Sleep disorders: Assessment
Dr Johnson’s clinic focuses primarily on the management of insomnia disorder, circadian rhythm disorders, and parasomnias in adults. Other sleep disorders, such as sleep-related breathing disorders and disorders of excessive sleepiness, are best assessed by respiratory sleep physicians. The clinic is part of the multidisciplinary Sleep Clinic at the Woolcock Institute of Medical Research, which also includes respiratory sleep physicians, sleep psychologists, neurologists, and other health professionals. The clinic has access to a sleep laboratory capable of performing a wide range of investigations to better clarify an individual’s sleep-related difficulties.
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For many people with a sleep disorder, treatment typically begins and ends with sleep hygiene advice provided in a general practice setting. This is frequently ineffective, largely because the core contributors to poor sleep have not been identified and appropriately addressed.
How are sleep disorders assessed ?
1) Clinical History (60 mins)
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The first step is to take a thorough clinical history, which not only involves asking about an individual’s nightly schedule but also includes questions regarding events that may occur during the night (such as snoring, nightmares, sleep paralysis, etc.) and daytime symptoms such as sleepiness, napping, attention, concentration, and mood issues. A cross-sectional snapshot, which clinical history provides, may not yield sufficiently detailed information; therefore, further investigations may be recommended.
2) Investigations (might be indicated)
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Overnight Sleep Study (PSG)
Sometimes investigations are warranted. Overnight sleep studies are necessary for conditions such as obstructive sleep apnoea, parasomnias (e.g. sleepwalking), and disorders of excessive sleepiness. In these cases, an overnight sleep study — technically called polysomnography (PSG) — can be useful in improving diagnostic accuracy, particularly where clinical history alone is insufficient.
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Actigraphy
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PSG is generally not particularly useful for conditions such as insomnia and circadian rhythm disorders. Individuals with these conditions frequently exhibit significant night-to-night variability, meaning that a single night of monitoring may not reflect their habitual sleep pattern. For this reason, actigraphy — which determines sleep by measuring movement and ambient light — can be a useful tool, as it captures an individual’s typical sleep pattern over an extended period (usually seven days).
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Sleep Diaries
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The simplest tool to evaluate sleep is a sleep diary. It is also the most cost-effective (effectively free) and has been proven sufficiently reliable for many conditions. Various formats exist, including free apps that can be downloaded to a smartphone. We frequently combine sleep diaries with actigraphy to enhance accuracy.
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