The purpose of this preliminary study was to test the hypothesis that subsyndromal depression is associated with the volume of medial prefrontal regional gray matter and that of white matter lesions (WMLs) in the brains of cognitively normal older people. We also explored the relationships between subsyndromal depression and medial prefrontal regional gray matter volume, limbic regional gray matter volume, and lobar WMLs in the brains of patients with mild cognitive impairment (MCI) and Alzheimer's disease (AD). We performed a cross-sectional study comparing patients with subsyndromal depression and nondepressed controls with normal cognition (n = 59), MCI (n = 27), and AD (n = 27), adjusting for sex, age, years of education, and results of the Mini-Mental State Examination. Frontal WML volume was greater, and right medial orbitofrontal cortical volume was smaller in cognitively normal participants with subsyndromal depression than in those without subsyndromal depression. No volume differences were observed in medial prefrontal, limbic, or WML volumes according to the presence of subsyndromal depression in cognitively impaired patients. The absence of these changes in patients with MCI and AD suggests that brain changes associated with AD pathology may override the changes associated with subsyndromal depression.
Maintaining cognitive function is essential for healthy aging and to function autonomously within society. White matter lesions (WMLs) are associated with reduced cognitive function in older adults. However, whether their anatomical location moderates these associations is not well-established. This review systematically evaluates peer-reviewed evidence on the role of anatomical location in the association between WMLs and cognitive function.
In accordance with the preferred reporting items for systematic reviews and meta-analysis (PRISMA) statement, databases of EMBASE, PUBMED, MEDLINE, and CINAHL, and reference lists of selected papers were searched. We limited our search results to adults aged 60 years and older, and studies published in the English language from 2000 to 2011. Studies that investigated the association between cognitive function and WML location were included. Two independent reviewers extracted: 1) study characteristics including sample size, sample characteristic, and study design; 2) WML outcomes including WML location, WML quantification method (scoring or volume measurement), strength of the MRI magnet in Tesla, and MRI sequence used for WML detection; and 3) cognitive function outcomes including cognitive tests for two cognitive domains of memory and executive function/processing speed.
Of the 14 studies included, seven compared the association of subcortical versus periventricular WMLs with cognitive function. Seven other studies investigated the association between WMLs in specific brain regions (e.g., frontal, parietal lobes) and cognitive function. Overall, the results show that a greater number of studies have found an association between periventricular WMLs and executive function/processing speed, than subcortical WMLs. However, whether WMLs in different brain regions have a differential effect on cognitive function remains unclear.
Evidence suggests that periventricular WMLs may have a significant negative impact on cognitive abilities of older adults. This finding may be influenced by study heterogeneity in: 1) MRI sequences, WML quantification methods, and neuropsychological batteries; 2) modifying effect of cardiovascular risk factors; and 3) quality of studies and lack of sample size calculation.
White matter lesions; Distribution; Cognition; Aging
Depressed mood is a frequent co-morbidity of dementia suggesting that they might share a common neuropathological substrate. Gray matter (GM) atrophy and white matter lesions (WML) have been described in both conditions. Our aims were to determine the relationship of GM and WML with cognition and depressed mood in the same population. Structural brain images were obtained from 42 controls, 20 Alzheimer’s disease (AD) patients and 32 subjects with cognitive impairment/dementia due to subcortical cerebrovascular disease (vascCIND/IVD) and segmented to obtain lobar GM, white matter and WML volumes. Lobar WML had a negative effect on GM in all lobes in controls, on frontal, parietal and occipital GM in AD and on frontal GM in vascCIND/IVD. Frontal, temporal and hippocampal GM were associated with cognitive functions and frontal WML load with depressed mood. Cognitive function is associated with GM atrophy and depressed mood is associated with frontal WML. This indicates that although both often occur together depressed mood and cognitive impairment are caused by different pathological correlates.
white matter lesion; gray matter atrophy; depression; mood; cognition; MRI
White matter lesions (WML) increase the risk of dementia. The relevance of WML location is less clear. We sought to determine whether a particular WML profile, based on the density and location of lesions, could be associated with an increased risk of mild cognitive impairment (MCI) or dementia over the following 7 years.
In 426 healthy subjects from a cohort of community-dwelling people aged 65 years and over (ESPRIT Project), standardized cognitive and neurological evaluations were repeated after 2, 4 and 7 years. Patterns of WML were computed with a supervised data mining approach (decision trees) using the regional WML volumes (frontal, parietal, temporal, and occipital regions) and the total WML volume estimated at baseline. Cox proportional hazard models were then constructed to study the association between WML patterns and risk of MCI/dementia.
