lee-Chiong T, et al. (2006) Standards of Practice Committee, American Academy of Sl eep Medicine. Practice parameters for the medical therapy of obstructive sleep apnea. Sleep 29: 1031 \200\2235. 3 NICE (Mar 2008) Technology appraisal 139 for CPAP treatment of OSA/h ypopnoea syndrome. M http://www.nice.org.uk/nicemedia/pdf/TA139Guidance.pdf 11_Semple_Chap11.indd 429 12/10/2012 6:28:58 PM CHAPTER 11 Sleep disorders 430 Hypersomnia 1: overview 1 Excessive sleepiness is a leading cause of road traf \201 c acci dents. Essence \200\230Hypersomnia \200\231 covers a number of different forms of excessive dayti me sleepiness (EDS). Patient may complain of \200\230sleep attacks \200\231 (recurrent day time sleep episodes that may be refreshing or unrefreshing), \200\230sleep drunkenness \200\231 (prolonged transition to a fully aroused state on waking), lengthening of night-ti me sleep, almost constant EDS, even recurrent periods of more or less permanent sleep lasti ng several days over several months. Diagnosis and treatment particularly relevant when the individual works in an industry or profession where vigilance and concentration are essent ial (e.g. hospital workers, pilots, train drivers, the military). The most commonly used ra ting scale is the Epworth Sleepiness Scale (see Table 11.4). Prevalence Common: moderate (occasional) EDS reported in up to 15% in the general populatio n (severe EDS 5%). Differential diagnosis (see Table 11.5) \200 \200 with or without cataplexy (b p. 432). Narcolepsy: Recurrent hypersomnia: hypersomnia, see b p. 434. Idiopathic hypersomnia: Behav iourally-induced insuf \201 cient sleep syndrome Hypersomnia due to a medical condition: d iencephalic tumors, thalamic infarcts, Parkinson \200\231s disease, multiple system atrophy , NPH, Arnold \200\223Chiari malformation, myotonic dystrophy, head injury \200\224 \200 \230post-traumatic hypersomnia \200\231: lesions (when they can be demonstrated) generally involve the brain stem (the tegmentum of the pons or thalamic projections) or the posterior hypothalamus), infectious (EBV, atypical viral pneumonia, hep B, Guillain \200\223Barr s yndrome, viral encephalitis, sleeping sickness [trypanosomiasis \200\224sleepiness, headach e, trembling, dyskinesias, choreoathetosis, mood changes]), metabolic, and endocrine disord ers (hypothyroidism, acromegaly, cause OSA). (see b p. 458): Hypersomnia due to a drug, sub stance or alcohol includes dependency-related sleep disorders (alcohol, hypnotics, opiates) , toxins (arsenic, bismuth, mercury, copper, other heavy metals, carbon monoxide, vitamin A ), medication-related (e.g. anticonvulsants, antidepressants, anti-emetics, antihistamines, anti- Parkinsonian drugs, antipsychotics, anxiolytics/hypnotics, clonidine, methyldopa, pr azosin, reserpine, hyoscine, progestogens). Hypersomnia not due to a substance or known phy siological condition (see b p. 454): essentially psychiatric causes. Hypersomnia associated with other sleep disorders: syndromes (b p. 428), PLMS (b p. 450), circadian rhythm disord ers, e.g. DSPS (b p. 436). Kleine \200\223Levin syndrome, menstrual-related \200 \200 with or without long sleep time (b p. 434). (b p. 435). neurological (altered ICP, e.g. sleep apnoea 11_Semple_Chap11.indd 430 12/10/2012 6:28:58 PM HYPERSOMNIA 1: OVERVIEW 431 Table 11.4 Epworth Sleepiness Scale (ESS)1 Score2 Chance of dosing situation Sitting and reading 0 1 2 3 Watching television 0 1 2 3 Sitting inactive in a public place (e.g. in a theater or a meeting) 0 1 2 3 As a passenger in a car for an hour without a break 0 1 2 3 Lying down to rest in the afternoon when circumstances permit 0 1 2 3 Sitting and talking to someone 0 1 2 3 Sitting quietly after a lunch without alcohol 0 1 2 3 In a car, while stopped for a few minutes in traf \201 c 0 1 2 3 1 Johns MW (1991) A new method for measuring daytime sleepiness: the Epworth Sleepiness Sca le. Sleep 14: 540 \200\2235. 