Imagine your brain is like a dense network of tiny roads, each one responsible for a different aspect of your memory and thinking abilities. In a recent scientific meta-analysis, researchers studied the relationship between a condition called cerebral small vessel disease (CSVD) and changes in the brain’s white matter using a powerful imaging technique called diffusion tensor imaging (DTI). By analyzing data from 77 studies involving over 6,500 participants, they found that alterations in the brain’s white matter were associated with specific types of cognitive impairment. The study showed that lower levels of fractional anisotropy (FA), which measures the structural integrity of white matter fibers, were linked to more severe cognitive impairment across multiple domains including general cognition, executive function, attention, construction, and motor performance. On the other hand, higher levels of mean diffusivity/apparent diffusion coefficient (MD/ADC), reflecting the movement of water molecules within white matter, were also associated with cognitive decline. Interestingly, certain regions of the brain such as the cingulate gyrus and frontal lobe showed particularly strong correlations with cognitive function. These findings provide valuable insights into how changes in the brain’s wiring can affect memory and thinking skills. To learn more about this fascinating research, explore the full article!

ObjectiveTo investigate the association between diffusion tensor imaging (DTI) findings and domain-specific cognitive impairment in cerebral small vessel disease (CSVD).MethodsDatabases such as PubMed, Excerpta Medical Database (EMBASE), Web of Science, Cochrane Library, Chinese National Knowledge Infrastructure Databases (CNKI), Wanfang, Chinese Biomedical Literature Database (SinoMed), and Chongqing Chinese Science and Technology Periodical Database (VIP) were comprehensively retrieved for studies that reported correlation coefficients between cognition and DTI values. Random effects models and meta-regression were applied to account for heterogeneity among study results. Subgroup and publication bias analyses were performed using Stata software.ResultsSeventy-seven studies involving 6,558 participants were included in our meta-analysis. The diagnosis classification included CSVD, white matter hyperintensities (WMH), subcortical ischemic vascular disease, cerebral microbleeding, cerebral amyloid angiopathy (CAA), cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), and Fabry disease. The pooled estimates showed that the fractional anisotropy (FA)-overall exhibited a moderate correlation with general cognition, executive function, attention, construction, and motor performance (r = 0.451, 0.339, 0.410, and 0.319), and the mean diffusitivity/apparent diffusion coefficient (MD/ADC)-overall was moderately associated with general cognition, executive function, and memory (r = −0.388, −0.332, and −0.303, respectively; ps < 0.05). Moreover, FA in cingulate gyrus (CG), cerebral peduncle (CP), corona radiata (CR), external capsule (EC), frontal lobe (FL), fornix (FOR), internal capsule (IC), and thalamic radiation (TR) was strongly correlated with general cognition (r = 0.591, 0.584, 0.543, 0.662, 0.614, 0.543, 0.597, and 0.571), and a strong correlation was found between MD/ADC and CG (r = −0.526), normal-appearing white matter (NAWM; r = −0.546), and whole brain white matter (WBWM; r = −0.505). FA in fronto-occipital fasciculus (FOF) (r = 0.523) and FL (r = 0.509) was strongly associated with executive function. Only MD/ADC of the corpus callosum (CC) was strongly associated with memory (r = −0.730). Besides, FA in CG (r = 0.532), CC (r = 0.538), and FL (r = 0.732) was strongly related to the attention domain. Finally, we found that the sample size, etiology, magnetic resonance imaging (MRI) magnet strength, study type, and study quality contributed to interstudy heterogeneity.ConclusionLower FA or higher MD/ADC values were related to more severe cognitive impairment. General cognition and executive function domains attracted the greatest interest. The FL was commonly examined and strongly associated with general cognition, executive function, and attention. The CC was strongly associated with memory and attention. The CG was strongly related to general cognition and attention. The CR, IC, and TR were also strongly related to general cognition. Indeed, these results should be validated in high-quality prospective studies with larger sample sizes.Systematic review registrationhttp://www.crd.york.ac.uk/PROSPERO, identifier: CRD42021226133.

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