A Canadian contribution to the commonly used cognitive screening instruments is the Montreal Cognitive Assessment (MoCA), published by Nasreddine et al in 2005.  Unlike the Mini-Mental State Exam (MMSE) or the clock-drawing test (CDT), the MoCA is designed to detect more subtle impairments of cognition, known clinically as Mild Cognitive Impairment (MCI).  Like the MMSE, it is scored out of 30, which can cause a misunderstanding about the severity of cognitive dysfunction for older adults.  It is not uncommon for a normally functioning older adult to score in the low 20s on the MoCA while the same individual can score high on the MMSE.  In an individual with limited education and normal intelligence, a low score on the MoCA may represent a false positive result.  However, the MoCA can pick up mild cognitive change in a highly intelligent and well-educated individual. Unlike the MMSE, it includes tests of higher level brain function such as: abstract ability (similarities); verbal fluency (word generation with the phonemic prime of the letter ‘F’); and it also includes the clock-drawing test and a more difficult delayed memory test.

To be of value, the MoCA needs to be interpreted in the context of a good history, appropriate investigations and importantly, what reliable informants say about an individual’s functioning.  It is especially valuable as a baseline to monitor cognitive change over time when the initial screen or assessment is equivocal with respect to a diagnosis of dementia. To repeat what has been highlighted in my previous blogs, a single score on the MoCA, is not diagnostic of dementia, and says very little about capacity per se.

So, now we have reviewed the principles behind cognitive screening and three of the most commonly used standardized screening tests, (MMSE, CDT, and now, the MoCA). While these screening instruments are of considerable clinical value, they must be viewed and interpreted with caution in the context of a capacity assessment.

Next time:  What William Shakespeare has to say about the vicissitudes of old age, estate planning and family dynamics. Yes, it is the story of King Lear.