Sleep Disorders Flashcards
Circadian rhythm = Process C is generated by output from ___ in __ which fluctuates in a cyclical fashion over ~24hrs.
Circadian rhythm = Process C is generated by output from Suprachiasmatic nucleus (SCN) in Anterior Hypothalamus which fluctuates in a cyclical fashion over 24hrs.
SCN becomes entrained to the external time by exposure to light through input from __ via ___.
Retinal ganglia cells via retinohypothalamic tract. A “nonvisual” pathway in the visual system.
Patients blinded by optic nerve lesion will:
Not become entrained and will develop free-running pattern with the “day” progressively starting later.
If a retinopathy preerves retinal ganglia cells and the patient is not aware of the light they:
Can still be “entrained” by proper light exposure.
Factors that modulate entrainment are called:
zeitbebers
Homeostatic process =
Process S
Caffeine’s wakefullness works how?
Blocks effect of adenosine. Adenosine accumulates during the day and at the end of the day ensures sleep.
Behaviorally induced insufficient sleep syndrome is:
When individuals have a pattern in which they choose to have (or have chosen for them) a schedule in which they are getting an inadequate amount of sleep
OSA affects at least __% of middle aged population and increases with age.
2-4%
Diagnosis of OSA can be confirmed with ___
Polysomnogram (PSG) showing an AHI (apnea-hypopnea index) or RDI (respiratory disturbance index) of at least 5 events per hour of sleep
Treatments for OSA:
Weight loss, positional therapy, positive airway pressure (PAP), oral appliances (mandibular advancement devices), a nasal expiratory pressure device (Provent®) and a variety of surgical procedures, the most definitive of which is tracheostomy. Of these, PAP is arguably the most extensively studied and consistently used treatment modality.
What %of OSA patients will use a PAP?
~40%
Narcolepsy prevalence:
0.02-0.19% (uncommon but not rare), similar to MS prevalence. Genetics play a role. Inability to maintain wakefulness.
Ancillary symptoms in narcolepsy:
- Cataplexy - loss of muscle tone caused by emotion, most often laughter.
- Hypnogogic hallucinations - visual as drift to sleep.
- Sleep Paralysis - loss of muscle tone, typically after arousal from light sleep.
- only 1/4 patients will have the whole “tetrad”
Narcolepsy is caused by absense/reduction in the number of:
hypocretin (orexin) neurons in the lateral hypothalamus
Treatment of narcolepsy:
- Sleep habits and naps
- Stimulants: methylphenidate, modafinil.
- TCAs and SSRIs suppress ancillary symptoms.
psychophysiological insomnia is:
conditioned behaviors usually seen in an individual with an intense, perfectionistic personality and a long history of being a poor or “light” sleeper, who experiences some kind of precipitating event (e.g., loss of job, divorce) and then develops perpetuating behaviors that continue the sleeplessness. They frequently associate the bed not with sleep or intimacy but an inability to sleep with resultant hyperarousal
Treatment of psychophysiological insomnia:
CBT is best.
Hypnotics, antihistamines are often used.
What fraction of patients presenting to Sleep Disorder clinic with complaint of insomnia have a psychiatric disorder as the cause? (most often anxiety)
1/3
Parasomnias that occur in NREM sleep include:
- Disorders of arousal
- Sleep terrors
- Sleep walking
- Confusional arousals
Parasomnias that occur in REM:
- REM sleep behavior disorder (RBD) - often a harbinger for neurodegenerative disorders, usually Parkinson’s, multple systems atrophy, or Lewy Body Dementia. These patients loose the muscle atonia characteristic of REM so they act out their dreams. Treat with clonazepam.
- Nightmare disorder