2 Patient is instructed to use scale to choose most appropriat e number for each situation: 0 = no chance of dozing, 1 = slight chance, 2 = moderate chanc e, 3 = high chance. Maximum score on this scale is 24; however, scores >10 often considered to be consistent with some degree of daytime sleepiness, while scores >15 considered to be consistent with EDS. Table 11.5 Classi \201 cation of hypersomnia not due to sleep-related breathing disorders with diagnostic codes ICSD-2 ICD-10 DSM-IV-TR Narcolepsy with cataplexy G47.41 Narcolepsy without cataplexy G47.419 Narcolepsy due to medical condition with cataplexy G47.42 Narcolepsy due to medical condition without cataplexy G47.42 Narcolepsy, unspeci \201 ed 347.00 Recurrent hypersomnia G47.13 307.44 Idiopathic hypersomnia with long sleep time G47.11 307.44 Idiopathic hypersomnia without long sleep time G47.12 307.44 Behaviourally induced insuf \201 cient sleep syndrome F51.12 Hypersomnia due to a medical condition G47.14 327.14 Hypersomnia due to a drug or substance F10 \200\22319 292.85 Hypersomnia due to alcohol F10 \200\22319 292.82 Hypersomnia not due to a substance or known physiological condition F51.19 327.15 Physiological (organic) hypersomnia, unspeci \201 ed G47.10 11_Semple_Chap11.indd 431 12/10/2012 6:28:59 PM CHAPTER 11 Sleep disorders 432 Hypersomnia 2: narcolepsy First described by Westphal in 18771 and given it name by G line au in 1880,2 narcolepsy is now divided into three separate entities: narcolepsy with catapl exy, without cataplexy, and due to medical disorder (see Table 11.5). Narcolepsy seriously impacts on education, work, relationships, abil- ity to drive, recreational activities, and can have negative effects on self- esteem and mood. Narcolepsy with cataplexy Prevalence The most common neurological cause of hypersomnia, esti- mated prevalence 0.20 \200\2230.40 per 1000 in the general population. Sex ratio is equal. Age range: 10 \200\223 50+yrs (70 \200\22380% before 25yrs). Etiology May be due to hypocretin de \201 ciency. Clinical features \200 3 excessive sleepiness, cataplexy, sleep The classical \200\230tetrad \200\231 of symptoms : paralysis, and hypnagogic hallucinations are suffered by only a minority of patients with narcolepsy. Excessive daytime sleepiness and associated cataplexy (sudden bilateral loss o f muscle tone, with preserved consciousness, triggered by a strong emotional reaction such as laughter or anger) are by far the most common complaints. More often a cataplectic attac k will be partial, e.g. involving jaw muscles (dif \201 culty with articulation), facial m uscles (grimacing), or thigh muscles (brief unlocking of the knees). Attacks vary from seco nds to minutes, with a frequency of a few a year to several a day, and very rarely repeated \200\230status cataplecticus \200\231. Other REM sleep phenomena also occur, but are not necessary for the diagnosis to be made. These include sleep paralysis (sometimes up to 10mi n long) and vivid hallucinations on falling asleep (hypnagogic) or, less commonly, waking u p (hypnopompic). Sleep may also be disturbed due to frequent awakenings, disturbing dreams, sleep-talking, and REM-related sleep behaviors (from phasic muscle twitching to more drama tic dream enactment). Course Usually chronic, although some of the symptoms may improve or remit. Hallucinations and sleep paralysis present variably, and sometimes cataplexy may disappear over time. Poor sleep quality tends to persist. Treatments are directed at the most troublesome symptoms. Differential diagnosis \200 Sleep attacks in narcolepsy are usually irresistible and refreshing, whereas in other forms of hypersomnia they tend to be more frequent, of longer duration, easier to resist, and un refreshing. The attacks also tend to occur in unusual and often dangerous situations in nar colepsy (e.g. talking, eating, standing, walking, or driving). Disturbances and shortening of nocturnal sleep are more common in narcolepsy \200\224in other causes of hypersomnia noc turnal sleep is usually prolonged and there is dif \201 culty in waking in the morning. 