The Evolution of White Matter Hyperintensities

US Neurology ◽  
2010 ◽  
Vol 05 (02) ◽  
pp. 10 ◽  
Author(s):  
Vanessa G Young ◽  
Jillian J Kril ◽  
◽  

White matter hyperintensities (WMHs) are a common finding on magnetic resonance imaging (MRI) scans of elderly subjects. Despite their frequency, the clinical correlates and etiology of WMH remain controversial, with many conflicting results published. This is due, in part, to the varied populations studied. Nevertheless, the prevailing opinion is that these lesions are of vascular origin due to the strong associations with vascular risk factors and stroke. Neuropathological studies have also yielded varied results. Interestingly, while a number of associations with variables such as demyelination and gliosis have been reported, no single pathological variable has been found to account for the MRI changes. The most consistent associations are with reduced vascular integrity and increased blood–brain barrier permeability. Further studies investigating the blood–brain barrier may assist in elucidating the origin of these common abnormalities.

2019 ◽  
Vol 9 (1) ◽  
pp. 16 ◽  
Author(s):  
Imama Naqvi ◽  
Emi Hitomi ◽  
Richard Leigh

Objective: To report a patient in whom an acute ischemic stroke precipitated chronic blood-brain barrier (BBB) disruption and expansion of vascular white matter hyperintensities (WMH) into regions of normal appearing white matter (NAWM) during the following year. Background: WMH are a common finding in patients with vascular risk factors such as a history of stroke. The pathophysiology of WMH is not fully understood; however, there is growing evidence to suggest that the development of WMH may be preceded by the BBB disruption in the NAWM. Methods: We studied a patient enrolled in the National Institutes of Health Natural History of Stroke Study who was scanned with magnetic resonance imaging (MRI) after presenting to the emergency room with an acute stroke. After a treatment with IV tPA, she underwent further MRI scanning at 2 h, 24 h, 5 days, 30 days, 90 days, 6 months, and 1-year post stroke. BBB permeability images were generated from the perfusion weighted imaging (PWI) source images. MRIs from each time point were co-registered to track changes in BBB disruption and WMH over time. Results: An 84-year-old woman presented after acute onset right hemiparesis, right-sided numbness and aphasia with an initial NIHSS of 13. MRI showed diffusion restriction in the left frontal lobe and decreased blood flow on perfusion imaging. Fluid attenuated inversion recovery (FLAIR) imaging showed bilateral confluent WMH involving the deep white matter and periventricular regions. She was treated with IV tPA without complication and her NIHSS improved initially to 3 and ultimately to 0. Permeability maps identified multiple regions of chronic BBB disruption remote from the acute stroke, predominantly spanning the junction of WMH and NAWM. The severity of BBB disruption was greatest at 24 h after the stroke but persisted on subsequent MRI scans. Progression of WMH into NAWM over the year of observation was detected bilaterally but was most dramatic in the regions adjacent to the initial stroke. Conclusions: WMH-associated BBB disruption may be exacerbated by an acute stroke, even in the contralateral hemisphere, and can persist for months after the initial event. Transformation of NAWM to WMH may be evident in areas of BBB disruption within a year after the stroke. Further studies are needed to investigate the relationship between chronic BBB disruption and progressive WMH in patients with a history of cerebrovascular disease and the potential for acute stroke to trigger or exacerbate the process leading to the development of WMH.


2016 ◽  
Vol 37 (2) ◽  
pp. 644-656 ◽  
Author(s):  
Susana Muñoz Maniega ◽  
Francesca M Chappell ◽  
Maria C Valdés Hernández ◽  
Paul A Armitage ◽  
Stephen D Makin ◽  
...  

