Light therapy phototherapy luminotherapy

Exposure to bright light has an alerting effect and leads to sleep phase changes. These are influenced by the following. The effect of light on the sleep phase is determined by the phase response curve (page 31). This has an inflection point at around the time of the temperature nadir (3.00-5.00 am). Light has more effect on changing the phase of sleep when it is applied close to the inflection point. Before this time it delays the onset of sleep and afterwards it causes a sleep phase advance....

Indications in sleep disorders

Some of the claims for the efficacy of melatonin have been exaggerated and there have been few controlled studies, particularly of its long-term use. Different doses and timing of administration of melatonin have been used in these reports, and some of the results are conflicting. It has two main indications as described below. Chronobiological (chronobiotic) agent This relies on its ability to reset the sleep phase. Its efficacy depends more on the timing than the size of the dose, although 5...

Aviation accidents

Awareness of the risks of flying while tired surfaced after Charles Lindbergh's flight from New York to Paris in 1927 which involved him being awake for 24 h beforehand and 33.5 h during the flight. Investigation into the crash of flight US2860 at 02.38 am on 18 December 1977 near Salt Lake City revealed that this was due to flight-crew fatigue, coupled with inadequate advice from an air traffic controller who was also sleep deprived. The pilot's reliance on automatic controls, which makes...

Disorders of the ribs

Congenital abnormalities rarely cause hypoventilation. Apart from a flail chest due to multiple traumatic rib fractures, the most important condition is that following a thoracoplasty. This was frequently performed for pulmonary tuberculosis before effective chemotherapy was introduced in the 1950s. Up to 11 ribs were resected, leading to a severe restrictive defect with paradoxical movement of the rib cage on the operated side. Diaphragmatic excursion is reduced and the combination of pleural...

Problems with use

This has not been well documented, but may develop in some narcoleptics. Table 4.5 Comparison of amphetamines and modafinil. Modafinil has little potential for drug dependency since it does not cause any euphoria. Cessation of treatment does not lead to any withdrawal symptoms or sleep rebound. Modafinil causes reversible inhibition and induction of some of the cytochrome P-450 enzymes and on theoretical grounds care should be taken if it is administered with anticoagulants and anticonvulsants,...

Restless Legs Syndrome Rating Scale

Have the patient rate his her symptoms for the following ten questions. The patient and not the examiner should make the ratings, but the examiner should be available to clarify any misunderstandings the patient may have about the questions. The examiner should mark the patient's answers on the form. (1) Overall, how would you rate the RLS discomfort in your legs or arms (2) Overall, how would you rate the need to move around because of your RLS symptoms (3) Overall, how much relief of your RLS...

Benign rolandic epilepsy benign epilepsy with centrotemporal spikes sylvian seizures

These seizures occur more frequently in males than in females and usually between the ages of 2 and 12 years. They are the most common simple partial seizures in childhood and represent 25 of childhood epilepsy. Twitching of the face, lips and tongue associated with dysarthria, difficulty in swallowing and drooling are characteristic. There may also be dysarthria after the episodes. Seventy-five per cent of subjects only have these seizures during sleep and in a further 15 they are seen both...

Sleep EEG changes during childhood

The EEG features during sleep change considerably with age as the brain matures. Normal values are less well established in young children than at other ages. Beta-delta complexes are present from around 26-38 weeks' gestation and are irregular 0.3-1.5 Hz waves of moderate to high amplitude superimposed on bursts of low-amplitude faster activity. They are a mark of prematurity, together with temporal theta bursts which appear at 26-33 weeks and temporal alpha bursts which follow them. Sleep...

Pathogenesis

The cyclical changes in respiration are due to an instability in the respiratory control system (Fig. 11.1). Within each stage of NREM sleep the respiratory drive remains constant, but it differs between stages. The frequent changes, at the onset of sleep and with arousal, lead to an unstable respiratory pattern. As the stage of sleep deepens, the arterial Pco2 which is required to act as a respiratory stimulus (the apnoeic threshold) rises. This leads to a central apnoea until the carbon...

Other actions and sideeffects

The benzodiazepines have little effect on the auto-nomic nervous system, but can cause the following. 1 Anxiolysis. This is seen with lower doses than are required to induce sedation or sleep and is common with long-acting hypnotics taken at night. Their anxiolytic effect probably has a similar underlying mechanism to the hypnotic effect. Oxazepam has relatively more anxiolytic and less hypnotic effect than other benzodiazepines. 3 Amnesia. Transient global anterograde amnesia is independent of...

Adenotonsillectomy

A tonsillectomy with adenoidectomy is the treatment of choice and should be performed in most children with OSA. Surgery should be considered even if the tonsils and adenoids are not markedly enlarged since it is not their absolute size, but their size relative to the airway diameter, that is important. Adenotonsillec-tomy is effective in around 90 of children, except in conditions such as Down's syndrome and craniofacial abnormalities where other factors contribute to the OSA. The long-term...

