Block 6 Flashcards
what is consciousness?
state of being aware of and responsive to ones surroundings
what is the psychological definition of consciousness?
a persons awareness of perception of something
what are the levels of consciousness? (14)
- fully conscious
- clouding of consciousness
- confusional state
- delirium
- lethargy
- obtundation
- stuper
- hypersomina
- minimally responsive state
- unresponsive wakefulness syndrome
- akinetic mutism
- locked in syndrome
- coma
- brain death
what is a normal loss of consciousness?
sleep
what is an abnormal loss of consciousness? (3)
- coma
- anaesthesia
- unresponsive wakefulness syndrome
what is the most common cause of unconsciousness worldwide?
Malaria (cerebral)
what is the most common cause of unconsciousness in the UK?
stroke
what ways can you assess consciousness? (4)
- ABC
- history
- screening
- glasgow coma scale
what are the 3 domains of the Glasgow coma scale?
- eye opening
- verbal response
- motor response
what Glasgow coma scale score does a fully conscious patient have?
15
what Glasgow coma scale score does a deep coma patient have?
3
what do the scores on the Glasgow coma scale show? (3)
- 13-15 - mild head injury
- 9-12 - moderate head injury
- 3-8 - severe head injury
what % of cases of Unresponsive Wakefulness Syndrome were misdiagnosed?
40%
what are the features brainstem death? (3)
- person must be unconscious and fail to respond to stimulation
- heartbeat and breathing maintained by a ventilator
- clear brain damage has occurred - incurable
what is the definition of brainstem death?
the irreversible cessation of the function of the brainstem and loss of capacity for consciousness
how do we test for brainstem death? (6)
- pupil response - shine torch
- corneal reflex - stroke cornea
- vestibule-occular reflex - ice-cold water in ear
- cranial nerve response - supraorbital pressure to elicit motor response
- cough/gag reflex - Catheter down trachea
- respiratory effort - disconnect ventilator for 5 mins
what regulates consciousness?
Reticular Activating System (RAS)
what is the reticular formation?
collection of nuclei found throughout midbrain and extends into the hindbrain
what four nuclei make up the Reticular Activating System?
- locus coeruleus
- raphe nuclei
- ventral tegmental area
- cholinergic nuclei
what is the main neurotransmitter of the locus coeruleus?
noradrenaline
what is the main neurotransmitter of the raphe nuclei?
seretonin
what is the main neurotransmitter of the ventral tegmental area?
dopamine
what is the main neurotransmitter of the cholinergic nuclei?
acetylcholine
what two other areas are considered to be involved in consciousness?
- anterior hypothalamus
- posterior hypothalamus
what is the main neurotransmitter of the anterior hypothalamus?
GABA
what is the main neurotransmitter of the posterior hypothalamus?
histamine
what is the Reticular Activating System involved with? (3)
- sleep-wake cycle
- arousal
- attention
what areas are involved in sleep? (3)
- cerebral cortex
- reticular nucleus
- thalamus
what happens to cholinergic fibres when awake?
increase firing
what happens to cholinergic fibres when asleep?
decrease firing
what are features of the wake cycle when awake? (4)
- Ach active
- sensory thalamus facilitated
- reticular nucleus inhibited
- EEG desynchronous
what are features of the wake cycle when asleep? (4)
- Ach inactive
- sensory thalamus inhibited
- reticular nucleus active
- EEG synchronous
what three neurons interact to form oscillations in EEGs?
- thalamocortical
- reticular
- corticothalamic
what are the two main types of sleep?
- non-REM
- REM
what are the EEG waves in NREM sleep? (2)
slow and synchronised
what are the EEG waves in REM sleep?
high frequent activity
which sleep is associated with dreams?
REM
how long does each sleep cycle last?
90 minutes
what are some common sleep disorders? (3)
- sleep apnoea
- enuresis
- epilepsy
what are the short term consequences of sleep deprivation? (6)
- slower reflexes
- memory disorder
- muscle fatigue
- mood swings
- aggressive behaviour
- disorientation
what are the long term consequences of sleep deprivation? (4)
- obesity
- diabetes
- high BP
- CVD
what is antisocial behaviour?
behaviour that transgresses a society’s rules, norms and laws that is likely to cause harm to others
what does the 2003 Anti-Social Behaviour define antisocial behaviour as?
behaviour by a person which causes or is likely to cause harassment, alarm or distress to person not of the same household
how many 5-19yr olds present antisocial behaviour?
4.6%
what is the % difference for boys and girls displaying antisocial behaviour?
- boys - 5.8%
- girls - 3.4%
how much does conduct disorder cost per young person?
