Brain injury as a cause of SZ Flashcards
What are enlarged ventricles?
Fluid filled spaces in the brain which cushion the brain, supply nutrients and removed waste.
How are enlarged ventricles caused?
Due to 40 lesions in the brain which occur during pregnancy/ fetal development or during the birth process ie oxygen starvation
What do enlarged ventricles cause?
Areas of the brain is prefrontal cortex become underdeveloped and don’t reach the normal size. The brain is lighter.
Give a stat about enlarged ventricles in Sz patients.
Sz patients ventricles are 15% larger then the general population.
What does enlarged ventricles cause?
Disorganised thoughts. Cognitive deficiencies. Negative symptoms.
Give twin study evidence to support enlarged ventricles.
12 out of 15 sets of MZ twins with SZ had an mRI scan and found it was caused by enlarged ventricles.
MRI scans are scientific.
However twins share the same environment so we cannot establish cause or effect.
How can the Prefrontal cortex be a cause of negative symptoms of SZ?
Matures around age 16 explains why typical onset of SZ is during adolescence. Pfc is responsible for thinking, reasoning and decision making. Reduced volume size therefore leads to disorganised thoughts, speech, poor concentration. Negative symptoms such as social withdrawal as they are unable to complete day to day tasks due to the inability to be decisive. Ie they can’t work or maintain social life. this is support by castner who damages fetal monkeys brains during embody development. There were no detected signs until adolescence
How does the pfc cause positive symptoms of SZ?
Due to irrational thinking as pfc is linked to logic and attention. Ie leads to believing something that isn’t true. Damaging ability to reason.
Give evidence to support pfc as a cause of SZ
Castner - damaged the brains of monkeys when developing fetal. Found symtoms of Sz develop at adolescence.
Animals study lacks generalisability
Can establish cause and effect. Studied before and after the symptoms.
How can the amygdala be a cause of Sz
Amygdala responsible for fear and raw emotions. Tends to be smaller. Explains apathy and flattening.
Visual and auditory cortical tend to be abnormal in structure and function in patients with Sz. Explain what symptoms this causes.
Linked to sight and tearing such as hallucinations and hearing voices.
What is cataleptic stupor? what cause this
Inability to move. Abnormalities in the basal ganglia.