11_Semple_Chap11.indd 432 12/10/2012 6:28:59 PM HYPERSOMNIA 2: NARCOLEPSY 433 Investigations \200 Polysomnography (SOREMP) is highly speci \201 c (25 \200\22350% of cases); increased N1 sl eep and repeated awakenings. ICSD-2 criteria: sleep latency of 10min or less, REM sleep lat ency of 20min or less, MSLT: mean sleep latency of 8min or less, and two or more SOREMPs. l evels below 110pg/mL are highly speci \201 c and CSF hypocretin-1 levels: sensitive for na rcolepsy with cataplexy (in 10% levels may be normal). HLA (human leukocyte antigen) typing : between HLA-DR2 haplotypes coded on chromosome 6 and narcolepsy: HLA DQB1*0602 and DQA1*0 102 are found in up to 85 \200\22395% of individuals, compared with 12 \200\22338% in the g eneral population. (sleep EEG and MSLT): sleep onset REM period there is a strong association Management \200 Daytime somnolence methylphenidate, dexamfetamine). Possibly sodium oxybate (GHB). Cataplex y possibly other antidepressants: venlafaxine, nefazodone, mirtazapine, atomoxetine). These drugs may also improve REM-related symptoms, hypnagogic/hypnopompic hallucinations, and sl eep paralysis. Note: abrupt withdrawal of antidepressants may potentially cause cataplectic episodes or even \200\230status cataplecticus \200\231. Sodium oxybate is newly licensed for cataplexy,4 is not associated with a rebound cataplexy on withdrawal, but can cause sig ni \201 cant side-effects (nausea, nocturnal enuresis, confusional arousals, headache) and there is a danger of abuse. Other treatments for poor sleep and REM-related symptoms: benz odiazepines (e.g. clonazepam) and possibly sodium oxybate. Regular naps, stimulants (moda \201 nil, TCAs (clomipramine 10 \200\22375mg/day is licensed) or SSRIs (and Narcolepsy without cataplexy The occurrence of EDS and irresistible episodes of sleep witho ut associ- ated cataplexy. Other features may also be present, e.g. automatic behav- iour, hypnic hallucinations or sleep paralysis. Nocturnal sleep is usually less disturbed than in narcolepsy with cataplexy. PSG with MSLT showing mean sleep latency of <8min and >2 SOREMP s is required for diagnosis. Cataplexy may develop later in the course of the disorder. Narcolepsy due to medical condition An extremely rare form of narcolepsy, ICSD-2 requires t he following criteria: \200 \200 \200 The co-occurrence of EDS with cataplexy. PSG with MSLT showing mean sleep latency of <8min and >2 SOREMPs. CSF hypocretin-1 levels less than 110pg/mL (provided the patient is not com atose). A consistent chronological link with the presumed underlying causative medical cond ition. 1 Westphal C (1877) Eigent mliche mit Einschlafen verbundene Anf lle. Arch Psychiat Nerve nkrankeheiten 7: 631 \200\2235. 2 G lineau J (1880) De la narcolepsie. Gaz H p (Paris) 53 : 626 \200\2238; 635 \200\2237. 3 Yoss RE, Daly DD (1957) Criteria for the diagnosis of the narcoleptic syndrome Mayo Clin Proc 32: 320 \200\2238. 4 http://www.ukmi.nhs.uk/NewMateria l/html/docs/SodiumOxybateNMP0603.pdf 11_Semple_Chap11.indd 433 12/10/2012 6:28:59 PM CHAPTER 11 Sleep disorders 434 Hypersomnia 3: other causes Recurrent hypersomnia Kleine \200\223Levin syndrome1 A rare syn drome of \200\230periodic somnolence and morbid hunger \200\231, occur- ring almost exclus ively in male adolescents, usually following a course of decreasing frequency of attacks, w hich may persist for many years before complete cessation. Clinical features Periods lasting from days to weeks of attacks of hypersomnia accompa- nie d by excessive food intake (megaphagia). Other behavioral symptoms may occur including sexu al disinhibition (which may appear compulsive in nature), along with a variety of other psy chiatric symptoms such as confusion, irritability, restlessness, euphoria, hallucinations, delusions, and schizophreniform states. Attacks may occur every 1 \200\2236mths, and last f rom 1 day to a few weeks. Between attacks the patients recover