Total WML volume and percentage of WML in the temporal region proved to be the best predictors of progression to MCI and dementia. Specifically, severe total WML load with a high proportion of lesions in the temporal region was significantly associated with the risk of developing MCI or dementia.
Above a certain threshold of damage, a pattern of WML clustering in the temporal region identifies individuals at increased risk of MCI or dementia. As this WML pattern is observed before the onset of clinical symptoms, it may facilitate the detection of patients at risk of MCI/dementia.
The 5,10-methylenetetrahydrofolate reductase gene (MTHFR) has been linked to unipolar major depressive disorder (MDD) and MRI hyperintensities. We examined the relationship between the MTHFR C677T polymorphism (C677T) and a) geriatric depression, b) MRI hyperintense lesion volume, and c) neurocognitive test performance.
Duke University Medical Center.
Depressed (N=178) and comparison (N=85) elderly subjects.
Subjects had blood drawn to assess MTHFR genotype, were imaged by MRI to determine their white (WML) and gray (GML) matter hyperintense lesion volume, and assessed using a comprehensive neurocognitive battery evaluating multiple domains of function. Linear regression models were fit to test the effect of genotype, a depression by genotype interaction, and an age by genotype interaction on both hyperintense lesion volume measures and neurocognitive task performance.
The MTHFR C677T genotype by age interaction term was significantly associated with MRI WML volume (p=0.0175), however this relationship was no longer statistically significant when WML volumes underwent a log transformation to produce a more normal distribution. The 677T allele was neither more frequent in depressed subjects nor associated with either gray matter hyperintensity volume or neurocognitive test performance.
MTHFR genotype affects the relationship between age and WML volume, where individuals who carry the 677T allele exhibit greater WML volume by age, although this relationship should be verified given the failure to replicate the finding using transformed WML volumes. Genotype was not related to GML volume, cognitive function, or presence of depression, although demographic differences could account for this negative finding.
MTHFR polymorphism; depression; white matter lesion; folate; homocysteine; elderly
Cerebral white matter lesions (WMLs) reflect small vessel disease, are common in elderly individuals and are associated with cognitive impairment. We sought to determine the relationships between WMLs, age, gray matter (GM) volume, and cognition in the Cardiovascular Health Study (CHS).
From the CHS we selected 740 cognitively normal controls with a 1.5 T MRI scan of the brain and a detailed diagnostic evaluation. WML severity was determined using a standardized visual rating system. GM volumes were analyzed using voxel-based morphometry implemented in the Statistical Parametric Mapping software.
WMLs were inversely correlated with GM volume, with the greatest volume loss in the frontal cortex. Age related atrophy was observed in the hippocampus and posterior cingulate cortex. Regression analyses revealed links among age, APOE*4 allele, hypertension, WMLs, GM volume, and digit symbol substitution test scores.
Both advancing age and hypertension predict higher WML load, which is itself associated with GM atrophy. Longitudinal data are needed to confirm the temporal sequence of events leading to a decline in cognitive function.
White matter lesions; age; gray matter volume; cognition
To prospectively assess the relation between carotid plaque characteristics and the development of new cerebral white matter lesions (WMLs) at MRI.
Fifty TIA/stroke patients with ipsilateral 30–69% carotid stenosis underwent MRI of the plaque at baseline. Total plaque volume and markers of vulnerability to thromboembolism (lipid-rich necrotic core [LRNC] volume, fibrous cap [FC] status, and presence of intraplaque hemorrhage [IPH]) were assessed. All patients also underwent brain MRI at baseline and after one year. Ipsilateral cerebral WMLs were quantified with a semiautomatic method.
Mean WML volume significantly increased over a one-year period (6.52 vs. 6.97 mm3, P = 0.005). WML volume at baseline and WML progression did not significantly differ (P>0.05) between patients with 30–49% and patients with 50–69% stenosis. There was a significant correlation between total plaque volume and baseline ipsilateral WML volume (Spearman ρ = 0.393, P = 0.005). There was no significant correlation between total plaque volume and ipsilateral WML progression. There were no significant associations between LRNC volume and WML volume at baseline and WML progression. WML volume at baseline and WML progression did not significantly differ between patients with a thick and intact FC and patients with a thin and/or ruptured FC. WML volume at baseline and WML progression also did not significantly differ between patients with and without IPH.
The results of this study indicate that carotid plaque burden is significantly associated with WML severity, but that there is no causal relationship between carotid plaque vulnerability and the occurrence of WMLs.
The objectives were first to compare the effects of subcortical ischemic vascular dementia (SIVD) and Alzheimer's disease (AD) on cerebral blood flow (CBF) and second to analyze the relationship between CBF and subcortical vascular disease, measured as volume of white matter lesions (WML).
