Sleep, Coma, and Cognition Flashcards
Describe consciousness
-Assessed by behaviour (continuum= inter-observer variability)
=Alert
=Drowsy/ asleep
=Stupor
=Coma
Stimuli used to elicit responses
-Verbal
-Pain
=Supra-orbital pressure
=Knuckles on sternum
=Pinch nailbed
=Pinch Achilles tendon
GCS eyes
4= spontaneous
3= to command
2= to pain
1= nil
GCS verbal response
5= orientated
4= confused
3= words
2= sounds
1= none
GCS motor response
6= obeys commands
5= localises pain
4= flexion/ withdrawal
3= abnormal flexion
2= extends to pain
1= none
What is a coma defined in GCS?
-GCS 8 or below (E2M4V2)
=E: not opening spontaneously/ to command
=V: no speech/words
=M: no movements spontaneously/ to command
Definition of a coma
-Deep sustained unconsciousness
-Resulting from dysfunction of RAS and/or cerebral hemispheres
-Duration > 1 hr
=(to distinguish from other conditions)
Causes of coma
-Brainstem dysfunction
=Anything directly affecting brainstem
=Cerebral hemisphere lesion causing secondary brainstem compression (coning)
-Diffuse bilateral hemisphere dysfunction
Examples of causes of coma
-TRAUMA
-INFECTION
-TUMOUR
-INFARCTION/HAEMORRHAGE
-EPILEPTIC SEIZURES
-TOXIC
-METABOLIC
-HYPOXIC
Clinical assessment of coma
-Critical causes: oxygen, glucose and circulation
-GCS
-Brainstem reflexes
=pupillary responses to light
=eye movements (including oculo-cephalic reflexes)
=corneal reflex
=gag reflex
What is a vegetative state?
-Akinetic mutism/ apallic syndrome/ coma vigile
-Centring around idea of arousal without awareness/ brainstem function but not cortical function
-No speech
-Lies inert: no voluntary movement
-No meaningful response
-Appears intermittently alert (sleep/ wake cycle)
-Persistent state of severely altered consciousness
-Typically, severely frontal lobe/ diffuse brain dysfunction
Cognitive domains
-Language (expression, reception/understanding)
-Learning and memory (verbal, non-verbal, episodic, semantic, procedural)
-Perceptual-motor function
-Complex attention
-Executive function
-Social cognition
Examples of acquired cognitive disorders
-Specific cognitive deficits
-Confusion/ delirium
-Dementia/ major cognitive disorder
Clinical neuroscience definition of dementia
-Acquired
-Impairment in 2 or more domains
-In a setting of clear consciousness
-Syndrome, not a disease
-Disability (not just functional impairment)
What is assessed for cognition in a clinical setting?
-2 initial broad assessments
-Consciousness
-Attention, concentration, orientation
What is asked in a history assessing cognition?
-Patient/ Relatives, friends, colleagues/ Nursing staff
-Speech vs language (reception and expression, reading and writing)
-Disturbed attention
=putting things in wrong place
=what did I come in here for?
Three general steps in syndromic diagnosis and aetiological diagnosis
-Is there a major cognitive disorder?
=Acquired, in clear consciousness, 2 or more domains affected, disability
-What is the cognitive profile?
=Which domains affected
-What is the underlying cause?
=Cognitive profile, time course, age
=Any other neurological features
=Any specific PH, PMH, FH
Investigations in cognitive assessment
-Routine blood tests (renal-hepatic, hypothyroid, vitamin deficiency)
-Brain imaging
-Depends on context
=Detailed neuropsychology assessment
=Genetic tests, autoimmune, specific infections, malignancy (paraneoplastic syndromes)
Classification of sleep disorders
-Insomnias
-Sleep-related breathing disorders (drowsiness in day)
-Non-respiratory related hypersomnia (narcolepsy)
-Circadian rhythm disorders (timing of sleep)
-Parasomnias (experiences/ behaviours in and around sleep)
-Sleep-related movements
Elements of the sleeping history
-Establish main complaint
-What happens in sleep/ wakefulness/ transitions (typical 24hr profile)
=Time to bed/ sleep/ waking/ rising
=Sleep rituals and maintenance
=Events in sleep (including dreaming)
=Feelings on waking
=Additional drowsiness/ sleep at other times
=Snoring (apnoea)
=Drug history
=History related to other relevant factors (stress)
The Epworth sleepiness scale
-Sleep during the day
0-3 likelihood in 8 situations
>10/24 significant EDD (excessive daytime drowsiness)
Two sleeping histories needed
-Past personal sleep history
=eye-witness account?
-Family sleep history (genetic elements)
Timing in sleep disorders
-NREM (1 hour after sleep)
-REM (corresponding)
-Sleep onset/offset problems
Parasomnias
-NREM:
=Night terrors
=confusional arousals
=sleep walking
-REM:
=REM sleep behaviour disorder (Parkinsons)
=Sleep paralysis
=nightmare disorder
Sleep-related movement disorders
-Restless legs syndrome
-Periodic limb movements
-Hypnic jerks
-Some forms of epilepsy specifically related to sleep
