Neurologic Sleep Disorders

Question 1

3 broad categories of sleep disorders?

Answer 1

Excessive sleepiness
Insomnia
Abnormal behaviors during sleep

Question 2

4 conditions causing excessive sleepiness mentioned in lecture? (recall that this is a very incomplete list)

Answer 2

Narcolepsy
Sleep apnea
Insufficient sleep
Medication effects

Question 3

3 causes of insomnia mentioned in lecture?

Answer 3

Mood disturbance
Circadian rhythm disturbance
Restless leg syndrome

Question 4

3 conditions causing unusual movements or behaviors during sleep?

Answer 4

Parasomnias from non-REM or REM sleep
Nocturnal seizures
Movement disorders

Question 5

What’s an actigraph?

Answer 5

Wrist accelerometer that detects movements. It’s used to get an objective measure of when people are actually asleep.

Question 6

What is the narcolepsy tetrad + one other common symptom?

Answer 6

Hypersomnolence
Cataplexy
Hypnogogic/hypnopompic hallucinations (i.e. while falling asleep and waking up)
Sleep paralysis
\+ Impairment of sleep quality

Question 7

What is cataplexy?

Answer 7

Weakness / loss of muscle tone provoked by emotion.

Question 8

How do polysomnograms look in patients with narcolepsy?

Answer 8

“unremarkable except for frequent arousals”

Question 9

What is / what do you test for in multiple sleep latency tests?

Answer 9

Four or five 20 minute naps at 2 hour intervals.
Looking to see how quickly patient falls asleep / what stages of sleep they reach / anything unusual such as sleep paralysis.

Question 10

What will the results of a multiple sleep latency test on a patient with narcolepsy be?

Answer 10

Will fall asleep much more rapidly than normal.
Will enter REM sleep, which is not normal for a 20 minute nap.
May have sleep paralysis.

Question 11

What will be frequently seen on a electromyogram (EMG) of a patient with narcolepsy upon awakening?

Answer 11

Abrupt loss of muscle tone -> paralysis.

Question 12

Do people remain conscious during attacks of cataplexy?

Answer 12

Yes, but they often lack so much muscle tone that they are unresponsive.

Question 13

Most common age range for onset of narcolepsy?

Answer 13

“2nd to 4th decade” (…. does that mean age 10 - 39? a quick Google search makes me think so. It often presents in adolescence.)

Question 14

Is narcolepsy equally present in all parts of the world?

Answer 14

Nope. It’s more common in Japan and less common in Israel.

Question 15

What’s different about REM sleep in patients with narcolepsy?

Answer 15

The boundary between REM sleep and wakefulness is not as discreet as is normal.

Question 16

What kind of molcule is hypercretin? (What else is it called?) Where is it made?

Answer 16

Hypercretin aka. orexin is a neuropeptide made in the posterolateral nucleus of the hypothalamus. Hypercretinergic neurons project to areas controlling sleep/wake cycles.

Question 17

What’s hypercretin got to do with narcolepsy?

Answer 17

Patients with narcolepsy with cataplexy have markedly lower hypercretin levels.

Question 18

What does hypercretin do? What does it act on? (3 things)

Answer 18

Hypercretin promotes wakefulness by promoting the activity of the LC, TMN, and Raphe nuclei (which promote wakefulness and inhibit VLPO).

Question 19

What is the flip-flop model for wakefulness? How is hypercretin involved?

Answer 19

VLPO and eVLPO promote sleep, inhibit LC/TMN/Raphe nuclei, and inhibit hypercretin activity.
LC/TMN/Raphe nuclei promote wakefulness and inhibit VLPO/eVLPO.
Hypercretin promotes LC/TMN/Raphe nuclei activity, tipping the balance toward wakefulness.

Question 20

Treatment for somnolence in narcolepsy? (3 things, one is pretty obvious)

Answer 20

Conventional stimulants
Modafinil / armodafinil (new stimulants)
Naps.

Question 21

3 treatments for cataplexy?

Answer 21

Tricyclic antidepressants (suppress REM)
SSRIs (suppress REM)
Gamma hydroxybutarate aka. Xyrem (“produces consolidated sleep”)

Question 22

What are parasomnias? Are they necessarily pathological?

Answer 22

Undesirable behavioral, motor, or sensory phenomena that happen during sleep. They’re not necessarily pathological, but some are. They range from nightmares to leg movement to sleepwalking.