Eight mildly demented patients with SIVD (77 ± 8 years, 26 ± 3 MMSE) and 14 patients with AD were compared to 18 cognitively normal elderly. All subjects had CBF measured using arterial spin labeling MRI and brain volumes assessed using structural MRI.
AD and SIVD showed marked CBF reductions in frontal (p = 0.001) and parietal (p = 0.001) cortex. In SIVD, increased subcortical WML were associated with reduced CBF in frontal cortex (p = 0.04) in addition to cortical atrophy (frontal: p = 0.05; parietal: p = 0.03).
Subcortical vascular disease is associated with reduced CBF in the cortex, irrespective of brain atrophy.
Magnetic Resonance Imaging; Cerebral blood flow; Subcortical ischemic vascular dementia; Alzheimer's disease; Cortex; Segmentation; White matter lesions
Lacunar lesions (LLs) and white matter lesions (WMLs) affect cognition. We assessed whether lesions located in specific white matter tracts were associated with cognitive performance taking into account total lesion burden.
Within the Second Manifestations of ARTerial disease Magnetic Resonance (SMART-MR) study, cross-sectional analyses were performed on 516 patients with manifest arterial disease. We applied an assumption-free voxel-based lesion-symptom mapping approach to investigate the relation between LL and WML locations on 1.5 Tesla brain MRI and compound scores of executive functioning, memory and processing speed. Secondly, a multivariable linear regression model was used to relate the regional volume of LLs and WMLs within specific white matter tracts to cognitive functioning.
Voxel-based lesion-symptom mapping identified several clusters of voxels with a significant correlation between WMLs and executive functioning, mostly located within the superior longitudinal fasciculus and anterior thalamic radiation. In the multivariable linear regression model, a statistically significant association was found between regional LL volume within the superior longitudinal fasciculus and anterior thalamic radiation and executive functioning after adjustment for total LL and WML burden.
These findings identify the superior longitudinal fasciculus and anterior thalamic radiation as key anatomical structures in executive functioning and emphasize the role of strategically located vascular lesions in vascular cognitive impairment.
Causes of cognitive impairment in subcortical ischemic vascular disease (SIVD) are less well understood than in AD, but have been thought to result from direct effects of subcortical lacunes and white matter lesions, perhaps related to disruption of important cortical-subcortical pathways.
To examine the relation between cognitive abilities and quantitative MRI measures of subcortical cerebrovascular disease and cortical and hippocampal atrophy.
Subjects were 157 participants in a multicenter study of SIVD and AD who included cognitively normal, cognitively impaired, and demented individuals with and without subcortical lacunar infarcts. Dependent variables were neuropsychological tests of global cognitive function, memory, language, and executive function. Independent variables were quantitative MRI measures of volume of lacunar infarcts in specific subcortical structures, volume of white matter lesion (WML), volume of cortical gray matter (cGM), and total hippocampal volume (HV). Multiple regression analyses were used to identify MRI predictors of cognition.
Subcortical lacunes were not related to cognitive measures independent of effects of other MRI variables. WML was independently related to selected, timed measures. HV and cGM were strong and independent predictors of cognitive variables, with effects that did not differ in subjects with and without subcortical lacunes.
Results suggest that cognitive impairment associated with subcortical ischemic vascular disease is primarily a result of associated hippocampal and cortical changes.
This longitudinal study examined the relationship between 2-year change in white matter hyperintense lesion (WML) volume and polymorphisms in genes coding for the angiotensin-II type 1 and type 2 receptors, AGTR1 A1166C and AGTR2 C3123A. 137 depressed and 94 nondepressed subjects age 60 years or older were enrolled. Standard clinical evaluations were performed on all subjects and blood samples obtained for genotyping. 1.5T MRI was obtained at baseline and approximately two years later. These scans were processed using a semi-automated segmentation process which allowed for the calculation of WML volume at each time point. Statistical models tested for the relationship between change in WML volume and genotype, while also controlling for age, sex, diagnostic strata, baseline WML volume, and comorbid cerebrovascular risk factors. In men, AGTR1 1166A allele homozygotes exhibited significantly less change in WML volume than 1166C carriers. We also found that men reporting hypertension with the AGTR2 3123C allele exhibit less change in WML volume than hypertensive men with the 3123A allele, or men without hypertension. There were no significant relationships between these polymorphisms and change in WML volume in women. No significant gene-gene or gene-depression interactions were observed. Our results parallel previously observed gender differences of the relationship between other renin-angiotensin system polymorphisms and hypertension. Further work is needed to determine if these observed relationships are secondary to polymorphisms affecting response to antihypertensive medication, and if antihypertensive medications can slow WML progression and lower the risk of morbidity associated with WMLs.
