Understanding Alzheimer's Disease and Diagnosis

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Questions and Answers

What percentage of dementia cases is accounted for by Alzheimer's disease?

90%

70% (correct)

50%

80%

Which of the following is the first and most prominent symptom of Alzheimer's disease?

Visual impairment

Depression

Gradually progressive memory loss (correct)

Behavioural impairment

What is required for the diagnosis of dementia according to the diagnostic criteria?

Cognitive decline affecting one domain only

Concerns expressed only by the individual

Cognitive impairment severe enough to interfere with independence (correct)

Cognitive impairment occurring in a delirium

How does Alzheimer's disease typically progress regarding cognitive domains?

Multiple cognitive domains become affected Signup and view all the answers

Which of these symptoms are common neuropsychiatric symptoms of Alzheimer's disease?

Apathy Signup and view all the answers

What does the clinical diagnosis of dementia not specify?

The cause of the dementia Signup and view all the answers

In what condition is cognitive impairment not attributed to according to the diagnostic criteria?

Delirium Signup and view all the answers

What is meant by the aetiological subtype in the context of dementia diagnosis?

The specific brain pathology causing dementia Signup and view all the answers

What is a characteristic cognitive profile associated with MCI due to Alzheimer's disease?

Prominent impairment in episodic memory Signup and view all the answers

What factor greatly influences the likelihood of developing dementia after an MCI diagnosis?

The age of the individual at diagnosis Signup and view all the answers

Which subtype of MCI is the most consistent predictor for progression to Alzheimer's dementia?

Amnestic MCI Signup and view all the answers

In Mr. Campbell's MoCA score, which area did he score the lowest?

Word recall Signup and view all the answers

What is a possible outcome for individuals diagnosed with MCI?

Some may remain stable or even improve over time Signup and view all the answers

Which of the following factors is NOT mentioned as a way to predict progression from MCI to dementia?

Genetic testing Signup and view all the answers

What does the term 'amnestic MCI' refer to?

A stage prior to Alzheimer's dementia with episodic memory impairment Signup and view all the answers

What notable symptom did Mr. Campbell NOT report during his appointment?

Difficulty finding his way in familiar areas Signup and view all the answers

What is characterized as fibrous intraneuronal aggregates of protein in Alzheimer's disease?

Neurofibrillary tangles Signup and view all the answers

Which protein is primarily associated with the extracellular plaques found in Alzheimer's disease?

Amyloid-beta protein Signup and view all the answers

Which individual is credited with introducing the eponym Alzheimer's disease?

Alois Alzheimer Signup and view all the answers

What advanced imaging techniques are being used for in vivo assessment of Alzheimer's disease pathology?

CT and MRI, amyloid and tau PET imaging Signup and view all the answers

What does the amyloid cascade hypothesis propose about the pathogenesis of Alzheimer's disease?

Abnormal accumulation of amyloid-beta is the primary driver. Signup and view all the answers

What type of dementia is associated with patients diagnosed at a relative young age?

Presenile dementia Signup and view all the answers

What leads to the degeneration of nerve cells in Alzheimer's disease?

Accumulation of neurofibrillary tangles Signup and view all the answers

What is necessary for the definitive diagnosis of Alzheimer's disease?

Post-mortem autopsy and neuropathology examination Signup and view all the answers

What does FDG-PET primarily measure in the brain?

Cerebral metabolic rate for glucose Signup and view all the answers

Which brain regions exhibit glucose metabolism abnormalities in early Alzheimer's disease?

Temporo-parietal regions Signup and view all the answers

What type of PET scan is currently mainly used for research purposes?

Tau PET Signup and view all the answers

What is a typical cerebrospinal fluid profile for Alzheimer's disease?

Decreased amyloid-beta and increased tau and P-tau levels Signup and view all the answers

What is one advantage of cerebrospinal fluid diagnostics over amyloid PET scans?

It is quicker and lower in cost Signup and view all the answers

Why are amyloid PET scans not recommended for routine examinations?

Abnormal scans can be found in older individuals without dementia Signup and view all the answers

In what situation may amyloid PET scan be considered despite its non-routine status?

In younger adults (< 65 years) to differentiate types of dementia Signup and view all the answers

How does the diagnostic value of CSF biomarkers for Alzheimer’s change with age?

