Neurologic Sleep Disorders Flashcards
3 broad categories of sleep disorders?
Excessive sleepiness
Insomnia
Abnormal behaviors during sleep
4 conditions causing excessive sleepiness mentioned in lecture? (recall that this is a very incomplete list)
Narcolepsy
Sleep apnea
Insufficient sleep
Medication effects
3 causes of insomnia mentioned in lecture?
Mood disturbance
Circadian rhythm disturbance
Restless leg syndrome
3 conditions causing unusual movements or behaviors during sleep?
Parasomnias from non-REM or REM sleep
Nocturnal seizures
Movement disorders
What’s an actigraph?
Wrist accelerometer that detects movements. It’s used to get an objective measure of when people are actually asleep.
What is the narcolepsy tetrad + one other common symptom?
Hypersomnolence Cataplexy Hypnogogic/hypnopompic hallucinations (i.e. while falling asleep and waking up) Sleep paralysis \+ Impairment of sleep quality
What is cataplexy?
Weakness / loss of muscle tone provoked by emotion.
How do polysomnograms look in patients with narcolepsy?
“unremarkable except for frequent arousals”
What is / what do you test for in multiple sleep latency tests?
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.
What will the results of a multiple sleep latency test on a patient with narcolepsy be?
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.
What will be frequently seen on a electromyogram (EMG) of a patient with narcolepsy upon awakening?
Abrupt loss of muscle tone -> paralysis.
Do people remain conscious during attacks of cataplexy?
Yes, but they often lack so much muscle tone that they are unresponsive.
Most common age range for onset of narcolepsy?
“2nd to 4th decade” (…. does that mean age 10 - 39? a quick Google search makes me think so. It often presents in adolescence.)
Is narcolepsy equally present in all parts of the world?
Nope. It’s more common in Japan and less common in Israel.
What’s different about REM sleep in patients with narcolepsy?
The boundary between REM sleep and wakefulness is not as discreet as is normal.
What kind of molcule is hypercretin? (What else is it called?) Where is it made?
Hypercretin aka. orexin is a neuropeptide made in the posterolateral nucleus of the hypothalamus. Hypercretinergic neurons project to areas controlling sleep/wake cycles.
What’s hypercretin got to do with narcolepsy?
Patients with narcolepsy with cataplexy have markedly lower hypercretin levels.
What does hypercretin do? What does it act on? (3 things)
Hypercretin promotes wakefulness by promoting the activity of the LC, TMN, and Raphe nuclei (which promote wakefulness and inhibit VLPO).
What is the flip-flop model for wakefulness? How is hypercretin involved?
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.
Treatment for somnolence in narcolepsy? (3 things, one is pretty obvious)
Conventional stimulants
Modafinil / armodafinil (new stimulants)
Naps.
3 treatments for cataplexy?
Tricyclic antidepressants (suppress REM)
SSRIs (suppress REM)
Gamma hydroxybutarate aka. Xyrem (“produces consolidated sleep”)
What are parasomnias? Are they necessarily pathological?
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.
What are 3 steps on the continuum of severity of “Disorders of Arousal”?
Confusion arousal - appear to be awake and confused, but not actually.
Sleepwalking.
Night terrors = sleepwalking with sympathetic overdrive.
From which phase of sleep to disorders of arousal originate?
non-REM (usually slow wave) sleep
Do people usually remember having had an episode of sleepwalking / night terror?
No.
Do disorders of arousal run in families?
Yes.
When is the peak incidence of sleepwalking?
About age 12.
What is the treatment for disorders of arousal? (5 things)
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.
What will polysomnography of a person with REM sleep behavior disorder show?
Muscle tone during REM sleep where there shouldn’t be any.
and movements / behaviors…
3 features of REM sleep behavior disorder? (2 positive, 1 negative)
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).
Where, anatomically, is REM sleep generated? What does it do to suppress movement during REM sleep?
The pons. Sends active inhibition to spinal nerves.
What muscles aren’t paralyzed in REM sleep?
Occular muscles, the diaphragm
6 causes of REM sleep behavior disorder?
Ideopathic. Narcolepsy. Overlap with non-REM parasomnias. Neurodegenerative disease. Medications, esp. SSRIs. Disrupted REM sleep.
What 3 neurodegenerative diseases are associated with REM sleep behavior disorder?
Parkinson’s disease
Dementia with Lewy Bodies
Multi-system Atrophy
3 treatments for REM sleep behavior disorder?
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).
How are “restless legs” defined?
An awake sensory phenomenon that is relieved by volitional motor activity.
How are “periodic limb movements” defined (in the context of restless leg syndrome)?
An involuntary, sleep-related motor phenomenon. (remember that the arms can also be involved)
What are the URGE criteria for restless leg syndrome (RLS)?
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.
3 (non-URGE) features that support a diagnosis of RLS?
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.
4 exacerbating factors for RLS?
Psychological stress
Physical confinement (i.e. being in jail?)
Caffeine
Poor sleep
What’s more likely to rapidly progress: Early or late onset RLS?
Late onset. - it’s more likely to be secondary to some other condition.
3 conditions associated with secondary RLS?
Iron deficiency anemia.
Pregnancy.
Chronic Renal Failure.
What’s thought be the pathophysiology of RLS?
Iron deficiency? -> impaired dopaminergic activity? -> reduced supra-spinal motor inhibition.
Maybe.
What might be the RLS - Periodic Limb Movement link?
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
5 treatments of RLS?
Dopamine agonists
Opiates
Gabapentin
Iron (or tell them to stop donating blood so much)
Benzodiazepines (doesn’t actually treat the RLS part, though)