Asthma

Asthma is characterized by a widespread but variable increase in airflow resistance together with hyperinflation of the lungs. It has a circadian rhythm irrespective of the many environmental factors that affect its severity (Fig. 12.1) 2 . Nocturnal asthma may cause frequent arousals from sleep, particularly after the first cycle of NREM and REM sleep, and it may lead to excessive daytime sleepiness. The arousals are partly due to the increased work of breathing, but also to frequent coughing,...

Parkinsons disease idiopathic Parkinsonism

Parkinson's disease (page 226) frequently causes excessive daytime sleepiness 49 . This is reported in around 40 of subjects and polysomnography reveals a reduced sleep efficiency proportional to the disease severity, and often markedly shortened MSLTs. There is a reduction in stages 3 and 4 NREM sleep and REM sleep, but sleep-onset REM sleep is common. The cerebrospinal fluid hypocretin concentration may be reduced in advanced disease, but there is no association with HLA DQB1*0602, unlike in...

History

A careful history is essential to accurately assess insomnia (Chapter 3) (Table 7.4). The issues that should be considered are described below. 1 What is the nature of the insomnia Is the complaint mainly about poor sleep, or feeling tired during the day Is the insomnia at night due to a difficulty in initiating or maintaining sleep, or to early morning awakening, and is there a pattern of sleep reversal 2 What are the subject's sleep-wake routines and sleep hygiene The timing of sleep onset...

Trt

Fig. 3.2 Polysomnography definitions.TRT total recording time, time from switching on to switching off recording equipment. TIB time in bed, time from lights out to time of getting out of bed. TSP total sleep period (SPT sleep period time), time from sleep onset to end of sleep. TDT total dark time, time from lights out to lights on in the morning. SO sleep onset, time of sleep onset. SL sleep latency, time from lights out until sleep onset. Final wake time time of final wakening. TST total...

Sleepiness

Excessive daytime sleepiness is a characteristic effect of OSA 22 . Its severity is mainly related to the number of arousals from sleep, particularly NREM sleep. There may be a minimum duration of an arousal which contributes to excessive daytime sleepiness, or of sleep between arousals, which protects against this. The degree of sleepiness is not closely related to any objective measure of severity of sleep apnoeas, such as the apnoea-hypopnoea index, and depends on other factors such as...

Hypopnoeas

There has been considerable variation in the use of this term, but it usually implies a reduction in airflow or respiratory movements by over 50 for 10 s or more from the baseline, associated with either oxygen desaturation or evidence of an arousal. It therefore requires more complex monitoring than is needed to identify a sleep apnoea. A reduction in the airflow signal by more than 50 does not necessarily imply that airflow has fallen to this extent, because of the non-linearity of the...

Other relevant actions

Many of the antidepressants are sedative and this effect often parallels the anticholinergic properties of the drugs which are most marked with trimipramine and amitriptyline, absent with protriptyline and nortriptyline, and rarely a problem with SSRIs which may increase alertness and even cause agitation. Sedating tricyclic antidepressants should be taken in the evening while SSRIs can be taken in the morning. SSRI antidepressants may reduce the degree of loss of tone in upper airway dilator...

Investigations

Polysomnography may be required to establish the cause of the sleep symptoms. It shows a prolonged sleep latency with reduced sleep efficiency and often alpha intrusion into NREM sleep. Rapid eye movement sleep latency is normal, but the duration of REM sleep is reduced, and there is an increased frequency of arousals and awakenings from sleep. Multiple sleep latency tests are normal. These changes occur even in the absence of depression and anxiety, but these can cause sleep disturbances which...

Natural history

Age has an important influence on the clinical features. Below the age of around 3 years respiration is more dependent on the diaphragm than in later life and the rib cage is very compliant. Any weakness of the diaphragm predisposes to its fatigue and to respiratory failure, particularly since there is a greater proportion of REM sleep in children than in adults, and this is when respiration is particularly dependent on the diaphragm. The rate at which the clinical features develop depends on...

Accident prevention

Counter-measures to reduce the risk of a motor vehicle accident 20 due to sleepiness include 1 Avoiding sleep deprivation and, if possible, shift work before driving, together with encouraging good sleep hygiene practices and a greater awareness of the problems of driving while sleepy. 2 Treat any underlying sleep disorder. Effective treatment of obstructive sleep apnoeas with nasal continuous positive airway pressure (CPAP) treatment reduces the risk of road traffic accidents 21 . 3 If driving...