It decreases with age. Signup and view all the answers

What is the primary issue observed in the patient's speech?

Fluent speech but notable word-finding problems Signup and view all the answers

Which brain regions exhibit the most pronounced atrophy in the patient's MRI results?

Parietal lobe Signup and view all the answers

What aspect of cognitive function remains within the normal range for the patient?

Visuospatial functions Signup and view all the answers

What is a dominant symptom of the behavioural/dysexecutive variant of Alzheimer’s disease?

Apathy or disinhibition Signup and view all the answers

How is early-onset Alzheimer's disease different from typical Alzheimer's disease?

Symptoms may initially resemble other age-related issues Signup and view all the answers

Which of the following cognitive abilities is most likely impaired in the patient based on the neuropsychological test results?

Focused attention Signup and view all the answers

What kind of changes can be expected in a patient with the behavioural variant of frontotemporal dementia?

A wide range of behavioural changes like disinhibition Signup and view all the answers

What was the patient's MoCA score, indicating cognitive impairment?

19/30 Signup and view all the answers

Study Notes

Alzheimer's Disease

A neurodegenerative disease causing dementia, affecting about 70% of all dementia cases
Characterized by gradual, progressive memory loss, eventually affecting multiple cognitive domains
Leads to increasing interference with daily activities and development of neuropsychiatric symptoms like depression, apathy, and anxiety
In the final stage, complete cognitive loss occurs, requiring assisted living

Diagnostic Criteria

Dementia is a clinical syndrome defined by significant cognitive decline interfering with independence in daily activities
Alzheimer's disease, a specific cause of dementia, is diagnosed based on the presence of Alzheimer's disease pathology in the brain
NIA-AA criteria provide guidelines for diagnosing Alzheimer's disease dementia with high, medium, or low probability

Case: MCI

Mr. Campbell, 67 years old, presents with increasing forgetfulness, positive family history of Alzheimer's disease, and minimal interference with daily activities
His MoCA score is 26/30, with minor impairments in word recall and orientation in time
Neurofibrillary tangles are observed, a characteristic pathology of Alzheimer's disease
Based on his age, a possibility of a new syndrome, presenile dementia, was initially considered, but later recognized as Alzheimer's disease

Aetiology and Neuropathology

Characterized by the deposition of amyloid-beta plaques and tau tangles, leading to neuronal degeneration and brain atrophy
The amyloid cascade hypothesis postulates amyloid-beta accumulation as the primary driver of Alzheimer's disease
Supported by research on APP gene mutations, leading to amyloid-beta overproduction and Alzheimer's disease development
FDG-PET scans reveal abnormalities in glucose metabolism, particularly in temporo-parietal regions, as an early indicator of Alzheimer's disease progression
Amyloid-beta and tau deposition can be visualized through PET scans, allowing in vivo detection of Alzheimer's disease pathology
CSF analysis can also determine amyloid-beta, tau, and P-tau concentrations to detect Alzheimer's disease pathology

Atypical Variants:

Logopenic Primary Progressive Aphasia (lvPPA):
- Starts with predominant language impairment, specifically difficulty finding words and completing sentences
- MoCA score of 19/30, with impairments in naming, repeating sentences, and phonology
- MRI shows symmetrical parietal atrophy, more pronounced left-sided frontal and temporal lobe atrophy

The behavioural/dysexecutive variant

Presents with behavioural changes and impairments in executive function and social cognition as predominant symptoms
Behavioural changes range from disinhibition to apathy
Cortical atrophy is initially most pronounced in the frontal lobe regions
Clinical presentation resembles the behavioural variant of frontotemporal dementia, but underlying Alzheimer's pathophysiology is evidenced by PET and CSF biomarkers

Early-onset Alzheimer’s disease

Alzheimer's disease, with memory impairment as the primary symptom, beginning before the age of 65
Can be a diagnostic challenge due to potential atypical presentation and initial symptom overlap with other age-related causes

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Description

This quiz explores Alzheimer's disease, its characteristics, and diagnostic criteria. It covers neurodegenerative aspects, cognitive impairment, and specific case studies such as mild cognitive impairment (MCI). Test your knowledge on this prevalent form of dementia.