Lecture 7 - Clinical Neuropsychology - disorders of executive function

Question 1

Is dementia a disease or clinical syndrome?

Answer 1

It is a clinical syndrome.

Question 2

Is behavioural variant frontotemporal dementia (bvFTD) a clinical syndrome or a disease?

Answer 2

A clinical syndrome.

A syndrome refers to the signs and symptoms that go together reliably for a given disease.

Question 3

Are dementias are always slow moving, and progressive?

Do they always involve impairments to activities of daily living?

Answer 3

Yes.

Question 4

Is it true that PET scanning is not very sensitive to tau pathology in the mesial temporal lobes?

What does this mean for using this form of imaging as a way of determing whetther someone has AD?

Answer 4

Yes.

PET imaging is not very sensitive to hyperphosphorylated tau in the mesial temporal lobes.

What this means is that PET imaging is normally only useful when tau pathology has spread to the lateral temporal and parietal lobes. This occurs late in disease progression and therefore it is not that helpful in terms of prevention or management. Not useful for detecting AD early in progression.

Question 5

Is bvFTD caused by a tauopathy (abnormality in tau)?

Would pts with this disorder have lowered amyloid in their CSF?

Answer 5

Yes.

No. Amyloid fucntion is normal.

Question 6

What is underlying disease that causes frontotemporal dementia?

Answer 6

Frontotemporal lobar degeneration (FTLD).

Degeneration of neurons in the frontal and temporal lobes.

Question 7

FTD causes a focal cortical atrophy. What does this mean?

Answer 7

That the clinical syndrome is caused by damage/impairment to the cortex that governs the function that is impaired in the syndrome.

Question 8

What does FTLD stand for?

Answer 8

Frontotemporal lobar degeneration.

This causes FTD.

Question 9

Are there multiple clinical syndromes of frontotemporal dementia?

Answer 9

Yes.

They are defined by the initial presenting symptoms, such as behaviour or language. As the disease progresses they often have similar presenting symptoms.

Question 10

Does FTD often present in younger people than Alzheimer’s dementia?

Answer 10

Yes.

Question 11

What percentage of bvFTD is caused by tauopathy?

Answer 11

About 50%. The rest are caused by multiple different pathologies.

Question 12

Are some types of FTD caused by genetics, such as abnormalities in the tau gene?

Answer 12

Yes. But these cases are very rare.

Question 13

Is it true that in those with bvFTD that they will experience behavioural changes before abnormalities become apparent on brain imaging scans?

Answer 13

Yes.

Brain imaging not that helpful in detecting early stages of bvFTD.

Question 14

Those suffering with bvFTD are often brought into a clinic by a family member or friend?

Why is it quite rare for someone with bvFTD to present to a clinician themselves?

Answer 14

Oftentimes those suffering with bvFTD do not think that there is anything wrong. This is because insight/self-awareness is a frontal lobe function. Frontal lobes are disrupted in bvFTD.

Question 15

Why are cognitive tests not that helpful at the beginning stages of bvFTD?

Answer 15

Cognitive scores tend to remain within healthy range well into the disease. Behavioural change is what is normally apparent initially.

This is why taking a client history is so important, so that you can see whether their current behaviour is significantly different to their prior behaviour?

“Living with a child.”
“Living with a different person.”

Question 16

What are some examples of executive functions?

Answer 16

Emotional regulation.
Social awareness and interactions.
Goal-directed behaviour.
Behavioural initiation.

Question 17

What type of functions are altered in those with bvFTD?

Answer 17

Executive functions.

Question 18

What functions are generated or controlled by the DLPFC?

Answer 18

Cold cognitive tasks, such as planning, making a hypothesis.

E.g. saying the days of week backwards.

Question 19

What functions is the ventromedial prefrontal cortex (VMPFC) responsible for?

Answer 19

‘Hot’ cognitive tasks, such as emotion regulation, social awareness, empathy.

Question 20

What functions is the orbitofrontal prefrontal cortex responsible for?

Answer 20

Response inhibition, such as not hitting someone when you’re annoyed at them.

Question 21

What parts of the brain are normally damaged in those with bvFTD?

Answer 21

The DLPFC, VMPFC and OFPFC.

Question 22

Do FTDs progressive faster than AD?

Answer 22

Yes.

Question 23

What is a test that examines response inhibition, and is used to assess whether there may be orbitofrontal prefrontal cortex degeneration?

Answer 23

The Stroop incongruent trials test.

The name of colours are written in an ink that is a different colour to the word written.

Person instructed to say the name of the ink, not the word written, as fast as they can. You have to actively inhibit yourself from reading and saying the word written.

Those with orbitofrontal prefrontal cortex damage would not get good results for this test.

Question 24

What test can be used to examine executive functions?

Answer 24

The orthohraphic Lexical Retrieval test (OLR).

People are given a letter and they need to come up with as many words starting with that letter as they can in a given amount of time.

This can very difficult for those with FTLD.

Question 25

What is another cognitive test to measure response inhibition?

Answer 25

The Hayling test.

Individual asked to give a word that would logically finish a sentence they are presented with. Then they are asked to give a word that does not correspond to the sentence in any way.

Those with OFC damage will really struggle with not saying a word that fits with the sentence. They cannot inhibit the natural, initial response.

Question 26

What does the Tower of London cognitive test measure?

Answer 26

Individual given an image of balls that need to make a certain configuration. There are a couple of rules and the person needs to achieve the configuration in as little moves as possible.

Those with frontal lobe damage will struggle with this.

Question 27

What are some neurobehavioural exmainations that can be done to test cognitive function?

Answer 27

Asking a patient to perform a sequence of hand gestures you have shown them.

Asking a patient to tap their hand once when you tap the surface twice and to tap twice when you tap the surface twice.

Those with executive dysfunction will struggle with these tasks, especially if damage is in DLPFC??

Question 28

Do primal reflexes that we have as a baby often come back when people have damage to their frontal lobes?

Answer 28

Yes.

Examples are the grasp reflex. If you tap or put your hand in their hand they will automatically grasp your hand, even if you instruct them not to.

Question 29

The behavioural changes that occur for those with FTD can often appear contradictory across individuals as well as within the same individual.

What are some examples of this?

Answer 29

Some may experience depression. Some may experience mania.

Some may experience emotional apathy. Some may experience severe emotional lability.

Question 30

What are some behavioural examples of response inhibition?

Answer 30

Eating more sweet food, alcohol, cigarettes. Note, this should occur outside of an emotional response.

Question 31

What are some cognitive functions that would be conserved in those with bvFTD?

Answer 31

Visuospartial ability.

Arbitraty associative learning.

Memory.

Question 32

What is seen in those with bvFTD on a Rey Auditory Verbal Learning Test?

Answer 32

When they are asked to recall words after a break from hearing and repeating them they perform poorly. When they are provided with a cue, however, they perform well.

This suggests that the damage in their brain is in areas required for recall (frontal lobes) and not in the memory structures themselves. Recall is an executive function as opposed to a strictly memory function.

Question 33

Do those with bvFTD have a recall profile when it comes to memory?

Answer 33

Yes.

Those with Alxheimer’s dementia have an encoding profile.

Question 34

Consider how knowledge of how AD and FTLD spread and progress would inform how a neurospych would examine a pt. For example, knowing that bvFTD often presents as behavioural disturbances would mean clinician would need to really consider the pt’s history and insights from carers/partners and not just rely on cognitive exams.