£103k
where in society does antisocial behaviour affect? (5)
- policing
- social work
- education provision
- impact of crime
- criminal justice process
what are examples of antisocial behaviour syndromes? (3)
- Oppositional Defiant Disorder - younger children <10
- Conduct Disorder - adolescents
- Antisocial Personality Disorder - adults
what is conduct disorder? (2)
- persistent behavioural problems
- defiant, disobedient, provocative, spiteful behaviours
what are the three domains of Limited Prosocial Emotions?
- daring impulses
- callous unemotional
- grandiose manipulative
what are some common learning difficulty co-morbidities with conduct disorder? (6)
- learning problems
- literacy issues
- speech & language problems
- global learning disability
- autism spectrum conditions
- ADHD
what are some common mental health co-morbidities with conduct disorder? (7)
- depression
- anxiety
- psychosis illness
- substance misuse
- PTSD
- attachment issues
- personality disorder
how do we assess young people with conduct issues? (6)
- NICE guidelines
- multidisciplinarys
- cognitive assessment
- info from different sources
- developmental history
- mental health assessment
what are some examples of adverse childhood experiences? (8)
- physical abuse
- verbal abuse
- sexual abuse
- alcoholic parent
- physical neglect
- emotional neglect
- family members in jail
- family members diagnosed with illness
what did Kendler’s (2014) Scandinavian adoption studies show? (2)
- risk for all conduct behaviour was higher in the adopted offspring of biological parents with conduct behaviour
- risk higher if there are environmental risk factors in adoptive home
what is the environmental argument for antisocial behaviour?
- ‘warrior gene’
- Monoamine oxidase A gene
what is the role of the monoamine oxidase A gene?
breaks down MA neurotransmitters (dopamine, serotonin, etc…) in synaptic cleft
what happens to MAOA in antisocial behaviour individuals?
low activity results in higher aggression
what are the psychosocial management techniques for conduct disorder? (3)
- Parent-Management Training (PMT)
- Cognitive Behavioural Therapy (CBT)
- Multi-Systemic Therapy
what are the two major groups of neurotransmitters?
- small molecules
- neuropeptides
what are four classes of neurotransmitters?
- Ach
- Biogenic amines
- Amino acids
- Gases -
what is co-transmission?
releasing more than one neurotransmitter at the same time
what is low frequency stimulation?
release of small vesicles
what is high frequency stimulation?
release of small and large vesicles
what are the characteristics for a chemical messenger to be a neurotransmitter? (5)
- chemicals must be synthesised in the neuron
- when released, must produce a response in target cell
- specific receptors are on post synaptic cell
- induce the same response when on target
- must be removed from synaptic cleft
what are two main receptors on the post-synaptic cell?
- ionotropic - ion channels
- metabotropic - binds to G proteins
what is the most common neurotransmitter in the PNS?
acetylcholine
where is acetylcholine found?
neurons of the hippocampus and cerebral cortex
how does acetylcholine transmission work? (4)
- choline and acetyl coA bind to form Ach
- Ach packaged with vesicle
- fuse with membrane and release Ach
- Ach broken down by acetylcholine-esterase
what are the two types of cholinergic receptors?
- nicotinic receptors
- muscarinic receptors
what type of receptor is the nicotinic receptor?
ionotropic
what type of receptor is the muscarinic receptor?
metabotropic
what are the three amino acids involved in neurotransmission?
- glutamate
- GABA
- Glycine
how does glutamine transmission work? (4)
- glutamine converted to glutamate by glutaminase
- glutamate processed in vesicle, released into synapse
- binds to receptors OR gets taken back up by cell to be released
- Glial cells reuptake and process back to glutamine for the presynaptic cell
what are the three subtypes of glutamate receptor?
- AMPA
- NMPA
- Kainate
How do the glutamate receptors work? (5)
- release glutamate into synaptic cleft
- glutamate binds to ADMA receptor
- AMDA receptor opens, allow Na+ entry, depolarises cell
- NMDA receptors release Mg+, allowing calcium entry
- This drives the signal
How does GABA transmission work? (3)
- glutamate is converted to GABA by glutamate decarboxylase
- released into synaptic cleft
- uptake by glial cell, turned back to glutamine, re-enters the pre-synaptic cell
what type of receptor are GABA receptors?
ionotrophic
how many subunits do glutamate receptors have?
3
how many subunits do GABA receptors have?
5
what do benzodiazapams treat?
