Age differences in periventricular and deep white matter lesions

The ageing central nervous system in multiple sclerosis: the imaging perspective

The interaction between ageing and multiple sclerosis is complex and carries significant implications for patient care. Managing multiple sclerosis effectively requires an understanding of how ageing and multiple sclerosis impact brain structure and function. Ageing inherently induces brain changes, including reduced plasticity, diminished grey matter volume, and ischaemic lesion accumulation. When combined with multiple sclerosis pathology, these age-related alterations may worsen clinical disability. Ageing may also influence the response of multiple sclerosis patients to therapies and/or their side effects, highlighting the importance of adjusted treatment considerations. MRI is highly sensitive to age- and multiple sclerosis-related processes. Accordingly, MRI can provide insights into the relationship between ageing and multiple sclerosis, enabling a better understanding of their pathophysiological interplay and informing treatment selection. This review summarizes current knowledge on the immunopathological and MRI aspects of ageing in the CNS in the context of multiple sclerosis. Starting from immunosenescence, ageing-related pathological mechanisms and specific features like enlarged Virchow-Robin spaces, this review then explores clinical aspects, including late-onset multiple sclerosis, the influence of age on diagnostic criteria, and comorbidity effects on imaging features. The role of MRI in understanding neurodegeneration, iron dynamics and myelin changes influenced by ageing and how MRI can contribute to defining treatment effects in ageing multiple sclerosis patients, are also discussed.

Quantification of white matter hyperintensities in type 1 diabetes and its relation to neuropathy and clinical characteristics

AIMS

The aims were to quantify periventricular and deep white matter hyperintensities (WMHs) in adults with type 1 diabetes with different neuropathic phenotypes and to correlate WMH measurements to explanatory factors in diabetes.

METHODS

WMH measurements were obtained from brain magnetic resonance imaging of 56 adults with type 1 diabetes in subgroups including painful diabetic peripheral neuropathy (DPN), painless DPN, without DPN and 20 healthy controls using Fazekas scale and automatic segmentation analysis.

RESULTS

No differences in Fazekas assessed WMHs were found (individuals with periventricular lesions: diabetes 66 % vs. controls 40 %, p = 0.063, deep lesions: diabetes 52 % vs. controls 50 %, p = 1.0). Using automatic detection, there were no significant differences in count of periventricular (p = 0.30) or deep (p = 0.31) WMHs. Higher periventricular lesion burden was present in diabetes compared with controls (0.21 % vs. 0.06 %, p = 0.048), which was associated with more severe DPN, increased age, decreased cognitive function, and reduced volumetric and metabolic brain measures (all p < 0.05).

CONCLUSIONS

Our findings indicate increased burden of periventricular WMHs in diabetes which were associated to DPN severity and measurements reflecting neurodegeneration. Deep WMHs, often considered as chronic ischemic, were not significantly different. Mechanisms reflecting neurodegeneration and accelerated brain aging could be an overlooked aspect of peripheral and central neuropathy.

The relationship between intracranial atherosclerosis and white matter hyperintensity in ischemic stroke patients: a retrospective cross-sectional study using high-resolution magnetic resonance vessel wall imaging

Background

Both intracranial atherosclerosis and white matter hyperintensity (WMH) are prevalent among the stroke population. However, the relationship between intracranial atherosclerosis and WMH has not been fully elucidated. Therefore, the aim of this study was to investigate the relationship between the characteristics of intracranial atherosclerotic plaques and the severity of WMH in patients with ischemic stroke using high-resolution magnetic resonance vessel wall imaging.

Methods

Patients hospitalized with ischemic stroke and concurrent intracranial atherosclerosis at Beijing Tsinghua Changgung Hospital, a tertiary comprehensive stroke center, who underwent high-resolution magnetic resonance vessel wall imaging and conventional brain magnetic resonance imaging were continuously recruited from January 2018 to December 2018. Both intracranial plaque characteristics (plaque number, maximum wall thickness, luminal stenosis, T1 hyperintensity, and plaque length) and WMH severity (Fazekas score and volume) were evaluated. Spearman correlation or point-biserial correlation analysis was used to determine the association between clinical characteristics and WMH volume. The independent association between intracranial plaque characteristics and the severity as well as WMH score was analyzed using logistic regression. The associations of intracranial plaque characteristics with total white matter hyperintensity (TWMH) volume, periventricular white matter hyperintensity (PWMH) volume and deep white matter hyperintensity (DWMH) volume were determined using multilevel mixed-effects linear regression.