Chronotherapy

The aim of this, as with light therapy and melatonin, is to reset the circadian rhythm. Over a period of days or weeks the sleep-wake cycle is shifted by gradually introducing a phase delay and avoiding naps during the day. The time of sleep onset should be retarded in 3-h steps each night until it reaches the desired or socially acceptable sleep time. The sleep cycle is in effect lengthened to 27 h and kept constant until it has been realigned. Hypnotics may help to reduce sleep during the...

Differential diagnosis

1 Anatomical abnormalities, e.g. bladder neck obstruction, ureteric stenosis. These often cause daytime enuresis or sleep enuresis after a period of continence has been established (secondary enuresis). 2 Vesico-ureteric reflux. This is often associated with detrusor instability and detrusor-sphincter incoordination which leads to enuresis. 3 Central nervous system abnormalities, e.g. lumbar spinal cord disorders. 4 Acquired disorders, e.g. recurrent urinary tract infections. 5 Disorders...

Melatonin estimations

Melatonin is affected by fewer confounding factors than most of the other indicators of circadian rhythms. Its secretion is not affected by sleep, physical activity, food or stress, but is modified by certain drugs and posture which need to be controlled for. Melatonin secretion is suppressed even by low light levels of around 10 lux. Salivary melatonin levels can be estimated at hourly intervals in the evening and overnight. The subject is exposed to a low light level of less than around 8...

Excessive daytime sleepiness in children

Excessive daytime sleepiness in children is usually manifested not by a tendency to sleep, but by 'paradoxical' hyperactivity, impulsiveness and lack of concentration. It leads to emotional lability, frustration and disinhibition, shown by aggression and cognitive impairment, such as changes in mood and inattention. Failure to cope with school work and to develop friendships is common. Sleep deprivation also leads to failure to thrive with lack of growth. The causes of excessive daytime...

Info

Those with RLS have PLMS and around 35 of those with PLMS have RLS. The prevalence of PLMS is uncertain, but may be around 5 between the ages of 30 and 50 years, 30 between 50 and 65 years, and 45 in the population over the age of 65. The severity of PLMS fluctuates, but overall usually worsens with age. Forty per cent of adults with RLS and PLMS date the onset of their symptoms to before the age of 20. In children the symptoms may be mild and difficult to diagnose (Table 9.9). PLMS symptoms...

J

Does the patient wake during the night Is he or she aware of this or is it the partner who notices that an awakening has taken place, for instance because of the subject speaking or moving Why does the awakening happen Is there any sensation of pain, anxiety, panic, intrusive thoughts or nightmares What happens when awakening occurs and how long is it before sleep is re-entered The frequency, time during the night (or more precisely during the sleep episode), and awareness of any mental or...

Secondary symptomatic narcolepsy

This is due to an organic abnormality in the hypothalamus, midbrain or pons. Secondary narcolepsy should be suspected if symptoms develop before the age of 5 years, since idiopathic narcolepsy is unusual at this age. Sudden sleep attacks may be present and it is usual for the subject to sleep for an abnormally long time during each 24 h, unlike idiopathic narcolepsy. Cranial nerve abnormalities, such as conjugate gaze defects, are usually present and there may be other features of a...

Disorders of the hypothalamus

These may be focal lesions, as in multiple sclerosis, tumours, or trauma, following surgery and the effects of radiotherapy. Excessive daytime sleepiness is associated with lesions of the posterior hypothalamus which increase the homeostatic sleep drive, but circa-dian rhythm disorders develop if the suprachiasmatic nuclei in the anterior hypothalamus are damaged. Hypothalamic lesions are often associated with endocrine and autonomic abnormalities and may also cause secondary narcolepsy. There...

Cerebral palsy

This is usually due to birth trauma and the extent of the brain damage correlates with the degree of sleep disturbance. Excessive daytime sleepiness is common and may be due to obstructive sleep apnoeas and an abnormality of sleep control, but also to drugs, especially anticonvulsants, and to poor sleep hygiene. Polysomnography is hard to interpret because of the poor definition of NREM and REM sleep, particularly in those who are severely affected. The number of arousals is increased, there...

Electroencephalogram EEG recording

The electrical potentials that are recorded on the scalp reflect the synaptic activity rather than the action potentials of, in particular, the pyramidal cells in the underlying cerebral cortex. These neurones are predominantly radially orientated and generate an electrical field which enables the potential difference between two points on the scalp to be recorded. The orientation of the cortical synapses generates a larger detectable electrical field than that from the spinal cord and...

Druginduced sleepiness

Some drugs help to reduce accident rates, for instance anticonvulsants for epilepsy, treatment for diabetes and antidepressants in certain situations. Sedative drugs and alcohol accentuate sleepiness following sleep restriction and irregular sleeping patterns 17 , particularly if they are taken when the circadian rhythms facilitate sleep (2.00-6.00 am and 2.00-4.00 pm). The effect of one drink of alcohol at these times may be equivalent to two or three taken at 10.00 am 18 . The risk of a...

