Learning and Memory 4: MCI and Dementia

Question 1

What area of the brain is believed to be mainly affected in the normal, mild cognitive decline of aging?

Answer 1

The frontal lobes.

Question 2

Four things that commonly get worse in cognitive aging?

Answer 2

Information processing speed
Working memory / switching attention
Memory of context, word-finding (esp. peoples’ names)
Decision-making / problem-solving

Question 3

What’s usually preserved in normal cognitive aging?

Answer 3

vocabulary, semantic memory.

Question 4

What’s MCI? Diagnostic criteria? (2 postives, 2 negatives)

Answer 4

Mild cognitive impairment (can be normal or pre-dementia)
+ Subjective cognitive decline
or
+ Objective cognitive decline in at least one cognitive domain (to a greater extent than is average for age / education level)
- Normal ADLs
- Do not meet criteria for dementia

Question 5

Treatable causes of cognitive decline that you want to exclude? (name 4)

Answer 5

depression, anxiety, metabolic causes (hypothyroidism, B12 deficiency), vascular disease

Question 6

When you see MCI, what’s the first diagnostic branch-point? Second branch-point?

Answer 6

1st: Is it amnesic or non-amnesic MCI?
2nd: Is it single or multiple-domain impairment?

Question 7

What disease might be more likely to progress from amnesic MCI? How about from non-amnesic MCI?

Answer 7

From amnesic MCI: Alzheimer’s disease

From non-amnesic MCI: non-AD dementia (naturally…)

Question 8

Two highlighted risk factors for progression from MCI to AD / dementia?

Answer 8

Hippocampal atrophy (seen on MRI)
Amyloid deposition (seen with PiB binding in PET scan)

Question 9

What treatment, though not actually approved, can help memory problems in MCI?

Answer 9

Cholinesterase inhibitors.

Question 10

3 important non-AD dementias to know?

Answer 10

Frontotemporal Dementia
Dementia with Lewy Bodies
Vascular Dementia

Question 11

Age of onset for frontotemporal dementia? Involvement of memory?

Answer 11

45-65 years old. Memory is “relatively spared.”

Question 12

What is bv-FTD? Which two regions of the frontal lobes does it affect?

Answer 12

Behavioral variant frontotemporal dementia.
Affects the orbitofrontal cortex, anterior cingulate gyrus and…
The dorsolateral prefrontal area.

Question 13

4 things altered in bv-FTD?

Answer 13

Personality - inability to function socially, etc.
Emotional reactivity - apathy, loss of empathy, etc.
Disinhibition - overeating, impulsiveness, etc.
Executive Function

Question 14

Where is Progressive Non-Fluent Aphasia (PNFA) localized?

Answer 14

To the left frontal lobe, involving Broca’s region.

Question 15

Where does semantic dementia localize?

Answer 15

To the temporal lobes (MRIs suggest a bilateral process…)

Question 16

What is surface dyslexia? What does it show?

Answer 16

Patients can sound out words that follow normal pronunciation rules, but can’t properly read words that don’t follow normal pronunciation rules (like “yacht” or “choir”). They have lost the meaning associated with the word, can thus can’t draw on that meaning to help them read the whole word at once.

Question 17

What’s one (temporary) upside of FTD sometimes seen?

Answer 17

People often unleash artistic abilities… (I think there’s a Radiolab about this)

Question 18

What 2 underlying processes account for most frontotemporal degeneration? 1 minor cause?

Answer 18

Tau-opathy
TDP (TAR DNA binding protein) proteinopathy
Alzheimer’s is a minor cause

Question 19

How is FTD treated? (5 things)

Answer 19

Symptomatically.

Antidepressants, mood stabilizers, atypical antipsychotics, stimulants, memantine (NMDA antagonist)

Question 20

Difference between Parkinson’s Disease with Dementia (PDD) and Dementia with Lewy Bodies?

Answer 20

Distinguished clinically by cognitive symptoms having onset within 1 year of onset of parkinsonism. But… they may well be different presentations of the same disease.

Question 20

Review: What are Lewy Bodies?

Answer 20

Extracellular aggregates of alpha-synuclein.

Question 21

Core features of Dementia with Lewy Bodies? (4 things)

Answer 21

Progressive dementia (esp attention and executive function)
Visual hallucinations (usu. non-frightening at first...)
Fluctuating cognition
Spontaneous parkinsonism (more about the gait and posture, less about the tremor)

Question 22

Why do you have to give “atypical” neuroleptics to Dementia with Lewy Bodies patients?

Answer 22

They don’t do well with dopamine antagonism by neuroleptics such as Haldol. Recall that parkinsonisms are characterized by a lack of dopamine signaling…

Question 23

Treatment for Dementia with Lewy Bodies?

Answer 23

Symptomatic
Levodopa (but can worsen hallucinations
Acetylcholinesterase inhibitors
Atypical neuroleptics
Antidepressants
Benzodiazepines for REM disturbances

Question 24

Will you get a gradual cognitive decline in vascular dementia?

Answer 24

Yes, somewhat surprisingly. But it tends to occur in stepwise decrements, with accumulating vascular accidents.

Question 25

3 clinical subtypes of vascular dementia?

Answer 25

Multi-infarct dementia Subcortical vascular dementia Strategic infarct dementia

Question 26

An infarct to which vessels will cause apathy, abulia (lack of initiative), and akinetic mutism (sitting around and not saying anything).

Answer 26

ACA - frontal lobes lesioned

Question 27

An infarct of which major blood vessels could cause amnesia, agnosia, and anomia?

Answer 27

PCA infarct.

Question 28

4 features of subcortical dementia?

Answer 28

``` Psychomotor slowing Impaired concentration Forgetfulness Anxiety and depression (absence of focal cortical deficits like aphasia, agnosia, apraxia, etc.) ```

Question 29

What is subcortical vascular dementia?

Answer 29

Lesions of small blood vessels of white matter in the brain.

Question 30

What is strategic infarct dementia? 2 possible localizations?

Answer 30

A small infarct that interrupts fronto-subcortical communication, leading to broad effects. Anterior and dorsomedial thalamus. Genu of internal capsule.