Results

A total of 159 subjects (mean age: 64.0±12.5 years; 103 males) were included into analysis. Spearman correlation analysis indicated that age was associated with TWMH volume (r=0.529, P<0.001), PWMH volume (r=0.523, P<0.001) and DWMH volume (r=0.515, P<0.001). Point-biserial correlation analysis indicated that smoking (r=-0.183, P=0.021) and hypertension (r=0.159, P=0.045) were associated with DWMH volume. After adjusting for confounding factors, logistic regression analysis showed plaque number was significantly associated with the presence of severe WMH [odds ratio (OR), 1.590; 95% CI, 1.241-2.035, P<0.001], PWMH score of 3 (OR, 1.726; 95% CI, 1.074-2.775, P=0.024), and DWMH score of 2 (OR, 1.561; 95% CI, 1.150-2.118, P=0.004). Intracranial artery luminal stenosis was associated with presence of severe WMH (OR, 1.032; 95% CI, 1.002-1.064, P=0.039) and PWMH score of 2 (OR, 1.057; 95% CI, 1.008-1.109, P=0.023). Multilevel mixed-effects linear regression analysis showed that plaque number was associated with DWMH volume (β=0.128; 95% CI, 0.016-0.240; P=0.026) after adjusted for age and sex.

Conclusions

In ischemic stroke patients, intracranial atherosclerotic plaque characteristics as measured by plaque number and luminal stenosis were associated with WMH burden.

A multiphysics model to predict periventricular white matter hyperintensity growth during healthy brain aging

Periventricular white matter hyperintensities (WMH) are a common finding in medical images of the aging brain and are associated with white matter damage resulting from cerebral small vessel disease, white matter inflammation, and a degeneration of the lateral ventricular wall. Despite extensive work, the etiology of periventricular WMHs remains unclear. We pose that there is a strong coupling between age-related ventricular expansion and the degeneration of the ventricular wall which leads to a dysregulated fluid exchange across this brain-fluid barrier. Here, we present a multiphysics model that couples cerebral atrophy-driven ventricular wall loading with periventricular WMH formation and progression. We use patient data to create eight 2D finite element models and demonstrate the predictive capabilities of our damage model. Our simulations show that we accurately capture the spatiotemporal features of periventricular WMH growth. For one, we observe that damage appears first in both the anterior and posterior horns and then spreads into deeper white matter tissue. For the other, we note that it takes up to 12 years before periventricular WMHs first appear and derive an average annualized periventricular WMH damage growth rate of 15.2 ± 12.7 mm2/year across our models. A sensitivity analysis demonstrated that our model parameters provide sufficient sensitivity to rationalize subject-specific differences with respect to onset time and damage growth. Moreover, we show that the septum pellucidum, a membrane that separates the left and right lateral ventricles, delays the onset of periventricular WMHs at first, but leads to a higher WMH load in the long-term.

White Matter Hyperintensities in Young Patients from a Neurological Outpatient Clinic: Prevalence, Risk Factors, and Correlation with Enlarged Perivascular Spaces

(1) Background: to investigate the prevalence of white matter hyperintensities (WMH), risk factors, and correlation with enlarged perivascular spaces (ePVS) among young patients (age, 16–45 years) in a neurological outpatient clinic. (2) Methods: a total of 887 young patients who underwent a head magnetic resonance imaging (MRI)examination between 1 June 2021, and 30 November 2021, were included in this study. Paraventricular WMH (PWMH), deep WMH (DWMH), ePVS in the centrum semiovale (CSO-ePVS), and basal ganglia (BG-ePVS) were rated. Logistic regression analysis was used to identify the best predictors for the presence of WMH and, for the association of the severity of ePVS with the presence of WMH. Goodman–Kruskal gamma test was used to assess the correlation between the severity of ePVS and WMH. (3) Results: the prevalence of WMH was 37.0%, with low severity. Age, hypertension (p < 0.001), headache (p = 0.031), syncope (p = 0.012), and sleep disturbance (p = 0.003) were associated with the presence of DWMH. Age, sex (p = 0.032), hypertension (p = 0.004) and sleep disturbance (p < 0.001) were associated with the presence of PWMH. The severity of CSO-ePVS was associated with the presence and the severities of DWMH. The severity of BG-ePVS was associated with the presence and severities of DWMH and PWMH. (4) Conclusions: the prevalence of WMH was 37% and mild in young patients without specific causes. Older age, female, hypertension, headache, syncope, and sleep disturbance were associated with WMH. The severity of ePVS had an impact on the presence and severity of WMH in the corresponding brain regions.

Classification of white matter lesions and characteristics of small vessel disease markers

OBJECTIVES

Radiological markers for cerebral small vessel disease (SVD) may have different biological underpinnings in their development. We attempted to categorize SVD burden by integrating white matter signal abnormalities (WMSA) features and secondary presence of lacunes, microbleeds, and enlarged perivascular spaces.

