Lecture 20 - Psychosis Flashcards
What is the definition of Psychosis?
The presence of hallucinations or delusions
Its not a diagnosis it describes symptoms
What are hallucinations?
Perception without stimuli
Can be in any sensory modality (visual or auditory etc..)
What are the 2 types of hallucinations healthy individuals can experience?
Hypnogogic
Hypnopompic
What are hypnogogic hallucinations?
Hallucinations where you get them while going to sleep
What are hypnopompic hallucinations?
Hallucinations when waking up
What are delusions?
A fixed false belief which is unshakeable and outside of cultural norms
Do patients with schizophrenia have a split mind or personality?
No
Are schizophrenic patients more dangerous than other patients?
No not generally
What are Schneiders First Rank Symptoms of Schizophrenia?
(Pathognomic of schizophrenia)
Auditory hallucinations
Passivity experiences
Though withdrawal, broadcast or insertion
Delusional perceptions
Somatic hallucinations
What are auditory hallucinations in schizophrenia?
Thoughts echo
Running commentaries of action
Third person voice talking about patient
What are passivity experiences in schizophrenia?
Belief that action or feelings are caused by external forces (someone else is moving their limbs)
What are thought withdrawals, broadcast or insertion in schizophrenia?
Withdrawal (something taking their thoughts away)
Broadcast (people know what patients thinking)
Insertion (thoughts being implanted)
What are delusional perceptions?
New meanings to a normally perceived object
(Red traffic light = alien invasion)
What are somatic hallucinations?
Sense of being touched when not actually being touched
What are positive symptoms and negative symptoms in schizophrenia?
Added symptoms = Positive
Symtoms that take away from patient = Negative
What are some positive symptoms of Schizophrenia?
Delusions
Hallucinations
Thought disorders (cant organise thoughts)
Lack of insight
What are some negative symptoms of schizophrenia?
Under activity
Low motivations
Social withdrawal
Emotional flattening
Self neglect
What is the main theory of why Schizophrenia occurs?
Dopamine theory
What is the Dopamine Theory of Schizophrenia?
Drugs that release dopamine (excess) causes Psychotic symptoms
Medications antagonising Dopamine receptors treat psychosis and those who have highest affinty to D2 receptors work most effectively
What types of drug cause the releaese of lots of dopamine leading to schizophrenia psychosis?
Amphetamines
What are the 4 Dopamine pathways in the brain?
Mesolimbic
Mesocortical
Nigrostriatal
Tuberoinfundibular pathway
What 2 dopamine pathways are thought to have different activities in schizophrenia?
Mesolimbic pathway
Mesocortical pathway
How is the activity of the Mesolimbic pathway affected in schizophrenia?
Overactive
How is the activity of the Mesocortical pathway affected in schizophrenia?
Under active
What symptoms of schizophrenia does the overactive mesolimbic pathway produce in schizophrenia?
Positive symptoms
What symptoms of schizophrenia does the underactive Mesocortical pathway produce in schizophrenia?
Negative symptoms
What are some structures in the mesolimbic pathway?
Starts from ventral tegmental area to:
-amygdala
-hippocampus
-nucleus accumbens
What symptoms of schizophrenia does the under active mesocortical pathway produce in schizophrenia?
Negative symptoms
What are some structures in the mesolimbic pathway?
Ventral tegmental area to:
-amygdala
-hippocampus
-nucleus accumbens
What are some structures in the mesocortical pathway?
From ventral tegmental area to:
-frontal cortex
-cingulate cortex
What are some brain changes in schizophrenia?
Enlarged ventricles
Reduced grey matter
Decreased temporal lobe volume
Reduced hippocampal formation, amygdala, parahippocampal gurus (all lambic structures)
Reduced prefrontal cortex formation
What are the neuorpathological changes seen in schizophrenia?
Decreased synaptic markers
Decreased Oligodendrocytes
Less thalamic neurones
Why can some patients with schizophrenia present with motor symtoms?
Sometimes basal ganglia can be affected
What is the treatment for Schizophrenia?
Antipsychotics that block D2 receptors in dopaminergic pathways in CNS
(Typical and Atypical antipsychotics)
Where is the main site of action of typical antipsychotics?
D2 receptors in all CNS dopaminergic pathways but mainly on Mesolimbic and Mesocortical pathways
What causes the side effects of typical antipsychotics?
Antagonism of D2 receptors in other pathways that aren’t the mesolimbic and Mesocortical pathways in the CNS
Why do atypical antipsychotics have milder side effects than typical antipsychotics?
They dissociates rapidly from D2 receptors since have lower affinty
What other receptors except for D2 receptors to atypical antipsychotics block?
5HT2 so have some action on serotonin systems
What are some side effects of atypical antipsychotics?
Obesity
Hyperlipidaemia
Glucose intolerance
Why can giving antipsychotics lead to drug induced Parkinson’s?
Dopamine blocked in the nigrostriatal pathway
Less dopamine = less movement harder to initiate movement
So direct pathway of basal ganglia not stimulated so the thalamus doesn’t receive as much inhibition so get tremor
What structures are part of the nigrostriatal pathway?
Substantial nigra pars compacta
Striatum (caudate and putamen)
What are the 4 key signs in Parkinson’s disease?
Brady Kinesin
Lead pipe rigidity
Pil rolling tremor
Hypertonia
What is Catatonia?
What causes it?
Excess of dopamine for some reason leads to slow movement
Seen in extreme schizophrenia
What is thought to cause catatonia?
How’s it treated?
Excess dopamine in schizophrenia leads to less GABA being able to bind so lose inhibitory effects of neurones
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What is the tuberoinfundibular pathway?
From arcuate and periventricular nuclei of hypothalamus
To infundibular region of hypothalamus
Why can you get Hyperprolactinaemia when giving antipsychotics?
Antipsychotics antagonise dopamine
Dopamine normally inhibits prolactin
So giving antipsychotics mean less dopamine to inhibit prolactin
What are the side effects of antipsychotics causing Hyperprolactinaemia?
Decreased fertility
Reduced libido
Amenorrhoea
Galactorrhoea
Long term, osteopenia/osteoporosis
Why is it difficult to treat people with schizophrenia?
They lack insight (don’t believe they’re unwell)
Medication adherence is therefore often poor
How can antipsychotic medications be administered with schizophrenics?
PO
Short acting IM
Depot
What are some good prognostic factors for schizophrenia?
Absence of FHx
Good premorbid function
Acute onset
Mood disturbance
Prompt treatment
Maintenance of initiative and motivation
What are some long term complications of schizophrenia?
Mortality is twice as high as in general population
Shorter life expectancy (-ve symptoms so unlikely to make healthy choices and drugs given increase CVS risk)
Higher CVS disease, resp and cancer incidence
Inc suicide risk
Substance misuse problems
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