Question 23

What are 3 steps on the continuum of severity of “Disorders of Arousal”?

Answer 23

Confusion arousal - appear to be awake and confused, but not actually.
Sleepwalking.
Night terrors = sleepwalking with sympathetic overdrive.

Question 24

From which phase of sleep to disorders of arousal originate?

Answer 24

non-REM (usually slow wave) sleep

Question 25

Do people usually remember having had an episode of sleepwalking / night terror?

Answer 25

No.

Question 26

Do disorders of arousal run in families?

Answer 26

Yes.

Question 27

When is the peak incidence of sleepwalking?

Answer 27

About age 12.

Question 28

What is the treatment for disorders of arousal? (5 things)

Answer 28

Reassurance that it’s probably not the sign of some serious problem.
Secure environment.
Warning device.
Avoid precipitating factors (EtOH, stress, insufficient sleep).
Medication, if severe: benzodiazepines.

Question 29

What will polysomnography of a person with REM sleep behavior disorder show?

Answer 29

Muscle tone during REM sleep where there shouldn’t be any.

and movements / behaviors…

Question 30

3 features of REM sleep behavior disorder? (2 positive, 1 negative)

Answer 30

Violent dream-enacting by history or polysomnography.
Increased tonic or phasic EMG recordings during REM sleep.
Absence of epileptiform activity (on EEG and otherwise, presumably).

Question 31

Where, anatomically, is REM sleep generated? What does it do to suppress movement during REM sleep?

Answer 31

The pons. Sends active inhibition to spinal nerves.

Question 32

What muscles aren’t paralyzed in REM sleep?

Answer 32

Occular muscles, the diaphragm

Question 33

6 causes of REM sleep behavior disorder?

Answer 33

Ideopathic.
Narcolepsy.
Overlap with non-REM parasomnias.
Neurodegenerative disease.
Medications, esp. SSRIs.
Disrupted REM sleep.

Question 34

What 3 neurodegenerative diseases are associated with REM sleep behavior disorder?

Answer 34

Parkinson’s disease
Dementia with Lewy Bodies
Multi-system Atrophy

Question 35

3 treatments for REM sleep behavior disorder?

Answer 35

Clonazepam (a benzodiazepine) - 90% effective
Melatonin - sometimes effective
Secure environment (comedian Mike Birbiglia sleeps in a sleeping bag and wears mittens so he can’t get out).

Question 36

How are “restless legs” defined?

Answer 36

An awake sensory phenomenon that is relieved by volitional motor activity.

Question 37

How are “periodic limb movements” defined (in the context of restless leg syndrome)?

Answer 37

An involuntary, sleep-related motor phenomenon. (remember that the arms can also be involved)

Question 38

What are the URGE criteria for restless leg syndrome (RLS)?

Answer 38

Urge to move legs, usually with dysthesias.
Rest or inactivity brings on these urges/dysthesias.
Getting up to walk around provides partial or total relief.
Evenings - in the evenings, symptoms are usually worse.

Question 39

3 (non-URGE) features that support a diagnosis of RLS?

Answer 39

Periodic limb movements - in 80-90% of patients with RLS, but not specific at all (lots of people have periodic limb movement).
Family history.
Response to dopaminergic therapy.

Question 40

4 exacerbating factors for RLS?

Answer 40

Psychological stress
Physical confinement (i.e. being in jail?)
Caffeine
Poor sleep

Question 41

What’s more likely to rapidly progress: Early or late onset RLS?

Answer 41

Late onset. - it’s more likely to be secondary to some other condition.

Question 42

3 conditions associated with secondary RLS?

Answer 42

Iron deficiency anemia.
Pregnancy.
Chronic Renal Failure.

Question 43

What’s thought be the pathophysiology of RLS?

Answer 43

Iron deficiency? -> impaired dopaminergic activity? -> reduced supra-spinal motor inhibition.
Maybe.

Question 44

What might be the RLS - Periodic Limb Movement link?

Answer 44

Both might be caused by loss of supraspinal inhibition:
RLS - suppression of afferent sensory info is lost
PLM - suppression of efferent motor activity is lost

Question 45

5 treatments of RLS?

Answer 45

Dopamine agonists
Opiates
Gabapentin
Iron (or tell them to stop donating blood so much)
Benzodiazepines (doesn’t actually treat the RLS part, though)