++
The term ‘sleep apnoea’ is used to describe cyclical brief interruptions of ventilation, each cycle lasting 15–90 seconds and resulting in hypoxaemia, hypercapnia and respiratory acidosis, terminating in an arousal from sleep (often not recognised by the patient). The interruption is then followed by the resumption of normal ventilation, a return to sleep, and further interruption of ventilation.
++
Sleep apnoea is broadly classified into obstructive and central types.
++
Obstructive sleep apnoea (OSA) refers to the presence of apnoeas and hypopnoeas during sleep together with daytime dysfunction, predominantly excessive daytime sleepiness. The effects include snoring (see FIG. 71.2).
++
++
Predisposing causes include:
++
diminished airway size (e.g. macroglossia obesity, tonsillar-adenoidal hypertrophy)
upper airway muscle hypotonia (e.g. alcohol hypnotics, neurological disorders; see FIG. 71.3)
nasal obstruction
++
++
Central sleep apnoea (CSA), which occurs when there is either brief or prolonged loss of breathing during sleep, is less common (accounts for <10% of sleep-disordered breathing). It is due mainly to neurological conditions such as brain stem disorders leading to reduced ventilatory drive, and neuromuscular disorders such as motor neurone disease. Cardiorespiratory disease is also a risk factor. It requires specialist referral. Treatment of CSA is based on optimal therapy for these underlying conditions and attending to lifestyle modification as outlined below.
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Clinical effects of sleep apnoea syndromes5,7
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Important clinical presentations include:
++
excessive daytime sleepiness and tiredness
nocturnal problems (e.g. loud snoring, thrashing, ‘seizures’, choking, pain reactions)
morning headache
subtle neuropsychiatric disturbance—learning difficulties, loss of concentration, personality change, depression
sexual dysfunction
occupational and driving problems
++
Causes of excessive daytime sleepiness are presented in TABLE 71.3. In OSA, sleepiness results from repeated arousals during sleep and the effects of hypoxaemia and hypercapnia on the brain. Physical examination may reveal few or no signs.
++
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Management of sleep apnoea7
++
Referral to a comprehensive sleep disorder centre especially for sleep polysomnography (the gold standard diagnostic test) is advisable if this disorder is diagnosed or suspected. Consider also the Berlin questionnaire8 or the Epworth sleepiness scale.9
++
The general principles are as follows:
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Lifestyle modification
Weight loss (e.g. loss of 10–15%, e.g. 7–10 kg can significantly reduce severity).
Achieve physical fitness with regular exercise.
Good sleep hygiene and adequate sleep hours (increase time in bed).
Reduce or cease sedatives/hypnotics.
Avoid alcohol for up to 3 hours before going to sleep and drugs in general.
Cease cigarette smoking (increases nasal resistance).
Medical management of nasal obstruction (e.g. short-course nasal decongestants) or 6-week trial intranasal topical corticosteroids.
Obtain positional therapy, avoid supine sleep—sleeping on side is best. Consider neck support.
Continuous positive airway pressure (CPAP)
CPAP is currently the most effective treatment for OSA (consider it for CSA)—the gold standard treatment.
Delivered by nasal (or facial) mask.
Provides an air splint to the upper airway and prevents pharyngeal collapse.
Sleepiness and neurocognitive function improved.
Not tolerated by all patients.
Surgery
In children, OSA is usually due to tonsillar and/or adenoid hypertrophy and is relieved by surgery (see FIG. 71.4). In adults, depending on the cause, the options are:
correction of the specific upper airway anatomical problem—up to 2% of problems
correction of nasal obstruction (improves snoring and OSA)
palatal surgery: uvulopalatopharyngoplasty for carefully selected patients—conventional or laser assisted
nasal polypectomy
tonsillectomy
base of tongue surgery
radiofrequency treatment to soft palate and base of tongue (‘somnoplasty’)
Oral appliances
Medication
There are no reliable drug treatment options for OSA. Consider:
amitriptyline 25–100 mg (o) nocte, in severe cases during REM sleep and intolerance of CPAP
trial of corticosteroid sprays in children with mild OSA
+++
Obesity hypoventilation syndrome (OHS)—Pickwickian syndrome
++
OHS may occur alone or secondary to OSA. The main features of the OHS patient are:
++
++
There is impaired breathing leading to hypercapnia (↑ PaCO2) and hypoxia. Diagnosis is by sleep studies. Treatment is weight loss plus CPAP. It is a complex problem with a risk of premature death.
