How do you assess executive function?

How to Test Executive Function

Begin with a general cognitive screening test (MoCA, ACE-III, or DCQ), and if abnormalities are detected or clinical suspicion remains high, add dedicated executive function tests such as the IFS or FES, supplemented by bedside tests like Luria motor sequences and Go/No-Go tasks. 1

Screening Approach

Start with general cognitive screening using one of these validated instruments 1:

• Montreal Cognitive Assessment (MoCA) - includes executive function subtests
• Addenbrooke's Cognitive Examination-III (ACE-III)
• Dépistage Cognitif de Québec (DCQ)

If screening is normal but clinical suspicion persists, proceed directly to dedicated executive function testing rather than relying solely on global screening scores. 1

Dedicated Executive Function Tests

Standardized Bedside Instruments

The Institute of Cognitive Neurology Frontal Screening (IFS) demonstrates superior discriminatory power compared to other brief screening tools and can differentiate executive dysfunction across various neurological and psychiatric conditions. 1

The Frontier Executive Screen (FES) shows 71% sensitivity and 73% specificity for detecting executive dysfunction, though it requires further validation in broader clinical contexts. 1

Simple Bedside Tests

Complement formal testing with these quick bedside maneuvers 1:

• Luria motor sequences - tests motor planning and sequencing
• Loop drawing tasks - assesses perseveration and planning
• Go/No-Go tasks - evaluates response inhibition

These bedside tests are less evidence-based than standardized instruments but provide valuable qualitative information about executive control. 1

Comprehensive Neuropsychological Testing

When diagnostic ambiguity exists or mild deficits are suspected, formal neuropsychological testing provides the most comprehensive assessment. This is particularly critical in patients with high premorbid intellect where subtle deficits may be masked on screening tests. 1

Core Executive Function Battery

Administer tests targeting these specific executive domains 1:

Working Memory:

• Digit Span Backwards - holds and manipulates information 1

Processing Speed and Activation:

• Trail Making Test Part A - measures processing speed 1
• Digit Symbol-Coding - provides direct measure of processing speed 1

Set Shifting and Cognitive Flexibility:

• Trail Making Test Part B - assesses ability to shift between tasks 1
• Stroop Test - evaluates response inhibition and cognitive flexibility 1, 2

Verbal Fluency (dual executive/language function):

• Letter (phonemic) fluency - tests executive control and activation (use CFL or PRW letter sets) 1
• Category fluency (Animal Naming) - reflects semantic access and executive organization 1

Complex Executive Tasks:

• Hayling Sentence Completion Test - particularly useful for differential diagnosis 1

Interpretation Considerations

Timed executive function tests are especially sensitive to executive dysfunction because they capture slowed information processing, a hallmark of many conditions affecting executive systems. 1

The Stroop test specifically evaluates psychomotor speed, cognitive flexibility, and response inhibition, making it valuable for detecting executive dysfunction in vascular cognitive impairment and frontotemporal dementia. 2

Analyze both quantitative scores and qualitative performance - patients may score within normal ranges while demonstrating aberrant strategies, impulsivity, rigidity, perseveration, or stereotyped behaviors during testing. 1 These qualitative observations often provide critical diagnostic information that raw scores miss.

Consider additional scoring options beyond standard administration 1:

• First 15 seconds of fluency tasks reflects automatic processing and activation
• Subsequent 45 seconds reveals working memory and executive control through clustering strategies
• Analysis of learning strategies on memory tests (like HVLT-R) provides measures of executive organization

Clinical Pitfalls and Caveats

Never base diagnostic conclusions on a single test or global screening score alone - executive dysfunction requires assessment across multiple domains and tasks. 1

Account for confounding factors including educational level, language proficiency, visual impairments, cultural background, medication effects, fatigue, and test anxiety when interpreting results. 2

Serial/longitudinal assessments are superior to single evaluations for detecting progressive executive dysfunction, particularly when distinguishing neurodegenerative conditions from psychiatric disorders. 1

Executive dysfunction is not always the most prominent or earliest deficit in conditions traditionally associated with frontal impairment - some patients with confirmed frontotemporal pathology show normal executive test results early in disease. 1

Use alternate test forms when available to avoid practice effects with repeated testing. 2

Context-Specific Testing Strategies

For vascular cognitive impairment: Emphasize timed executive function tests, as processing speed is characteristically slowed and executive dysfunction predominates over memory deficits. 1, 3

For suspected frontotemporal dementia: Combine executive testing with language assessment (particularly action naming) and social cognition evaluation, as executive deficits alone are not specific. 1

For primary care or rapid screening: Use the 5-minute MoCA subtests including 5-word memory, 6-item orientation, and 1-letter phonemic fluency, supplemented by Animal Naming and Trail Making Test when time permits. 1