Lecture 9: Structural brain changes in sz (Part II) Flashcards
What are the Key structural differences in SZ?
1) Enlarged ventricles
2) Decrease in whole-brain volumes
3) Reduced volume of the temporal lobe
- Auditory and superior temporal gyrus
- Hippocampus
4) Prefrontal cortex
5) Basal ganglia (dopamine system)
6) Mirror neuron system
Changes in the _______ are related to changes in total brain volume.
ventricles
Structural differences are ______ for people recently diagnosed with SZ compared to those with chronic symptoms
similar
What are the structural differences that are similar in 1st episode and chronic SZ?
- Brain changes occur ______ in development
- Brain changes may occur _______
- early in development
- before the onset of symptoms
[May be early indicators of possible disorder]
However we found increasing evidence that there are ___________
changes over time
Ventricles enlarge and total brain volume decreases in SZ which is related to ______________ (hint: 3)
- Symptom severity
- Cognitive measures
- Poor outcome
There are specific changes in grey and white matter in which areas of the brain?
Frontal and temporal lobes and the connections between them
What were the main findings of the Three group comparison (chan, 2011) study?
Regions where brain structure is different than controls are:
1) _________
2) ___________
Greater changes in ___________
1) Left frontal lobe
2) Bilateral auditory regions
Greater changes in chronic SZ as disease progresses
In first episode SZ, reduced volume in ____and ___ lobes were found.
frontal and temporal
More specifically, in 1st episode SZ, there was a reduced volume in which regions?
1) Frontal episodic memory regions
2) Auditory regions
They also found that the basal ganglia was reduced in the _____ group compared to _____ group
Basal ganglia reduced in Chronic compared to 1st Episode
Some auditory and frontal regions smaller in ________ group compared to _____ group
Some auditory and frontal regions smaller in 1st Episode compared to chronic.
Diffusion tensor imaging (DTI) only looks at ____ matter
white
DTI is a measure of what?
A measure of:
- number,
- integrity (health)
- and myelination of fibres connecting different brain regions
DTI studies have shown us that people with SZ often show _____ diffusion: _____ integrity, ____ myelination, ______ fibres
People with SZ often show greater diffusion:
lower integrity, less myelination, fewer fibres
People with SZ often show greater diffusion: lower integrity, less myelination, fewer fibres in which lobes?
Frontal lobe
Temporal lobe
People with SZ often show greater diffusion in temporal and frontal lobes. What is the hypothesis concerning these changes?
These changes may not be present at initial diagnosis
Grey matter changes ___________
White matter changes __________
Grey matter changes present early
White matter changes develop over time
SZ showed reduced or damage white matter in tracts connecting which regions? ( Kelly, 2018) [ hint: 3]
1) Temporal, parietal and frontal lobes (attention, mirror neuron)
2) connection between hemispheres (corpus callosum)
3) Cingulate (attention, error monitoring) to frontal
Pantelis study (2003) looked at 1st episode versus high risk SZ patients in a cross-sectional comparison, what was their findings? [high-risk means they had a relative with SZ].
In which lobes did they find reductions?
frontal and temporal
Then in the Pantelis (2002), they looked at longitudinal comparisons comparing people who developed psychosis to 1st episodes patients. What was their finding? What were the Changes in those who developed SZ?
Reductions in frontal and cerebellum
Are changes in brain volume in specific areas related to specific symptoms?
In general, temporal lobe volumes related to _____, frontal lobe related to __________.
positive symptoms (ex: Temporal lobe and thought disorder)
negative symptoms.
What were the findings of the The Shenton (1992) study on Temporal lobe and hippocampus related to thought disorder?
Methodology:
1) Measured volumes of superior temporal lobe (auditory) and hippocampus
2) Assessed thought disorder
[Responded to a picture, rated content, logical flow, grammatical structure]
- Both showed reduced volume in SZ
- Volume negatively related to thought disorder
(Lower volume –> Higher thought disorder)
Similar brain regions associated with Bipolar, but changes are _______
smaller
PTSD and Alzheimer’s disease both show changes in the __________
hippocampus
Because the frontal lobe, temporal lobes and hippocampus are so important for cognitive function, perhaps not surprising that they are involved in many disorders. However, this means that _________
there is no diagnostic marker based on brain structure
The Mirror neuron system and SZ was observed in the Sally-Anne task with SZ and healthy controls (Mehta, 2014), what were the main findings?
Reduced activity in the mirror neuron system
This reduced mirror neuron activity (Sally-Anne task) was related to:
- Poorer performance on _____________
- More _______ symptoms
- social cognition
- negative symptoms [Impoverished emotional expression, reduced sociality, poor motivation]
Grey matter and white matter changes in SZ are most constantly found in which regions of the brain?
Frontal and temporal lobes (including hippocampus)
What is another consistent finding in SZ?
Enlargement of ventricles and reduced brain volume
Cognitive deficits were associated with ____ and ____
symptom severity and outcome
In SZ, early differences may be present ________
before symptom onset
Later changes may be related to ___________
- disease progression,
- medication,
- other psychosocial factors such as stress, drugs or alcohol