MRI; Major Depressive Disorder; Volumetric Study; Cerebrovascular Disease; Renin-Angiotensin System; Genetic Polymorphisms
Extracellular vesicles (EVs) and their protein levels have been identified as a potential risk marker for the development of vascular disease. In the present study, we assessed whether levels of four previously identified EV proteins (cystatin C, serpin G1, serpin F2 and CD14) are associated with cerebral white matter lesions (WMLs) and brain atrophy.
Cohort study; cross-sectional and prospective.
Single centre, secondary and tertiary setting.
1309 patients with manifest vascular disease from the Second Manifestations of ARTerial disease-MR (SMART-MR) study, of which 994 had successful brain MRI and EV protein level measurements.
WML and brain parenchymal fraction (BPF), as parameter for brain atrophy, at baseline and follow-up.
The relationship between EV protein levels and WML volume (expressed as log transformed percentage of intracranial volume) and BPF (expressed percentage of intracranial volume) on 1.5 T brain MRI was assessed with multivariable linear regression modelling. Subsequently, the relationship between baseline EV protein levels and progression of atrophy and WML was analysed in 534 patients, in whom a follow-up MRI was obtained after 4 years.
Higher EV-cystatin C and EV-CD14 were significantly associated with larger WML volume (linear regression coefficient (95% CI) 0.10 log %/SD (0.04 to 0.17) and 0.14 log %/SD (0.07 to 0.20), respectively. Higher EV-CD14 was associated with more brain atrophy (–0.14%/SD; –0.27 to –0.01). Baseline EV-CD14 was significantly associated with increase of WMLs (0.11 log %/SD (0.04 to 0.18)). No relationship with EV-serpins was observed at baseline or at follow-up.
EV proteins cystatin C and CD14 are related to cerebral WMLs and the progression of brain atrophy in patients with manifest vascular disease, potentially identifying EVs in the aetiology of structural brain changes.
extracellular vesicles; White matter lesion; Brain atrophy
White matter lesions (WML) and brain atrophy are important biomarkers in stroke and dementia. Stroke lesions, either acute or old, symptomatic or silent, are common in older people. Such stroke lesions can have similar signals to WML and cerebrospinal fluid (CSF) on magnetic resonance (MR) images, and may be classified accidentally as WML or CSF by MR image processing algorithms, distorting WML and brain atrophy volume from the true volume. We evaluated the effect that acute or old stroke lesions at baseline, and new stroke lesions occurring during follow-up, could have on measurement of WML volume, cerebral atrophy and their longitudinal progression.
We used MR imaging data from patients who had originally presented with acute lacunar or minor cortical ischaemic stroke symptoms, recruited prospectively, who were scanned at baseline and about 3 years later. We measured WML and CSF volumes (ml) semi-automatically. We manually outlined the acute index stroke lesion (ISL), any old stroke lesions present at baseline, and new lesions appearing de novo during follow-up. We compared baseline and follow-up WML volume, cerebral atrophy and their longitudinal progression excluding and including the acute ISL, old and de novo stroke lesions. A non-parametric test (Wilcoxon's signed rank test) was used to compare the effects.
Among 46 patients (mean age 72 years), 33 had an ISL visible on MR imaging (median volume 2.05 ml, IQR 0.88–8.88) and 7 of the 33 had old lacunes at baseline: WML volume was 8.54 ml (IQR 5.86–15.80) excluding versus 10.98 ml (IQR 6.91–24.86) including ISL (p < 0.001). At follow-up, median 39 months later (IQR 30–45), 3 patients had a de novo stroke lesion; total stroke lesion volume had decreased in 11 and increased in 22 patients: WML volume was 12.17 ml (IQR 8.54–19.86) excluding versus 14.79 ml (IQR 10.02–38.03) including total stroke lesions (p < 0.001). Including/excluding lacunes at baseline or follow-up also made small differences. Twenty-two of the 33 patients had tissue loss due to stroke lesions between baseline and follow-up, resulting in a net median brain tissue volume loss (i.e. atrophy) during follow-up of 24.49 ml (IQR 12.87–54.01) excluding versus 24.61 ml (IQR 15.54–54.04) including tissue loss due to stroke lesions (p < 0.001). Including stroke lesions in the WML volume added substantial noise, reduced statistical power, and thus increased sample size estimated for a clinical trial.
Failure to exclude even small stroke lesions distorts WML volume, cerebral atrophy and their longitudinal progression measurements. This has important implications for design and sample size calculations for observational studies and randomised trials using WML volume, WML progression or brain atrophy as outcome measures. Improved methods of discriminating between stroke lesions and WML, and between tissue loss due to stroke lesions and true brain atrophy are required.
