2 - Sleep & Sleep Disorders
Light therapy
Daylight is 10,000 lux (unit of light) Put patients in front of artificial light of 10,000 lux for one hour to readjust internal clock Used in seasonal affective disorder, ASPS, DSPS
What are the medical risks of sleep apnea?
Blocks off upper airway in sleep - drop in O2 levels - Right sided cardiac problems & cardiac arrhythmias - Fragmented sleep - Diaphoretic sleep - Daytime sleepiness & MVAs
Why do people normally get drowsy in the early afternoon?
Body temp drops throughout night until 5am, then comes back up. Also drops during afternoon after lunch and triggers sleepiness
Sleep apnea tx
CPAP Rhinoplasty Tonsilectomy Other sx
Narcolepsy with cataplexy
Cataplexy - loss of muscle tone - they can fall over when they fall asleep - many times triggered by emotion (such as laughing)
Rhythmic movement disorder
Child - some rhythmic movement that is self soothing
Multiple Sleep Latency Testing (MSLT)
Criteria: Mean sleep latency of less than 8 minutes - Going into REM sleep after a few minutes - 2 or more onset REM periods (SOREMPs) - No other sleep disorder that accounts for the findings
Tx for Periodic limb movement disorder/restless leg syndrome
Dopamine agonists - pramipexole, ropinirole - Involved - dopamine. For appropriate synthesis need adequate O2 levels. IF you have anemia you may be deficient Gabapentin Benzos Opioids - not first line
What usually happens during REM sleep?
Dreaming Saccadic eye movements Muscle paralysis Penile Tumescence
What makes children more prone to disorders of arousal?
Enlarged tonsils causing upper airway obstruction
What are the usual means of entrainment?
Entrainment 1. The process by which external time cues influence the timing and periodicity of biological rhythms. - Physiologic processes linked to each other 2. Nonentrained rhythm is free of all external time cues, and is called free-running - Non-entrainment rhythms- escape physiologic linkages
Circadian rhythm disorders
Follow the 24hour sleep-wake cycle - sleep usually follows sundown Body temp drops throughout night until 5am, then comes back up. Also drops during afternoon after lunch and triggers sleepiness
Delta waves
Higher amplitude, low frequency Different from the rest, slow waves, seen in N3
Narcolepsy Tx
Inhibit REM sleep from occurring: low dose *TCAs* & SSRIs To control sleep attacks - stimulations - dopamine releasing, amphetamines, Modafinil (PROVIGIL) Nighttime medication - Xyrem (gamma hydroxybutrate - date rape drug?)
How do the levels of melatonin, cortisol, prolactin, and growth hormone change during the night? Which ones are dependent on sleep for change as compared to circadian rhythms?
Melatonin- most closely liked to the circadian system - Pineal gland secretes melatonin during darkness and is regulated by light from SCN pathways, hence the name hormone of darkness - The SCN holds a high density of high affinity receptors for melatonin Cortisol- released from the adrenal gland in response to stimulation by ACTH from the pituitary gland. - Needed for metabolism, and its absence leads to reduced energy and decreased metabolism - Important in the response to stress - The pattern of cortisol rhythm appears between the ages of 2 and 8 - Cortisol serves as a marker for circadian rhythms and may modulate other rhythms - The secretion of cortisol is tightly linked to the circadian clock - The sleep-wake pattern has only a minimal effect on this hormone. Growth Hormone- regulated by sleep itself and not by circadian rhythms. About 80% of total daily secretion occurs in a large pulse during slow wave sleep, stages N3-N4 - Kids have the most growth hormone, Growth hormone is needed to lose weight Prolactin- modulated by and increased by sleep, Circadian rhythms have little effect on secretion - More sleep you have, more prolactin production, Fertility problems may be due to lack of sleep
What are the different sleep stages and how do they differ?
REM sleep alternated with periods of non rapid eye movement sleep (NREM) in cycles of 90-100 minutes. BUT as night goes on, REM sleep length & frequency increases NREM sleep was further divided into 4 stages of increasing depth - 1,2,3 Deepest sleep - N3, this *occurs in first half of night* REM sleep - controlled by pons, essentially paralyzed
Narcolepsy
Neurologic condition producing sleep attacks. Marked sleepiness during the day. May fall asleep without warning during normal daily activity They fall immediately into REM sleep (can cause cataplexy) Onset - 15-20 years. Can start in children or elderly Automatic behavior often present - such as typing non-coherent notes without realizing. Incidence ↑ w/ 1st degree relative - HLABQ1
What the risk factors for sleep apnea?
Overweight Neck size, greater than 18in in men, 14in in women Snoring Essential HTN
Periodic limb movement disorder/restless leg syndrome
Periodic limb movement disorder - occurs while you are sleeping, repetitive movement of foot or leg, usually due to contraction of anterior tibialis muscle for a few seconds, then happens again after 30-90 seconds Restless leg syndrome - while you are awake
Why do we sleep?
