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Flashcards in Psych - Sleep Deck (18):

Neurotransmitters of WAKEFULNESS

GLUTAMATE - most important

DA, NE, Histamine (anti-histamines make us drowsy), ACh

Neurons in brainstem reticular formation are in charge of cortical activation and keeping us awake. They project from the RF to the cortex (via the ascending reticular system) which has two pathways -- dorsal (through thalamus) and ventral (extrathalamic)


Neurotransmitters of SLEEP


GABA inhibits the brainstem, hypothalamus and RF -- thalamocortical systems then get hyper polarized

Also a shift from sympathetic to parasympathetic

EEG --> low frequency high amplitude --> theta waves, SPINDLES and K complexes, delta waves


NON-REM sleep (no dreams)


Composed of:

superficial or light sleep (stages 1 and 2) --> 50% of the night!

Deep or slow wave sleep (stage three - 20-25% of the night)


REM SLEEP (dreams)

REM is often known as PARADOXICAL sleep (EEG is same as awake! High frequency!)

Metabolic and physiologic activity of the brain INCREASES; DREAMS!!!

REM sleep --> increased ACh release (an awake NT!!!!) --> 20-25% of the night


Sleep and age

Kids get a lot of stage 3 (deep) sleep

As we age we get less and less deep sleep

Two phases REM/NONREM cycle every 90-120 minutes

We should be in REM sleep at 90 minutes

REM usually lasts 10-20 minutes, amount gets longer and longer with each cycle

Need about 7-9 hours on avg



In NREM sleep, the brain is inactive and the respiratory drive is thus decreased -- additionally, sensitivity at chemo receptors decreases

As we drift between stages 1 and 2, brain activity and thus respiratory drive fluctuates, leading to periodic breathing/short periods of apnea -- Cheyne-Strokes Respiration --> this is normal

Overall, the respiratory drive during NREM IS STABLE, but LESS than wakefulness

Compared to being awake, during NREM there is:

1-2 L/min reduction in minute ventilation
2-8 mmHg PaCO2 increase
5-10 mmHg paO2 decrease

This is all NORMAL, but breathing problems (COPD, Asthma) these changes may be too much


Muscle tone and sleep

During REM sleep there is INHIBITION OF MUSCLE TONE (hypotonia) --> why we don't act out our dreams!


ONLY the diaphragm is spared, but since it is working alone, the breathing is depressed

In BOTH NREM and REM, the muscles of the UPPER AIRWAY are influenced, increasing upper airway resistance (REM > NREM > Awake) --> important for APNEA


Insomnia overview

Unsatisfactory Sleep

10-50% of adults

Around 50% suffer from 1 symptom, 10 from severe/chronic insomnia which interferes with daily life

Have difficulty falling asleep, maintaining sleep, or complain that sleep is poor quality

Can be transient/acute (few days to weeks), subacute (up to 3 months) or chronic (more than 3 months)

Risk factors -- female, single, pain/illness, depression/anxiety and any number of stressors

Treating acute = treating the stressor; but acute can become chronic if untreated


Primary Insomnia


or Paradoxical - patients think they are, but are actually sleeping well

or Psychophysiologic (90%) --> most common type; can be acute or chronic; person gets stressed and sleeps poorly for a few nights, then they get all paranoid, trying to sleep well, but bad habits are hard to break; if they sleep well at other places, then this is the diagnosis


Secondary Insomnia

Can also be caused by:

Sleep disorders
Circadian factors
Environmental causes (loud environment)

Psychiatric/Psychological --> 40% of insomniacs have a diagnosable psych disorder! Can also be an early symptom of another psych disorder

Medical Reasons -- this is the third leading cause of insomnia!! Includes a lot of diseases (pain, fibromyalgia, asthma, COPD, neuro disorders, etc etc)

Drug related --> caffeine, alcohol, decongestants, hypnotic-dependent insomnia, BP meds, birth control, SSRIs; abrupt stoppage of a sleep med

Inadequate sleep/hygiene --> bad habits, too much coffee, irregular sleep routine, lack of exercise or exercise just before bed, etc.



Most patients who see a sleep specialists complain about excessive daytime sleepiness

Most of the time, insufficient sleep or apnea is o blame

We can evaluate with the EPWORTH SLEEPINESS SCALE

Patients evaluate whether or not certain situations make them sleepy or not

8 categories are scored from 0-3, and a score LESS THAN 10 is NORMAL


Obstructive Sleep Apnea

Defined as an upper airway obstruction which can stop breathing, leading to arousals and oxygen de-saturation

Affects 2% of women and 4% of men

Most patients are 30-60 years of age

Hypopnea index *how many times per hour patient stops breathing* = 5+

ventilation is depressed normally! So apnea is a problem!

Apnea is associated with SLEEPINESS, SNORING, AROUSALS, and more serious conditions (arrhythmias, uncontrolled HTN, stroke, MI, DEATH!!!)

Risk factors -- obesity, crowded oropharynx, collar size > 17 inches in guys, hypothyroid, weird shaped jaws


Apnea and Hypopnea

Apnea is defined as the ABSENCE of airflow at the nose and mouth for 10 seconds or longer

Hypopnea is a REDUCTION in airflow by 30% from baseline for 10 seconds or longer, with a 4% or greater drop in O2 saturation from baseline


Gold Standard for diagnosing Apnea?


Records ECG, EMG, EEG, O2 sat, airflow, body position, effort


Categories of Apneas

CENTRAL - no effort is taken to breathe, meaning something is wrong up in the brain; and can be caused by heart failure or stroke

Obstructive - patient is trying to breathe, but airways are not cleared; you can see paradoxical movement between the chest and abdomen

Mixed - starts as central and ends as obstructive


Treating apnea

Open the airways!

Lose weight, sleep on side (uses gravity)

Nasal Continuous Positive Airway Pressure (CPAP) -- keeps the airways open and pushes air in

Surgery in extreme cases



Sleep is UNREGULATED, especially REM

Prevalence is 0.03-0.05% of the general population

Peak onset is adolescence and 40 years old



Sleep attacks --> instead of taking 90-120 minutes to get into REM, patient can do it in 20 minutes! or go from WAKING STATE directly to REM!

Cataplexy --> loss of muscle tone during periods of intense emotions (laughing, angry, crying) --> patients may experience facial droop or complete loss of tone and collapse! Consciousness IS ALWAYS MAINTAINED and the loss of tone is SYMMETRICAL --> 70% have cataplexy; it is pathognomonic for narcolepsy!!!

Hypnagogic Hallucinations --> vivid sensory sensation (auditory or visual) which occurs when a person is awake but about to fall asleep; hallucination is often recurrent.

Sleep Paralysis -- Loss of muscle tone at sleep onset or awakening (cataplexy happens at any time with a strong emotion); Patient wakes up, cannot move, and may have trouble breathing.

Do NOT need all 4