Have you mastered all these questions about the routine examination of Alzheimer's disease?

Alzheimer's disease (AD), the most common form of dementia, is a chronic, progressive neurodegenerative disease characterized by cognitive and behavioral impairment
.

Although the only way to diagnose AD is by autopsy or brain biopsy, in routine practice the diagnosis is usually based on the patient's medical history and mental status examination, as well as clinical, neuropsychological, and neuroimaging assessments
.

Patients are usually diagnosed in a mild stage of the disease
.

Today, let's learn about the routine examination of Alzheimer's disease
.

Compiled and organized by Yimaitong, please do not reprint without authorization
.

 Question 1 What are the primary goals of the diagnostic criteria developed by the National Institute on Aging and the Alzheimer's Association? A.
Identify ADB early in the course of the disease.
Eliminate other causes of cognitive decline C.
For the convenience of research D.
Identify biomarkers before symptoms appear Scroll to see the answer↓↓↓↓↓↓↓↓↓【Answer and Analysis】Answer: C.

_
Figure 1
.

Coronal MRI in a patient with advanced AD showed severe generalized brain atrophy with marked loss of temporal lobe tissue
.

Figure 1 The primary goal of the diagnostic criteria developed by the National Institute on Aging and the Alzheimer's Association is to facilitate research
.

For healthcare providers who cannot perform CSF testing or advanced imaging, the American Institute of Neurological Disorders and the Alzheimer's Association and American Academy of Neurology propose core clinical criteria for the diagnosis of mild cognitive impairment
.

These criteria are primarily clinical, with biomarkers playing a secondary role
.

Question 2 For patients with typical AD manifestations, what method is recommended for routine examination? A.
Lumbar puncture B.
Brain SPECT scan or PET scan C.
Measurement of hippocampal volume D.
CT scan or MRI Slide to see the answer↓↓↓↓↓↓↓↓↓【Answer and Analysis】Answer:
D.

In the initial evaluation of patients with dementia, the American Academy of Neurology recommends structural neuroimaging with CT or MRI
.

This is primarily to identify any lesions that may contribute to cognitive impairment and to rule out potentially treatable causes of progressive cognitive decline, such as chronic subdural hematoma or normal pressure hydrocephalus
.

Although brain MRI or CT scans can show diffuse cortical and/or brain atrophy in AD patients, these findings are not considered diagnostic
.

 Lumbar puncture is only used to exclude differential diagnoses such as normal pressure hydrocephalus or central nervous system infections (eg, neurosyphilis, cryptococcosis, etc.
)
.

 Brain SPECT scans or PET scans are not recommended for routine examination in patients with typical AD
.

However, in patients with atypical AD presentation or suspected frontotemporal dementia, brain SPECT scan or PET scan may be an appropriate approach
.

 In clinical studies, hippocampal atrophy on coronal MRI has been considered a valid biomarker of AD neuropathology
.

However, this method is not used for the routine diagnosis of AD
.

Question 3 Which patient subgroup is suitable for amyloid imaging? A.
Patients with persistent mild cognitive impairment B.
Suspected autosomal mutation carriers C.
Dementia patients with typical age of onset D.
Patients with early-onset dementia symptoms Scroll to see the answer↓↓↓↓↓↓↓↓↓ 【Answer and Analysis】Answer:
A.

Guidelines for the use of amyloid PET imaging to differentiate AD from frontotemporal dementia have been developed by the Amyloid Imaging Working Group, composed of experts from the Alzheimer's Society and the Society for Nuclear Medicine and Molecular Imaging
.

These guidelines outline three situations in which determination of amyloid-positive or negative would improve diagnostic certainty and change clinical decision-making
.

 According to the guidelines, amyloid imaging is indicated for: • Patients with persistent or progressive unexplained mild cognitive impairment • Patients who meet the core clinical criteria for probable AD due to unclear clinical presentation • People with progressive dementia and age of onset There are also several situations in which imaging is not recommended in atypical patients
.

It should not be used in asymptomatic individuals or in patients with a definite diagnosis of AD at a typical age of onset, nor should it be used as a substitute for genotyping of suspected autosomal mutation carriers
.

Finally, scans cannot be used to determine the stage of dementia or to assess its severity
.

Question 4 Which statement is most accurate regarding genotyping of AD patients? A.
Genotyping can be used to predict AD risk in individual patients B.
Genotyping can be used to predict AD risk in patient populations C.
Apolipoprotein E ( APOE) Patients with genotypes ε22, ε32, ε42 and ε33 have the highest risk of AD D.
Patients with APOE genotypes ε43 and ε44 have the lowest risk of AD Analysis] Answer:
B.

Genotyping of APOE alleles can help determine AD risk in patient populations, but the consensus statement recommends against using APOE genotyping to predict AD risk
.

 Plasma APOE*E4 levels were associated with dementia risk independent of APOE genotype
.

The risk of AD increased with decreasing APOE levels, with patients with the lowest APOE levels having a three-fold higher risk than those with the highest levels
.

This association remained unchanged even after adjusting for APOE genotypes
.

The APOE genotypes associated with the highest risk of AD were ε43 and ε44, and the genotypes associated with the lowest risk of AD were ε22, ε32, ε42, and ε33
.

Question 5 Which statement about genetic testing of AD patients is the most accurate? A.
Not recommended as this may lead to negative psychological reactions B.
Recommended for patients with unexplained progressive cognitive problems C.
Recommended for early-onset AD patients with a family history of autosomal dominant dementia D.
Recommended for patients with unknown family history (eg, due to adoption) Scroll to see the answer↓↓↓↓↓↓↓↓↓【Answer and Analysis】Answer:
C.

In the past, health care providers have been very cautious about conducting genetic testing
.

Many worry that finding an increased risk outcome may prompt an unduly negative psychological response in otherwise asymptomatic individuals
.

In a study of APOE genotyping outcomes in 162 asymptomatic adults with a family history of AD, follow-up testing found no significant differences between overt and undisclosed measures of mean time to anxiety, depression, or test-related distress
.

 According to guidelines from the American College of Medical Genetics and the National Association of Genetic Counselors, genetic testing for APP and PSEN associated with early-onset autosomal dominant AD should be offered in the following clinical settings: • Patients with symptomatic early-onset AD , with a family history of dementia or unknown family history (eg adoption) Patients with a family history of autosomal dominant dementia, including one or more cases of early-onset AD Mutations with early-onset AD (PS-1, PS-2, APP) consistent patient relatives Yimaitong compiled from: Jasvinder P.
Chawla.
Fast FiveQuiz: Alzheimer's Disease Workup - Medscape - Feb 22, 2022.