Quite simply we sleep because we get sleepy and can't function or tend to our usual activity such as work or attend class. As yet we really don't fully know why we sleep. All mammals as well as most birds and reptiles sleep. Actually we can demonstrate rest-activity cycles in all living things including plants. Perhaps sleep is a way of recharging the body including the mental circuits. Sleep is critical for tissue repair and healing. The immune system is impaired without sleep. Feeling sleepy is not the only driving force behind sleep. What happens when we don't get enough sleep
Dream activity occurs in
REM sleep - when you have saccadic eye movements
N3
Skin regeneration Immune system maintenance
What are the stages/components of Normal Human Sleep
Sleep is entered through NREM NREM and REM alternate in 90-minute cycles Slow wave sleep predominates in the first third of the sleep period REM sleep predominates in the latter portion of the sleep period Wakefulness within sleep usually accounts for less than 5% of the night Stage 1 comprises about 2-5% of sleep Stage 2 comprises about 45-55% of sleep Stage 3 comprises about 3-8% of sleep Stage 4 comprises about 10-15% of sleep NREM sleep is usually 75-80% of sleep REM sleep is 20-25% of sleep
How does age affect the composition and quality of sleep?
Sleep varies from 16 hours at birth to 7.5 hours in the elderly - Infants: 16 hour/day -1 year old: 12 hour/day - Grade school: 10 hour/day- Deepest sleepers - Teenager: 9 hour/day - Adult: 8 hour/day - Elderly: need sleep, but it's more difficult to get → Harder to fall asleep, Wake up more often during night, More complaints about sleep → More daytime sleepiness since need has not decreased but nighttime sleep has
Parasomnias; sleep walking, sleep terrors, REM sleep behavior disorder
Sleep walking - common in children, occurs in first part of night, N3 sleep disturbance but not enough to wake Sex somnia - engaging in sex while asleep Sleep terrors - occurs in first part of night, usually in child, screams in the middle of the night, doesn't remember in the morning.
Types of sleep disorders
There are 85 specific sleep disorders diagnoses. Essential disorders to understand: - Narcolepsy - Sleep apnea syndrome - Periodic limb movement disorder and Restless Leg Syndrome - Parasomnias; sleep walking, sleep terrors, REM sleep behavior disorder - Insomnia - Effect of medication
How does the sleep of a depressed person differ from someone who is not depressed?
clear chronobiological aspects to affective disorders. Diurnal variations occur in depression with early morning awakening and seasonal changes. These effects are seen in nonseasonal depression of the unipolar or bipolar type.
1. Chronotherapy
delay their ability to go to sleep every day - Treatment for patients with delayed or advanced sleep phase disorders - let child go to sleep when they want, and let them wake when they want - Treatment involves gradually delaying the sleep period 1 hour daily. This causes the major sleep episode to shift around the clock to a more desirable sleep onset time c. Need to keep a very rigid sleep schedule afterward
Shift work
demands the constant adjustment and readjustment of sleep patterns and circadian rhythms to the changing sleep-wake pattern of shift work. - Difficulties in aligning one's own clock with light, sleep, work, and social cues, lead to circadian rhythm disorders and predispose to accidents in the work place - Do not function as well during the night as during the day
What is jet lag? What difference does direction of travel make?
desynchronization of circadian rhythms with the external environment due to travel across *three or more time zones*. This syndrome is due to the inability of endogenous clocks to adjust quickly to shifted zeitgebers in a new location. - Generally takes about a day per time zone crossed - If flying west to east, start taking melatonin at bedtime of where you're going
Delayed sleep phase syndrome (DSPS)-
inability to fall asleep at night until early morning that results in the desire to awaken in the late morning or early afternoon. - Sleep is delayed and attempts to realign the sleep pattern fails, causing a sleep onset insomnia and daytime sleepiness when required to rise at 7-8 am. - Usually affects adolescents, usually happens from unscheduled sleep over summer Tx - give melatonin 3 hours before bed time, helps reset clock
When is the maximum level of alertness?
most alert in morning - Subjective tests of alertness indicate that there is a peak in alertness in the late morning or the late afternoon, approximately 8-10 hours after awakening. - Alertness is also a function of body temperature, increasing and decreasing proportionately with temperature
Children with sleep apnea
not sleepy during the day, actually hyper, can't concentrate, no focus - big palatine tonsils can cause upper airway obstruction Tx: remove tonsils, tx underlying problem
Advanced sleep phase syndrome (ASPS)
onset of sleep at an inconvenient, early time in the evening (8-9 pm) and consequently awakening in the early morning (3-5 am) - Symptoms include an inability to stay awake in the evening, early morning awakenings, and daytime sleepiness - Usually in older individuals Tx. light therapy