++
Narcolepsy is a specific, permanent neurological disorder that is characterised by brief spells of irresistible sleep during daytime hours in inappropriate circumstances, even during activity and usually at times when the average person simply feels sleepy. It is uncommon with an incidence of two to five per 100 000.
++
Usual onset between adolescence and 30 years of age—in teens and 20s (but has been reported in children as young as 2 years).
++
Daytime hypersomnolence: sudden brief sleep attacks (15–20 minutes).
Cataplexy: a sudden decrease or loss of muscle tone in the lower limbs that may cause the person to slump to the floor, unable to move. These attacks are usually triggered by sudden surprise or emotional upset.
Sleep paralysis: a frightening feeling of inability to move while drowsy (between sleep and waking).
Hypnagogic (terrifying) hallucinations on falling asleep or waking up (hypnopompic hallucination).
++
Several attacks per day are possible.
++
The diagnosis is clinical through the taking of an appropriate history. If doubtful, include:
++
++
Treatment is mainly symptomatic and initiated by a consultant. Central nervous system psychostimulants are of proven effectiveness in increasing alertness:
++
dexamphetamine 5–10 mg (o), half an hour before breakfast and lunchtime; up to 40 mg daily may be required in slowly increasing doses
or
methylphenidate (Ritalin) 10–20 mg (o) half an hour before breakfast and lunchtime; up to 60 mg daily may be required
++
Drug holidays from these drugs may be necessary.
++
Tricyclic antidepressants are used to treat cataplexy, sleep paralysis and hypnagogic hallucinations (e.g. clomipramine 20–100 mg (o) daily).
Modafinil is used successfully in some countries.
++
Reflect on driving licence issues as appropriate.
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Idiopathic hypersomnia10
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This type of excessive daytime sleepiness (EDS) can present similarly to narcolepsy without cataplexy. The condition, which accounts for 5–10% of patients in sleep clinics with EDS, is diagnosed despite adequate sleep and exclusion of other causes. They usually have non-refreshing deep nocturnal sleep but, unlike narcolepsy, naps are not refreshing. The onset is usually insidious before 30 years and persists for life. Treatment is usually based on psychostimulant therapy to improve EDS.
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Snoring is a sonorous sound with breathing during sleep, caused by vibrations in the upper airways from the nose to the back of the throat. It is caused by partially obstructed breathing during sleep (see FIG. 71.5).
++
++
Sometimes indicates OSA, especially in perimenopausal women7
Three times more common in obese persons
Generally harmless, but if very severe, unusual or associated with periods of no breathing (>10 s) assessment is advisable
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Aggravating factors9,11
++
Obesity
Old age
Sleeping on the back
Sleep deprivation
Excess alcohol
Neck problems, especially a ‘thick’, inflexible neck
Various drugs, especially sedatives and sleeping pills
Hay fever and other causes of nasal congestion
Problems in the upper airways, such as nasal polyps, enlarged tonsils or a foreign body (e.g. a piece of plastic or metal)
Endocrine abnormalities (e.g. acromegaly, hypothyroidism)
++
If an examination rules out a physical problem causing obstruction in the back of the nose and OSA, then the following simple advice can be given to patients.
++
Obtain and keep to ideal weight.
Avoid drugs (including sedatives and sleeping tablets), alcohol in excess and smoking.
Treat nasal congestion (including hay fever) but avoid the overuse of nasal decongestants.
