Anatomic Correlation of the Mini-Mental State Examination: A Voxel-Based Morphometric Study in Older Adults.

Mickael Dinomais,Robert Bartha,Sebastien Celle,Frederic Roche,Samir Henni,Cedric Annweiler,Olivier Beauchet,Guillaume T Duval,Adam J Schwarz

doi:10.1371/journal.pone.0162889

Abstract

The clinical utility of the Mini-Mental State Examination (MMSE) and its shorter version (SMMSE) is still debated. There is a need to better understand the neuroanatomical correlates of these cognitive tests. The objective of this cross-sectional study was to determine whether lower MMSE and SMMSE scores correlated with focal brain volume reduction in older adults. Participants from the GAIT study (n = 207; mean, 70.9±5.9 years; 57% female; mean MMSE 26.2±3.9; mean SMMSE 5.1±1.1) were evaluated using the MMSE and SMMSE and received a 1.5-Tesla MRI scan of the brain. Cortical gray and white matter subvolumes were automatically segmented using Statistical Parametric Mapping. Age, gender, education level, and total intracranial volume were included as potential confounders. We found correlations between the MMSE score and specific cortical regions of the limbic system including the hippocampus, amygdala, cingulate gyrus, and parahippocampal gyrus, independently of the diagnostic category (i.e., mild cognitive impairment or Alzheimer disease or controls). Regarding correlations with the SMMSE score, only one cluster in the left hippocampus was identified, which overlapped with the cluster that was positively correlated with the MMSE score. There were no correlations with the volume of white matter. In conclusion, worse MMSE and SMMSE scores were associated with gray matter atrophy mainly in the limbic system. This finding highlights that atrophy of specific brain regions are related to performance on the MMSE and the SMMSE tests, and provides new insights into the cognitive function probed by these tests.

Highlights

The Mini-Mental State Examination (MMSE), published in 1975 by Folstein and colleagues, is a practical method of grading cognitive impairment [1,2] that has gradually become the most common cognitive test, used by almost 9 out of 10 specialists [3]
Regarding correlations with the SMMSE score, the voxel-based morphometry (VBM)-DARTEL analysis identified only one cluster located in the left hippocampus ([-–17], t = 5.25; [-–23], t = 5.04), which overlapped with the cluster that was positively correlated with the MMSE score (Fig 2, Fig 4, and Table 1)
Among community-dwelling older adults with memory complaint, the MMSE score correlated positively with gray matter (GM) volume in the limbic system and in the middle temporal gyrus

Summary

Introduction

The Mini-Mental State Examination (MMSE), published in 1975 by Folstein and colleagues, is a practical method of grading cognitive impairment [1,2] that has gradually become the most common cognitive test, used by almost 9 out of 10 specialists [3]. We had the opportunity to examine the correlations of MMSE and SMMSE scores with gray matter (GM) and white matter (WM) volumes in a large representative community survey of older adults with memory complaint in the GAIT (Gait and Alzheimer Interactions Tracking) study [14]. The objective of this crosssectional analysis was to determine whether lower MMSE and SMMSE scores correlated with focal brain volume reduction

Participants

Discussion