Pathophysiology

Snoring is due to vibration of the tissues of the upper airway, usually during inspiration but occasionally during expiration or both. Unlike OSA there is no interruption of airflow into the lungs since the closure of the airway is at most only momentary and is not sustained throughout one or more inspirations. The noise of snoring is generated by turbulent flow in the column of air in the upper airway. Vibration of the upper airway can occur at any level down to the larynx but usually involves...

Seasonal affective disorder SAD

This is a seasonal circadian rhythm disorder which is four times more common in women than in men, is occasionally familial and is most frequent between the ages of 20 and 40 years. It is most prevalent in high latitudes where there is a greater seasonal change in the intensity and duration of exposure to light. Abnormalities of clock genes, for instance per 2, have been identified. They may change porphyrin metabolism which influences melatonin production. The seasonal affective disorder...

Haematological changes

Chronic hypoxia may lead to polycythaemia, which increases blood viscosity and which not only predisposes to thrombosis, but also in effect increases the vascular resistance. OSA may also induce a hypercoagulable state due primarily to an increase in fibrinogen levels 11 . Fibrinogen is an acute phase protein which promotes thrombus formation and also leads to platelet aggregation and smooth muscle proliferation. The increased fibrinogen level is mainly due to oxygen desaturations. It peaks in...

References

Low-concentration carbon dioxide is an effective adjunct to positive airway pressure in the treatment of refractory mixed central and obstructive sleep-disordered breathing. Sleep 2005 28(1) 69-77. 2 Khoo MCK, Gottschalk A, Pack AI. Sleep-induced periodic breathing and apnea a theoretical study. J Appl Physiol 1991 70 2014-24. 3 Fanfulla F, Mortara A, Maestri R et al. The development of hyperventilation in patients with chronic heart failure and Cheyne-Stokes...

Parkinsonism

This is due to degeneration and loss of dopamine in the basal ganglia and causes bradykinesia, tremor and rigidity. There are two main forms which are discussed below. Idiopathic Parkinsonism (Parkinson's disease) This is due to degeneration in the basal ganglia and related structures. The substantia nigra in the mid-brain has close relationships with the LDT PPT in the pons which controls REM sleep, and with the raphe nuclei and locus coeruleus which are involved with NREM sleep. The initial...

Treatment

Treatment is usually not required, but if the attacks are frequent or if the subject is at risk of injury the following measures should be considered. 2 Reduction of stress and sleep deprivation. 3 Scheduled awakenings 15-30 min before the usual time of the sleep walking. 4 Benzodiazepines, such as clonazepam 0.25-2 mg or diazepam, prevent arousals and consolidate stages 1 and 2 NREM sleep, although they are usually used only intermittently. 5 Environmental protection. This includes closing and...

Clinical features

Sleep-related eating is common in children, particularly if there is parentally induced poor sleep hygiene and overfeeding during the day. This combination leads to alterations in the circadian rhythms, particularly of endocrine function. This is probably an arousal disorder related to confu-sional arousals and sleep walking and is most common between the ages of 20 and 40 years 65-90 of subjects are female. It is characterized by recurrent, often nightly, episodes of eating, drinking and...

Inflammatory reaction

Vascular endothelial dysfunction is a feature of OSA. It is a pro-inflammatory state which triggers the increases in C-reactive protein, TNF-alpha and IL-6 that are seen in OSA 12 . It leads to proliferation of vascular smooth muscle cells, platelet aggregation and adhesion. Platelet activation increases neutrophil chemotaxis so that these cells reach the media and promote atheroma. Adhesion molecules are also liberated by endothelial cell damage and by white cells due to intermittent hypoxia,...

Arousals

The increase in intensity of inspiratory muscle effort combined with hypoxia and hypercapnia leads to microarousals which may occur up to 500 times each night. They have the protective effect of enabling the respiratory system to come temporarily under the control mechanisms of wakefulness, which increase pharyngeal dilator muscle activity, and improve the blood gases. They have the disadvantage that they lead to sleep fragmentation, which reduces ventilatory drive and probably the strength and...

Consequences of dreams

Dreams are thought to represent the amalgamation of new experiences and ideas into existing neural networks. Dreams may alter the mood of the dreamer and facilitate solution of problems from the previous day. The loose association of ideas in REM sleep opens the opportunity for creative associations to be made and this type of information processing may be particularly important in children. It may lead to finding creative new solutions to current problems. Dreams affect the emotional state of...