METHODS

Data were acquired from 610 older adults (aged > 40 years) who underwent brain magnetic resonance imaging exam as part of a health checkup. The WMSA were classified individually by the number and size of non-contiguous lesions, distribution, and contrast. Age-detrended lacunes, microbleeds, and enlarged perivascular space were quantified to further categorize individuals. Clinical and laboratory values were compared across the individual classes.

RESULTS

Class I was characterized by multiple, small, deep WMSA but a low burden of lacunes and microbleeds; class II had large periventricular WMSA and a high burden of lacunes and microbleeds; and class III had limited juxtaventricular WMSA and lacked lacunes and microbleeds. Class II was associated with older age, diabetes, and a relatively higher neutrophil-to-lymphocyte ratio. Smoking and higher uric acid levels were associated with an increased risk of class I.

CONCLUSION

The heterogeneity of SVD was categorized into three classes with distinct clinical correlates. This categorization will improve our understanding of SVD pathophysiology, risk stratification, and outcome prediction.

KEY POINTS

• Classification of white matter signal abnormality (WMSA) features was associated with different characteristic of lacunes, microbleeds, and enlarged perivascular space and clinical variability. • Class I was characterized by multiple, small, deep WMSA but a low burden of lacunes and microbleeds. Class II had large periventricular WMSA and a high burden of lacunes and microbleeds. Class III had limited juxtaventricular WMSA and lacked lacunes and microbleeds. • Class II was associated with older age, diabetes, and higher neutrophil-to-lymphocyte ratio. Smoking and higher uric acid levels were associated with an increased risk of class I.

Use of proton pump inhibitor may be associated with progression of cerebral small vessel disease

Proton pump inhibitors (PPIs) are widely used for the treatment of gastrointestinal diseases. However, recent studies have shown that chronic PPI use is associated with the progression of endothelial senescence and cerebrovascular diseases. We hypothesized that PPI users might be vulnerable to fast progression of cerebral small vessel disease (SVD) with cumulative effects. Four hundred and eleven patients, who underwent brain magnetic resonance imaging, more than twice between January 2010 and December 2016 were screened. Patients aged < 50 years, and those who had concomitant diseases that might affect the progression of cerebral SVD were excluded. Baseline characteristics were collected. We evaluated the severity of SVD using the Fazekas score, the number of cerebral microbleeds (CMBs), and assessed the progression of SVD or CMBs based on the cumulative dose of PPIs. Among the included patients (N = 137), 39 were PPI ever-users. Univariate Cox regression analysis showed that PPI use was independently associated with the progression of Fazekas score only in the deep white matter hyperintensities (WMH) (hazard ratio [HR] 2.891, 95% confidence interval [CI] 1.210-6.906, P = 0.017). In multivariate Cox regression analysis, long-term PPI use was associated with a progression of Fazekas score in the deep WMH (HR 3.453, 95% CI 1.027-9.475, P = 0.045). However, PPI use was not associated with the progression of CMB. The present study results suggest that long-term use of PPIs is associated with the progression of deep cerebral WMH. Further research is needed using a large number of patients to validate this relationship.

Hormonal factors moderate the associations between vascular risk factors and white matter hyperintensities

To examine the moderation effects of hormonal factors on the associations between vascular risk factors and white matter hyperintensities in men and women, separately. White matter hyperintensities were automatically segmented and quantified in the UK Biobank dataset (N = 18,294). Generalised linear models were applied to examine (1) the main effects of vascular and hormonal factors on white matter hyperintensities, and (2) the moderation effects of hormonal factors on the relationship between vascular risk factors and white matter hyperintensities volumes. In men with testosterone levels one standard deviation higher than the mean value, smoking was associated with 27.8% higher white matter hyperintensities volumes in the whole brain. In women with a shorter post-menopause duration (one standard deviation below the mean), diabetes and higher pulse wave velocity were associated with 28.8% and 2.0% more deep white matter hyperintensities, respectively. These findings highlighted the importance of considering hormonal risk factors in the prevention and management of white matter hyperintensities.

