Dementia Diagnosis

Question 1

Estimated economic burden of dementia by 2038

Answer 1

> 872 billion

Question 2

4 proposed interventions to reduce the economic burden of dementia

Answer 2

1. Increased physical activity
2. Hypothetical program to delay dementia onset
3. Caregiver development and support program
4. System navigator

Question 3

What is construct validity?

Answer 3

The ability of a test to measure what it was designed to measure (and not other things)
ex. a test designed to measure depression should measure that and not anxiety

Question 4

What is criterion-related validity?

Answer 4

The ability of a test to correlate with the gold standard

Question 5

What is reliability?

Answer 5

The consistency of a measure
Being reliable is necessary but not sufficient for validity

Question 6

What is internal consistency?

Answer 6

Consistency across items

Question 7

What is inter rater reliability?

Answer 7

Consistency across researchers or raters

Question 8

Test-retest reliability

Answer 8

Consistency across time
Ex. using same test on different occasions to same group of test takers, not practical because of carry-over effect

Question 9

What is validity?

Answer 9

The extent to which scores from a measure represent the variable they are intended to

Question 10

Rising Tide current number of people living with dementia?

Answer 10

500 000

Question 11

Rising Tide projected number of people with dementia in 2030?

Answer 11

912 000

Question 12

Rising Tide incidence of new dementia dx per year?

Answer 12

25 000

Question 13

Rising Tide, those 65+ what % of dementia dx are among women?

Answer 13

65%

Question 14

Rising Tide, proportion of Canadians who experience caring for someone with dementia?

Answer 14

1 in 5

Question 15

Rising Tide, incidence and prevalence of dementia in 2038?

Answer 15

Incidence (# new cases/yr) = 250 000/year
Prevalence (total # cases) = 1.1 million (2.8%)

Question 16

Rising Tide, projected demand for LTC by 2038?

Answer 16

10 times current (2008) demand

Question 17

6 factors that affect psychometric properties in screening cognitive tools

Answer 17

Reliability
1. Inter rater
2. Test-retest
Validity
1. Construct
2. Concurrent (ability to distinguish between groups)
3. Predictive (ability to predict something)
4. Convergent (degree to which it’s similar to tests it should be similar to)
5. Discriminant (degree to which it’s not similar to tests it should be similar to)
6. Face
7. Content

Question 18

List 5 cons of the MMSE

Answer 18

1. Not sensitive for detecting MCI and mild dementia
2. Limited usefulness with low level English literacy
3. Limited usefulness in those either end of educational spectrum
4. Not much capacity to test frontal/executive and visuospatial
5. Now proprietary and not free

Question 19

What two impairments could cause this? What lobes are affected? (clock draw)

Answer 19

1. Impaired executive function/abstraction
2. Superior quadrantanopia

Lobes:frontal, temporal, occipital

Question 20

Give 3 reasons why cognitive screening for asymptomatic individuals above 65 is not recommended?

Answer 20

1. Low dementia prevalence and only moderately high Sp, number of FP>number TP
2. FP could lead to psychological harm, anxiety, unnecessary tests
3. Screening could lead to loss of autonomy (employment, drivers license, finances)

Question 21

Name each cut on imaging and what structures are seen best in each view.

Answer 21

1. Saggital - midline and lateral structures
2. Axial - all lobes
3. Coronal - temporal lobes (esp hippocampus) and perisylvian fissures

Question 22

What are the indications for neuroimaging based on CCCDTD-5 guidelines?

Answer 22

1. Onset cognitive changes last 2 years
2. Unexpected decline in cog/fxn in pt with known dementia
3. Recent/sig head trauma
4. Unexplained neurological sx at onset or during evolution (HA, seizure, gait, Babinski)
5. Anticoagulant use or bleeding disorder
6. Sig vascular risk factors
7. Hx cancer
8. Hx UI and gait disorder

Question 23

Type of imaging and biomarker recommendations for new dx of dementia

Answer 23

1. MRI recommended over CT, use 3D T1, FLAIR, T2 or DWI
2. If CT = non contrast, coronal views
3. FDG-PET or SPECT if standard work up done and unclear pathology
4. Imaging biomarkers (tau or neuroinflammation) not recommended
5. Don’t recommend CSF unless diagnostic uncertainty and <65 yo to R/O AD, diagnostic uncertainty and predominance of language, visuospatial, dysexecutive or behavioural to rule out AD

Question 24

What lab investigations recommended in work up of dementia?