Emw

Early onset of sleep, often with daytime naps Other symptoms of depression Other neurological symptoms often present Daytime sleepiness and cataplexy suggest narcolepsy Awakenings associated with recognizable symptom, e.g. angina, wheeze, nocturia Other symptoms of the underlying disorder Daytime sleepiness often accompanies insomnia Irregular but recognizable pattern of non-24-h sleep-wake cycles Risk factor, e.g. shift work, transmeridian travel, blind, CNS lesion ASPS, advanced sleep phase...

Cheyne Stokes respiration CSR periodic breathing

Cheyne-Stokes respiration is closely related to central sleep apnoeas. It is characterized by a regular waxing and waning of tidal volume with little change in respiratory frequency during the phases when breathing is taking place. Between these cycles there may be a short or prolonged apnoea, which if it exceeds 10 s is classified as a central sleep apnoea using conventional criteria. Occasionally, however, the waxing and waning of tidal volume occurs without any cessation of breathing...

Causes of excessive daytime sleepiness

Questions should be asked regarding 1 Sleep hygiene, especially the duration and regularity of sleep times. 2 Drugs, such as sedatives, analgesics or anti-depressants. 3 Causes of sleep fragmentation, such as obstructive sleep apnoeas, periodic limb movements in sleep, asthma, pain or discomfort at night. 4 REM sleep-related symptoms might indicate narcolepsy or a similar disorder. Table 6.5 Differential diagnosis of sleepiness. Physical tiredness Mental fatigue Boredom (sleep drunkenness)...

Physiological effects

The electroencephalogram shows lower delta power and increased beta activity than normal during sleep in primary insomnia, suggesting that there may be a reduction in the homeostatic drive to sleep as well as hyperarousal. Intrusion of alpha waves is common and may be due to a lower threshold for arousal to stimuli such as pain or noise. It is associated with awareness of thoughts during sleep, and with the perception that sleep is unrefreshing. The peak melatonin secretion is reduced in...

Time zone changes jet lag

Jet lag, which is the term used for the symptoms arising from time zone changes, is due to a failure of the circadian rhythms to synchronize with the new environment after a sudden time zone shift. Jet lag does not occur with travel from north to south or south to north, but only with transmeridian journeys. It is not due to sleep deprivation, but this may contribute to the problems that develop. Sleep may be lost because of the timing of the departure and arrival, and the poor quality of sleep...

Cardiac dysfunction

This is associated with CSR for several reasons. First, the hypoxia and pulmonary venous distension increase respiratory drive. Secondly, the prolonged circulation time, which is often a feature of cardiac failure or low cardiac output states, leads to the CSR pattern. Lastly, cardiac disease is often associated with changes in the cerebral circulation so that its reactivity to changes in Pco2 is lost and this alters the ventilatory response to Pco2 4 . Cheyne-Stokes respiration is associated...

Principles of treatment

The aims of treatment are as follows. 1 Explain the nature of the disorder to the subject and reassure when appropriate. 2 Sleep hygiene advice. This minimizes the risk of sleep deprivation which may precipitate motor disorders during sleep, and can also be directed to reduce the risk of arousal which is important in preventing sleep-wake transition disorders. Changes in the use of any drugs that may be adversely affecting the sleep-wake patterns should be considered. 3 Treat the underlying...

Cardiovascular conditions

The metabolic rate and cardiac output fall during NREM sleep and the loss of sympathetic vasoconstriction reduces the systemic vascular resistance so that the blood pressure falls. NREM sleep is cardio-protective despite the drop in perfusion pressure. In contrast, in REM sleep autonomic control is unstable. Fluctuations in heart rate and blood pressure are common and the cerebral blood flow increases. These changes protect against some cardiovascular problems during sleep, but predispose to...

Genetic factors

There is an abnormality in the short arm of chromosome 6 which is closely associated with the HLA type DR2 and subtype DR15 and more particularly with the subtype DQB1*O602 (Table 6.7). Human leucocyte antigen is a protein which is present in cell membranes and is linked to the susceptibility to autoimmune diseases. There is a close association between HLA type and classical idiopathic narcolepsy. This association with the HLA type is the strongest of any disease 27 , but only around 50 of...

Rem

OSA, ventilatory failure, pain Drugs CSA, central sleep apnoea CSR, Cheyne-Stokes respiration OSA, obstructive sleep apnoeas PLMS, periodic limb movements in sleep RLS, restless legs syndrome, REM, rapid eye movement. Table 3.5 Common causes of sleep-stage abnormalities on polysomnography.

Hypnagogic and the hypnopompic hallucinations and vivid dreams

The characteristic features are the realistic nature of the hallucination while drowsy and the often intense emotions and perceived activities, often including flying, in the nocturnal dreams. Dreams may occur during brief naps during the day. The hallucinations of epilepsy are much more stereotyped than the dreams of narcolepsy (Table 6.10). The diagnosis of narcolepsy is highly likely if there is a combination of EDS and well documented or observed cataplexy 34 . The probability of this being...

