Schizophrenia: Pathophysiology, Clinical Presentation and Tx. Flashcards
Contrast thought and perception.
thought is organization and evaluation of highly processed multi-sensory information to inform decision making; perception is the way in which sensory events achieve conscious awareness
List positive symptoms: (Schneider’s first rank).
hallucinations (auditory, tactile)
paranoia
delusions (persecutory delusion, idea of reference, thought broadcasting, thought insertion or withdrawal and delusion of passivity)
other perceptual abnormalities
List negative symptoms (Bleuler’s four A’s).
flat affect alogia (limited thought and speech) avolition, anhedonia in ability to persist in goal-directed activities preservation emotional blunting or lability
List cognitive symptoms.
disorganized speech and behavior decreases in overall cognitive function anosognosia (lack of insight into illness) poor coordination R/L confusion gait impairment
Describe the dysfunction of the prefrontal cortex that contributes to schizophrenia? What is its normal function?
decreased prefrontal activity leads to less regulation of thought and perception
dorsolateral usually works in planning, prioritizing, behavioral flexibility and shifting response
orbitofrontal: affective/emotional regulation via connection to the amygdala
Describe the dysfunction of the temporal lobe that contributes to schizophrenia? What is its normal function?
the temporal cortex, amygdala and hippocampus is activated during hallucinations due to other stimulation
normally it regulates information processing and perception
Describe the dysfunction of the dopamine system that contributes to schizophrenia? What is its normal function?
lower then optimal levels of dopamine in the ventral tegemental area and mesocorticolimbic systems are required for normal thought and perception
normally the VTA is connected to the PFC, accumbent and the temporal lobe in the mesocorticolimbic system which is important for reward and reinforcement
**DA agonists cause psychosis
How does the presence of autistic spectrum disorder complicate schizophrenia diagnosis?
if there is a history of autistic spectrum disorder or communication disorder, schizophrenia diagnosed only with prominent delusions or hallucinations
Tactile or olfactory hallucinations are less common in schizophrenia than in this disorder on the differential for psychosis.
medical or substance-induced psychosis
What anatomical changes can be observed as associated with schizophrenia.
reduced frontal cortex volumes
temporal lobe reduction
ventricular enlargement (indicative of atrophy)
cytoarchitectural changes in temporal and frontal regions
Integrate the brain systems that are dysfunctional in schizophrenia to explain the “cognitive dysmetria” hypothesis.
(1) PFC fails to send inhibitory signals to limbic (temporal lobe) and VTA and dopamine pathways between brainstem and limbic/PFC are unchecked
(2) Hypoactivity of the PFC likely due to neuronal disorganization, high DA levels further inhibit PFC activity
(3) Other NT involved include glutamate (antongonism of glutamatergic NMDA receptors cause psychyosis) and glycine (promotes glutamate binding to NMDA receptors)
What do scientists hypothesize to be possible triggers to schizophrenia?
genetic abhorrence that causes cytoarchietectural changes
abnormalities in neurodevelopment that cause failure to form and prune appropriate connections
environmental stress
2nd trimester distress
pot use during adolescence
Contrast the activity of typical and atypical antipsychotics in addressing the symptoms of schizophrenia.
typicals address positive symptoms well
atypicals address positive and negative symptoms well
it is stand treatment to start with an atypical antipsychotic with concern of metabolic and extra pyramidal side effects
In what situations would you use clozapine and why not use it with all patients?
used only with patients with severe schizophrenia that is refractive to treatment; serious side effects include seizures, cardiomyopathy and agranulocytosis
What is neuroleptic malignant syndrome and what causes it?
a serious reaction to antipsychotics or neuroleptics that includes:
mental status changes
muscle rigidity
hyperthermia
autonomic instability
elevated creatine kinase
failure to recognized and treat can lead to kidney failure and death
