Sleep Medicine

Question 1

Functions of Sleep

Answer 1

• Memory consolidation
• Energy conservation
• Brain restoration
• Protective behavioral adaptation–periods of darkness to avoid exposure to predators
• Immune function regulation

Question 2

Non-REM Sleep

Answer 2

• Stages 1-4*
• Respiratory pattern is regular
• HR and BP are lower
• Activity in the brainstem are lower
• Cerebral blood flow & cerebral glucose utilization are lower

*Unfocused thought with occasional short dreams (stage 3 and 4)

Question 3

REM

Answer 3

= rapid eye movement (e.g. dreaming)

• EEG waves as active as when we are awake
• Muscle tone is decreased

Question 4

Sleep in Children

Answer 4

• Neonates sleep ~16 hours per day, equally b/t night and day
• Nighttime sleep gradually consolidates into one interrupted block in 90% of infants by the end of the 1st year
• Daytime sleep gradually decreases over the first 3 years (by age 4 most do no nap)
• Infants up to age 6 months spend 50% of sleep time in REM sleep
• After 6 months sleep resembles adult sleep

Question 5

Adult Sleep

Answer 5

• Adults average 7-8 hours
• Natural short sleepers = 5 hrs
• Natural long sleepers = 10 hrs

Question 6

Sleep in Elderly

Answer 6

• Total sleep time decreases with age (but bedtime & rise time stays constant)
• Elderly nap more frequently
• Sleep architecture changes–decreases in SWS (stages 3 and 4 of non-REM), increase in the # of nighttime awakenings, & slight reduction in REM sleep

Question 7

Zeitgebers

Answer 7

Environmental variables capable of entraining circadian rhythms

*most potent zeitgeber = exposure to bright daylight

Question 8

Melatonin

Answer 8

A hormone secreted by the pineal gland in the brain
- Helps regulate other hormones
- Maintains body’s circadian rhythm–24 hrs. (when dark, more melatonin is produced & when light, less melatonin is produced)
^ disrupted by abnormal light/dark exposure
(e.g. jet lag, shift work, poor vision)

Question 9

Consequences of Daytime Sleepiness

Answer 9

• Trouble with memory and concentration
• Irritability and anxiety
• Lack of motivation
• Impaired work performance
• Drowsy driving

Question 10

Primary Snoring

Answer 10

Vibration of the soft tissues of the pharynx, soft palate, & sometimes the uvula
- TX: avoid smoking, alcohol, muscle relaxing agents, & sleep deprivation (esp. before bed)