Epilepsy
how do benzodiazapams work to treat epilepsy?
enhances the inhibition, this controls the excessive excitation
in the postsynaptic cell, what does acetylcholine get converted back to? (2)
choline and acetic acid
in the presynaptic cell, what does glutamine get converted to? (2)
glutamate by glutaminase
in the presynaptic cell, how is glycine produced? (2)
serin converted to glycine by SHMT
in the glial cell, what does glycine get broken down into? (2)
CO2 and NH3
how does glycine work? (2)
- Renshaw cells use Glycine to link to the reccurent neuron
- Neuron acts as inhibitor, switches off motor neuron
what are examples of biogenic amines? (2)
- catecholamines (noradrenaline, adrenaline, dopamine)
- seretonin
how are catecholamines inactivated? (3)
- uptake
- enzymatic breakdown
- diffusion away from receptors
how is dopamine synthesised? (2)
- tyrosine converted to L-DOPA by tyrosine hydroxase
- L-DOPA converted to dopamine by dopa decarboxylase
what three pathways is dopamine involved in? (3)
- mesolimbic - reinforcement
- mesocortical - planning
- nigrostriatal - movement
how is noradrenaline synthesised? (1)
Dopamine converted to noradrenaline by dopa-B-hydroxylase
how is serotonin synthesised? (2)
- tryptophan converted to 5-Hydroxtytophan by tryptophan hydroxylase
- 5-Hydroxtytophan converted to 5 Hydroxytryptamine by 5-HTP decarboxylase
what can serotonin be broken down into?
melatonin
which serotonin receptor is involved in anxiety?
5-HT1a
what is a neuromodulator?
neurotransmitters that do not conform to their actions
what is substance P?
peptide neurotransmitter
which receptor does substance P bind strongest to?
NK1
what is a mental state exam?
covers psychiatric symptomatology shown at interview
how do you start a mental state exam?
- private space
- quiet space
- face towards patient
what are the components of the mental state exam? (7)
- appearance and behaviour
- speech
- mood
- thought content
- abnormal beliefs
- cognitive state
- insight
what do you look for appearance of the mental state exam? (2)
- general appearance
- facial appearance
what are the features of appearance in schizophrenic patients? (5)
- echopraxia
- tics
- poor eye contact
- increased movements
- restlessness
what is stupor?
mute, immobile but fully conscious
what is depressive retardation?
a lesser form of psychomotor retardation
what is obsessional slowness?
secondary to repeated doubts and compulsive rituals
what is psychomotor agitation?
overactivity usually unproductive
what is compulsion?
- repetitive and stereotyped
- seemingly purposeful
what do you look for speech of the mental state exam? (4)
- rate
- quality
- articulation
- form
what is poverty of speech?
restricted amount of speech
what is pressure of speech?
increased rate & quantity
what is dysarthria?
difficulty in articulation of speech
what is neologism?
new words being constructed
what is echolalia?
automatic imitation by patient of another persons speech even when they dont understand it
what is thought blocking?
sudden interruption in train of thought leaving a blank
what is knights move thinking?
odd associations between ideas leading to disruption in continuity
what two assessments should be carried out for mood in a mental health exam?
- objective assessment
- subjective assessment
what is dysphoric mood?
unpleasant mood
what is anhedonia?
loss of ability and interest in regular activities
what is euphoria?
elevation of mood
what is irritable mood?
annoyed and provoked to anger
what is anxiety?
feeling of apprehension, tension or uneasiness owing to anticipation of an external/internal danger
what is affect?
pattern of observable behaviours that is the expression of emotion
what is an inappropriate affect?
appearing cheerful when talking about recent bereavement
what is a flat affect?
total absence of signs of expression of affect
what is a delusion?
fixed, false personal belief based on incorrect inference about external reality
what is a primary delusion?
arises fully formed without any discernible connection with previous events
what is secondary delusion?
arises when trying to make sense of their experiences
what is an illusion?
false perception of a real external stimulus
what is a hallucination?
false sensory perception in the absence of a real external stimulus
what do you look for cognitive of the mental state exam? (4)
- orientation - time, place, person
- attention and concentration - spelling backwards
- memory - recall
- general knowledge - current news event
What is episodic memory?
Memory of events
What is semantic memory?
Factual knowledge
Why are childhood memories spared in amnesia?
Through a process of consolidation, memories lose their reliance on the hippocampus
What are the two stores of long-term memory?
- Hippocampus
- Anterior temporal lobes
What type of memory does the anterior temporal lobe store?
Sematic memory
What condition is there damage to the anterior temporal lobe?
Semantic dementia
What is amnesia?
Inability to learn new long-term memories
What is semantic dementia?