White matter disease; Infarcts; Lacunes; Atrophy; Magnetic resonance imaging
Alzheimer's disease (AD) and cerebrovascular disease (CVD) including chronic small vessel disease of the brain (SVD) are the most frequent causes of dementia. AD is associated with metabolism of amyloid precursor protein (APP) and low levels of amyloid-β peptide (Aβ) X-42 in the cerebrospinal fluid (CSF). CVD and SVD are established risk factors for AD, brain white matter lesions (WML) are established surrogate markers for SVD and are also associated with reduced CSF AβX-42.
A cohort survey was performed to examine whether SVD or acute CVD affects APP metabolism and to explore a potential association between WML and APP metabolism in two groups; cognitively impaired patients, subjective and mild (SCI and MCI) and stroke patients. Through measurements of CSF APP metabolite levels in patients with a wide range of WML volumes, this study aimed to determine how SVD influences APP metabolism.
Sixty-three patients were included: 37 with subjective cognitive impairment (SCI) or mild cognitive impairment (MCI) without stroke, and 26 after acute stroke. Chronic and acute WML volume and infarct volume were determined by magnetic resonance imaging (MRI) post-scan processing, and CSF levels of α- and β-cleaved soluble APP (sAPP-α and sAPP-β, AβX-38, AβX-40 and AβX-42) were determined. The Mann-Whitney test was used to compare the patient groups. Chronic and acute WML volumes, infarct volume, age, and sex were used as predictors for CSF biomarker levels in linear regression analysis.
CSF levels of sAPP-α and sAPP-β were strongly correlated (r = 0.95, p < 0.001) and lower levels of these biomarkers were found in the stroke group than in the SCI/MCI group; median sAPP-α 499.5 vs. 698.0 ng/mL (p < 0.001), sAPP-β 258.0 vs. 329.0 ng/mL (p < 0.005). CSF levels of sAPP-α, sAPP-β, AβX-38, AβX-40 and AβX-42 were inversely correlated with chronic WML volume (p ≤ 0.005; p ≤ 0.01; p ≤ 0.01; p ≤ 0.05; p ≤ 0.05 respectively), but not with acute WML or infarct volumes.
Lower CSF levels of sAPP-α and sAPP-β in the stroke group than in the SCI/MCI group and an inverse correlation with chronic WML indicate that ischemia lowers the levels of CSF sAPP metabolites and suggests that APP axonal transport or metabolism may be affected in SVD of the brain.
Background: Cerebral white matter lesions (WML), evident on CT and MRI brain scans, are histopathologically heterogeneous but associated with vascular risk factors and thought mainly to indicate ischemic damage. There has been disagreement over their clinical prognostic value in predicting conversion from mild cognitive impairment (MCI) to dementia.
Methods: We scrutinised and rated CT and MRI brain scans for degree of WML in a memory clinic cohort of 129 patients with at least 1 year of follow-up. We examined the relationship between WML severity and time until conversion to dementia for all MCI patients and for amnestic (aMCI) and non-amnestic (naMCI) subgroups separately.
Results: Five-year outcome data were available for 87 (67%) of the 129 patients. The proportion of patients converting to dementia was 25% at 1 year and 76% at 5 years. Patients with aMCI converted to dementia significantly earlier than those with naMCI. WML severity was not associated with time to conversion to dementia for either MCI patients in general or aMCI patients in particular. Among naMCI patients, there was a tendency for those with a low degree of WML to survive without dementia for longer than those with a high degree of WML. However, this was not statistically significant.
Conclusions: MCI subtype is a significant independent predictor of conversion to dementia, with aMCI patients having higher risk than naMCI for conversion throughout the 5-year follow-up period. WML severity does not influence conversion to dementia for aMCI but might accelerate progression in naMCI.
survival analysis; conversion; amnestic; non-amnestic; white matter lesions; dementia; Alzheimer's disease; cerebrovascular disease
In cross-sectional studies periventricular white matter lesions (WML) were related to low plasma levels of vitamin B12. Whether low vitamin B12 levels are also related to progression of WML is still unknown. We studied baseline vitamin B12 levels and its association with progression of WML over 2 years of follow-up in first-ever lacunar stroke patients. In 107 first-ever lacunar stroke patients in whom baseline brain MRI and vitamin B12 status were available, we obtained a follow-up brain MRI after 2 years. We assessed progression of periventricular WML (pWML) and deep WML (dWML) using a visual WML change scale. We studied the relationship between baseline levels of plasma vitamin B12 and progression of WML after 2 years of follow-up by binary logistic regression analyses. Vitamin B12 deficiency was more frequent in patients with progression of pWML compared to those without progression (41.9% and 19.7% respectively, p = 0.02). Corrected for sex and age, progression of pWML was associated with lower baseline levels of vitamin B12 (OR 1.42 per 50 unit decrease, 95% CI 1.00-1.92). Vitamin B12 levels were not associated with progression of dWML. In conclusion progression of pWML after 2 years of follow-up relates to low levels of vitamin B12 at baseline in first-ever lacunar stroke patients. Whether this population could benefit from vitamin B12 supplementation is unknown and requires further investigation.