Answer 24

1. CBC
2. Electrolytes
3. Calcium
4. Fasting glucose
5. TSH
6. B12 (supplement if low)
   Optional: folate if celiac, inadequate diet
   Insufficient evidence: homocysteine

Question 25

Cognitive tests to use for MCI

Answer 25

MOCA, cut off <26 Sn 90, Sp 87 TORCA Sn 80, Sp 79

Question 26

Risk factors and rate of progression from MCI to MNCD

Answer 26

RFs 1. Older age 2. Less education 3. Stroke 4. Diabetes 5. Amnestic subtype Testing 1. Positive amyloid PET 2. APOE4 3. Low CSF AB42, high CSF total tau and pTau 4. Dual task gait impairment 5. Lower MMSE Rate of progression About 10% per year May remain stable, return to normal or progress Follow up annually with serial assessments

Question 27

Sn and Sp of APOE4 screening?

Answer 27

1 allele 53% Sn, 67% Sp 2 alleles 21% Sn, 93% Sp Homozygotes 50% lifetime risk Heterozygotes 20-30% lifetime risk Average risk 11% M, 14% F

Question 28

Prevalence of amyloid in CSF in individuals with no cognitive impairment?

Answer 28

65 yo - 20% 75 yo - 30% 85 yo - 40%

Question 29

Why would you not advise CSF testing for patient with dementia?

Answer 29

1. Cost - not covered 2. Not required for currently available therapies 3. Risks of LP 4. Limited diagnostic value for classic presentation AD

Question 30

Why would you not advise CSF testing for family member of patient with dementia?

Answer 30

1. Unclear clinical trajectory for those biomarker positive without clinical syndrome 2. Absence of preventative therapies 3. Psychological implications 4. False reassurance if false negative

Question 31

What does ATN stand for?

Answer 31

3 categories of AD biomarkers 1. Amyloid beta plaques (CSF AB42, amyloid PET) 2. Tauopathy (CSF pTau, Tau PET) 3. Neurodegeneration (structural MRI, FDG-PET, CSF total tau)

Question 32

3 reasons why screening for AD biomarkers not appropriate

Answer 32

1. Lack of standardization of biomarkers b/w labs 2. AD pathology may occur in people who are never symptomatic in their lifetime 3. Access to biomarkers is limited 4. Lack of disease modifying therapy for AD 5. Health system burden

Question 33

Social, economical and ethical issues involved in informing patient of diagnosis of AD early in the course

Answer 33

Social 1. Stigma, discrimination 2. Caregiver burden Economical 1. May impact ability to work/get money 2. May impact driver's license and therefore costs of alternative arrangements Ethical 1. Capacity/decision making ability 2. Patient privacy and confidentiality

Question 34

Limitations of DSM-V criteria in diagnosing dementia

Answer 34

1. Heterogeneity - dementia is not a single disorder but a syndrome with multiple underlying causes, criteria doesn't address this 2. Ongoing updates - published in 2013 3. Not better explained by another mental disorder - may be concurrent with depression etc. 4. Says significant cognitive decline but doesn't specify what this means

Question 35

What is the main difference between using brief cognitive tests for screening versus case finding with regards to tests such as the MOCA or MMSE?

Answer 35

* Cognitive assessments are not recommended to be used as population screening for cognitive impairment (CCDDTD-5) * Screening involves testing individuals without prior identification of concerns for cognitive impairment (a.k.a. ‘Asymptomatic older adults’) * This would result in many false positives (low overall prevalence of dementia in ‘all-comers’ over the age of 65) * Neither the MMSE or MoCA have not been validated for this purpose, and lack the sensitivity (esp. the MMSE) to function as screening tests * Cognitive assessments are recommended to be used for case finding when there is a diagnostic suspicion of cognitive impairment * They have been validated for this purpose * Based on the test characteristics (PPV, NPV, Sn, Sp), the clinician is able to strengthen the diagnosis / their clinical suspicion of cognitive impairment Used in this way, the MMSE and MoCA (used in the correct education and language-matched population) have good specificity for a diagnosis of cognitive impairment

Question 36

List 5 advantages to telemedicine (telephone or video) for cognitive assessment. List 5 disadvantages to telemedicine (telephone or video) for cognitive assessment.

Answer 36

Advantages * Patient doesn’t have to be present (mobility limitation) * Patients in remote areas can be assessed * Easier to schedule * Testing can be done by RN or whomever while physician gets collateral * Evidence supporting virtual cognitive assessment (e.g. TICS) * “The TICS was adapted from and correlates highly with the MMSE (Pearson correlation 0.94, p < 0.0001).” * “Videoconference-based cognitive assessments were 100% sensitive and specific for diagnosing dementia compared with in-person cognitive assessments in a third study.” Disadvantages * Gaps still remain in diagnostic certainty * “No studies compared telephone with inperson cognitive assessment accuracy” * Several tests (e.g. MMSE, RUDAS) don’t have a virtual option (i.e. test is modified) * Telephone assessment less accurate at differentiating * Sensory challenges (e.g. patient must have intact hearing if telephone)