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Psych12345

some doubts ..... spring 2007

11 posts in this topic

6)

Options

BOLD MRI

11 c iomazenil labeled SPECT

fMRI

Radiolabelled iodine SPECT

FDG labeled SPECT

Volumetric MRI

Lead in: Choose the most appropriate investigations to

1. Measure progressive memory loss in Alzheimer’s dementia

2. Determine cerebral dominance prior to surgery

3. Measure absolute neuronal loss in Alzheimer’s dementia

2)

Options

Living in an institution

Living alone

Previous poor relationship with carer

Male carer

Male patient

Patient has a diagnosis of dementia

Carer married to patient

High physical dependency in the patient

Lead in: Choose the most common associated risk factors for the following:

1. Carer stress Choose 2

2. Depression Choose 3

3. Non accidental injury from carer Choose 2

1.In large families school refusal is more common in first born child

.Men who abuse alcohol are more likely than women who abuse alcohol to develop Wernicke's

.The prevalence of specific reading difficulty is 10 times more in UK compared to Japan

Non accidental injury to child is less likely in mothers with OCD.

Fluid restriction is a reasonable course if action in an eight year old child with primary enuresis.

The IQ of girls with Fragile X is more impaired than boys with Fragile X

Testosterone is the biggest predictor of aggression in boys.

Atypical facial pain is chronic

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Tricky.

I think BOLD MRI is the same thing as fMRI- blood oxygenation level dependent MRI- uses deoxyhaemoglobin as an endogenous magnetic contrast.

Iomazenil labelled SPECT is a radioactive ligand which binds to benzo Receptors and therefore GABA receptors- used in Alzheimers to detect ?decrease in synaptic connections (cos GABA is the main inh neurotranmitter throughout the whole brain).http://www.springerlink.com/content/ul770382v4w10026/

FDG is a radioactive deoxyglucose ligand. Found it on t'internet related to PET, but not SPECT.

Radiolabelled Iodine SPECT sounds like a red herring- you can stick it as the iodine part of a drug (eg iomazenil) to act as a radioactive ligand, but as far as I know it's only useful on its own to measure thyroid metabolism.

Volumetric MRI is a structural, rather than functional scan.

So my guess would be:

Progressive memory loss in AD- iomazenil labeled SPECT

Cerebral dominance- BOLD MRI (to show you know the posh name for it?)

Absolute neuronal loss in AD- volumetric MRI

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Men who abuse alcohol are more likely than women who abuse alcohol to develop Wernicke's

False

Wernicke's 1.7:1 M:F

Alcohol dependence 3-4x commoner in men.

Therefore women who abuse alcohol are more likely to get wernicke's than men who abuse alcohol.

http://www.emedicine.com/emerg/topic642.htm

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Tricky.

I think BOLD MRI is the same thing as fMRI- blood oxygenation level dependent MRI- uses deoxyhaemoglobin as an endogenous magnetic contrast.

Iomazenil labelled SPECT is a radioactive ligand which binds to benzo Receptors and therefore GABA receptors- used in Alzheimers to detect ?decrease in synaptic connections (cos GABA is the main inh neurotranmitter throughout the whole brain).http://www.springerlink.com/content/ul770382v4w10026/

FDG is a radioactive deoxyglucose ligand. Found it on t'internet related to PET, but not SPECT.

Radiolabelled Iodine SPECT sounds like a red herring- you can stick it as the iodine part of a drug (eg iomazenil) to act as a radioactive ligand, but as far as I know it's only useful on its own to measure thyroid metabolism.

Volumetric MRI is a structural, rather than functional scan.

So my guess would be:

Progressive memory loss in AD- iomazenil labeled SPECT

Cerebral dominance- BOLD MRI (to show you know the posh name for it?)

Absolute neuronal loss in AD- volumetric MRI

Just one doubt... considering that Iomazenil is a ligand for the GABA receptors and progressive memory loss in AD is probably associated with cholinergic neurons in the hippocampal region, would an Iomazenil labelled SPECT be of any use???? (the one study which I saw has used HMPOA as the label rather than Iomazenil)

Moreover, to activation while doing tasks like memory tasks I believe an fMRI would be more useful.... for eg a prospective study showing a decline in performance on memory tasks correlating with changes in the MRI...or a cross sectional one compating AD with normals

SPECT has lower spatial resolution for deeper structures like the hippocampus...

The answer could also be FDG PET... which could show a correlation between the glucose metabolism and cognition...

So I would suggest the answer to 1 be fMRI/FDG PET..

(BOLD is one type of functional MRI imaging... )

Please correct me if I am wrong...