3D finite-element brain modeling of lateral ventricular wall loading to rationalize periventricular white matter hyperintensity locations

Aging-related periventricular white matter hyperintensities (pvWMHs) are a common observation in medical images of the aging brain. The underlying tissue damage is part of the complex pathophysiology associated with age-related microstructural changes and cognitive decline. PvWMH formation is linked to blood-brain barrier dysfunction from cerebral small vessel disease as well as the accumulation of cerebrospinal fluid in periventricular tissue due to progressive denudation of the ventricular wall. In need of a unifying theory for pvWMH etiology, image-based finite-element modeling is used to demonstrate that ventricular expansion from age-related cerebral atrophy and hemodynamic loading leads to maximum mechanical loading of the ventricular wall in the same locations that show pvWMHs. Ventricular inflation, induced via pressurization of the ventricular wall, creates significant ventricular wall stretch and stress on the ependymal cells lining the wall, that are linked to cerebrospinal fluid leaking from the lateral ventricles into periventricular white matter tissue. Eight anatomically accurate 3D brain models of cognitively healthy subjects with a wide range of ventricular shapes are created. For all models, our simulations show that mechanomarkers of mechanical wall loading are consistently highest in pvWMHs locations (p < 0.05). Maximum principal strain, the ependymal cell thinning ratio, and wall curvature are on average 14%, 8%, and 24% higher in pvWMH regions compared to the remaining ventricular wall, respectively. Computational modeling provides a powerful framework to systematically study pvWMH formation and growth with the goal to develop pharmacological interventions in the future.

Obstructive sleep apnea and white matter hyperintensities: correlation or causation?

Obstructive sleep apnea (apnea) is thought to cause small vessel ischemic episodes in the brain from hypoxic events, postulated as white matter hyperintensities (hyperintensities) identified on MRI which are implicated in cognitive decline. This study sought to evaluate these correlations. A retrospective evaluation of adults who underwent polysomnography (4/1/2016 to 4/30/2017) and a brain MRI prior to apnea diagnosis or within a year post-diagnosis was completed. MRI visual evaluation of hyperintensities using Fazekas scores were collected blind to clinical data. Collated clinical/MRI data were stratified and analyzed using chi-square, fishers t-tests, ANOVA/ANCOVA and linear regression. Stratification by apnea category revealed no significant differences in any variables including hyperintensity measures (Fazekas p=0.1584; periventricular p=0.3238; deep p=0.4618; deep total p=0.1770). Stratification by Fazekas category, periventricular and deep hyperintensities revealed increasing prevalence with age (p=0.0001); however, apnea categories were not significantly associated (Fazekas p=0.1479; periventricular p=0.3188; deep p=0.4503), nor were any individual apnea indicators. Continuous apnea measurements werre not associated with any hyperintensity factor; total deep hyperintensities were not associated with any apnea factors. Continuous BMI was not found to be associated with any apnea or hyperintensity factors. Only hypertension was noted to be associated with Fazekas (p=0.0045), deep (p=0.0010) and total deep (p=0.0021) hyperintensities; however, hypertension was not associated with apnea category (p=0.3038) or any associated factors. These data suggest apneas alone from OSA are insufficient to cause WMH, but other factors appear to contribute to the complex development of small vessel ischemic injury associated with age and cognitive decline.

Brain aging mechanisms with mechanical manifestations

Brain aging is a complex process that affects everything from the subcellular to the organ level, begins early in life, and accelerates with age. Morphologically, brain aging is primarily characterized by brain volume loss, cortical thinning, white matter degradation, loss of gyrification, and ventricular enlargement. Pathophysiologically, brain aging is associated with neuron cell shrinking, dendritic degeneration, demyelination, small vessel disease, metabolic slowing, microglial activation, and the formation of white matter lesions. In recent years, the mechanics community has demonstrated increasing interest in modeling the brain's (bio)mechanical behavior and uses constitutive modeling to predict shape changes of anatomically accurate finite element brain models in health and disease. Here, we pursue two objectives. First, we review existing imaging-based data on white and gray matter atrophy rates and organ-level aging patterns. This data is required to calibrate and validate constitutive brain models. Second, we review the most critical cell- and tissue-level aging mechanisms that drive white and gray matter changes. We focuse on aging mechanisms that ultimately manifest as organ-level shape changes based on the idea that the integration of imaging and mechanical modeling may help identify the tipping point when normal aging ends and pathological neurodegeneration begins.

Performance of the 2017 and 2010 Revised McDonald Criteria in Predicting MS Diagnosis After a Clinically Isolated Syndrome: A MAGNIMS Study

BACKGROUND AND OBJECTIVES

To compare the performance of the 2017 revisions to the McDonald criteria with the 2010 McDonald criteria in establishing MS diagnosis and predicting prognosis in patients with clinically isolated syndrome (CIS) suggestive of multiple sclerosis (MS).

METHODS

CSF examination, brain and spinal cord MRI obtained ≤5 months from CIS onset, and a follow-up brain MRI acquired within 15 months from CIS onset were evaluated in 785 CIS patients from 9 European centers. Date of second clinical attack and of reaching Expanded Disability Status Score (EDSS) ≥ 3.0, if they occurred, were also collected. Performance of the 2017 and 2010 McDonald criteria for dissemination in space (DIS), time (DIT) (including oligoclonal bands assessment) and DIS + DIT for predicting a second clinical attack (clinically definite [CD] MS) and EDSS ≥ 3.0 at follow-up was evaluated. Time to MS diagnosis for the different criteria was also estimated.