White matter hyperintensities accumulate with age and occur in patients with stroke, but their pathogenesis is poorly understood. We measured multiple magnetic resonance imaging biomarkers of tissue integrity in normal-appearing white matter and white matter hyperintensities in patients with mild stroke, to improve understanding of white matter hyperintensities origins. We classified white matter into white matter hyperintensities and normal-appearing white matter and measured fractional anisotropy, mean diffusivity, water content (T1-relaxation time) and blood–brain barrier leakage (signal enhancement slope from dynamic contrast-enhanced magnetic resonance imaging). We studied the effects of age, white matter hyperintensities burden (Fazekas score) and vascular risk factors on each biomarker, in normal-appearing white matter and white matter hyperintensities, and performed receiver-operator characteristic curve analysis. Amongst 204 patients (34.3–90.9 years), all biomarkers differed between normal-appearing white matter and white matter hyperintensities ( P < 0.001). In normal-appearing white matter and white matter hyperintensities, mean diffusivity and T1 increased with age ( P < 0.001), all biomarkers varied with white matter hyperintensities burden ( P < 0.001; P = 0.02 signal enhancement slope), but only signal enhancement slope increased with hypertension ( P = 0.028). Fractional anisotropy showed complex age-white matter hyperintensities-tissue interactions; enhancement slope showed white matter hyperintensities-tissue interactions. Mean diffusivity distinguished white matter hyperintensities from normal-appearing white matter best at all ages. Blood–brain barrier leakage increases with hypertension and white matter hyperintensities burden at all ages in normal-appearing white matter and white matter hyperintensities, whereas water mobility and content increase as tissue damage accrues, suggesting that blood–brain barrier leakage mediates small vessel disease-related brain damage.


2006 ◽  
Vol 14 (7S_Part_9) ◽  
pp. P499-P500
Author(s):  
Whitney M. Freeze ◽  
Heidi IL. Jacobs ◽  
Joost J. de Jong ◽  
Inge C.M. Verheggen ◽  
Ed Gronenschild ◽  
...  

Neurology ◽  
2021 ◽  
Vol 96 (17) ◽  
pp. e2192-e2200
Author(s):  
Danielle Kerkhofs ◽  
Sau May Wong ◽  
Eleana Zhang ◽  
Julie Staals ◽  
Jacobus F.A. Jansen ◽  
...  

ObjectiveTo investigate the 2-year change in parenchymal diffusivity, a quantitative marker of microstructural tissue condition, and the relationship with baseline blood-brain barrier (BBB) permeability, in tissue at risk, i.e., the perilesional zone surrounding white matter hyperintensities (WMH) in patients with cerebral small vessel disease (cSVD).MethodsPatients with sporadic cSVD (lacunar stroke or mild vascular cognitive impairment) underwent 3T MRI at baseline, including dynamic contrast-enhanced MRI to quantify BBB permeability (i.e., leakage volume and rate) and intravoxel incoherent motion imaging (IVIM), a diffusion technique that provides parenchymal diffusivity D. After 2 years, IVIM was repeated. We assessed the relation between BBB leakage measures at baseline and change in parenchymal diffusivity (∆D) over 2 years in the perilesional zones (divided in 2-mm contours) surrounding WMH.ResultsWe analyzed 43 patients (age 68 ± 12 years, 58% male). In the perilesional zones, ∆D increased 0.10% (confidence interval [CI] 0.07–0.013%) (p < 0.01) per 2 mm closer to the WMH. Furthermore, ∆D over 2 years showed a positive correlation with both baseline BBB leakage volume (r = 0.29 [CI 0.06–0.52], p = 0.013) and leakage rate (r = 0.24 [CI 0.02–0.47], p = 0.034).ConclusionBBB leakage at baseline is related to the 2-year change in parenchymal diffusivity in the perilesional zone of WMH. These results support the hypothesis that BBB impairment might play an early role in subsequent microstructural white matter degeneration as part of the pathophysiology of cSVD.


2020 ◽  
Vol 85 ◽  
pp. 113-122 ◽  
Author(s):  
Whitney M. Freeze ◽  
Heidi I.L. Jacobs ◽  
Joost J. de Jong ◽  
Inge C.M. Verheggen ◽  
Ed H.B.M. Gronenschild ◽  
...  

