Cognitive Screens for People with Parkinson’s: All Are Not Created Equal

apples_to_oranges

By Heather Jeng

Do you know what cognitive screening tool is used in your local healthcare community to screen for cognitive deficits in individuals with Parkinson’s disease (IWPD)? Chances are, it’s the MMSE. This tool was suggested for physician office visit screenings for this population by the Task Force on Dementia in Parkinson’s Disease (part of Movement Disorders Society) back in 2007. The general guideline for physicians was not to pursue further cognitive assessment if the patient scored at least 26 on the MMSE.

A group of researchers, however, found that this guideline results in missing many IWPD who would benefit from in-depth cognitive testing – including some who already have progressed into dementia.

The study in brief:

Target demographic

  • IWPD who score 26 or higher on MMSE

What did the study look at?

  • sample: 788 IWPD who scored 26 or higher on MMSE; multiple sites
  • underwent further neuropsychological testing (global cognition, executive function, language, memory, and visuospatial skills)

What did the study find?

  • 67% of subjects scored 1.5 SD below the normative mean on at least one test
  • more than 20% of subjects scored at least 1.5 SD below the normative mean on 8 out of the 15 tests
  • overall sensitivity (ability of the test to accurately identify those with cognitive impairment) of the MMSE in detecting dementia in IWPD was 45% 

For those of us who use the MoCA, the MMSE, or both, it’s very useful to note that “more than half (51.9%) of those with MMSE scores of 26 or greater scored 25 or below on the MoCA” (1261).   That’s right: over half the subjects who scored within the “normal” range on the MMSE were found to have some degree of cognitive impairment on the MoCA.

Take-Away

The researchers rightly point out that “early detection of CI [cognitive impairment] will permit appropriate planning for financial and medical contingencies while cognitive abilities are relatively preserved, reduce caregiver stress, and potentially delay placement in nursing homes” (1259). For those patients who want to proceed with this testing, we should help facilitate those referrals. The knowledge—and time—may mean the world to the person and their family.

This article (which is short and sweet, by the way!) is an excellent inter-professional education tool. Great for sharing with your rehab team and local practices.

Reference

Burdick, D.J., Cholerton, B., Watson, G.S., Siderowf, A., Trojanowski, J.Q., Weintraub, D., … Leverenz, J.B. (2014). People with parkinson’s disease and normal MMSE score have a broad range of cognitive performance. Movement Disorders, 29, 1258-1264. doi: 10.1002/mds.25924

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