For neck problems, keep the neck extended at night by wearing a soft collar.
Consider a trial of an intranasal device such as the Breathing Wonder, which is a hollow intranasal plastic insert. Pharmacists can advise about the range of such devices.
Try to sleep on your side. If you tend to roll on to your back at night, a maverick method is to consider sewing ping pong balls or tennis balls on the back of the nightwear. Others wear a bra (with tennis balls) back to front.
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Periodic limb movements (nocturnal myoclonus)
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Periodic limb movements (PLMs) and restless legs syndrome are important causes of insomnia and excessive daytime sleepiness. They may coexist in the same patient. Periodic limb movements, which are also referred to as nocturnal myoclonus or ‘leg jerks’, tend to occur usually in the anterior tibialis muscles of the leg but can occur in the upper limbs. The prevalence increases with age. Most people with PLMs are completely asymptomatic. The diagnosis is often made during sleep studies.12 If troublesome, referral to a sleep clinic or neurologist may be appropriate.12
++
Medication that may help includes:
++
levodopa plus carbidopa (e.g. Sinemet 100/25, tablets before bedtime)
or
clonazepam 1 mg (o) nocte increasing to 3 mg (o) nocte
or
sodium valproate 100 mg (o) nocte
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This is the temporary inability to move or speak when falling asleep or upon awakening, with intact consciousness. It is REM atonia. It can occur in the general population (8%) and about 30% of those with narcolepsy. It can be terrifying but is not dangerous.
++
Treatment is educational and preventive with optimal sleep hygiene.
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Restless legs syndrome (RLS)
++
RLS, also known as periodic limb disorder or Ekbom syndrome, is a rather common movement disorder of the nervous system where the legs feel as though they want to exercise or move when the body is trying to rest. Sensations that may be experienced include ‘twitching’, ‘prickling’ and ‘creeping’.11,13 The major complaint of sufferers is of disruption both to sleep and of relaxing activities, such as watching television or reading a book. Prolonged car or airplane travel can be difficult.
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RLS is frequently an undiagnosed disorder because people often don’t complain about it to their doctor. A Canadian study reported that 15% of people sampled reported ‘leg restlessness’ at bedtime.
++
The diagnosis is made from the history—there are no special diagnostic tests.
++
Its prevalence increases with age so it mainly affects elderly people. Women are more prone to get RLS and it is aggravated by pregnancy. The exact cause of primary RLS is not clear. It is not related to exercise and does not appear to follow strenuous exercise.
++
There is an urge to move legs upon resting, particularly after retiring to bed. This urge is a response to unpleasant sensations in the legs, especially in the calves. The sensations are commonly and variously described as crawling, creeping, prickly, tingling, itching, contractions, burning, pulling or tugging, electric shock-like. However, sometimes patients are unable to describe the sensation or refer to it as simply a compulsion to move the legs.
++
In some patients the arms are affected in a similar way. The symptoms seem to be aggravated by warmth or heat. Many patients with RLS also experience nocturnal myoclonus.
++
Secondary (medical) causes include:
++
anaemia (common)
iron deficiency (common)
uraemia
hypothyroidism
pregnancy (usually ceases within weeks of delivery)
drugs (e.g. antihistamines, anti-emetics, selective antidepressants, lithium, selective major tranquillisers and antihypertensives)
++
Iron studies should be performed and, if low, treat with iron and vitamin C tablets. Advise patients that although RLS can come and go for years, it usually responds well to treatment.
++
Perform activities that can reduce symptoms, for example, a modest amount of walking before bedtime, massage or prescribed exercises (see FIG. 71.6).
Note: getting out of bed and going for a walk or run does not seem to help RLS.
Good sleep hygiene, namely regular sleeping hours, gradual relaxation at bedtime, avoidance of non-sleep activities in bed (e.g. reading, eating).
Diet: follow a very healthy diet. Avoid caffeine drinks, smoking and alcohol.