REM sleep suppressant drugs

Both tricyclic antidepressants and selective serotonin re-uptake inhibitors (SSRIs) reduce the duration of REM sleep and are effective if OSA are confined or almost confined to REM sleep. Protriptyline 5-20 mg nocte has been most widely used, but has been withdrawn in the UK. It is non-sedating, but side-effects such as constipation and urinary retention are common with a dose of more than around 10 mg. Selective serotonin re-uptake inhibitor antidepressants, such as paroxetine, may also reduce...

Sudden infant death syndrome SIDS

Sudden infant death syndrome is a heterogeneous disorder that affects children usually between the ages of 2 and 4 months. It is thought to occur only during sleep and is commonest in premature infants and in the winter. It usually follows or is associated with an upper respiratory infection. 'Apparent life threatening events' (ALTEs) are episodes which are frightening to the observer and characterized by a cessation of breathing, colour change, loss of muscle tone, choking or gagging. These...

Noisy breathing in sleep

Sleep apnoeas usually follow many years of loud snoring and are associated with a change in the pattern of the noise. At the end of the apnoea the airway snaps open with a loud snorting or similar noise. The variety of irregular snoring noises indicates how many different patterns of hypopnoea, apnoea and arousal can occur. Acoustic frequency analysis of these noises shows them to be distinct from simple snoring, and a stridor-like character suggests that the obstruction is arising at laryngeal...

Nature of Sleep and its Disorders

Sleep is recognizable by its contrast to wakefulness. It is a state of reduced awareness and responsiveness, both to internal and external stimuli. This reduced awareness is, however, selective 1 . It is an active process in which the significance of stimuli to the individual is interpreted and this determines whether arousal from sleep occurs. The crying of a child is, for instance, more likely to wake the parent than a different noise of the same intensity. A second feature of sleep is motor...

Polysomnography

This may help to establish the diagnosis of narcolepsy, exclude other diagnoses and assess the presence of complications, such as insomnia, periodic limb movements in sleep, obstructive sleep apnoeas, or REM sleep behaviour disorder. It characteristically shows a short sleep latency, usually less than 5 min, without an increase in the total sleep time at night, although the total sleep time during each 24-h cycle is slightly greater than normal because of the daytime naps (Fig. 3.4)....

Epworth Sleepiness Scale

How likely are you to doze off or fall asleep in the following situations, in contrast to just feeling tired This refers to your usual way of life in the last few weeks. Even if you have not done some of these things recently, try to work out how they would have affected you. Use the following scale to choose the most appropriate number for each situation. Please tick one box on each line.

Neuropsychological effects

The level of alertness falls, concentration deteriorates, and attention for prolonged monotonous tasks shortens (Table 6.2). The subject is usually distractible and mood changes, particularly irritability, are common. These deficits can be partially offset by an increased effort and by caffeine and other wakefulness promoting drugs. Stereotyped behaviours with a loss of innovative responses to stimuli, a more limited vocabulary 4 , and a loss of mental creativity and of flexibility of thought...

Hypnagogic and hypnopompic hallucinations pre and postsleep dreams

Dreams normally occur during sleep but they may arise before any other features of sleep have developed. This occurs in normal subjects who are extremely sleep deprived, particularly of REM sleep, and may occur with jet lag due to east-west travel, since this induces an acute advanced sleep phase and sleep-onset REM sleep. It is, however, commonest during drowsiness in narcolepsy, in which the hallucinations are particularly vivid. The images and forms that these presleep dreams, or hypnagogic...

Mandibular advancement or positioning devices

These hold the mandible and hyoid forwards during sleep and may also modify upper airway muscle activity 36 . The contraction of the genioglossus muscle is increased, possibly because it is stretched, and it becomes less compliant. The dimensions of the upper airway are increased, particularly at the level of the tongue base rather than at palatal level. The diameter increases especially anteroposteriorly, but also laterally, due to an effect on the anterior and posterior digastric muscles....

Physical examination

A general physical examination is often not required to assess the patient with a sleep disorder, but there are specific aspects which should be noted in certain situations (Table 3.2). The degree of sleepiness or alertness, depression or anxiety should be recorded as well as any psychiatric features, for instance, schizophrenia or a personality disorder. The attitudes of the patient and the partner to the sleep complaint are important. The physical appearance may suggest a condition such as...

Panic attacks

Panic attacks are commoner in adolescents and young adults and two to three times more frequent in females than in males. They occur during wakefulness, usually in the morning but also in sleep, particularly during the first third of the night and usually at the time of NREM sleep transition from stage 2 to 3 or 3 to 4. They are not associated with dreams and the patient awakens fully, often with a sensation of intense fear, choking, breathlessness, palpitations, tremor and hyperarousal which...