completely, and the syndrome may easily be confused for other neurological, meta- bolic, or psychiatric disease. Management \200 \200 Hypersomnia Preventative measures : for suf \201 ciently frequent episodes causing major d isruption of social or occupational functioning \200\224lithium, carbamazepine, or valproat e. : stimulants (only effective for short periods of time). Menstrual-related hypersomnia Characterized by excessive daytime sleepiness preceding menst ruation, with detectable alterations in polysomnography when symptomatic. Etiology Unknown; no clear hormonal differences have been found. Management Stimulants \200\224reserved only for symptomatic periods. Idiopathic hypersomnia2 Clinical features \200 nocturnal sleep is With long sleep time (polysymptomatic form): prolonged (10hrs or more), with sleep drunkenn ess on waking, and constant or recurrent EDS with frequent, unrefreshing naps. EDS alone. W ithout long sleep time (monosymptomatic form): Course A chronic condition with marked impact on social and occupa- tional functioning. Diagnosis Detailed history (to exclude other causes of hypersomnia); PSG normal; MSLT <8min (longer than narcolepsy), <2 SOREMPs. Differential diagnosis Narcolepsy, sleep apnoea syndromes, periodic limb movement disorder, or upper airways resistance syndrome. Management As for narcolepsy (but naps do not help). 11_Semple_Chap11.indd 434 12/10/2012 6:28:59 PM HYPERSOMNIA 3: OTHER CAUSES 435 Hypersomnia not due to substance or known physiological condition EDS due to underlying (un diagnosed) psychiatric disorder, e.g. bipolar II disorder, dysthymic disorder, SAD, undiffe rentiated somatoform disorder, adjustment disorder, personality disorder. Prevalence May be the cause of up to 7% of hypersomnia referred to sleep centers. More comm on in women. Clinical features Marked reported EDS, high Epworth Sleepiness Scale scores, sleep perceive d as poor quality and non-restorative, excessive time spent in bed during both day and nigh t ( \200\230clinophilia \200\231). Diagnosis Careful history essential. PSG (not usually necessary): increased sleep latency, increased wake time after sleep onset, low sleep ef \201 ciency. MSLT usually normal. Management Directed at the underlying psychiatric disorder. Behaviourally-induced insuf \201 cient sleep syndrome Persistently failing to obtain suf \201 cient nocturnal sleep required to support normally alert wakefulness. Prevalence Unknown, but may be the most common cause of hypersom- nia in the general popula tion, particularly amongst parents of young chil- dren, doctors, students, long-distance lo rry drivers, and other occupations where unsociable long hours of work are commonplace. Clinical features Periods of excessive sleepiness concentrated in the afternoon and early e vening. Rest days usually characterized by late rising from bed and frequent naps. Associat ed reduced productivity, dif \201 culty in concentration and attention, low mood or irrita bility, and somatic symp- toms (usually gastrointestinal or musculoskeletal). Diagnosis Made on history alone. Management Directed towards scheduling increased time asleep, either at night or with regul ar short naps during the day. 1 Originally described by Willi Kleine in 1925 and subsequently by Max Levin in 1936, the e ponym \200\230Kleine \200\223Levin syndrome \200\231 was coined by Critchley and Hoffman i n 1942. 2 Roth B (1976) Narcolepsy and hypersomnia: review and classi \201 cation of 642 p ersonally observed cases. Schweiz Arch Neurol Neurochir Psychiat 119: 31 \200\22341. 