Sleep Phys and Disorders

Question 1

What part of the brain, in very general terms, regulates sleep?

Answer 1

diencephalic nuclei

Question 2

See slide 5 for ambient light summary

Answer 2

ok

Question 3

Body temperature does what during sleep periods?

Answer 3

Falls

Question 4

Growth hormone is released most when?

Answer 4

Just after we fall asleep

Question 5

Cortisol is released most when

Answer 5

Just before we wake up

Question 6

Method of measuring sleep is known as

Answer 6

polysomnography

Question 7

How many stages of sleep are there

Answer 7

5

Question 8

What are the different divisions of EEG frequency

Answer 8

Beta- Over 13 hz
Alpha- 8-13 hz
Theta- 4-7 hz
D- less than 4

Question 9

Beta frequency EEG

Answer 9

Over 13 hz. Most commonly seen in normal awake human beings

Question 10

As frequency falls, what happens to ampltude>

Answer 10

It rises

Question 11

So, basically as you progress from “Awake” through stage 4, the frequency of the EEG falls while the amplitude of the waves rise.

Answer 11

ok

Question 12

What is unique about the EEG in REM sleep?

Answer 12

It is appears to be very similar to that of the awake sleep

Question 13

Stages I-IV together are called

Answer 13

Non- REM sleep

Question 14

Stage I is the lightest sleep and stage 4 is the…

Answer 14

deepest

Question 15

Sleep spindles and K complexes are characteristics of what stage of sleep

Answer 15

2

Question 16

What type of EEG activity characterizes stage I and II of sleep?

Answer 16

Theta

Question 17

Stage 3 and 4 sleep are characterized by what kinds of EEG waves

Answer 17

Delta

Question 18

The duration of sleep in stages 3 and 4 is longest when?

Answer 18

Early in a sleep cycle

Question 19

The duration of REM sleep is longest when>

Answer 19

Late in the sleep cycle

Question 20

Compare Non-REM with REM. Physiologically

Answer 20

NREM- Eye movements are slow, movement occurs but muscle tone is decreased

• Decreased BP, HR, RR, metabolic rate
• Dreams less vivid, low emotional content
• Sleep walking and night terrors occur during slow wave
• All reach a maximum during Stage IV sleep

REM-

• Rapid eye movements
• muscle paralysis
• HR, BP, RR, temp and metabolism approach awake level
• Dreams Vivid, high emotional content

Question 21

Penile and clitoral erection occur when?

Answer 21

During REM sleep

Question 22

Brain activity is increased where during REM sleep?

Answer 22

_ Amygdala, parahippocampal gyrus, anterior cingulate cortex

Question 23

What brain areas are inhibited during REM

Answer 23

• Frontal Cortex and posterior Cingulate cortex.

Question 24

What is the significance of these active and inactive brain regions

Answer 24

• The activity explains the vivid, emotional dreams that occur during REM.
• The inhibition of the certain brain regions may explain the bizarre nature of some dreams due to reduced executive reasoning and ratinal thought

Question 25

Make a chart for the Neural sleep circuits

Answer 25

ok

Question 26

The Neural sleep Circuit that is Cholinergic in nature is

Answer 26

- Cholinergic neurons from the pedunculopontine (PPT) and Lateral Dorsal Tegmental (LDT) project to the thalamus and other brainstem areas. - Triggers thalamic cortical signaling that produces high frequency, low voltage EEG activity consistent with arousal. - Also active during REM sleep

Question 27

Noradrenergic sleep circuit?

Answer 27

Noradrenergic input comes from the locus ceruleus to the neocortex Highly activated during wakefullness, none during REM

Question 28

Dopaminergic wakefullness cicuits originate where?

Answer 28

Substantia Nigra This circuit is most important for full wakefullness

Question 29

Serotonergic circuits originate where?

Answer 29

dorsal and medial raphe nuclei

Question 30

Histaminergic output during wakefulness comes from

Answer 30

tuberomammillary nucleus

Question 31

What is important about the Orexin pathway

Answer 31

90% of pts with narcolepsy have significantly decreased or undetectable levels of orexin

Question 32

Ventrolateral preoptic nucleus

Answer 32

Significant because it harbors GABAergic and Galanin neurons both of which innervate and inhibit all of the nuclei that activate arousal. Thus, activation of the VLPO causes decreased forebrain arousal and the onset of NREM sleep

Question 33

Lesions of the VLPO would lead to

Answer 33

insomnia

Question 34

What are somnogens

Answer 34

endogenous sleep- promoting chemicals that may accumulate during wakefulness and promote sleep onset.

Question 35

Adenosine

Answer 35

a somnogen that builds up in the CNS during wakefullness and declines during sleep

Question 36

Cytokines IL-1B and TNF

Answer 36

promote sleep

Question 37

Melatonin

Answer 37

synthesis turned on by decreasing light

Question 38

Multiple sleep latency test

Answer 38

EEG defined sleep latency, i.e, the time required to fall asleep during 4-5 daytime naps

Question 39

Epworth sleepiness sclae

Answer 39

self-reported tendency to fall asleep in 8 diff situations

Question 40

Obstructive Sleep Apnea

Answer 40

Repetitive blockage of the resp pathway during sleep causing apneic periods lasting - Longer than 10 senconds - and causing oxyhemoglobin desaturations of more than 4%

Question 41

Strong association b/w OSA and

Answer 41

heart disease and HTN

Question 42

Check out OSA phys findings and symptoms slide

Answer 42

``` - May have: Nasal obstruction Tonsillary hypertrophy HTN CHF Pitting Edema with large hands and feet ``` Snoring, heartburn, memory loss, depression, nocturia, impotnece

Question 43

Narcolepsy

Answer 43

Excessive daytime sleepiness associated with one or more of the following tetrad: - sleep attacks/ intrusions - cataplexy- abrupt loss of muscle tone - sleep paralysis- persistent REM sleep atonia after waking - hypnagogic hallucinations

Question 44

90% of ppl with narcolepsy develop it when

Answer 44

by 2nd or 3rd decade

Question 45

Pathogenesis of Narcolepsy

Answer 45

loss of hypocretin/orexin secreting neurons in the posterior lateral hypothalamus - related to HLA genes DQ1 and DQB1 that may predispose to autoimmune attack on orexin secreting neurons

Question 46

Dx of narcolepsy

Answer 46

- clinical pres | - Low CSF hypocretin level

Question 47

REM sleep behavior disorder

Answer 47

- Loss of atonia/paralysis during REM sleep. - Very rare, most common in adult males over 50 See slide for pathogenesis info

Question 48

Melatonin produced where

Answer 48

Pineal Gland

Question 49

Sleep Cycle Stage Progression

Answer 49

Awake- stage 1 - stage 2- stage 3- stage 4 | Back to 3, 2, 1 etcc... periodically moving into REM

Question 50

one sleep cycle =

Answer 50

begins at stage one and ends with a period of REM....takes about 90 minutes