The association between white matter hyperintensities, cognition and regional neural activity in healthy subjects

• Published in: The European journal of neuroscience Vol. 54; no. 4; pp. 5427 - 5443
• Main Authors: Porcu, Michele, Cocco, Luigi, Cocozza, Sirio, Pontillo, Giuseppe, Operamolla, Annunziata, Defazio, Giovanni, Suri, Jasjit S., Brunetti, Arturo, Saba, Luca
• Format: Journal Article
• Language: English
• Published: Chichester Wiley Subscription Services, Inc 01.08.2021
• Subjects: Aging; Brain mapping; Cerebellum; Cognition; Cognition & reasoning; Cognitive ability; Cortex (parietal); Functional magnetic resonance imaging; functional MRI; Neuroimaging; Prefrontal cortex; Statistical analysis; Structure-function relationships; Substantia alba; white matter hyperintensities
• ISSN: 0953-816X; 1460-9568; 1460-9568
• DOI: 10.1111/ejn.15403

White matter hyperintensities (WMH) are common findings that can be found in physiological ageing. Several studies suggest that the disruption of white matter tracts included in WMH could induce abnormal functioning of the respective linked cortical structures, with consequent repercussion on the cerebral functions, included the cognitive sphere. In this cross‐sectional research, we analysed the effects of the total WMH burden (tWMHb) on resting‐state functional magnetic resonance imaging (rs‐fMRI) and cognition. Functional and structural MR data, as well as the scores of the trail making test subtests A (TMT‐A) and B (TMT‐B) of 75 healthy patients, were extracted from the public available Leipzig Study for Mind–Body–Emotion Interactions dataset. tWMHb was extracted from structural data. Spearman's correlation analyses were made for investigating correlations between WMHb and the scores of the cognitive tests. The fractional amplitude of low‐frequency fluctuations (fALFF) method was applied for analysing the rs‐fMRI data, adopting a multiple regression model for studying the effects of tWMHb on brain activity. Three different subanalyses were conducted using different statistical methods. We observed statistically significant correlations between WMHb and the scores of the cognitive tests. The fALFF analysis revealed that tWMHb is associated with the reduction of regional neural activity of several brain areas (in particular the prefrontal cortex, precuneus and cerebellar crus I/II). We conclude that our findings clarify better the relationships between WMH and cognitive impairment, evidencing that tWMHb is associated with impairments of the neurocognitive function in healthy subjects by inducing a diffuse reduction of the neural activity. The presence of white matter hyperintensities (WMH) is associated with cognitive impairment. In this cross‐sectional study, we investigated the effect of the total burden of WMH (tWMHb) by calculating the tWMHb for every subject of the study population, and then we analysed the effects of WMH on the regional neural activity with the fractional amplitude of low‐frequency fluctuations (fALFF) technique. The results of our analysis evidenced that WMH is associated with the reduction of the activity of several areas of the brain.