Loss of knowledge
What are positive symptoms of schizophrenia? (2)
- Hallucinations
- Delusions
What are first-rank symptoms of schizophrenia? (3)
- Thought interference
- Delusion of control
- 3rd person auditory-verbal hallucinations
What are negative symptoms of schizophrenia? (4)
- Lack of motivation
- Reduced speech
- Reduced emotion
- Social withdrawal
What two factors contribute to neurodevelopment abnormality?
- Genetic component
- Environmental factors
What are the arguments for the dopamine hypothesis? (3)
- Antipsychotics block postsynaptic dopamine receptors
- PET and SPECT scans show increase dopamine activity in ppl with schizophrenia
- Evidence of elevated presynaptic dopamine synthesis and release
What are the arguments against the dopamine hypothesis? (3)
- Cause of schizophrenia may be upstream
- Antipsychotics take 2+ weeks to work on symptoms
- Other transmitters appear to be involved with psychosis e.g. glutamate
What is the aim of treatment for negative schizophrenia symptoms? (2)
- Increase dopamine transmission
- Via mesocortical pathway
What is the aim of treatment for positive schizophrenia symptoms? (2)
- Decrease dopamine transmission
- Via mesolimbic pathway
Which receptor do antipsychotics target? (2)
- Antagonise D2 receptors
- In mesolimbic system
Which receptors do first generation antipsychotics target?
D1 and D2
Which receptors do second generation antipsychotics target?
D2 and seretonin, less on D1
How does a partial agonist exert it’s effect on dopamine? (2)
- Act as a D2 antagonist where there is too much dopamine
- Act as a D2 agonist where there is too little dopamine
What is depression?
Persistent low mood/self-esteem with reduced enjoyment/interest
What is depression a result of?
Deficient in brain monoamine neurotransmitters - noradrenaline, serotonin and dopamine
What does serotonin influence? (3)
- Mood
- Emotional behaviour
- Sleep
What does noradrenaline influence? (4)
- Sleep
- Wakefulness
- Attention
- Feeding behaviour
What does dopamine influence? (2)
- Motivation
- Reward
What are the arguments of the Monoamine theory of depression? (3)
- Antidepressants increase the available of monoamine at synapses
- Reserpine which depletes MOA transmission causes depression
- People with depression have lower levels of MOA precursors in the blood
What are the arguments against the Monoamine theory of depression? (2)
- Take 2+ weeks to work
- Cocaine and amphetamine mimic serotonin but do not act as antidepressants
What are examples of antidepressant therapies? (4)
- Tricyclic antidepressants
- SSRIs
- Monoamine Oxidase Inhibitors (MAOIs)
- Serotonin Noradrenaline reuptake inhibitors (SNRI)
What are the side effects of tricyclics to treat depression? (4)
- Antagonises H1 receptors - sedation
- Antagonises muscarinic receptors - dry mouth, blurred vision
- Antagonises alpha adreno receptors - postural hypotension
- Toxic in overdose
What are the side effects of SSRIs to treat depression? (5)
- Nausea and vomiting
- Sexual dysfunction
- Inhibit metabolism of other drugs
- Withdrawal reaction
- Safer in overdose
Why do antidepressants take two weeks to work? (3)
- Initial increase in 5HT is cancelled out by presynaptic auto-receptors reducing 5HT release and more reuptake of the extra 5HT in the synapses
- After couple of weeks auto receptors desensitize and block reuptake transporters
- Eventual 5HT increase in synapse
What happens when GABA receptors are stimulated? (2)
- GABA receptors allow flux of Cl ions across post synaptic membrane
- Hyperpolarises the neurone
What do benzodiazepines bind to?
GABA receptor allosteric site
What is the effect of benzodiazepines?
Increases Cl- flux and more inhibition
What are the side effects of benzodiazepines? (4)
- Drowsiness
- Confusion
- Forgetfulness
- Impaired motor control
What is the enteric system responsible for?
Gastric system
How does vesamicol presynaptically block nerve function?
Blocks Ach uptake into vesicles
How does Hemicholinium presynaptically block nerve function?
Blocks reuptake of Ach into presynaptic cell
How does Botulinium presynaptically block nerve function?
Blocks release of Ach vesicles into the cleft
What are the two types of cholinesterase inhibitors? (2)
- Reversible
- Irreversible
How do reversible cholinesterase inhibitors work? (2)
- Bind to the enzyme for a period of time
- Enzyme inhibited until inhibitor is removed
How do irreversible cholinesterase inhibitors work?
Covalent bond preventing reactivation
How do non-depolarising agents work as post synaptic inhibitors? (3)
- Act as competitive antagonists
- Does NOT cause an action potential
- Causes muscle relaxation
How do depolarising agents work as post synaptic inhibitors? (2)
- Bind to Ach receptors and generate an AP
- Causes muscle fasculations