RESULTS

At follow-up (median = 69.1 months), 406/785 CIS patients developed CDMS. At 36 months, the 2017 DIS + DIT criteria had higher sensitivity (0.83 vs 0.66), lower specificity (0.39 vs 0.60) and similar area under the curve values (0.61 vs 0.63). Median time to MS diagnosis was shorter with the 2017 vs the 2010 or CDMS criteria (2017 revision = 3.2; 2010 revision = 13.0; CDMS = 58.5 months). The 2 sets of criteria similarly predicted EDSS ≥ 3.0 milestone. Three periventricular lesions improved specificity in patients ≥45 years.

DISCUSSION

The 2017 McDonald criteria showed higher sensitivity, lower specificity and similar accuracy in predicting CDMS compared to 2010 McDonald criteria, while shortening time to diagnosis of MS.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that the 2017 McDonald Criteria more accurately distinguish CDMS in patients early after a CIS when compared to the 2010 McDonald criteria.

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

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.

MTT and Blood-Brain Barrier Disruption within Asymptomatic Vascular WM Lesions

BACKGROUND AND PURPOSE

White matter lesions of presumed ischemic origin are associated with progressive cognitive impairment and impaired BBB function. Studying the longitudinal effects of white matter lesion biomarkers that measure changes in perfusion and BBB patency within white matter lesions is required for long-term studies of lesion progression. We studied perfusion and BBB disruption within white matter lesions in asymptomatic subjects.

MATERIALS AND METHODS

Anatomic imaging was followed by consecutive dynamic contrast-enhanced and DSC imaging. White matter lesions in 21 asymptomatic individuals were determined using a Subject-Specific Sparse Dictionary Learning algorithm with manual correction. Perfusion-related parameters including CBF, MTT, the BBB leakage parameter, and volume transfer constant were determined.

RESULTS

MTT was significantly prolonged (7.88 [SD, 1.03] seconds) within white matter lesions compared with normal-appearing white (7.29 [SD, 1.14] seconds) and gray matter (6.67 [SD, 1.35] seconds). The volume transfer constant, measured by dynamic contrast-enhanced imaging, was significantly elevated (0.013 [SD, 0.017] minutes-1) in white matter lesions compared with normal-appearing white matter (0.007 [SD, 0.011] minutes-1). BBB disruption within white matter lesions was detected relative to normal white and gray matter using the DSC-BBB leakage parameter method so that increasing BBB disruption correlated with increasing white matter lesion volume (Spearman correlation coefficient = 0.44; P < .046).

CONCLUSIONS

A dual-contrast-injection MR imaging protocol combined with a 3D automated segmentation analysis pipeline was used to assess BBB disruption in white matter lesions on the basis of quantitative perfusion measures including the volume transfer constant (dynamic contrast-enhanced imaging), the BBB leakage parameter (DSC), and MTT (DSC). This protocol was able to detect early pathologic changes in otherwise healthy individuals.

Cerebral Small-Vessel Disease in Individuals with a Family History of Coronary Heart Disease: The Atherosclerosis Risk in Communities Study

INTRODUCTION

The degree to which a family history of coronary heart disease (FHCHD) is associated with silent cerebral small-vessel disease (cSVD) among healthy adults, independent of prevalent CHD and traditional risk factors, is unknown.

METHODS

The Atherosclerosis Risk in Communities (ARIC) study is a community-based cohort study with self-reported family history data and brain magnetic resonance imaging (ages 68-88). The association between markers of cSVD (lacunar infarcts and cerebral microbleeds), or log-transformed white matter hyperintensity (WMH) volume, and FHCHD, or the number of affected relatives was examined using separate adjusted logistic or linear regression models, respectively. Race interaction terms were evaluated.

RESULTS

Of 1,639 participants without prevalent CHD (76 ± 5 years, 62% female, 29% black), 686 (42%) had FHCHD. There were higher odds of lacunar infarct (OR 1.40, 95% CI 1.07-1.84) among those with parental FHCHD and higher odds of microhemorrhages (lobar OR 1.86, 95% CI 1.13-3.06; subcortical OR 1.47, 95% CI 1.01-2.15) among those with sibling FHCHD. A greater number of any relative affected was associated with higher odds of lacunar infarct (OR 1.24, 95% CI 1.04-1.47) and lobar microhemorrhages (OR 1.31, 95% CI 1.05-1.64) but not subcortical microhemorrhages (OR 1.09, 95% CI 0.92-1.28). Odds of having a lacunar infarct were higher among blacks (p-interaction 0.04) with paternal FHCHD (OR 2.20, CI 1.35-3.58) than whites with paternal FHCHD (OR 1.17, CI 0.87-1.56). There was no association with WMH.

