- Last edited on November 27, 2021
Introduction to Cognitive Testing
Primer
Cognitive Testing is an exam to localize possible areas of the brain that may be causing a cognitive impairment. Cognitive testing also helps inform diagnosis and gives clinicians a sense of a patient's overall level of function.
Cognitive Testing Tips
When doing cognitive testing, always ask first:- Is the person able to pay attention? Attention and concentration is the foundation on which all cognitive tests are based. A patient without adequate attention (e.g. - delirious) cannot be tested accurately for cognitive impairment.
- Also think:
- Is this the patient giving significant effort during the testing?
- Is there an underlying primary psychiatric condition (e.g - severe depression)?
- Could there be a medication-induced cognitive deficit?
- Is the patient very anxious about doing the testing?
Choosing a Cognitive Test
Comparing Cognitive Tests
| Cognitive Test | Pros | Cons |
|---|---|---|
| MMSE | • Shorter, easier to do • Widespread use (30+ years) • Standardized norms for age and education | • Does not examine executive function • Low sensitivity for mild cognitive impairment and individuals with high intelligence or education • Individuals with language/culture differences may score lower • False positive in those in very advanced age, low education, and/or different culture |
| MoCA | • Examines more cognitive domains, especially executive function • Greater sensitivity for detecting mild cognitive impairment • More suitable to those in high education and intelligence • Many different versions and languages | • Longer, more complicated assessment • Now proprietary (unfortunately!) |
| Mini-Cog | • Shorter, easier to do | • Very limited interpretation of test results, only a brief screening tool |
| Clock-drawing Test | • Very quick to do • Tests multiple domains of executive function, visuospatial, attention, and language comprehension | • Only a single task |
Neuroanatomical Locations
Neuroanatomy of Cognitive Domains
| Location | Function | Cognitive Tests |
|---|---|---|
| Frontal lobe | Executive function and attention | • Digit span • WORLD backwards • Serial 7s • Letter fluency • Modified Trails B • Clock-drawing Test (CDT) |
| Temporal lobe | Memory | • Orientation • Immediate Recall • Delayed Recall • Category fluency |
| Mesial temporal lobe (R>L) | Facial Recognition | • Identification of celebrities and politicians |
| Left hemisphere | Language | • Reading and Comprehension • Writing • Naming • Repetition • Semantic fluency |
| Occipital and biparietal lobes | Visuospatial | • Cube copying (MoCA) • Pentagon copy (MMSE) |
| Left parietal | Arithmetic | • Addition or subtraction (serial 7s) |
| Left parietal | Praxis | • Comb hair or brush teeth |
Tests of Executive Function in the Real World
Many jurisdictions and organizations across world use the modified Trials B test, and/or the clock-drawing test as a measure of executive function. For example, in assessing older adults' ability to drive and keep their driver's license.Visual
Visual spatial/constructional information is processed differently between the left and right hemisphere. Left hemisphere damage disrupts the detailed reproduction of a visual pattern, while right hemisphere damage interferes with the configurational perception (i.e. - the “gestalt”) of a visual pattern. For example, studies have shown that stroke patients with left hemisphere lesions tend to reproduce the visual patterns (e.g. - the Rey–Osterrieth complex figure, ROCF) by breaking the design into simplistic elements, but the overall gestalt of the pattern is preserved. On the other hand, patients with right hemisphere lesions have difficulty forming an overall “gestalt” of the figure, often missing crucial configurational units of the ROCF.[1]
Neuropsychological Testing
- While short bedside cognitive testing may identify some deficits, for certain individuals, after finding impairments on cognitive testing, they may benefit from a comprehensive neuropsychological assessment.
- Such assessments are much longer and range from 2 to 6 hours in length, compared to the 30 to 60 minutes that a psychiatrist or neurologist may examine a patient.