Complexity Analysis of the Default Mode Network Using Resting-State fMRI in Down Syndrome: Relationships Highlighted by a Neuropsychological Assessment.

María Dolores Figueroa-Jimenez,Joan Guàrdia-Olmos,Maribel Peró-Cebollero,Daniel Zarabozo-Hurtado,Cristina Cañete-Massé,María Carbó-Carreté,José Guadalupe Salazar-Estrada

doi:10.3390/brainsci11030311

María Dolores Figueroa-Jimenez, Joan Guàrdia-Olmos + Show 5 more

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https://doi.org/10.3390/brainsci11030311

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Abstract

Background: Studies on complexity indicators in the field of functional connectivity derived from resting-state fMRI (rs-fMRI) in Down syndrome (DS) samples and their possible relationship with cognitive functioning variables are rare. We analyze how some complexity indicators estimated in the subareas that constitute the default mode network (DMN) might be predictors of the neuropsychological outcomes evaluating Intelligence Quotient (IQ) and cognitive performance in persons with DS. Methods: Twenty-two DS people were assessed with the Kaufman Brief Test of Intelligence (KBIT) and Frontal Assessment Battery (FAB) tests, and fMRI signals were recorded in a resting state over a six-minute period. In addition, 22 controls, matched by age and sex, were evaluated with the same rs-fMRI procedure. Results: There was a significant difference in complexity indicators between groups: the control group showed less complexity than the DS group. Moreover, the DS group showed more variance in the complexity indicator distributions than the control group. In the DS group, significant and negative relationships were found between some of the complexity indicators in some of the DMN networks and the cognitive performance scores. Conclusions: The DS group is characterized by more complex DMN networks and exhibits an inverse relationship between complexity and cognitive performance based on the negative parameter estimates.

Highlights

IntroductionThe neuropsychological Down syndrome (DS) profile is characterized by alterations in motor abilities, language (morphosyntax), verbal short-term memory and explicit long-term memory; in contrast, visuospatial short-term memory and implicit long-term memory are relatively preserved [2,3]
Estimates of the standard error of the mean were obtained by bootstrapping with small sample size, we believe that it is important to observe the behavior of the indicators
Despite the small sample size, we described to establish the individual and group differences concerning the connectivity believe that it is important to observe the behavior of the indicators described to establish the networks studied

Summary

Introduction

The neuropsychological DS profile is characterized by alterations in motor abilities, language (morphosyntax), verbal short-term memory and explicit long-term memory; in contrast, visuospatial short-term memory and implicit long-term memory are relatively preserved [2,3]. These patterns in DS were described in a recent systematic review [4]. The authors concluded that these dysfunctions were related to chronic health conditions, basically sleep disorders In addition to these sleep disorders present in DS, another important issue addressed in the DS population related to neuropsychological aspects is Alzheimer’s disease [5,6,7].

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