DISCUSSION/CONCLUSION

Markers of cSVD, specifically lacunar infarcts and microhemorrhages, appear to be associated with FHCHD, potentially representing shared mechanisms in different vascular beds, and perhaps a genetic propensity for vascular disease.

Association of Coronary Artery Atherosclerosis With Brain White Matter Hyperintensity

[Figure: see text].

White Matter Lesions as Possible Predictors of Audiological Performance in Adults after Cochlear Implantation

The presented prospective study investigated whether structural brain damage, measured with the Fazekas score, could predict hearing rehabilitation outcomes with cochlear implantation (CI). With a follow-up period of 24 months, this study included 49 bilaterally, postlingually hearing impaired CI candidates for unilateral CI (67.3 ± 8.7 years; 20 men, 29 women) older than 50 at the time of implantation. The differences in the predictive value between two age groups, 50-70 year-olds (mid-age; n = 26) and over 70-year-olds (elderly; n = 23), were analyzed. The patients were evaluated using speech perception (SP) measured in quiet (Freiburg monosyllabic test; FMT) and noise (Oldenburg sentence test; OLSA). The subjective hearing ability was assessed using Oldenburg inventory (OI). The Fazekas PVWM score predicted postoperative speech perception two years after CI in the mid-age population. The periventricular white matter lesions (PVWM) could explain 27.4% of the speech perception (FMT) variance. Our findings support the hypothesis about the influence of pre-existing WMLs on CI outcome. We recommend the evaluation of Fazekas score as a predictive factor for post-implantation hearing ability.

Increased internal cerebral vein diameter is associated with age

OBJECTIVE

A recent study described the relationship between cerebral venous diameter and white matter hyperintensity (WMH) volume. However, the adults were not further grouped; therefore, we aimed to compare across age groups and use susceptibility-weighted imaging (SWI) to explore whether there is also a relationship between a larger cerebral draining venous diameter and age, which could provide evidence of a temporal relationship.

METHODS

We retrospectively analysed data collected from 405 subjects (90 youths, 166 middle-aged participants, and 149 elderly subjects) and respectively used T2-weighted fluid-attenuated inversion recovery (FLAIR) and SWI to assess WMHs and venous diameter.

RESULTS

An increased internal cerebral vein (ICV) diameter was associated with age in different WMH groups (F = 3.453, 10.437, 11.746, and 21.723, respectively, all p < 0.001; multiple comparisons all p < 0.05), whereas the effect of the anterior septal vein (ASV) was opposite (F = 1.046, 1.210, 0.530, and 0.078, respectively, p > 0.05). There was a positive correlation between the ICV diameter and age with increasing WMH severity (R = 0.727, 0.709, 0.754, and 0.830, respectively, all p < 0.001). A statistically significant relationship between the thalamostriate vein (TSV) diameter and age was observed only in the moderate and severe WMH groups (F = 4.070 and 3.427, respectively, all p < 0.05; multiple comparisons all p < 0.05).

CONCLUSIONS

Our study demonstrates that increased TSV and ICV diameters are associated with age with increasing WMH severity, especially the ICV diameter using SWI.

Heterogeneity of Cerebral White Matter Lesions and Clinical Correlates in Older Adults

BACKGROUND AND PURPOSE

Cerebral white matter signal abnormalities (WMSAs) are a significant radiological marker associated with brain and vascular aging. However, understanding their clinical impact is limited because of their pathobiological heterogeneity. We determined whether use of robust reliable automated procedures can distinguish WMSA classes with different clinical consequences.

METHODS

Data from generally healthy participants aged >50 years with moderate or greater WMSA were selected from the Human Connectome Project-Aging (n=130). WMSAs were segmented on T1 imaging. Features extracted from WMSA included total and regional volume, number of discontinuous clusters, size of noncontiguous lesion, contrast of lesion intensity relative to surrounding normal appearing tissue using a fully automated procedure. Hierarchical clustering was used to classify individuals into distinct classes of WMSA. Radiological and clinical variability was evaluated across the individual WMSA classes.

RESULTS

Class I was characterized by multiple, small, lower-contrast lesions predominantly in the deep WM; class II by large, confluent lesions in the periventricular WM; and class III by higher-contrast lesions restricted to the juxtaventricular WM. Class II was associated with lower myelin content than the other 2 classes. Class II was more prevalent in older subjects and was associated with a higher prevalence of hypertension and lower physical activity levels. Poor sleep quality was associated with a greater risk of class I.