11_Semple_Chap11.indd 435 12/10/2012 6:28:59 PM CHAPTER 11 Sleep disorders 436 Circadian rhythm sleep disorders 1: overview Essence When an individual \200\231s sleep/wake schedule is not in synchrony with the sleep \200\223wake schedule of their cultural environment or society, it may lead to complaints of insomnia or EDS, causing marked distress or interference with social or occupational fun ctioning. Subtypes (see Table 11.6) Table 11.6 Classi \201 cation of circadian rhythm sleep disorders (CRSD) with diagnostic c odes ICSD-2 ICD-10 DSM-IV-TR Delayed sleep phase type G47.21 327.31 Advanced sleep phase type G47.22 Irregular sleep-wake type G47.23 Non-entrained type (free running) G47.24 Circadian rhythm sleep disorder due to a medical condition G47.20 Other circadian rhythm sleep disorder G47.20 Jet lag type F51.21 327.35 Shift work type F51.22 327.36 Circadian rhythm sleep disorder due to a drug or substance F11 \200\22319.x 292.85 Circadian rhythm sleep disorder due to alcohol F10.x 291.82 Delayed sleep phase syndrome (DSPS) The late appearance of sleep (typically around 02.00hr) , but normal total sleep time and architecture, which may lead to complaints of sleep-onset insomnia and dif \201 culty awakening at the desired time in the morning. Cause is unknow n, although some cases are related to head injury, psychiatric disorder, or personality tra its (e.g. schizoid, avoidant). Usually presents in adolescence, running a continuing course until old age. Individuals may adapt to the condition by taking evening or night jobs. Advanced sleep phase syndrome (ASPS) The opposite of DSPS, this syndrome leads to complaint s of evening sleep- iness, early sleep onset (e.g. 18.00 \200\22320.00hr), and early mornin g wakening. May be confused with depression (due to early morning wakening), partic- ularly in elderly patients in whom the syndrome occurs more frequently. Irregular sleep \200\223wake pattern Sleep occurrence and waking behavior are very variable , leading to con- siderable disturbance of the normal sleep \200\223wake cycle and complain ts of 11_Semple_Chap11.indd 436 12/10/2012 6:28:59 PM CIRCADIAN RHYTHM SLEEP DISORDERS 1: OVERVIEW 437 insomnia (inadequate nocturnal sleep and daytime somnolence/frequent napping). The idiopath ic form is rare, and it is associated with Alzheimer \200\231s disease, head injury, develo pmental disorders, and hypothalamic tumors. Non-entrained type (free running) Rare occurrence of a greater than 24-hr sleep \200\223wak e period, leading to a chronic pattern of 1 \200\2232hr daily delays in sleep onset and wak e times, with an \200\230in-phase \200\231 period every few weeks (free of symptoms). Asso ciated with schizoid personality traits and may occur more frequently in blind individuals. Jet lag type Sleep disorder secondary to moving between time zones. Symptoms include varyin g degrees of dif \201 culty in initiating or maintaining sleep, day- time fatigue, decreme nts in subjective daytime alertness and performance, feelings of apathy, malaise or depress ion, and somatic symptoms (GI upset, muscle aches, or headaches). Shift work type Symptoms of insomnia or excessive sleepiness occur as transient phe- nomena in most people working shifts. Adaptation to a change in shift- work schedule usually take s 1 \200\2232wks; however, rotating day/night shifts may present particular dif \201 culti es. Often sufferers consult with somatic complaints (general malaise, GI upset), rather tha n the underlying disorder of sleep. Investigations \200 \200 \200 \200 Comprehensive history. Use of a 14-day sleep \200\223wake chart. Actigraphy \200\224objecti ve measurement of the rest \200\223activity cycle. Polysomnography is rarely needed. Differential diagnosis \200 Poor sleep hygiene. \200 Depressive disorder. \200 Misuse of drugs (particularly stimulants or sedatives) and alcohol. ICSD-2 codes this as \200 \230CRSD due to drug or substance/alcohol \200\231. Note: lifestyle factors are also clearl y important. Physical conditions such as: dementia, head injury, other causes of brain dama ge or injury, and recovery from coma. ICSD-2 also codes this separately as \200\230CRSD du e to medical condition \200\231. 