Insomnia
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Introduction
Insomnia is defined as difficulty falling asleep, maintaining sleep, early-morning wakening, or non-refreshing sleep.
The Case of...
a simple case introducing clincial presentation and calling for a differential diagnosis to get students thinking.
Causes and Risk Factors
Primary insomnia can be a diagnosis.
secondary causes include:
- medical conditions: COPD, asthma, CHF, hyperthyroidism, chronic pain, benign prostatic hypertrophy
- drugs: EtOH, caffeine, nicotine
- medications: anticonvulsants, appetite suppressants, dieuretics, thyroxine, bronchodilators, antidepressants, steroids
- psychiatric disorders: especially mood and anxiety disorders
- lifestyle factors: stress, shift work
- restless leg syndrome
- narcolepsy
However, people often react to insomnia with fear or anxiety around bedtime, or with a change in sleep situations (new environment, new responsibilties, etc). This can lead to a chronic disorder, ie psychophysiological insomnia.
Pathophysiology
Signs and Symptoms
- history
- physical exam
History
Inquire into
- chronicity of problem
- changes over time
- sleep during the day
- activities leading up to bedtime
- activities in bed
- caffeine, food, and exercise
A sleep diary, completed every morning for 1-2 weeks can help understand insomnia. Record:
- bedtime
- sleep latency
- total sleep time
- awakenings
- quality of sleep
Regarding causes, ask about:
- low mood
- mania
- anxiety
- psychosis
- substance abuse
- life stressors
- fever, weight loss, night sweats
- pain
- dyspnea
- nocturia
Past medications used
The patient's ideas of what is happening
Past medical history, other medications, smoking, drugs
A sleep study referral can be done to test for periodic leg movements
Physical Exam
Investigations
- lab investigations
- diagnostic imaging
Lab Investigations
Rule out specific medical problems:
- CBC +differential
- TSH
Diagnostic Imaging
Differential Diagnosis
Treatments
Treat any suspected medical or psychiatric cause
- Medications
- sleep hygiene
- Non-Medication Treatments
Medications
Benzodiazepines are best avoided, as they may decrease slow wave sleep and result in declined effect with chronic use (ie 1-2 weeks).
Safe options:
- trazodone
- zopiclone
Other options include:
- nortriptyline
- mirtazapine
Avoid anti-histamines (eg diphenhydramine, dimenhydrinate)
Herbal remedies include
Valerian (indicated for agitation and sleep)
L-Tryptophan: may induce relaxation and enhance sleep; be cautious of seratonin syndrome
Melatonin: popular, but currently no evidence (recent meta-analysis of 6 RCTs)
Sleep Hygiene
It is important to counsel patients on effective practices:
- have a regular schedule
- go to bed when sleepy
- have the bedroom be a comfortable room
- avoid daytime naps
- use the bedroom for sleep and sex only
- no caffeine or nicotine 6 hours before bed
- avoid alcohol
- avoid heavy meals before bed
- use diuretics only in the morning
- excercise regularly, but avoid 3 hours before bed
- move the clock away from view
- if in bed for more than 20 minutes (or so; remember the clock has been moved!) go to another room and return when sleepy
Non-Medication Treatments
Cognitive behavioural therapy, in combination with zolpidem, appears more effective than CBT alone (NNT=8 at 6 months) (Morin et al, 2009).
Relaxation therapy can be used: deep-breathing, biofeedback.
Stimulus control: re-association of bed with sleep' re-establishment of consistent sleep-wake cycle, reduce activities cuing being awake.
Sleep restriction therapy: total time in bed should closely match total sleep time
Consequences and Course
Insomnia can range from transient to ongoing, and from the annoying to the devestating.
Resources and References
Topic Development
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