Sleep Disorders

describe the physiology of sleep in terms of Non-REM cycles

• makes up majority of total sleep

• has 3 stages: N1, N2, and N3

• N1: light sleep → transition from wakefulness, easy to wake

• N2: deeper relaxation → heart rate and temperature drop

• N3: slow-wave sleep → deep sleep, brain activity slows, important for physical recovery, immune function and memory consolidation

describe the physiology of sleep in terms of REM sleep

• rapid eye movement sleep first appears about 1.5 hrs after falling sleep

• key features are rapid eye movements, vivid dreaming, brain activity similar to wakefulness, muscle paralysis to prevent acting out dreams

• important for emotional regulation and memory processing

describe the physiology in terms of circadian rhythms

• body’s internal 24-hr clock

• controlled by suprachiasmatic nucleus (SCN) in the hypothalamus

• regulates sleep-wake timing, body temperature and hormone release

• aligns sleep with day/night cycle

• key influence to circadian rhythms = light exposure:

  • light signals SCN and promotes wakefulness

  • dark promotes sleep

describe the physiology of sleep in terms of hormonal influences

• melatonin: produced by pineal gland, released in darkness, promotes sleepiness and helps regulate circadian rhythm

• cortisol: produced by adrenal gland, peaks in early morning :. promotes wakefulness, lowest at night

• growth hormone: released mainly during deep non-REM N3 sleep, important for tissue repair, growth and metabolism

what are the key benefits of sleep?

• physical recovery

• memory consolidation

• emotional wellbeing

what is the impact of sleep on an individual level?

• physical health: weakens immune function, disrupts hormones

• cognitive function: impairs attention and concentration, memory consolidation, decision-making and reaction time

• mental health

• performance and quality of life: reduced productivity, lower motivation and energy

what is the impact of sleep on a societal level?

• economic costs: sleep deprivation can cause reduced workplace productivity, increased absence, higher healthcare costs

• public safety: increased risk of road and workplace accidents

• education system: poorer academic outcomes

• healthcare burden: chronic sleep disorders increase demand for healthcare services and long-term disease burden

what is the impact of sleep on a global level?

• economic productivity: sleep loss reduces global GDP due to lower workforce efficiency, and increased errors and accidents

• public health: rise in non-communicable disease e.g. CVD, diabetes

• inequalities: sleep disparities exist with lower income populations experiencing poorer sleep due to stress, work schedules, living conditions

what are the most common types of sleep disorders?

• insomnia: inability to sleep affects 30% of population within any one year and 1/3 of these are affected in the day

• hypersomnia: excessive work time sleepiness affecting 5-10% of population

• parasomnias: unwanted behaviour during sleep (mainly affects children)

what are the reasons for people being sleepy?

• insufficient sleep

• interrupted sleep→ snoring and sleep apnea, restless elgs, pain, asthma, other co-morbidities

• intrinsic sleepiness e.g. narcolepsy

what is sleep apnea?

sleep disorder where breathing repeatedly stops and starts during sleep :. poor-quality sleep and reduced oxygen levels

• airflow is reduced or completely blocked

• breathing pauses can last 10-30 seconds or longer

• brain briefly wakes you up to restart breathing (usually don’t notice this)

• cycle can happen dozens or hundreds of times per night

what are the 2 different types of sleep apnea?

• obstructive sleep apnea: breathing interruptions during sleep caused b physical blockage of airway by throat muscles relaxing too much → most common fort

• central sleep apnea: lack of respiratory effort where brain fails to send proper signals to breathing muscles

what are the common symptoms of sleep apnea?

• loud snoring

• gasping or choking during sleep

• excessive daytime sleepiness

• morning headaches

• poor concentration and irritability

• more common in men

how can we diagnose sleep apnea?

• snoring

• witnessed apneas with a Home Sleep Study

• respiratory polygraphies can assess airflow, breathing effort, blood oxygen levels, and heart rate during sleep

what is restless legs syndrome?

neurological condition that causes an uncomfortable urge to move the legs, usually when resting or trying to sleep

• tingling, crawling, itching or electric sensation in legs causing an irresistible urge to move

• symptoms start or worsen during rest, and improve with movement

• symptoms are worse at night

how is restless leg syndrome diagnosed?

• clinical presentation and history

• restless leg syndrome questionnaire assesses the following diagnostic criteria: urge to move legs accompanied by uncomfortable sensations, symptoms start or worsen at rest, relief with movement, worse in evening or at night

what is the International Classification of Sleep Disorders (ICSD-3)?

• insomnia disorders

  • difficulty initiating/maintaining sleep or waking too early, causes significant daytime impairment

• sleep relating breathing disorders

  • obstructive sleep apnea

  • central sleep apnea

• central disorders of hypersomnolence

  • excessive daytime sleepiness, includes narcolepsy and idiopathic hypersomnia

• circadian rhythm sleep-wake disorders

  • misalignment between internal body clock and external environment e.g. Shift Work Disorder

• Sleep-related movement disorders

  • movements that disrupt sleep e.g. RLS

what are the different interventions for sleep disorders?

• behavioural:

  • sleep hygiene

  • cognitive therapy

• medical interventions:

  • medication

  • Continuous Positive Airway Pressure device: keeps airway open during sleep by delivering a constant stream of air (primarily used in obstructive sleep apnea)

when should you suspect sleep apnea?

2 or more of the following feautures:

• snoring

• witnessed apneas

• unrefreshing sleep

• waking headaches

• choking during sleep

• unexplained excessive tiredness, fatigue

• nocturia (waking up from sleep to urinate)

• sleep fragmentation or insomnia

• cognitive dysfunction or memory impairment

what happens when someone with suspected sleep apnea has a negative respiratory polygraphy?

conduct a polysomnography = full sleep study

• comprehensive overnight test done in sleep lab

• more detailed than respiratory polygraphy → tells you about eye movements etc

what are the different strategies for integration of sleep health?

• pharmacy first referrals ‘sleep difficulties’

• posters in pharmacy

• when a patient comes in to buy an OTC product

• when a patient comes to collect their prescription → relevant comorbidity, at risk populations

• chronic disease management

what is sleep debt?

difference between amount of sleep you need and the amount you actually get

• e.g. you need 8 hrs/night, you get 6 hrs/night :. 2 hrs/night sleep debt → after 5 nights = 10 hrs sleep debt

• extra sleep can reduce sleep debt but does not fully reverse all effects of insufficient sleep

what are the diagnostic challenges for sleep disorders?

• non-specific symptoms e.g. fatigue, poor concentration, low mood

• patient underreporting → may not notice symptoms (e.g. apnea → often relies on bed partner observation), normalisation of poor sleep

• limited access to testing → gold standard = polysomnography but this is expensive, limited availability, long wait times

• sleep variability → one night test might not reflect actual sleep

• medication and lifestyle → can mimic or worsen sleep disorder, caffeine

what is the role of pharmacists in improving sleep

• screening and early identification → ask about sleep quality, identify red flags

• medication review → identify drugs that can affect sleep e.g. some antidepressants and manage this (dose times, drug interations)

• counselling on sleep hygiene

• referral

who can you refer a suspected sleep disorder patient to?

• GP - first line referral

• sleep specialist/sleep clinic

• respiratory physician for sleep apnea

• neurologist for RLS