Learning and Memory 4: MCI and Dementia Flashcards
What area of the brain is believed to be mainly affected in the normal, mild cognitive decline of aging?
The frontal lobes.
Four things that commonly get worse in cognitive aging?
Information processing speed
Working memory / switching attention
Memory of context, word-finding (esp. peoples’ names)
Decision-making / problem-solving
What’s usually preserved in normal cognitive aging?
vocabulary, semantic memory.
What’s MCI? Diagnostic criteria? (2 postives, 2 negatives)
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
Treatable causes of cognitive decline that you want to exclude? (name 4)
depression, anxiety, metabolic causes (hypothyroidism, B12 deficiency), vascular disease
When you see MCI, what’s the first diagnostic branch-point? Second branch-point?
1st: Is it amnesic or non-amnesic MCI?
2nd: Is it single or multiple-domain impairment?
What disease might be more likely to progress from amnesic MCI? How about from non-amnesic MCI?
From amnesic MCI: Alzheimer’s disease
From non-amnesic MCI: non-AD dementia (naturally…)
Two highlighted risk factors for progression from MCI to AD / dementia?
Hippocampal atrophy (seen on MRI) Amyloid deposition (seen with PiB binding in PET scan)
What treatment, though not actually approved, can help memory problems in MCI?
Cholinesterase inhibitors.
3 important non-AD dementias to know?
Frontotemporal Dementia
Dementia with Lewy Bodies
Vascular Dementia
Age of onset for frontotemporal dementia? Involvement of memory?
45-65 years old. Memory is “relatively spared.”
What is bv-FTD? Which two regions of the frontal lobes does it affect?
Behavioral variant frontotemporal dementia.
Affects the orbitofrontal cortex, anterior cingulate gyrus and…
The dorsolateral prefrontal area.
4 things altered in bv-FTD?
Personality - inability to function socially, etc.
Emotional reactivity - apathy, loss of empathy, etc.
Disinhibition - overeating, impulsiveness, etc.
Executive Function
Where is Progressive Non-Fluent Aphasia (PNFA) localized?
To the left frontal lobe, involving Broca’s region.
Where does semantic dementia localize?
To the temporal lobes (MRIs suggest a bilateral process…)
What is surface dyslexia? What does it show?
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.
What’s one (temporary) upside of FTD sometimes seen?
People often unleash artistic abilities… (I think there’s a Radiolab about this)
What 2 underlying processes account for most frontotemporal degeneration? 1 minor cause?
Tau-opathy
TDP (TAR DNA binding protein) proteinopathy
Alzheimer’s is a minor cause
How is FTD treated? (5 things)
Symptomatically.
Antidepressants, mood stabilizers, atypical antipsychotics, stimulants, memantine (NMDA antagonist)
Difference between Parkinson’s Disease with Dementia (PDD) and Dementia with Lewy Bodies?
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.
Review: What are Lewy Bodies?
Extracellular aggregates of alpha-synuclein.
Core features of Dementia with Lewy Bodies? (4 things)
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)
Why do you have to give “atypical” neuroleptics to Dementia with Lewy Bodies patients?
They don’t do well with dopamine antagonism by neuroleptics such as Haldol. Recall that parkinsonisms are characterized by a lack of dopamine signaling…
Treatment for Dementia with Lewy Bodies?
Symptomatic Levodopa (but can worsen hallucinations Acetylcholinesterase inhibitors Atypical neuroleptics Antidepressants Benzodiazepines for REM disturbances
Will you get a gradual cognitive decline in vascular dementia?
Yes, somewhat surprisingly. But it tends to occur in stepwise decrements, with accumulating vascular accidents.
3 clinical subtypes of vascular dementia?
Multi-infarct dementia
Subcortical vascular dementia
Strategic infarct dementia
An infarct to which vessels will cause apathy, abulia (lack of initiative), and akinetic mutism (sitting around and not saying anything).
ACA - frontal lobes lesioned
An infarct of which major blood vessels could cause amnesia, agnosia, and anomia?
PCA infarct.
4 features of subcortical dementia?
Psychomotor slowing Impaired concentration Forgetfulness Anxiety and depression (absence of focal cortical deficits like aphasia, agnosia, apraxia, etc.)
What is subcortical vascular dementia?
Lesions of small blood vessels of white matter in the brain.
What is strategic infarct dementia? 2 possible localizations?
A small infarct that interrupts fronto-subcortical communication, leading to broad effects.
Anterior and dorsomedial thalamus. Genu of internal capsule.
