Sleep/Wake disorders Flashcards
Sleep vs Coma
● Sleep
○ When sleep-promoting neurons are stimulated and wake-promoting
regions are inhibited.
○ Controlled by the body’s “internal clock” and by external forces.
○ Reduced responsiveness, but can be interrupted by sensory or other
stimuli
○ Also defined by typical Electroencephalographic (EEG) Patterns
● Coma - Unresponsive to the environment and cannot be interrupted by
stimuli, including pain
Physiologic changes during sleep
● ↑ Parasympathetic tone
● ↓ Sympathetic tone
● Constant neuronal activity
● Reduced overall Metabolism
Regulatory Neurons and Neurotransmitters of Arousal
Histamine (HA), Serotonin (5-HT), Noradrenalin (NA), Dopamine (DA),
Acetylcholine (ACH), Glutamate (GLU), Hypocretin/orexin (HCT)
Regulatory Neurons and Hormones of Sleep
○ Ventrolateral preoptic nucleus (VLPO)/Median preoptic nucleus (MnPO)
○ Melatonin
○ Adenosine (AD)
Ventrolateral preoptic nucleus (VLPO)/Median preoptic nucleus (MnPO)
Promotes sleep through monosynaptic GABAergic
inhibition of monoamine neurons
Suprachiasmatic Nucleus (SCN) is part of the_____
anterior hypothalamus and is
the “master clock” of the body
“master clock” of the body.
Suprachiasmatic Nucleus
Melatonin
: Helps regulate circadian rhythm
○ Produced in the pineal gland and controlled by light input as processed
by the SCN
Sleeps effects on the CNS
○ Assists with brain plasticity, neural maturation, memory consolidation,
and learning. This leads to improved cognition.
○ There is evidence that clearance of neurotoxic waste in the CNS occurs
Sleeps effect on General Restoration, Rejuvenation, and Energy conservation
○ Mitigates adverse consequences of stress
○ Physical growth, including muscle growth
○ Assists the immune system functions
○ Tissue repair
○ Protein and Hormone synthesis
Adults 18 to 60 years should sleep
_____ hours a night on a regular basis
seven or more
Prolonged Sleep Deprivation (ie, little or
no sleep):
● Decreased cognition and memory
● Abnormal moods and decreased
inhibition
● Potential psychosis
Microsleeps
Short episodes of uncontrollable sleep
lasting between a fraction of a second to 30 seconds. There is complete lapse of consciousness and no ability to respond to stimuli.
Fatal Familial Insomnia (FFI)
- Progressive genetically linked insomnia with loss of the normal
circadian sleep-activity pattern - FFI is a rapidly fatal disease with a mean duration of 13 months. There
is no specific treatment for FFI. Management is generally supportive
Electroencephalogram (EEG)
● Electrical activity is recorded from standardized placement sites on the scalp (usually 10 to 20)
● The electrical activity is described in terms of amplitude and frequency
Beta Waves Patterns
High frequency & low amplitude &
more desynchronous than other waves
Alpha wave EEG Patterns
Brain waves become slower (low
frequency), increase in amplitude
(high amplitude) & become more
synchronous
What waves are typical when you are awake?
Beta or alpha (calm wakefulness)
Stage 1 sleep EEG findings
Theta waves (lower frequency)
and greater amplitude
Stage 2 EEG findings
● EEG Findings: Theta waves continue,
interspersed with 2 phenomenon:
○ Sleep spindles: short bursts of ↑ wave
frequency
○ K-complexes: sudden ↑ wave amplitude
Sudden twitches or hypnic jerks are
common happen in this stage
Stage 1
Stage 3 (Slow Wave Sleep) EEG findings
Delta waves (slowest & highest
amplitude)
Rapid Eye Movement (REM) sleep (Stage R) EEG findings
Low voltage, mixed EEG pattern and “Sawtooth” waves.
○ These are similar to wakeful EEG findings
Atonia
inactivity of all voluntary muscles (except extraocular muscles,
diaphragm). Result of inhibition of alpha motor neurons.
Happens in REM sleep
T/F Brain is activity is high in Rem Sleep
T
Stage 1 is not repeated, but is replaced by ____
REM
Rapid onset to REM, occurring quickly after sleep begins, suggests
_____
narcolepsy or a circadian rhythm disorder