2006 ◽  
Vol 14 (7S_Part_2) ◽  
pp. P74-P74
Author(s):  
Whitney M. Freeze ◽  
Heidi IL. Jacobs ◽  
Joost J. de Jong ◽  
Inge CM. Verheggen ◽  
Ed Gronenschild ◽  
...  

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0249973
Author(s):  
Seongjin Choi ◽  
Margaret Spini ◽  
Jun Hua ◽  
Daniel M. Harrison

Although the blood-brain barrier (BBB) is altered in most multiple sclerosis (MS) lesions, gadolinium enhancement is seen only in acute lesions. In this study, we aimed to investigate gadolinium-induced changes in T1 relaxation time in MS lesions on 7-tesla (7T) MRI as a means to quantify BBB breakdown in non-enhancing MS lesions. Forty-seven participants with MS underwent 7T MRI of the brain with a magnitude-prepared rapid acquisition of 2 gradient echoes (MP2RAGE) sequence before and after contrast. Subtraction of pre- and post-contrast T1 maps was used to measure T1 relaxation time change (ΔT1) from gadolinium. ΔT1 values were interrogated in enhancing white matter lesions (ELs), non-enhancing white matter lesions (NELs), and normal appearing white matter (NAWM) and metrics were compared to clinical data. ΔT1 was measurable in NELs (median: -0.139 (-0.304, 0.174) seconds; p < 0.001) and was negligible in NAWM (median: -0.001 (-0.036, 0.155) seconds; p = 0.516). Median ΔT1 in NELs correlated with disability as measured by Expanded Disability Status Scale (EDSS) (rho = -0.331, p = 0.026). Multiple measures of NEL ΔT1 variability also correlated with EDSS. NEL ΔT1 values were greater and more variable in patients with progressive forms of MS and greater in those not on MS treatment. Measurement of the changes in T1 relaxation time caused by contrast on 7T MP2RAGE reveals clinically relevant evidence of BBB breakdown in NELs in MS. This data suggests that NEL ΔT1 should be evaluated further as a biomarker for disease severity and treatment effect in MS.


Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Yao Yao ◽  
Jyoti Gautam ◽  
Xuanming Zhang

Introduction: Laminin, a major component of the basement membrane, plays an important role in blood brain barrier (BBB) regulation. At the neurovascular unit, astrocytes, brain endothelial cells, and pericytes synthesize and deposit different laminin isoforms into the basement membrane. Previous studies from our laboratory showed that loss of astrocytic laminin induces age-dependent and region-specific BBB breakdown and intracerebral hemorrhage, suggesting a critical role of astrocytic laminin in vascular integrity maintenance. Laminin α4 (predominantly generated by endothelial cells) has been shown to regulate vascular integrity at embryonic/neonatal stage. The role of pericytic laminin in vascular integrity, however, remains elusive. Methods: We investigated the function of pericyte-derived laminin in vascular integrity using laminin conditional knockout mice. Specifically, laminin floxed mice were crossed with PDGFRβ-Cre line to generate mutants (PKO) with laminin deficiency in PDGFRβ + cells, which include both pericytes and vascular smooth muscle cells (vSMCs). To distinguish the contribution of pericyte- and vSMC-derived laminin, we also generated a vSMC-specific condition knockout line (TKO) by crossing the laminin floxed mice with Transgelin-Cre mice. In this study, mice of both genders on a C57Bl6 background were used. At least 5-6 animals were used in biochemical and histological analyses in this study. Results: Pericyte-derived laminin was abrogated in all PKO mice. However, only old but not young PKO mice showed signs of BBB breakdown and reduced vessel density, suggesting age-dependent changes. Consistent with these data, further mechanistic studies revealed reduced tight junction proteins, diminished AQP4 expression, and deceased pericyte coverage in old but not young PKO mice. In addition, neither BBB disruption nor decreased vessel density was observed in TKO mice, suggesting that these vascular defects are due to loss of pericyte- rather than vSMC-derived laminin. Conclusions: These results strongly suggest that pericyte-derived laminin active regulates BBB integrity and vessel density in an age-dependent manner. I would like this abstract to be considered for the Stroke Basic Science Award.


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