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Men who abuse alcohol are more likely than women who abuse alcohol to develop Wernicke's

False

Wernicke's 1.7:1 M:F

Alcohol dependence 3-4x commoner in men.

Therefore women who abuse alcohol are more likely to get wernicke's than men who abuse alcohol.

http://www.emedicine.com/emerg/topic642.htm

hmmmm... interesting...

Just to add...

Other causes for Wernicke's encephalopathy

Hyperemesis of pregnancy

Systemic malignancy

Gastrointestinal surgery

Hemodialysis or peritoneal dialysis

Prolonged intravenous feeding

Refeeding after prolonged fasting or starvation

Anorexia nervosa

Dieting and gastric plication

Acquired immunodeficiency syndrome

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Tricky.

I think BOLD MRI is the same thing as fMRI- blood oxygenation level dependent MRI- uses deoxyhaemoglobin as an endogenous magnetic contrast.

Iomazenil labelled SPECT is a radioactive ligand which binds to benzo Receptors and therefore GABA receptors- used in Alzheimers to detect ?decrease in synaptic connections (cos GABA is the main inh neurotranmitter throughout the whole brain).http://www.springerlink.com/content/ul770382v4w10026/

FDG is a radioactive deoxyglucose ligand. Found it on t'internet related to PET, but not SPECT.

Radiolabelled Iodine SPECT sounds like a red herring- you can stick it as the iodine part of a drug (eg iomazenil) to act as a radioactive ligand, but as far as I know it's only useful on its own to measure thyroid metabolism.

Volumetric MRI is a structural, rather than functional scan.

So my guess would be:

Progressive memory loss in AD- iomazenil labeled SPECT

Cerebral dominance- BOLD MRI (to show you know the posh name for it?)

Absolute neuronal loss in AD- volumetric MRI

Just one doubt... considering that Iomazenil is a ligand for the GABA receptors and progressive memory loss in AD is probably associated with cholinergic neurons in the hippocampal region, would an Iomazenil labelled SPECT be of any use???? (the one study which I saw has used HMPOA as the label rather than Iomazenil)

Moreover, to activation while doing tasks like memory tasks I believe an fMRI would be more useful.... for eg a prospective study showing a decline in performance on memory tasks correlating with changes in the MRI...or a cross sectional one compating AD with normals

SPECT has lower spatial resolution for deeper structures like the hippocampus...

The answer could also be FDG PET... which could show a correlation between the glucose metabolism and cognition...

[highlight]So I would suggest the answer to 1 be fMRI/FDG PET[/highlight]..

(BOLD is one type of functional MRI imaging... )

Please correct me if I am wrong...

You can't have both, Dorian! But unless the question was quoted incorrectly, PET wasn't an option..

But thanks for the above detailed info- I saw the HMPOA thing too, but that isn't given as an option.

As far as I understood, the implication about the iomazenil seemed to be that it measures synapse concentration generally, because GABA is everywhere. Didn't know about the deep structure thingy, though. What would you do with a demented patient in an MRI scanner to test this? The fact that it says progressive memory loss feels a bit more structural to me- like they want pictures at different points in time that control for each other. I would have thought fMRI would be more difficult to create identical conditions each time, because of the variables introduced by task performance. Just guessing, though.

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You can't have both, Dorian! But unless the question was quoted incorrectly, PET wasn't an option..

But thanks for the above detailed info-  I saw the HMPOA thing too, but that isn't given as an option.

As far as I understood, the implication about the iomazenil seemed to be that it measures synapse concentration generally, because GABA is everywhere. Didn't know about the deep structure thingy, though. What would you do with a demented patient in an MRI scanner to test this? The fact that it says progressive memory loss feels a bit more structural to me- like they want pictures at different points in time that control for each other. I would have thought fMRI would be more difficult to create identical conditions each time, because of the variables introduced by task performance. Just guessing, though.

Probably I am going a bit overboard... but I will brush up imaging and get back...

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Too much knowledge is a dangerous thing in Part 2- the worst thing you can do is know more than the examiners! :lol:

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You can download ISQs up to 2004 from superego-click 'mrcpsych exams', then isqs (on the left) or whatever, then download from the right hand side. Essays and PMPs likewise. Manchester course has past questions, and the College's critical appraisal book consists of past questions. I think you can get some also via the College website, but this may be just critical appraisal. (College won't give isqs emis as they use the same pot for many exams) Then look at the superego forum part 2 section for the dates just after the written exam has happened, and a couple of wonderful people usually post as many questions as they can remember. God Bless them :)

Hope this is what you meant.

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