CONCLUSIONS

We classified heterogeneous subsets of cerebral white matter lesions into distinct classes that have different clinical risk factors. This new method for identifying classes of WMSA will be important in understanding the underlying pathophysiology and in determining the impact on clinical outcomes.

An incomplete Circle of Willis is not a risk factor for white matter hyperintensities: The Tromsø Study

OBJECTIVE

The Circle of Willis (CoW) is often underdeveloped or incomplete, leading to suboptimal blood supply to the brain. As hypoperfusion is thought to play a role in the aetiology of white matter hyperintensities (WMH), the objective of this study was to assess whether incomplete CoW variants were associated with increased WMH volumes compared to the complete CoW.

METHODS

In a cross-sectional population sample of 1751 people (age 40-84 years, 46.4% men), we used an automated method to segment WMH using T1-weighted and T2-weighted fluid-attenuated inversion recovery image obtained at 3T. CoW variants were classified from time-of-flight scans, also at 3T. WMH risk factors, including age, sex, smoking and blood pressure, were obtained from questionnaires and clinical examinations. We used linear regression to examine whether people with incomplete CoW variants had greater volumes of deep WMH (DWMH) and periventricular WMH (PWMH) compared to people with the complete CoW, correcting for WMH risk factors.

RESULTS

Participants with incomplete CoW variants did not have significantly higher DWMH or PWMH volumes than those with complete CoW when accounting for risk factors. Age, pack-years smoking, and systolic blood pressure were risk factors for increased DWMH and PWMH volume. Diabetes was a unique risk factor for increased PWMH volume.

CONCLUSION

Incomplete CoW variants do not appear to be risk factors for WMH in the general population.

White Matter Injury Is Associated with Reduced Manual Dexterity and Elevated Serum Ceramides in Subjects with Cerebral Small Vessel Disease

INTRODUCTION

We have demonstrated that asymptomatic cerebral small vessel disease (cSVD) measured by white matter hyperintensity volume is associated with reduced manipulative manual dexterity on the Grooved Peg Board Test (GPBT) in middle-aged healthy individuals with a family history of early coronary artery disease. In this current study, we aim to identify the association of subcortical white matter microstructural impairment measured by diffusion tensor imaging, manual dexterity measured by GPBT and circulating serums ceramide, another marker for white matter injury. We hypothesize that lower regional fractional anisotropy (rFA) is associated with worse performance on GPBT and elevated serum ceramides in the same study population.

METHODS

rFA of 48 regions representing the subcortical white matters were analyzed in GeneSTAR participants in addition to serum ceramides and GPBT scores. Unadjusted univariable analyses with Bonferroni correction for multiple comparisons were completed using Spearman correlation for testing the associations between ceramides, rFA of subcortical white matter, and GPBT performance. Subsequently, sensitivity analyses were performed after excluding the participants that had any physical limitation that may influence their performance on GPBT. Finally, in the adjusted analysis using generalized estimating equation, linear regression models were performed for the areas that met significance threshold in the unadjusted analyses.

RESULTS

112 subjects (age [49 ± 11], 51% female, 39.3% African American) were included. Adjusted analyses for the significant correlations that met the Bonferroni correction threshold in the unadjusted univariable analyses identified significant negative associations between rFA of the right fornix (RF) and log-GPBT score (β = -0.497, p = 0.037). In addition, rFA of RF negatively correlated with log serum ceramide levels (C18: β = -0.03, p = 0.003, C20: β = -0.0002, p = 0.004) and rFA of left genu of corpus callosum negatively correlated with log C18 level (β = -0.0103, p = 0.027).

CONCLUSIONS

These results demonstrate that subcortical microstructural white matter disruption is associated with elevated serum ceramides and reduced manual dexterity in a population with cSVD. These findings suggest that injury to white matter tracts undermines neural networks, with functional consequences in a middle-aged population with cardiovascular risk factors.

Sex differences in risk factors for white matter hyperintensities in non-demented older individuals

White matter hyperintensities (WMH) are generally considered to be associated with cerebral small vessel disease, especially, in older age. Although significant sex differences have been reported in the severity of WMH, it is not yet known if the risk factors for WMH differ in men and women. In this study, magnetic resonance imaging brain scans from 2 Australian cohorts were analyzed to extract WMH volumes. The objective of this study is to examine the moderation effect by sex in the association between known risk factors and WMH. The burden of WMH was significantly higher in women compared to men, especially in the deep WMH (DWMH). In the generalized linear model that included the interaction between sex and body mass index (BMI), there was a differential association of BMI with DWMH in men and women in the exploratory sample, that is, the Sydney Memory and Aging Study, n = 432, aged between 70 and 90. The finding of a higher BMI associated with a higher DWMH in men compared to women was replicated in the Older Australian Twins Study sample, n = 179, aged between 65 and 90. The risk factors of WMH pathology are suggested to have a different impact on the aging brains of men and women.