Cerebral irradiation

Excessive daytime sleepiness often occurs within 6 weeks of radiotherapy to the brain. It may be due to a direct effect of the radiotherapy, possibly acting through cytokines and other inflammatory mediators, but occasionally the symptoms may be due to a raised intracranial pressure due to worsening of the tumour for which the radiotherapy was given. Excessive daytime sleepiness is common when a large volume of brain is irradiated, for instance with prophylactic treatment for leukaemia or small...

Maladaptive behaviour leading to poor sleep hygiene

A common sleep hygiene problem is lack of exposure to bright light. This is often reduced in the elderly because they remain indoors for longer and may have cataracts and macular degeneration which reduce the amount of light stimulating the retina. Exposure to bright light in the morning may also exacerbate the advanced sleep phase syndrome. Light exposure at night, even if it is brief, may reduce melatonin secretion and worsen insomnia. Lack of physical exercise, either due to a lack of...

Nasal continuous positive airway pressure CPAP and bilevel pressure support

The principle of CPAP is that it increases the pressure within the upper airway during both inspiration and expiration (Fig. 10.5). It acts as a pneumatic splint, counteracting the forces that tend to close the airway. It may also have effects on upper airway reflexes Fig. 10.6 Continuous positive airway pressure (CPAP) mask and pump. Fig. 10.6 Continuous positive airway pressure (CPAP) mask and pump. which activate the upper airway dilator muscles. Continuous positive airway pressure also...

Desaturation index DI

Oxygen desaturations are conventionally regarded as a fall in saturation of 4 or more, although often 3 or even 2 is used 11 . None of these values has, however, any specific biological significance. The degree of desaturation depends on the position of the baseline oxygen saturation on the oxyhaemoglobin desaturation curve, as described above. Small desatura-tions may be difficult to distinguish from variations in oxygen saturation due to, for instance, alterations in body position and...

Physiological Basis of Sleep and Wakefulness

Knowledge about the physiological basis of sleep has increased rapidly over the last few years. It is now recognized to be a highly complex and heterogeneous state, which is intimately connected with the state of wakefulness. There is a dynamic balance between the processes controlling both these states, which is complex and has important implications for many sleep disorders. The functions of sleep are still uncertain, but NREM and REM sleep almost certainly have different functions. Sleep is...

Sleepstate misperception pseudoinsomnia subjective insomnia

Sleep-state misperception is due to an inaccurate perception of the time spent asleep. There is a wide range of accuracy of perception of sleep in those with insomnia, but it is common for the sleep latency to be exaggerated and sleep efficiency to be underestimated. Sleep-state misperception probably represents the extreme end of the range of misperception and interestingly it may be associated with similar physiological changes to those seen in primary insomnia, despite apparently normal...

Sleep and obesity

The control of sleep is closely linked to feeding behaviour and energy expenditure. These determine the body weight and in particular the body fat and lean body mass. Body weight and body mass index (weight in kg height in m squared) are only indirect indicators of obesity because they do not assess body composition. Other measures, such as the waist to hip ratio and collar circumference, give an indication of the distribution of body fat and in particular whether it has a central rather than a...

Thalamic lesions

Thalamic lesions may prevent NREM sleep from being initiated and maintained, but the clinical pattern varies according to which nuclei within the thalamus are affected. Lesions of the mediodorsal and anterior thalamic nuclei lead to a combination of features known as agrypnia excitata 16 . This comprises insomnia with vivid dreams and hallucinations which are physically enacted. There is also generalized motor agitation with irregular movements and tremors, confusion and sympathetic...

Ullanlinna Narcolepsy Scale

When laughing, becoming glad or angry or in an exciting situation, have the following symptoms suddenly occurred Knees unlocking Mouth opening Head nodding Falling down 2. How fast do you usually fall asleep in the evening > 40 min 31-40 min 21-30 min 3. Do you sleep during the day (take naps) No need I wanted but Twice weekly On 3-5 days Daily or cannot sleep or less weekly almost daily 4. Do you fall asleep unintentionally during the day

Central nervous system stimulants and wakefulness promoting drugs

These should be considered once all the above measures have been implemented and if any residual excessive daytime sleepiness is sufficiently severe to have a significant impact on the subject's life, for instance by interfering with the ability to cope with interpersonal relationships, family responsibilities, driving or at work. The issues that should be addressed when choosing a stimulant preparation are as follows. 1 Effectiveness. The ability to convert sleepiness to wakefulness and the...

Pittsburgh Sleep Quality Index PSQI

Instructions The following questions relate to your usual sleep habits during the past month only. Your answers should indicate the most accurate reply for the majority of days and nights in the past month. Please answer all questions. 1. During the past month, when have you usually gone to bed at night 2. During the past month, how long has it usually taken you to fall asleep each night 3. During the past month, when have you usually gotten up in the morning 4. During the past month, how many...