Background: White matter lesions (WML) in elderly people co-occur with hypertension, depression, and cognitive impairment. Little is known about the density and distribution of WML in normal elderly people, whether they occur randomly in the aging brain or tend to cluster in certain areas, or whether patterns of WML aggregation are linked to clinical symptoms.
Objectives: To describe patterns of WML distribution in a large representative population of elderly people using non-inferential cluster analysis; and to determine the extent to which such patterns are associated with clinical symptomatology.
Method: A population sample of 1077 elderly people was recruited. Multiple analysis of correspondence followed by automatic classification methods was used to explore overall patterns of WML distribution. Correspondence was then sought between these patterns and a range of cerebrovascular, psychiatric, and neurological symptoms.
Results: Three distinct patterns of spatial localisation within the brain were observed, corresponding to distinct clusters of clinical symptoms. In particular WML aggregation in temporal and occipital areas was associated with greater age, hypertension, late onset depressive disorder, poor global cognitive function, and overall WML frequency.
Conclusions: WML localisation is not random in the aging brain, and their distribution is associated with age and the presence of clinical symptoms. Age differences suggest there may be patterns of progression across time; however, this requires confirmation from longitudinal imaging studies.
The purpose of this study is to investigate the relationship between the cognitive impairment and NAA/Cr and Cho/Cr ratios in the proton magnetic resonance spectroscopy (1HMRS), and to assess the importance of 1HMRS in the early diagnosis of cognitive impairment in patients with ischemic white matter lesions (WMLs).
Materials and Methods:
A total of 45 patients (23 males and 22 females) with the ischemic WML were divided into mild WML group (n = 15), moderate WML group (n = 15), and severe WML group (n = 15). A total of 15 healthy controls (8 males and 7 females) with no WML on magnetic resonance imaging were included. 1HMRS focusing on the frontal lobe white matter around the anterior horn of the lateral ventricle and Montreal Cognitive Assessment (MoCA) were conducted.
Patients with more severe WML had lower MoCA scores. The NAA/Cr ratio in 1HMRS was reduced in all the patients and was strongly correlated with the total MoCA scores (r = 0.845, P < 0.001). The Cho/Cr ratio in 1HMRS was increased in mild and moderate patients, was negatively correlated with the total MoCA scores (r = 0.907, P < 0.001). The Cho/Cr ratio was reduced in the severe patients and was positively correlated with the total MoCA scores (r = 0.937, P < 0.001). In addition, NAA/Cr and Cho/Cr ratios in 1HMRS were changed in patients with the mild WML whose total MoCA scores were similar to the controls.
Our results suggest that NAA/Cr and Cho/Cr ratios in 1HMRS are useful indicators for early diagnosis of ischemic WML and cognitive impairment in patients with ischemic WML.
1HMRS; Cho/Cr ratio; cognitive impairment; ischemic white matter; montreal cognitive assessment; NAA/Cr ratio; white matter lesions
Blood pressure (BP), age, and reduced renal function are major risk factors for white-matter lesions (WMLs) in the general population. However, it remains unclear whether or not the BP itself or other parameters related to the BP are associated with WMLs in hypertensive patients with well-controlled BP. We investigated the relationships of the presence of WMLs with the central systolic BP (cSBP) and estimated glomerular filtration rate (eGFR) in treated hypertensive patients.
We studied 185 hypertensive patients with median duration of hypertension, 10.0 years, whose BP is controlled to SBP and diastolic BP (DBP) of 139 ± 17 and 79 ± 10 mmHg, respectively. We measured cSBP and brain magnetic resonance imaging (MRI) was examined within 2 weeks after last BP and biological measurements.
