Sleep disorders

Question 1

A) OSA

Answer 1

snoring, observed apnoeas, nocturnal choking and nocturia. Daytime sleepiness, or fatigue, is the most common daytime symptom with irritability or mood changes also commonly noted.

Question 2

Examination

Answer 2

BMI, a crowded oropharynx (ie. large tonsils, a thick stumpy uvula and a large set back tongue), increased neck circumference
and retrognathia.
modified mallampati (MMP) score
neck circumference of greater than 40 cm-sensitivity of 60% and a specificity of 93% for OSA

Question 3

Epworth Sleepiness Scale (ESS)

Answer 3

> 10/24 is considered abnormal

Question 4

INV

Answer 4

investigations for OSA can be divided into four categories- in-laboratory polysomnography (PSG) undertaken with overnight observation, to a level four study, which consists of overnight pulse oximetry.

In-laboratory PSG is the gold standard for the diagnosis of OSA

Question 5

RTA and driving

Answer 5

legal responsibility for notifying the relevant state or territory authority regarding medical conditions, which may affect driving, lies with
the driver once they are aware of the impact that their condition may have on driving. However, if there are concerns that the patient continues to drive despite appropriate advice and poses a public safety risk then direct reporting to the licensing authority should be considered.

there are statutes that may protect health professionals who report without patient consent from litigation

Question 6

Confirmation

Answer 6

PSG occur at a frequency of >15 events/hour (also called the apnoea-hypopnoea index, or AHI) then a diagnosis of OSA is confirmed.

Question 7

Rx

Answer 7

Treatment for OSA should be multimodal and include weight loss, exercise, avoidance of alcohol and sedatives and positional therapy

Question 8

Return to work

Answer 8

sleep specialist may grant a conditional commercial licence after review where there has been a satisfactory response to treatment and the patient has demonstrated treatment compliance. Annual review is recommended.

Question 9

B) NARCOLEPSY

Answer 9

four classic symptoms of narcolepsy are
excessive daytime sleepiness,
cataplexy (loss of msc tone),
sleep paralysis and hypnagogic (sleep onset) hallucinations.

Question 10

Aeitiology

Answer 10

deficiency of the central
nervous system peptide hypocretin (also called orexin), which is a neurotransmitter that controls wakefulness and appetite
genetic factors involved

Question 11

Diagnosis and inv

Answer 11

ESS and multiple sleep latency test (MSLT)

Question 12

Diagnosis and inv

Answer 12

ESS and multiple sleep latency test (MSLT)
Diagnostic guidelines for narcolepsy require that the sleep/wake cycle has been assessed for at least 7 days prior
to PSG/MSLT with documentation such as a 7-day sleep diary and actigraphy. Actigraphy is a portable device that records movement over a prolonged period of time and provides information on sleep and waking times, as well as sleep duration and efficiency.

In the absence of cataplexy, to make a diagnosis of narcolepsy, a mean sleep latency of less than 8 minutes is required, with 2 or more sleep-onset REM periods

presence of HLA-DQB1*0602 and low CSF hypocretin are also supportive of a diagnosis of narcolepsy

Question 13

Implications

Answer 13

Patients with narcolepsy should be advised to avoid occupations where there is the possibility of physical harm from inattentiveness or sleepiness

Question 14

Advice regarding driving

Answer 14

advised not to drive until his symptoms are controlled
Not considered
fit to hold an unconditional driving licence

Question 15

MX

Answer 15

no cure for narcolepsy

strict attention to sleep hygiene, naps prior to attention-intensive tasks, and avoidance of alcohol and carbohydrate rich meals
dexamphetamine is used as first line treatment.
Modafinil, a wakefulness-promoting agent, can be considered if there is a contraindication to dexamphetamine

Management of REM phenomena including cataplexy requires use
of serotonin-noradrenaline reuptake inhibitors Alternative medications include tricyclic antidepressants (clomipramine is considered the treatment of choice) and fluoxetine.31

Question 16

C) RESTLESS LEG syd (RLS)

Answer 16

The essential criteria are:
• an urge to move the legs, usually accompanied by uncomfortable or unpleasant sensations in the legs
• the urge to move or unpleasant sensations usually begins during periods of rest or inactivity
• this urge is partially or completely removed by movement such as walking or stretching, at least as long as the activity continues, and
• the urge to move or unpleasant sensations are worse at night or in the evening than during the day or only occur at night.

supportive clinical features are not essential to make a diagnosis of RLS, but may be helpful where there is diagnostic uncertainty.
family history of the condition in one series, additional periodic leg movements during wakefulness or sleep (periodic leg movements are described as rhythmic big toe extension with ankle dorsiflexion and occasional knee or hip flexion) or improvement after starting a dopaminergic agent

Question 17

INV

Answer 17

iron studies, urea, electrolytes and creatinine and a test for thyroid function.

