ARAS Flashcards
Give 3 functions of the ARAS.
Wakefullness
Sleep-wake transitions
Consciousness
Why can anticholinergics cause drowsiness?
because basal forebrain nuclei which contain cholinergic neurones now involved in arousal
Why may anti-histamines cause drowsiness?
Histamine is excitatory on the cortex
Histaminergic neurones found in the hypothalamus product to the cortex involved in arousal.
What type of neurones found in the thalamus are involved in arousal?
glutamatergic
What three things are evaluated by thr Glasgow coma scale?
Eye opening
Motor response
Verbal response
What are the normal waves when awake on an EEG called?
Close eyes?
Stage 1 sleep?
beta waves (50Hz)
Alpha waves (10Hz)
Alpha waves + interspersed theta waves (5Hz)
Stage 2/3?
Stage 4?
REM sleep?
Background of theta with sleep spindles and K complexes.
Delta waves - 1Hz
Similar to beta waves
Where is REM sleep initated?
Why paralysed?
Why nocturnal bruxism?
POns
Release of inhibitor NT glycine into LMNs in the spinal cord running down reticulospinal tracts/
grinding teeth due to cranial nerve and eye movements being preserved
Which stage of sleep is involved with experiencing hypnogogic sensations?
Stage 1
Why do K complexes occur?
Due to environmental stimuli such as sounds in the bedroom
Why may no sleep be linked to higher rate of Alzheimers?
Extracellular debris accumulates in interstitium of brain and sleep needs to clear out these toxins.
What is the Tx for insomnia?
Sleep hygiene
CBT
Sleeping pills
What is often associated with narcolepsy?
Triggers?
Give two roles of orexin.
Cataplexy
Vivid hallucinations and inability to move
Emotional stimulation
Appetite and wakefullness
Two forms of sleep apnoea?
Cheyne stokes breathing in which one?
Give some risk factors for SA.
Central sleep apnoea
Obstructive sleep apnoea
Central
Overweight
Allergies
FHx
Large tonsils
Difference between coma and brain death EEG patterns.
PVS?
Give another disorder of consciousness.
No EEG on brain death
EEG detectable coma - but no sleep wake cycles
Sleep wake cycles detectable
Locked in syndrome.