Noradrenergic and adrenergic drugs and blockers

Clonidine is a central alpha 2 agonist as well as an H1 antagonist and an anticholinergic drug. It inhibits the locus coeruleus and causes sedation, increases the total sleep time, increases REM sleep latency, reduces the duration of REM sleep, causes vivid dreams and prolongs stages 3 and 4 NREM sleep. Methyldopa is also a sedative leading to lethargy, drowsiness and fatigue. It increases REM sleep and reduces the duration of stages 3 and 4 NREM sleep and predisposes to nightmares. These...

Multiple sleep latency test MSLT

This is an objective test which assesses the ease with which the subject can fall asleep during the day in the artificial environment of a sleep laboratory. Subjects should ideally have been following a normal sleep-wake routine for two weeks, without night or shift work and without taking any medication that might affect sleep. The sleep pattern can be documented by a sleep diary or actigraphy, but ideally polysomnography is carried out on the night before the MSLT to establish that the...

Mazindol

This is an imidazole derivative which differs chemically from the amphetamines. It is readily absorbed, has an onset of action within 30-60 min and its peak effect is at around 2 h. It is excreted in the urine. The usual dose is 2-12 mg daily given either as one or two doses. Two milligrams are equivalent in effectiveness to around 10 mg dexamphetamine. Its mechanism of action is uncertain, but it may inhibit noradrenaline and dopamine re-uptake, particularly in the limbic system. It has little...

EEG waveforms

Several patterns of electrical activity are characteristically seen in sleep. This is normal in relaxed wakefulness, but usually disappears at sleep onset. It may however intrude into sleep, particularly stages 1 and 2 NREM sleep and also stages 3 and 4 (alpha delta rhythm). It is less prominent in the frontocentral rather than occipital areas and has a frequency of 1-2 Hz slower than that during wakefulness. There is a circadian rhythm in alpha activity which is independent of sleep. Alpha...

Sleep related expiratory groaning catathrenia

This rare condition is characterised by prolonged expiratory groaning, which is often loud and disruptive. The groaning appears to arise at laryngeal level. Its onset is in adolescence and it may persist throughout life. There may be a family history, but there is no association with any psychological or medical disorder. Polysomnography shows that the abnormal respiration occurs particularly in stages 1 and 2 NREM sleep, although occasionally in REM sleep, and is often associated with brief...

Cholinergic drugs and antagonists

Acetylcholine is a neurotransmitter which has mus-carinic effects at postganglionic parasympathetic synapses and nicotinic effects in the CNS and at preganglionic synapses. It promotes REM sleep and wakefulness. Table 4.10 Drugs that influence REM sleep. Table 4.10 Drugs that influence REM sleep. Muscarinic agonists, e.g. pilocarpine Anticholinesterases, e.g. neostigmine

Generic questionnaires

These focus on general health and may thereby give an indication of the impact of any sleep disorder on the quality of life. The Short Form 36 Health Survey (SF36 (Appendix 3) ) has been most widely used. Normal values are available for males and females and different age groups and social classes in the USA, UK and other countries. The SF36 is sensitive to some sleep disorders, such as obstructive sleep apnoeas, but is probably less so than the sleep-specific questionnaires. The Functional...

Explain reassure and advise

Explanation, reassurance, and advice about modification of lifestyle and about accepting a degree of long-term insomnia if necessary may be helpful. Table 7.5 Causes of insomnia requiring polysomnography. Table 7.5 Causes of insomnia requiring polysomnography. Organic causes circadian rhythm disorder PLMS CSA and CSR Thalamic lesions Sleep-state misperception Multifactorial origin e.g. combination of drug effects and a hyperarousal state, or poor sleep hygiene and chronic fatigue syndrome...

Maintenance of wakefulness test MWT

The MWT is similar to the MSLT except that the subject is asked to sit in a comfortable chair in a quiet darkened room for 20-40 min and to resist falling asleep. It is a measure of the ability to remain awake in a non-stimulating environment and more closely simulates real life situations than the MSLT which measures the ease with which the subject can fall asleep. The onset of sleep is assessed as in the MSLT. The mean of four MWTs at 2-h intervals is taken as the value of the test. A normal...

Mechanisms of action

The biochemical basis of depression is thought to be related to over-activity of CNS cholinergic systems relative to that of the monoaminergic systems. Most antidepressants tend to restore the balance of these two in various ways. They probably act mainly in the pontine reticular formation, hypothalamus, thalamus, limbic system and neocortex and thereby regulate the level of arousal and sensory processing as well as mood. Monamineoxidase inhibitors (MAOIs), e.g. phenelzine, tranylcypromine...