Sleep disorders

Question 1

Characteristics of Non-REM sleep (NREM)

Answer 1

In this phase, your muscle tone decreases, eye movement decreases, heart rate and blood pressure decrease.It is easier to arouse a person in NREM and pulsatile release of growth hormone (GH) and gonadatropins (LH and FSH) are associated with this phase.

Question 2

Three phases of NREM

Answer 2

Stage N1 (Theta waves). This is the falling asleep phase when eye movements slow and overall loss of awareness, thought, and responsiveness.

Stage N2 (sleep spindles and K complexes). This is deeper sleep than stage N1 and is characterized by high voltage, slow waves appearing in EEG.

Stage N3 (slow wave sleep/delta sleep/deep sleep). This phase is even deeper sleep than stage N2 with many more high voltage, slow waves (delta waves).

Question 3

Characteristics of REM sleep

Answer 3

In this phase, the deepest sleep is established and you have rapid eye movements, irregular breathing and increased heart rate. There is loss of skeletal motor tone (muscles cannot move) and heightened brain neural activity and increased brain oxygen use. REM is decreased by alcohol, benzodiazepines, and barbiturates. Dreaming is associated with this phase.

Question 4

Two types of primary sleep disorders

Answer 4

Dyssomnias -difficulty initiating or maintaining the sleep or daytime sleepiness

Parasomnias- abnormal behavioral or physiological events occurring DURING sleep

Question 5

What are secondary sleep disorders

Answer 5

Secondary sleep disorders are sleep disorders related to another mental or medical condition

Question 6

Characteristics, causes, and TX of insomnia

Answer 6

Characteristics common with insomnia include fatigue, concentration or memory impairment, mood disturbances, lack of motivation, daytime sleepiness and impaired academic and social performance.

Causes of insomnia- can be idiopathic or caused by inadequate sleep hygiene. Secondary sleep disorder causes of insomnia include anxiety, depression, drug or other substances (caffeine) or other medical conditions.

Treatment of insomnia includes treatment of the underlying medical or psychological/psychiatric issue if there is a secondary cause. Non-pharmacologic treatments include normalizing the circadian rhythm, sleep hygiene, cognitive behavior therapy (ie only use the bedroom for sleep or sex , lie down only when you are sleepy, no clocks or TV in the bedroom) and sleep restriction therapy (restrict time in bed).

Question 7

What is hypersomnia

Answer 7

daytime sleepiness that is not caused by disturbed nocturnal sleep or misaligned circadian rhythms.

Question 8

What is narcolepsy

Answer 8

disorder that causes periods of extreme daytime sleepiness that can be associated with hallucinations and/or paralysis

Question 9

Characteristics of narcolepsy

Answer 9

recurrent episodes of rapid-onset, overwhelming sleepiness which occur more than 3 times a week. The narcoleptic sleep episodes start with REM sleep and is associated with sleep paralysis. Patients can have hallucinations just before going to sleep (hypnagogic) or just before awakening (hypnopompic). Some patients with narcolepsy can have cataplexy in which they have a sudden loss of muscle tone with an emotional trigger (laughing, crying or stress). Sometimes cataplexy can be partial with a lower limb collapse, head dropping or dysarthria. Patients with narcolepsy note that short naps are often refreshing but they often have fallen asleep in inappropriate situations.

Question 10

Causes and tx of narcolepsy

Answer 10

Causes: Narcolepsy has been linked to decreased orexin (hypocretin) neurotransmitter production in the hypothalamus. Orexin is a key regulator of sleep/wake states as well as feeding behavior. The presence of orexin seems to promote wakefulness.

Treatment of narcolepsy is mostly symptomatic:

a. Wake promoting agents during the day aka stimulants (modafinil)
b. Sedative hypnotics at nighttime (sodium oxybate)
c. Antidepressants for cataplexy
d. Good sleep hygiene by taking scheduled naps and having a regular sleep schedule

Question 11

Two types of sleep apnea

Answer 11

Central sleep apnea-caused when the brain fails to signal the muscles to breathe so there is a lack of physical effort to breathe, ie central signally defect from the BRAIN.

Obstructive sleep apnea (OSA)- caused by a proximal airway obstruction usually when the soft tissue in the back of the throat collapses during sleep. There is a physical effort to breathe. We will focus the rest of the discussion on sleep apnea on OSA.

Question 12

Symptoms of obstructive sleep apnea

Answer 12

Snoring, Gasping for air at night, Witnessed pauses in breathing, Morning headache, Dry mouth, Excessive daytime sleepiness, Memory complaints and Un-refreshing sleep.

Question 13

Risk factors and TX for sleep apnea

Answer 13

Modifiable Risk Factors for sleep apnea:

Obesity (BMI>30 and neck circumference >40 cm), Sedative medications, Alcohol, Endocrine disorders (hypothyroidism, acromegaly) and Nasal obstruction

Nonmodifiable Risk Factors for sleep apnea:

Gender (male), Age (older), Ethnicity, Menopausal status, Craniofacial anomalies (maxillary hypoplasia and micrognathia) and Congenital syndromes (such as Treacher Collins and Pierre Robin syndromes) which affect structure of the upper airway.