Patients with higher-grade WMLs, as assessed by the presence of Scheltens deep white-matter hyperintensity (SDWMH) in the frontal (grade 0–2 vs 3–6) and parietal areas (grade 0–2 vs 3–6) where small arteries are affected at earlier stage of hypertension, as well as that of Fazekas deep white-matter hyperintensity (FDWMH) (grade 2–3 vs 0–1) and Fazekas periventricular hyperintensity (FPVH) (grade 1–3 vs 0) were older, had higher serum creatinine levels, a longer duration of hypertension, and lower eGFR values. The grade of the WMLs was not associated with either the cSBP or the brachial SBP. In logistic regression analyses after adjustment for age, sex, cSBP, and hypertension duration, showed significant association between eGFR and WMLs. The patients with lower eGFR (<60 mL/minute/1.73 m2) tended to have higher grade WMLs. The odds ratio was 2.87 for FDWMH (P = 0.017), 1.99 for FPVH (P = 0.131), and 2.33 for SDWMH in the parietal area (P = 0.045).
Presence of WMLs was associated with eGFR, but not with either the brachial SBP or cSBP in hypertensive patients with well-controlled BP.
white-matter lesions; central systolic blood pressure; estimated glomerular filtration rate
This paper evaluates the relationship of blood pressure (BP) levels at Women’s Health Initiative (WHI) baseline, treatment of hypertension, and white matter abnormalities among women in conjugated equine estrogen (CEE) and medroxyprogesterone acetate and CEE-alone arms. The WHI Memory Study—Magnetic Resonance Imaging (WHIMS-MRI) trial scanned 1424 participants. BP levels at baseline were significantly positively related to abnormal white matter lesion (WML) volumes. Participants treated for hypertension but who had BP ≥140/90 mm Hg had the greatest amount of WML volumes. Women with untreated BP ≥140/90 mm Hg had intermediate WML volumes. Abnormal WML volumes were related to hypertension in most areas of the brain and were greater in the frontal lobe than in the occipital, parietal, or temporal lobes. Level of BP at baseline was strongly related to amount of WML volumes. The results of the study reinforce the relationship of hypertension and BP control and white matter abnormalities in the brain. The evidence to date supports tight control of BP levels, especially beginning at younger and middle age as a possible and perhaps only way to prevent dementia.
Objectives: To determine whether the extent of white matter high intensity lesions (WML) on magnetic resonance imaging (MRI) is an independent predictor of risk for stroke from arteriolosclerosis, and whether serial evaluation of WML can be used to identify patients who are at risk of strokes.
Methods: Prospective follow up with serial MRI scans was done in 89 patients who were either diagnosed as having symptomatic lacunar infarcts or were stroke-free, neurologically normal individuals with headache or dizziness. None had significant stenosis of major cerebral arteries or atrial fibrillation. Multivariable analysis with the Cox proportional hazards model was used to test the predictive value for subsequent stroke of risk factor status at entry and during follow up, lacunar infarction, and the extent of WML (scored from 0 to 16) on the baseline scans.
Results: During follow up (mean (SD), 51 (19) months), seven strokes occurred (five lacunar infarcts and two haemorrhages): four in nine patients with severe WML (score 9–16), and three in 40 patients with mild WML (score 1–8) (log-rank test; p < 0.005). None of 40 patients without WML experienced stroke. The extent of WML was an independent predictor of subsequent stroke (relative risk for a 1 point score increase, 1.60; 95% confidence interval, 1.02 to 2.54; p < 0.05). In three strokes among 80 patients without severe WML, two occurred in four patients with an increase in WML score during follow up, and one occurred in the other 76 patients without an increased score (p < 0.0001).
Conclusions: Severe WML at baseline is an independent predictor of risk for stroke from arteriolosclerosis, while progression of WML during follow up may be associated with subsequent stroke in patients with initially mild WML.
Apolipoprotein A-I (apoA-I), the major protein for high density lipoprotein, is essential for reverse cholesterol transport. Decreased serum levels of apoA-I have been reported to correlate with subcortical infarction and dementia, both of which are highly related to white matter lesions (WMLs). However, the association between apoA-I and WMLs has never been investigated. In this study, we sought to investigate the association between apoA-I and the presence of WMLs in middle-aged and elderly subjects.
Consecutive patients aged 50 years and older of our department were prospectively enrolled in this study (n = 1282, 606 men and 676 women, 65.9±9.4 years). All participants underwent MRI scans to assess the presence and severity of WMLs. Multivariate logistic regression analyses were performed to examine the association of apoA-I with WMLs.
Patients with WMLs were older and showed significantly higher proportion of male sex, hypertension, diabetes mellitus, previous stroke, and coronary heart disease whereas levels of total cholesterol, high density lipoprotein cholesterol, and apoA-I were lower. After adjustment for potential confounders, the lowest apoA-I quartile was independently associated with an increased risk of WMLs (odds ratio: 1.87, 95% confidence interval: 1.29–2.72). In sex-specific analyses, this relationship was observed only in women.
Our findings demonstrated that apoA-I was inversely associated with the presence of WMLs in middle-aged and elderly subjects. This results suggest that therapies which increase apoA-I concentration may be beneficial to reduce the risk of WMLs, dementia and stroke.