Question 18

secondary causes

Answer 18

common secondary cause of RLS is iron deficiency

Renal failure and hypothyroidism

Question 19

Referral

Answer 19

fewer than four of the essential clinical criteria of the International Restless Legs Syndrome Study Group are present

concerns about the possibility of a comorbid sleep problem-Individuals with RLS often have periodic limb movements in sleep (PLMS)

Question 20

Rx

Answer 20

treatment of primary RLS is pharmacological
Effective dopaminergic medications include levodopa-carbidopa and synthetic dopamine agonists

4 caterogies of medications used
in the treatment of RLS: dopaminergic agents, anticonvulsants, benzodiazepines and opiates.

medication of choice in Australia tends to be pramipexole
Other options such as gabapentin, long- acting benzodiazepines (i.e. clonazepam) and opiates are considered second line agents.

Question 21

pramipexole

Answer 21

Pramipexole is generally well tolerated, with nausea being the most frequent side effect. The most important potential side effects of pramipexole (and all non-ergoline dopamine agonists) are impulse control disorders.
These may manifest as compulsive shopping, pathological gambling, hypersexuality or punding (repetitive purposeless actions) with a mean duration of treatment of 9.5 months prior to the onset of such an adverse effect.

Question 22

Augmentation

Answer 22

A problem with the use of dopaminergic agents in the treatment of RLS is augmentation. Augmentation is defined as the usual daily onset of restless legs symptoms
>starting earlier than they did before treatment.
>Augmentation may also result in
>increased severity of symptoms,
>the spread of symptoms to other parts of the body
and
>reduced duration of relief from symptoms with treatment
Augmentation with pramipexole occurs on average after 8 months of treatment and is generally mild. These mild symptoms can typically be managed by giving the dose earlier in the day.39 When symptoms are more severe, the medication may need to be substituted for a non-dopaminergic agent for a month and then recommenced.

Question 23

D) CIRCADIAN RHYTHM SLEEP DISORDER in a shift worker

Answer 23

Circadian rhythm is the ‘body clock’ that assists in maintaining the sleep/wake cycle

The normal circadian rhythm is slightly longer than 24 hours, and so to be kept in check we rely on ‘environmental time cues’, the most important of which is the light/dark cycle from the sun

Question 24

Inv

Answer 24

Sleep diary- sleep diary is typically filled out for at least 7 days, and records meals, caffeine intake and exercise as well as bedtime, estimated time of getting to sleep and waking.

Seven-day actigraphy can be a useful adjunct to a sleep diary

Exclude-
Full blood examination, urea, electrolytes and creatinine, iron studies and a test for thyroid function are useful to look for the presence of anaemia, renal failure, iron deficiency and thyroid disorders.

Question 25

Interventions

Answer 25

One of the major problems faced by night shift workers is that typically the brightest light they are exposed to in a 24-hour period is on their way home to sleep

It has been shown that exposure to bright light (typically using a light box) during a night shift, in combination with wearing dark sunglasses on the commute home as well as a dark sleep environment, helps entrain the circadian rhythm and improve work function.

Melatonin administration prior to sleep has also been shown to be effective, however, it is worth noting that the effect
of light on circadian rhythm is much stronger than melatonin, and so a combined approach is required.

Question 26

Medications

Answer 26

Melatonin prior to daytime sleep improves sleep quality and duration, and in some patients can result in a shift in circadian rhythm

With regards to enhancing alertness during the night in those with shift work disorder, guidelines suggest that the use of modafinil or caffeine may be indicated.

