1. Screening for Stroke and Cognitive Impairment Chapter 3: Cognitive Screening in Stroke

2. Screening
By building screening for symptoms of VCI into regular workflows or practice, health care providers are participating in Taking Action to address cognition1.
Clinicians must bear in mind that although screening can provide highly useful information, it must not be confused with formal evaluation.
Rather, screening is for case finding to identify those who warrant further cognitive evaluation.

3. Validation of Screening in TIA/Stroke Outpatients
In a study by Pendlebury et al. (2012), the MoCA was validated as a screen for cognitive impairment in stroke prevention clinic patients in the UK returning >1 year after TIA/stroke. A MoCA score of <25 (77% sensitivity, 83% specificity) was found to be comparable to a MMSE<29 (77% sensitivity, 83% specificity)11.

4. Validation in Stroke Patients
The MoCA was also validated in the post stroke population in France with higher sensitivity, but lower specificity (MoCA<20; 94% sensitivity, 42% specificity; MMSE<24; 66% sensitivity; 97% specificity)8.

5. Who to Screen?
Canadian Best Practice Recommendation for Stroke Care 7.2.1: cognitive-impairment-and-dementia/
“All patients with vascular risk factors and those with clinically evident stroke or transient ischemic attack should be considered at increased risk for vascular cognitive impairment (VCI), particularly in patients with cognitive, perceptual or functional changes that are clinically evident or reported during history taking.”1

6. Who to Screen?
Canadian Best Practice Recommendation for Stroke Care 7.2.1:
cognitive-impairment-and-dementia/
Vascular risk factors include:
Hypertension
Diabetes
Transient ischemic attack or clinical stroke,
Atrial fibrillation
Other cardiac disease, and/or
Sleep apnea1.
In addition, all patients with:
Neuroimaging findings of covert stroke or white matter disease
Hypertension-associated damage to other target organs, should also be considered for VCI screening1.

7. When to Screen
Canadian Best Practice Recommendation for Stroke Care 7.2.2:
cognitive-impairment-and-dementia/
“All patients considered at high risk for cognitive impairment should be assessed periodically throughout the stages of care as indicated by the severity of clinical presentation, history and/or imaging abnormalities to identify cognitive, perceptual deficits, depression, delirium and/or changes in function.”1

8. When to Screen
Canadian Best Practice Recommendation for Stroke Care 7.2.2:
cognitive-impairment-and-dementia/
Cognitive Screening should occur through all stages and settings following a stroke, including:
“During presentation to emergency when cognitive, perceptual or functional concerns are noted;
During acute care stay, particularly if cognitive, perceptual or functional concerns, or evidence of delirium is noted;
Throughout rehabilitation within inpatient, outpatient, and home-based settings, according to client progress;
Following hospital discharge from the emergency department or inpatient setting to an outpatient or community-based healthcare setting.”1

9. When to Screen
Canadian Best Practice Recommendation for Stroke Care 7.2.2:
cognitive-impairment-and-dementia/
“While assessment at different stages of care is important for guiding diagnosis and management, it is also important to be aware of the potential impact of multiple assessments on both the validity of the results as well as on the patient (e.g., test fatigue, practice effects).”1

10. Cognitive Screening Tools
Canadian Best Practice Recommendation for Stroke Care 7.2.1:
cognitive-impairment-and-dementia/
“Screening for VCI should be conducted using a validated screening tool, such as the Montreal Cognitive Assessment”1 (MoCA) (
A Summary of Select Screening Tools for Assessment of Vascular Cognitive Impairment in Stroke Patients can be found at1:

11. What is the MoCA?
The Montreal Cognitive Assessment, MoCA, was created in 1996 by
Dr. Ziad Nasreddine5.
It was validated in the setting of mild cognitive impairment, and has subsequently been adopted in other clinical settings5.
The MoCA is a rapid screening instrument for mild cognitive impairment5.
Poor sensitivity of the Mini-mental State Examination (MMSE) in differentiating clients with mild cognitive impairment from elderly clients led to the development of the MoCA. Therefore, it was meant to be used in clients with a normal range score on MMSE6.

12. What is the MoCA? www.mocatest.org: 30 point test;
May be administered in approximately 10 minutes;
The MoCA assesses several different cognitive domains:
Visuospatial / Executive
Naming
Memory
Attention
Language
Abstraction
Delayed Recall
Orientation5.

13. What is the MoCA?
It can be used in a variety of settings and with culturally diverse populations;
The test is available in 36 languages and dialects;
Sensitive to detecting mild cognitive impairment;
Applicable to the stroke population;
Any health care professional with knowledge of the MoCA and how to administer it, can use the MoCA;
The test and administration instructions are readily available at
There is no cost5.

14. MMSE Background
MMSE was developed to identify dementia, delirium and cognitive changes over time6.
A score of <26 is an indication of potential cognitive deficit6.
It lacks sensitivity in detecting mild cognitive impairment and early stages of dementia6.
Additional limitations of the MMSE in the stroke population:
Ineffective in differentiating between focal & diffuse lesions7.
Performance is dependent on age, education factors, ethnicity, and sociocultural background6.
Insensitivity to right-sided lesions6.

15. Comparison of MMSE and MoCA Scores
MMSE vs. MoCA
2011 study by MacKenzie et al. examined 20 patients diagnosed with TIA in a stroke prevention clinic7.
All were screened for cognitive impairment7.
MMSE was administered upon admission to the study and the MoCA was administered 2 weeks later - scores were then compared7.
Findings demonstrated that patients were more likely to score as impaired on the MoCA in comparison to the MMSE: 7
Comparison of MMSE and MoCA Scores
Instrument
Participants
scoring in
Normal Range
(> 26)
Mean Score
Standard Deviation
MMSE
90%
27.9
2.15
MoCA
45%
23.65
4.082
P=<0.05

16. MoCA vs MMSE Possible Reasons for Increased Sensitivity:
MoCA has been shown to be more sensitive screening tool than MMSE in detecting the presence of cognitive impairment in the acute stroke population8.
Possible Reasons for Increased Sensitivity:
Memory testing involves more words, fewer learning trials and longer delayed recall.
More numerous and demanding tasks to assess for visuospatial processing, executive functions, and language abilities.
However, by adjusting the cut off scores it is sensitive to mild post-stroke cognitive impairment (MMSE & MOCA are similar)8.