Age-related white matter lesions (WML) are a risk factor for stroke, cognitive decline, and dementia. Different requirements are imposed on methods for the assessment of WML in clinical settings and for research purposes, but reliability analysis is of major importance. In this study, WML assessment with three different methods was evaluated. In the Gothenburg mild cognitive impairment study, MRI scans from 152 participants were used to assess WML with the Fazekas visual rating scale on T2 images, a manual volumetric method on FLAIR images, and FreeSurfer volumetry on T1 images. Reliability was acceptable for all three methods. For low WML volumes (2/3 of the patients), reliability was overall lower and nonsignificant for the manual volumetric method. Unreliability in the assessment of patients with low WML with manual volumetry may mainly be due to intensity variation in the FLAIR sequence used; hence, intensity standardization and normalization methods must be used for more accurate assessments. The FreeSurfer segmentations resulted in smaller WML volumes than the volumes acquired with the manual method and showed deviations from visible hypointensities in the T1 images, which quite likely reduces validity.
Multiple sclerosis (MS) is a heterogeneous disorder with a progressive course that is difficult to predict on a case-by-case basis. Natural history studies of MS have demonstrated that age influences clinical progression independent of disease duration.
To determine whether age would be associated with greater CNS injury as detected by magnetization transfer MRI.
Materials and methods
Forty MS patients were recruited from out-patient clinics into two groups stratified by age but with similar clinical disease duration as well as thirteen controls age-matched to the older MS group. Images were segmented by automated programs and blinded readers into normal appearing white matter (NAWM), normal appearing gray matter (NAGM), and white matter lesions (WMLs) and gray matter lesions (GMLs) in the MS groups. WML and GML were delineated on T2-weighted 3D fluid-attenuated inversion recovery (FLAIR) and T1 weighted MRI volumes. Mean magnetization transfer ratio (MTR), region volume, as well as MTR histogram skew and kurtosis were calculated for each region.
All MTR measures in NAGM and MTR histogram metrics in NAWM differed between MS subjects and controls, as expected and previously reported by several studies, but not between MS groups. However, MTR measures in the WML did significantly differ between the MS groups, in spite of no significant differences in lesion counts and volumes.
Despite matching for clinical disease duration and recording no significant WML volume difference, we demonstrated strong MTR differences in WMLs between younger and older MS patients. These data suggest that aging-related processes modify the tissue response to inflammatory injury and its clinical outcome correlates in MS.
•Magnetization transfer MRI was used in a cohort of 40 MS subjects differing by age.•MTR metrics were different between MS groups and controls, as expected.•MTR in normal appearing tissue did not differ between age-stratified MS groups.•MTR in white matter lesions was strongly different between age-stratified MS groups.•Results imply an age-related effect in tissue integrity in MR-visible lesions.
MTR, magnetization transfer ratio; NAWM, normal appearing white matter; NAGM, normal appearing gray matter; WM, white matter; GM, gray matter; WML, white matter lesion; GML, gray matter lesion; Magnetization transfer; MRI; Multiple sclerosis; Aging
White matter hyperintensities (WMHs) associate with both cognitive slowing and motor dysfunction in the neurologically normal elderly. A full understanding of the pathology underlying this clinicoradiologic finding is currently lacking in autopsy-confirmed normal brains. To determine the histopathologic basis of WMH seen on MRI, we studied the relationship between postmortem fluid-attenuated inversion recovery (FLAIR) intensity and neuropathologic markers of white matter lesions (WMLs) that correspond to WMH in cognitively normal aging brains. Samples of periventricular (n = 24), subcortical (n = 26), and normal-appearing white matter (NAWM, n = 31) from 4 clinically and pathologically-confirmed normal cases were examined. FLAIR intensity, vacuolation, and myelin basic protein (MBP) immunoreactivity loss were significantly higher in periventricular WML vs. subcortical WML; both were higher than in NAWM. The subcortical WML and NAWM had significantly less axonal loss, astrocytic burden, microglial density, and oligodendrocyte loss than the periventricular WML. Thus, vacuolation, myelin density and small vessel density contribute to the rarefaction of white matter whereas axonal density, oligodendrocyte density, astroglial burden and microglial density did not. These data suggest that the age-related loss of MBP and a decrease in small vessel density, may contribute to vacuolation of white matter. The vacuolation enables interstitial fluid to accumulate, which contributes to the prolonged T2 relaxation and elevated FLAIR intensity in the white matter.
Digital microscopy; Fluid attenuated inversion recovery; Normal aging; Oligodendrocytes; Postmortem magnetic resonance imaging; White matter