Question 27

Futher mx

Answer 27

Following the final night of work for the week, a shortened daytime sleep with some bright light exposure (preferably outdoor light)
after sleep with the aim of advancing the circadian clock slightly is recommended
It is advised that this is then followed by sleeping as late as possible on the days off (ie. from 3–4 am to 11 am–12 pm)

Question 28

E) INSOMINA

Answer 28

prevalence of 3.4–5% in Australia

Peri- and post-menopausal women appear to be particularly at risk

Question 29

Classification of insomnia

Answer 29

primary insomnia
– idiopathic
– psychophysiological: maladaptive conditioned response to an acute stressor where the bedroom is a place of heightened arousal
– sleep state misperception: mismatch between the patient’s perceived and actual sleep duration/quality.

secondary insomnia, which is due to one or more of the following factors:
– poor sleep hygiene or behaviours
– an active psychosocial stressor
– a psychiatric disorder such as depression or anxiety
– an abnormality of sleep causing arousal/awakening such as OSA, RLS, chronic pain or hot flushes
– a medication such as a beta blocker, or substance such as caffeine or alcohol.

Question 30

INV

Answer 30

Full blood examination, urea, electrolytes and creatinine, thyroid stimulating hormone and erythrocyte sedimentation rate – to help exclude medical conditions (such as anaemia, renal failure, thyroid disorders) and chronic inflammatory disorders (such as rheumatoid arthritis and sarcoidosis) that may contribute to symptoms.

A sleep diary – this can assist in evaluating sleep/wake cycles and sleep hygiene. This can be used with 7 day actigraphy.

In-laboratory PSG – this should be considered if a specific sleep disorder such as OSA needs to be excluded. Home-based sleep studies are generally not recommended in some patients

Question 31

Mx

Answer 31

how to ensure a good night’s sleep
• Obtain an appropriate amount of sleep
Most adults (including shift workers) require 7.5–8 hours of sleep.
• The bedroom is a place for sleep and intimacy only
Avoid eating, watching television or working in the bedroom.
• Develop a routine prior to retiring to bed
A routine prior to bed could involve reading or relaxing.
• Remove or reduce any environmental distractions in the bedroom
Remove enviromental distractions such as light (wear an eye mask), noise (wear ear plugs), temperature extremes and pets in
the bedroom.
• Use a comfortable mattress and pillow
• The most common cause of sleep onset insomnia is ‘racing thoughts’ or dwelling on the day’s events
Learn techniques to take your mind away from this.
• If you are unable to fall asleep within 30 minutes, leave the bedroom and perform a non-stimulating task in dim light. Only return to bedroom if ready to fall asleep
• Wake up at the same time every day and be exposed to natural light and exercise (ie. a brief walk is adequate)
• Avoid daytime naps
If a nap is necessary, nap in a room separate to your bedroom that is lit.
• Avoid vigorous exercise within 4 hours of bedtime
• Avoid coffee, tea, chocolate, cola and cigarettes
• Avoid large meals close to bedtime
• Reduce alcohol intake and avoid sedative medications
Use of alcohol or sedatives do not solve the problem.
• Address all medical issues that may interfere with sleep
Medical conditions causing symptoms such as pain, breathlessness, cough, reflux, chest pain, frequent urination may need to be addresssed.
Figure 7. How to ensure a good night’s sleep – improving your sleep hygiene. Adapted with permission from The Royal Melbourne Hospital Sleep Disorders Unit.

Question 32

F) SIMPLE SNORING

Answer 32

differential diagnosis includes OSA or upper airway resistance syndrome.

Question 33

Snoring

Answer 33

Snoring is a respiratory sound generated in the upper airway and typically occurs in inspiration, but may also occur in expiration
membranous part of the upper airway that lacks cartilaginous support may vibrate.
40–86% in men and 24–57% in women.57,58

Question 34

Advice

Answer 34

weight loss, reduction in alcohol intake, smoking cessation, avoidance of supine sleep and ensuring adequate sleep duration

Question 35

General measures

Answer 35

The decision to treat asymptomatic snoring is dependent on the individual’s wishes and should involve a discussion with the patient and their partner
ear plugs for a partner and explore the possibility of separate sleeping
mandibular advancement splints or CPAP

In general, surgical treatments for simple snoring are not usually indicated. significant psychosocial consequences of snoring, such as relationship breakdown or mood disorder, surgical options could be explored.

Question 36

Health consequences

Answer 36

It is unclear whether simple snoring conveys any risk for ischaemic heart disease, stroke or hypertension
The exception is stroke, with evidence suggesting that non-apnoeic heavy snorers have an increased risk for carotid atherosclerosis compared with non- snorers