Try keeping the legs cooler than the body for sleeping.
Exercises: a popular treatment is gentle stretching of the legs, particularly of the hamstring and calf muscles, for at least 5 minutes before retiring. This can be done by using a wide crepe bandage, scarf or other length of material around the foot to stretch and then relax the legs.
++
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Pharmacological treatment6
++
The following may be effective if simple measures fail: (taken before bedtime)
++
++
For more severe symptoms consider low-dose dopamine agonists:
++
pramipexole 0.125 mg (o) daily, increasing as tolerated to 0.75 mg
or
ropinirole 0.5 mg (o) → 4 mg daily
++
Cabergoline, gabapentin, codeine, baclofen and propranolol may be helpful. Carbamazepine, quinine, antipsychotics (avoid), antihistamines (avoid) and antidepressants are generally unhelpful.
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Bruxism (teeth grinding)
++
Bruxism is the habit of grinding, clenching or tapping teeth, which may occur while awake (especially in children) or more commonly while asleep. The usual symptom is annoying, teeth-grinding noises during sleep that disturb family members. It may result in headaches and TMJ dysfunction in the person during the day. The cause may be a habit or a response to subconsciously correct a faulty bite by making contact between the upper and lower teeth when the jaws are closed. It is aggravated by stress and is more common in heavy alcohol drinkers and SSRI users.
++
Educate the patient to recognise, understand and try to overcome the habit.
Practise keeping the jaws (and teeth) apart.
Slowly munch an apple before retiring.
Practise relaxation techniques, including meditation, before retiring.
Consider other stress-management techniques (e.g. counselling, relaxation exercises, yoga and tai chi).
Place a hot towel against the sides of the face before retiring to achieve relaxation.
If this fails and bruxism is socially unacceptable, a plastic night-guard mouthpiece can be fashioned by a dentist to wear at night.
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Parasomnias are defined as dysfunctional episodes associated with sleep, sleep stages or partial arousal. They are more common in children. Diagnosis is clinical.
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Nightmares (dream anxiety)
++
These dream-related anxiety episodes usually occur later in the REM sleep period and are accompanied by unconscious body movements, which usually cause the person to awaken.
++
Associations include traumatic stress disorders, fever, drug withdrawal (e.g. alcohol, barbiturates, drugs such as zolpidem, SSRIs, beta blockers, benzodiazepines, mirtazepine). Violent behaviour can occur during these dreams due to a REM behaviour disorder and this requires a sleep study and specialist evaluation.
++
Psychological evaluation with cognitive behaviour therapy (CBT) is appropriate. Medications that may help include phenytoin, clonazepam or diazepam.
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REM sleep behaviour disorder
++
A feature is complex and elaborate motor activity associated with dreams. The behaviour may be violent with profane verbalisation. It is more common in older males and among those with CNS degeneration disorders (e.g. dementia, Parkinson disease). Diagnosis is by sleep studies and treatment is low-dose clonazepam.
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Somnambulism (sleepwalking)2
++
This is a complex motor activity in which the person performs some repetitive activity in bed or walks around freely while still asleep. There is amnesia for the event. No treatment is usually required but, if it is repetitive and potentially dangerous, then the sleeping environment should be rendered safe. Psychological assistance is required for recurring episodes. Benzodiazepines such as clonazepam 0.5–2 mg (o) nocte may be useful, but withdrawal usually leads to rebound problems.
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Sleep-related leg cramps
++
Prevention is by stretching the affected muscles for several minutes before sleep. Consider magnesium. Refer to CHAPTER 68.
++
These are part of the same non-REM sleep cycle disorder as somnambulism. Characteristics of night terrors are sharp screams, violent thrashing movements and autonomic overactivity, including sweating and tachycardia. The sufferers, usually preadolescent, may or may not wake and usually cannot recall the event. They also require psychological evaluation and therapy. Similar medication as used for nightmares may help (e.g. a 6-week trial of phenytoin, diazepam or clonazepam).