11_Semple_Chap11.indd 437 12/10/2012 6:29:00 PM CHAPTER 11 Sleep disorders 438 Circadian rhythm sleep disorders 2: management General measures These include education abo ut the nature of sleep and establishing good sleep habits. This is particularly important f or shift work sleep disorder in which alcohol, nicotine, and caffeine may be used to self-m edicate symp- toms. Other advice for shift-workers should emphasize maintenance of regular sleep and mealtimes whenever possible, use of naps to limit sleep loss, and minimization of environmental factors (noise, light, other inter- ruptions) when sleeping during the day. Chronotherapy DSPS \200 Establishing a regular waking time, with only 1hr variability at weekends and holidays, may help initially. If unsuccessful, \200\230 phase shift of the sleep \200\223wake cycle. Th is involves: \200 phase-delay \200\2311 methods may be employed to achieve a Establishing a 27-hr day to allow progressive delay of the usual onset of sleep by about 3h rs in each sleep cycle. Sleep should only be permitted for 7 \200\2238hrs, with no napping. The disruption to the person \200\231s normal routine caused by undergoing this regime (wh ich may take 5 \200\2237 days to complete) requires appropriate measures to be taken to ens ure other family and work commitments are attended to. \200 An alternative strategy is to advise the individual to remain awake at the weekend for one full night, and to go to bed the next evening 90mins earlier than usual. \200 \200 Sleep periods should again be limited to 7 \200\2238hrs, with no napping. The procedure can then be repeated each weekend until a normal bedtime is achieved. ASPS \200 \200 Delaying sleep onset by increments of 15mins may be effective. Alternatively \200\230 \200 phase-advance \200\2312 methods may be used: The patient goes to bed 3hrs earlier each night until the sleep cycle is advanced back to a normal bedtime. May be dif \201 cult to implement, particularly with elderly patients. Light therapy3 This includes both the use of bright light (2500 \200\22310000lux) with UV r ays \201 ltered out, and light restriction. Bright light is assumed to suppress mela- ton in (which is sleep-promoting). DSPS Exposure to bright light is scheduled on waking to prevent morning leth- argy, usually for 2hrs daily for 1wk, often with adjunctive light restriction after 16.00hr. 11_Semple_Chap11.indd 438 12/10/2012 6:29:00 PM CIRCADIAN RHYTHM SLEEP DISORDERS 2: MANAGEMENT 439 ASPS Exposure to bright light is recommended 2hrs before scheduled bedtime, to delay this t o a more sociable time. Note: evidence for the effectiveness of light therapy in other intr insic circadian rhythm disorders of sleep (e.g. shift-work sleep disorders, jet lag) is lac king. Medication \200 The entrainment of circadian rhythms through the use of appropriately timed short-acting BD Zs4 (e.g. lormetazepam) has been advocated, particularly for the treatment of jet lag. 5 (0 .5 \200\2235mg) also appears capable of advancing the sleep Melatonin phase and resetting t he circadian rhythm in travelers with jet lag syndrome \202 ying across \201 ve or more time zones, particularly in an easterly direction, and especially if they have experienced jet lag on previous journeys. 1 Czeisler CA, Richardson GS, Coleman RM, et al. (1981) Chronotherapy: resetting the circad ian- clocks of patients with delayed sleep phase insomnia. Sleep 4: 1 \200\22321. 2 Moldofs ky H, Musisi S, and Phillipson EA (1986) Treatment of a case of advanced sleep phase syndro me by phase advance chronotherapy. Sleep 9: 61 \200\2235. 3 Terman M, Lewy AJ, Dijk DJ, et al. (1995) Light treatment for sleep disorders: consensus report. IV. Sleep phase and durat ion disturbances. J Biol Rhythms 10(135): 47. 4 Buxton OM, Copinschi G, Van Onderbergen A, et al. (2000) A benzodiazepine hypnotic facilitates adaptation of circadian rhythms and sle ep \200\223wake homeostasis to an eight-hour delay shift simulating westward jet lag. Sleep 23(915): 27. 5 Herxheimer A and Petrie KJ (2002) Melatonin for the prevention and treatmen t of jet lag. Cochrane Database Syst Rev CD001520. 11_Semple_Chap11.indd 439 12/10/2012 6:29:00 PM CHAPTER 11 Sleep disorders 440