Information processing speed in multiple sclerosis: Relevance of default mode network dynamics.
Neuroimage Clin
; 19: 507-515, 2018.
Article
em En
| MEDLINE
| ID: mdl-29984159
ABSTRACT
Objective:
To explore the added value of dynamic functional connectivity (dFC) of the default mode network (DMN) during resting-state (RS), during an information processing speed (IPS) task, and the within-subject difference between these conditions, on top of conventional brain measures in explaining IPS in people with multiple sclerosis (pwMS).Methods:
In 29 pwMS and 18 healthy controls, IPS was assessed with the Letter Digit Substitution Test and Stroop Card I and combined into an IPS-composite score. White matter (WM), grey matter (GM) and lesion volume were measured using 3â¯T MRI. WM integrity was assessed with diffusion tensor imaging. During RS and task-state fMRI (i.e. symbol digit modalities task, IPS), stationary functional connectivity (sFC; average connectivity over the entire time series) and dFC (variation in connectivity using a sliding window approach) of the DMN was calculated, as well as the difference between both conditions (i.e. task-state minus RS; ΔsFC-DMN and ΔdFC-DMN). Regression analysis was performed to determine the most important predictors for IPS.Results:
Compared to controls, pwMS performed worse on IPS-composite (pâ¯=â¯0.022), had lower GM volume (pâ¯<â¯0.05) and WM integrity (pâ¯<â¯0.001), but no alterations in sFC and dFC at the group level. In pwMS, 52% of variance in IPS-composite could be predicted by cortical volume (ßâ¯=â¯0.49, pâ¯=â¯0.01) and ΔdFC-DMN (ßâ¯=â¯0.52, pâ¯<â¯0.01). After adding dFC of the DMN to the model, the explained variance in IPS increased with 26% (pâ¯<â¯0.01).Conclusion:
On top of conventional brain measures, dFC from RS to task-state explains additional variance in IPS. This highlights the potential importance of the DMN to adapt upon cognitive demands to maintain intact IPS in pwMS.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Substância Branca
/
Esclerose Múltipla
/
Vias Neurais
Tipo de estudo:
Prognostic_studies
Limite:
Adult
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Female
/
Humans
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Male
/
Middle aged
Idioma:
En
Revista:
Neuroimage Clin
Ano de publicação:
2018
Tipo de documento:
Article