Mini-Mental State Examination (MMSE)
The mental status examination that uses intersecting pentagons or a three-dimensional cube on paper to assess suspected dementia is the Mini-Mental State Examination (MMSE), which includes the pentagon-copying test (PCT), though the cube-copying test (CCT) is featured in the Montreal Cognitive Assessment (MoCA), not the MMSE. 1
Key Distinctions Between Tests
The MMSE specifically uses intersecting pentagons as part of its visuospatial assessment component 1, 2, 3. This pentagon-copying test (PCT) is traditionally scored on a binary scale (correct/incorrect) and assesses visuospatial ability and constructional praxis 2.
The three-dimensional cube is part of the Montreal Cognitive Assessment (MoCA), not the MMSE 4. The MoCA's wire cube test has been shown to be more sensitive for detecting cognitive impairment than the MMSE's pentagon test, particularly in Parkinson's disease patients, with sensitivity/specificity of 0.74/0.63 versus 0.26/0.84 for the pentagons 4.
Clinical Utility of Each Test
Pentagon-Copying Test (MMSE Component)
- Sensitivity for dementia: 29.4%
- Specificity: 100% 5
- The difference between Memory subscale (M) and Pentagon-copying (P) scores can help differentiate Alzheimer's disease from dementia with Lewy bodies—a P-M score of 1 has a 97% positive predictive value for AD 3
Cube-Copying Test (MoCA Component)
- Sensitivity for dementia: 62%
- Specificity: 83.3% 5
- More complex than pentagons, making it more sensitive to mild cognitive impairment 4
- When combined with clock-drawing test, sensitivity increases to 78.4% 5
Practical Considerations
The MMSE remains the most widely known brief cognitive test, taking less than 10 minutes to administer, though it currently has copyright restrictions 1. The MoCA (10-15 minutes) is increasingly preferred in clinical practice because it demonstrates superior accuracy for detecting mild cognitive impairment and assesses multiple cognitive domains including the visuospatial function tested by the cube 1.
Common pitfall: Clinicians often conflate these two tests. The intersecting pentagons are exclusively part of the MMSE, while the three-dimensional cube belongs to the MoCA. Both assess visuospatial and constructional abilities, but the cube test is more sensitive for early cognitive changes 4.