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....

Problems with use

This is due to both enzyme induction in the liver and CNS adaptation to its hypnotic effects. Acute withdrawal of alcohol after long-term consumption causes REM sleep rebound with a short REM sleep latency, a reduction in stages 3 and 4 NREM sleep, and sleep fragmentation with an increase in the number of sleep stage shifts and awakenings. Sympathetic hyperactivity underlies the tachycardia, sweating and headaches, and an increase in muscle tone is common. Dreams may be vivid and frightening,...

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...

Indications in sleep disorders

Benzodiazepines are often considered as first-line hypnotic treatment for insomnia, but are similar in many ways to newer drugs such as zopiclone, zolpidem and zaleplon which are preferable in certain circumstances. The advantages of benzodiazepines over older hypnotic drugs are 1 greater sedation anxiolysis ratio 2 less tendency to tolerance and dependency, particularly compared to barbiturates 4 safer in overdose, especially compared to barbiturates 5 fewer drug interactions since they do not...

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...