Sleep - Givaty

Question 1

What are the consequences of lack of sleep?

Answer 1

• *Behavioral:**
• Sleepiness (subjective/objectve)
• Mood changes (depression/mania)
• Irritability, nervousness (violence)

Cognitive:
Impairment of function (new skills, short term memory, complex tasks, slow reaction time, risk taking-like alcohol use)

Neurological:
Nystagmus, tremor, ptosis, slurring of speech, increased reflexes, increased reflexes (gag, tendon), increased sensitivity to pain

• *Biochemical:**
• Increased metabolic rate (decreased weight in animals despite increased caloric intake, secondary to increased energy requirement)
• Increased thyroid activity
• Insulin resistance

Hypothermia immune funciton impairment

Question 2

Types of Sleep Studies

Answer 2

Day Time studies (actigraph for one week):

• MSLT – Multiple sleep latency test
• MWT - Maintenance of wakefulness test

ž Night time studies

• Polysomnography (most common)
• Partial Studies (only respi/cardiac)
• NPT (Nocturnal penile tumescence- measure erection during REMs)

ž Misc. : Questionnaire , Actigraph

Question 3

What does polysomnography include?

Answer 3

The gold standard sleep test, includes the following
channels (Setting may vary between sites)
EEG – electroencephalography (Usually 2, Up to 16)
EOG – Electrooculography (2)
EMG – Electromyography (2-3, chin and Leg)
ECG – Heart Rate(1)
Flow – Thermister and pressure
Breathing effort (2, for apnea detection)
• Abdomen
• Thorax
Snoring level – by decibels
Oxygen saturation

ž

Question 4

What are the stages of sleep and what characterizes each?

Answer 4

Stage I:
-a frew minutes,awakened by any noise

Stage 2:

• awakened by a big noise
• 50% of the night
• EEG shows K-complexes (high amplitude, low frequency) and sleep spindles (low amplitude high frequency)

Short wave sleep:

• Includes stages 3 and 4 but only differentiated for research
• Include delta waves (low frequency, high amplitude)
• Gives feeling of refreshment
• 25% of sleep

REM:

• 25% of sleep
• High frequency, low amplitude, sawtooth wave
• Important for formulating memories, knowledge and learning (moving short-long term)
• Includes dreaming
• Atonic

Each cycle is about 1.5 hours long, slow wave sleep predominates earlier and REM predominates towards the morning.

Question 5

What are the types of respiratory events in sleep?

Answer 5

Apnea: Cessation of breathing for 10 seconds or more, can be central, obstructive or mixed.

ž Hypopnea: reduction of air flow of 50%, followed by an arousal or desaturation of 3%. (Medicare criteria : followed by 4%desaturation only)

ž RERA : Respiratory Effort Related Arousal, can be measured by pressure flow only (a flow limitation pattern, with movement)

• Obstructive sleep apnea.
  Obstructive events during the night :
  • 5-15 Mild
  • 15-30 Moderate
  • 30 and higher Severe
  (žSnoring, žSomnolence, žWitnessed apneas, Dry mouth, žHeadaches, žNocturnal sweating, nocturia)

– Central Sleep Apnea (multiple events, not obstructive)
ž
–UARS – Upper airway resistance syndrome (ex: adenoids in chldren, most common)

–ž CO2 Retention

Question 6

What are the consequences of obstructive sleep apnea?

Answer 6

žSystemic hypertension (from oxidative stress)
žPulmonary hypertension
žIschemic heart isease,CHF
žCardiac arrhythmias
žMVA (slow reaction time)
žStroke
žGERD
žImpotence

In children:

• shallowed breathing and arousal
• looks like ADD, sometimes given ritalin mistakenly, just needs sleep
• High comorbidity with ADD (~30%)
• Connected to performance at school

Question 7

What is the common treatment for obstructive sleep apnea?

Answer 7

ž CPAP:
ž- Continuous Positive Air-Pressure
-ž A simple compressor with a nasal or full face mask
-ž Generate pressure in order to prevent airway collapse
-ž The pressure range between 4-20 cmH2O

Surgical Intervention (not much except for children-polyps)

ž Oral appliance

Question 8

What are the types of Circadian Rhythm Sleep Disorders?

Answer 8

1. Delayed sleep phase Syndrome (ex: 4am-noon)

ž 2. Advanced sleep phase syndrome (early to bed, early to rise, like 6pm-2am)

ž 3. Non-24-h sleep-wake (Free running- a different length of sleep cycle, some days morning is morning but some like the middle of the night)

ž 4. Irregular sleep wake syndrome (no cycle, asleep and awake on an irregular schedule)

ž 5. Shift work

ž 6. Jet leg

Question 9

What are characteristics of Narcolepsy?

Answer 9

• ž excessive daytime sleepiness
• cataplexy (muscle tone suddenly lost due to emotion)
• hypnagogic hallucinations (before falling asleep)
• sleep paralysis (brain wakes up but muscles still paralyzed)
• Disturbed nighttime sleep
• Theory of autoimmune origin, familial correspondence, often associated with triggers like a bed