Consciousness 1
What is consciousness?
A state of being aware and responsive to one's surroundings
Name the brainstem area that is particularly important for consciousness
Reticular activating system (RAS)
What are the 2 main kinds of sleep?
REM
non-REM
What system is used to assess levels of consciousness?
Glagow coma scale
What are the 2 not eye-based tests for brainstem death?
Cough/gag reflex to pharyngeal stroking
Respiratory effort when ventilator is disconnected
Name 4 of the 7 most common causes of loss of consciousness in the UK
- stroke
- diabetes
- drug induced
- epilepsy
- head injury
- raised intracranial pressure
- dementia
- metabolic disorders
Describe locked-in syndrome
Normal awareness, sleep wake cycles and meaningful behaviour but is isolated due to facial and body paralysis
Describe delta EEG rhythms
Large in amplitude
Hallmark of deep sleep
What GCS score (or less) mostly equals coma
8
What are the 4 eye-based tests for brainstem death?
Pupil response - shine torch in eyes to examine pupil constriction
Corneal reflex - stroke cornea
Vestibular ocular reflex - cold water in eyes
Apply supraorbital pressure to elicit motor response
What are the 4 main parts of the RAS?
Locus coerulus
Raphe nuclei
Ventral tegmental area
Cholinergic nuclei
What conditions are associated with the Ventral tegmental area?
Addiction
Schizophrenia
ADHD
has an inhibitory effect on AcH, 5-HT and NA
What are the eye responses in the Glasgow coma scale?
1) no response
2) opening in response to pain
3) opening in response to speech
4) spontaneous opening
Describe chronic coma
Lack of awareness and sleep wake cycles
Only displays reflexive behaviours
TOMMY T TRIPLE!!!!
Describe unresponsive wakefulness syndrome
Normal sleep wake cycles but lack of awareness
Displays only reflexive and non-purposeful behaviour
What neurotransmitters are used in the RAS?
(double points if you can name the nuclei each transmitter is used in)
Dopamine (ventral tegmental area)
Noradrenaline (locus coerulus)
ACh (cholinergic nuclei)
Serotonin (raphe nuclei)
What are the characteristics of REM sleep?
Desynchronised EEG rhythms - beta waves
Abolition of muscle tone
Increased sympathetic activity
What are the motor responses in the Glasgow coma scale?
1) no response to pain
2) extension posturing to pain
3) abnormal flexion response to pain
4) withdraws to pain
5) obeying command
What is the role of the Ventral tegmental area?
Involved in reward circuitry
Promotes wakefulness and attention
What is the role of the Raphe nucleus?
What is the role of the Raphe nucleus?
Regulates circadian rhythm
Regulates enkephalin release (pain response)
What is the role of the cholinergic nuclei in sleep?
Induce wakefulness and REM sleep
What are the verbal responses in the Glasgow coma scale?
1) no verbal response
2) incomprehensible speech
3) inappropriate speech
4) confused conversation
5) orientated conversation