Treatment of sleep apnea includes weight loss, continuous positive airway pressure (CPAP), oral appliances, positional therapy (sleeping on side or stomach) and surgical treatments to remove enlarged tonsil and adenoids or repair deviated septum.

Question 14

what are Circadian rhythym sleep disorders

Answer 14

occur when the normal sleep-wake cycle is affected.

Common causes include jet lag and shift work. Treatment often involved improving sleep hygiene.

Question 15

What are NREM parasomnias

Answer 15

Night terrors, sleep walking, sleep bruxism (teeth grinding), restless leg syndrome

Question 16

Symptoms of night terrors

Answer 16

Night terrors or sleep terrors occurs when a person wakes suddenly from sleep in a terrified state.

Usually occurs during stage N3 (slow wave/deep) NREM.

Common symptoms are an abrupt fear with vocalization (piercing scream at onset) and autonomic symptoms (tachypnea, tachycardia, mydriasis, diaphoresis) and prolonged inconsolability.

Patients are difficult to arouse in this state and typically cannot remember the night terror or the event.

Night terrors are common in children and are self-limited.

Question 17

Symptoms of sleep walking

Answer 17

Sleepwalking is also called somnambulism.

In this condition a person ambulates out of bed, and may even bolt.

Typically, they display inappropriate behavior (agitated, violent) and have disoriented, slow speech.

In sleepwalking people able to navigate, but prone to bumping into things and falling and injuries may not wake them.

Eyes are wide open while these individuals are sleep walking but they are still asleep!

Question 18

Symptoms of sleep bruxism

Answer 18

Sleep bruxism is grinding of the teeth when sleeping.

This often leads to deformed teeth (not to mention annoying for the person trying to sleep nearby!).

Treatment involves an oral appliance.

Question 19

Symptoms, cause. of restless leg syndrome (RLS)

Answer 19

Restless leg syndrome (RLS) is a neurological condition that is characterized by unpleasant sensations of the leg and an urge to move them when at rest and asleep.

The sensation is improved with movement and the urge to move is worse at night and when stationary.

The cause of RLS is mostly idiopathic, but is more common in pregnant women and in people with end stage renal failure (CKD). There is also evidence that central iron deficiency results in a state of dopaminergic dysfunction that is associated with RLS.

Question 20

TX for RLS

Answer 20

Treatment of RLS includes treating the underlying cause, if known, and exercise.

Remove offending agents, such as caffeine, alcohol, benadryl, certain antidepressants/antipsychotic.

Check for low iron with serum ferritin level (<50) since this has been associated with a predisposition to RLS.

Vibratory counter-stimulus device has also been used as therapy.

Pharmacologic treatments for RLS include gabapentin or dopamine agonist.

Question 21

What are REM parasomnias

Answer 21

Nightmares and sleep paralysis

Question 22

Symptoms of nightmares

Answer 22

Nightmares occur during REM sleep.

They are characterized by frightening dreams that interfere with daily functioning.

Unlike night terrors, a person with nightmares readily awakens from the dream, has detailed recall, and becomes oriented and alert quickly.

Nightmares are more common in children and can be induced by stress.

Question 23

Sleep paralysis symptoms

Answer 23

Sleep paralysis is a condition that prevents you from moving or speaking while waking up or falling asleep.

Sleep paralysis typically lasts only a few seconds to a few minutes.

Remember sleep paralysis is also associated with narcolepsy.

Question 24

What is a Polysomnogram (PSG).

Answer 24

A diagnostic sleep study

This test is typically performed in a sleep lab at a hospital or clinic. Brain waves, the oxygen level in the blood, heart rate and breathing, as well as eye and leg movements are monitored during the study.

Question 25

What is a titration test

Answer 25

A titration study is indicated if sleep disordered breathing is identified on diagnostic study. A titration study determines the appropriate therapeutic level of PAP (positive airway pressure) and oxygen for the patient based on their condition and the severity of the apnea. This is often performed to determine the appropriate treatment settings.

Question 26

What is a multiple sleep latency test

Answer 26

multiple sleep latency test is utilized to help diagnose hypersomnia and narcolepsy. This study is a bit more involved. First, stop all drugs that affect REM sleep at least 2 weeks prior to the test. Next, a complete diagnostic PSG is performed the night before. The PSG is to evaluate for sleep disordered breathing and to ensure patient is not sleep deprived. The next day a nap test is performed( a total of five 20 minute naps every 2 hours). Using this information mean sleep latency and REM is measured. Short mean sleep latency (<8 minutes) is diagnostic of hypersomnia. Sleep onset REM periods (at least 2) is diagnostic of narcolepsy.