12.1 Psychosis Flashcards
Definition of Psychosis
Presence of hallucinations or delusions. (describes symptoms, not a diagnosis in itself)
Definition of Hallucinations
Perception without a stimulus. (can be in any sensory modality, visual hallucinations are usually organic - caused by a problem with brain or eyes)
Give 2 different types of hallucinations and when they occur.
Hypnogogic = Going to sleep Hypnopomopic = Waking up
Definition of Delusions
Abnormal belief, outside of cultural norms, unshakable
Causes of organic psychosis
Delirium caused by infection Delirium tremens (alcohol withdrawal) Acute drug/alcohol intoxication Post-ictal psychosis (after a seizure) Hyperthyroidism Encephalitis (including NMDA receptor) Hypercalcaemia (moans part of moans, groans, bones, stones) Cerebral lupus Iatrogenic causes (steroids, L-DOPA)
List the 5 first rank symptoms of Schizophrenia
- Auditory hallucinations
- Passivity experiences
- Thought withdrawal, broadcast or insertion
- Delusional perceptions
- Somatic hallucinations
Give the 2 types of Auditory Hallucinations
- Thought echo (hearing thoughts aloud)
2. Running commentary (describe what they are doing - e.g. “he is sitting down, he is brushing his teeth”)
What are Passivity Experiences?
Patient believes an action or feeling is caused by an external force
“MI5 have been moving my leg”
What are thought withdrawal, thought broadcast and thought insertion?
Thought withdrawal = thoughts are being taken out of the mind
Thought broadcast = thoughts are being made known to others e.g. via radio
Thought insertion = thoughts implanted by others
What is Delusional Perception?
Attribution of new meaning, usually in the sense of self-reference to a normally perceived object
e.g. “the traffic light went red and I knew this was a sign that aliens were going to land soon”
What are Somatic Hallucinations?
Mimics feeling from inside the body (e.g. convinced a snake is living inside their stomach) - usually a lack of insight (patients don’t believe that they are unwell)
What are Positive Symptoms?
Positive symptoms are added symptoms They include: Delusions, Hallucinations, Thought disorder, Lack of insight
What are Negative Symptoms?
Negative symptoms are symptoms that take away from the patient (often they will neglect themselves) They include: Under-activity, Low motivation, Social withdrawal, Emotional flattening
ICD10 diagnosis
One of the following:
- Thought echo, insertion, withdrawal, broadcast
- Delusions of control, influence or passivity
- Hallucinatory voices giving a running commentary or other types of hallucinatory voices
- Persistent delusions of other kinds
Or at least 2 of the following:
- Persistent hallucinations in any modality (occur everyday for at least one month)
- Neologisms, breaks or interpolations in the train of thought; resulting in incoherent or irrelevant speech
- Catatonic behaviour
- Negative symptoms
Give some of the different types of Schizophrenia
- Paranoid Schizophrenia (delusions or hallucinations prominent)
- Simple Schizophrenia (similar to depression - loss of drive and interest, aimlessness, idleness etc…)
- Hebephrenic Schizophrenia (similar to mania - giggly, inappropriate behaviour etc…)
- Undifferentiated Schizophrenia (insufficient symptoms to meet criteria of any subtypes or so many symptoms fit more than one criteria)
- Catatonic Schizophrenia
Outline the structures involved in the Pathophysiology of Schizophrenia
- Dopamine pathways activity changing
- Brain changes
- Limbic system involvement
What Dopamine pathways are involved Schizophrenia?
Mesolimbic pathway - overactive in schizophrenia (from the ventral tegmental area to limbic structures and nucleus accumbens)
Mesocortical pathway - underactive in schizophrenia (from the ventral tegmental area to frontal cortex and cingulate cortex)
What are the 4 Dopaminergic pathways?
- Mesolimbic pathway
- Mesocortical pathway
- Nigrostriatal pathway
- Tuberohypophyseal pathway
What are the brain changes seen in Schizophrenia?
- Enlarged ventricles
2. Reduced hippocampal formation, amygdala, parahippocampal gyrus and prefrontal cortex
What is the role of the Limbic structures and Basal ganglia in Schizophrenia
Limbic structures - have a role in regulating emotional behaviour
Basal gangla - even untreated patients can present with motor symptoms
Outline the Autoimmune hypothesis of Schizophrenia.
Believed to be due to the involvement of anti-NMDA antibodies leading to anti-NMDA encephalitis. Antibodies bind to the NMDA receptor.
80% of patients are female - around 50% have an underlying tumour (mostly ovarian teratoma)
Treatment = Corticosteroids
Outline the Treatments for Schizophrenia
Typical antipsychotics (e.g. Haloperidol) - block D2 receptors in all CNS dopaminergic pathways (Mesolimbic, Mesocortical, Nigrostriatal, Tuberhypophyseal) - lots of side effects
Atypical antipsychotics - low affinity for D2 receptors, milder side effects as dissociate rapidly from D2 receptor
What are the different types of dopamine receptors and their families?
D1 receptor family = D1, D5 receptors - secondary messenger increases cAMP (via Gs)
D2 receptor family = D2, D3, D4 receptors - secondary messenger decreases cAMP (via Gi)
D2 receptors (not the family) found in striatum, substantia nigra and pituitary gland
What are the problems in treatment of Schizophrenia?
Antipsychotic medications cause side effects:
Typically Parkinsonian side effects (e.g. bradykinesia, tremor, muscle rigidity, pill rolling tremor, shuffling/propulsive gait etc…)
Can also get Acute Dystonia (development of Torticollis - another drug given to treat this)