Headache intensity is associated with increased white matter lesion burden in CADASIL patients

OBJECTIVES

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most common hereditary cause of vascular dementia in adults. Migraine is a major symptom of the disease. We aimed to identify clinical and demographical features of the headache associated with increased cerebral lesion burden in a cohort of CADASIL patients.

METHODS

Thirty-two patients with CADASIL were enrolled in this cross-sectional study. Demographics data, vascular risk factors and headache characteristics were collected through a structured questionnaire. MRI (3-T) was used to determine white matter hyperintensities burden evaluated by its volume (WMH-V).

RESULTS

Regression analysis showed that age (β = 1.266, 95%CI = [0.805, 1.726], p < 0.001), headache intensity (β = 5.143, 95%CI = [2.362, 7.924], p = 0.001) and female sex (β = 19.727, 95%CI = [8.750, 30.075], p = 0.001) were the main predictors of WMH-V.

DISCUSSION

Age, female sex and headache intensity are associated with increased white matter lesion volume in CADASIL.

The study on analysis of risk factors for severity of white matter lesions and its correlation with cerebral microbleeds in the elderly with lacunar infarction

This study aimed to explore the risk factors for severity of white matter lesions and its correlation with in the elderly with lacunar infarction.Patients (range, 70-85 years) with lacunar infarction treated in a hospital in China from 2016 to 2017were enrolled. Fazekas rating scale (0-6 points) was used to assess severity of white matter lesions. Risk factors for the severity of white matter lesions and correlation between cerebral microbleeds and white matter lesions in the elderly with lacunar infarction were studied.The elderly (81-85 years' old, odds ratio [OR]: 2.423, 95% confidence interval [CI]: 1.795-3.271, P = .018; 76∼80 years' old, OR: 3.113, 95% CI: 1.723-5.625, P = .043), carotid atherosclerosis (OR: 3.062, 95% CI:1.715-5.468, P < .001), history of hypertension (OR: 3.694, 95% CI: 2.031-6.717, P < .001) were risk factors for the severity of white matter lesions. The white matter lesions score increased corresponding to increase in the cerebral microbleeds grade (P < .001). The white matter lesions score was higher in the cerebral microbleeds combined with the white matter lesions group than in the white matter lesions group (P < .01). After correcting the effects of age, there was a correlation between white matter lesions and cerebral microbleeds (P < .001). Logistic analysis revealed that the patients' age (81-85 years' old, OR: 2.722, 95% CI: 1.985-3.734, P = .019; 76∼80 years' old, OR: 1.857, 95% CI: 1.075-3.207, P = .031), history of hypertension (OR: 2.931, 95% CI: 1.136-7.567, P = 0.0.036), systolic blood pressure (OR: 1.049, 95% CI: 1.015-1.084, P = .007), high-sensitivity C-reactive protein (OR: 1.504, 95% CI: 1.254-1.803, P < .001), homocysteine (OR: 1.076, 95% CI: 1.020-1.136, P = .009), and carotid atherosclerosis (OR: 1.389, 95% CI: 1.103-1.748, P = .010) were significant risk factors for combined cerebral microbleeds with white matter lesions in patients with lacunar infarction.The elderly, carotid atherosclerosis, history of hypertension were risk factors for the severity of white matter lesions. Cerebral microbleeds were positively correlated with the severity of white matter lesions.

The effect of white matter hyperintensities on regional brain volumes and white matter microstructure, a population-based study in HUNT

Even though age-related white matter hyperintensities (WMH) begin to emerge in middle age, their effect on brain micro- and macrostructure in this age group is not fully elucidated. We have examined how presence of WMH and load of WMH affect regional brain volumes and microstructure in a validated, representative general population sample of 873 individuals between 50 and 66 years. Presence of WMH was determined as Fazakas grade ≥1. WMH load was WMH volume from manual tracing of WMHs divided on intracranial volume. The impact of age appropriate WMH (Fazakas grade 1) on the brain was also investigated. Major novel findings were that even the age appropriate WMH group had widespread macro- and microstructural changes in gray and white matter, showing that the mere presence of WMH, not just WMH load is an important clinical indicator of brain health. With increasing WMH load, structural changes spread centrifugally. Further, we found three major patterns of FA and MD changes related to increasing WMH load, demonstrating a heterogeneous effect on white matter microstructure, where distinct patterns were found in the proximity of the lesions, in deep white matter and in white matter near the cortex. This study also raises several questions about the onset of WMH related pathology, in particular, whether some of the aberrant brain structural and microstructural findings are present before the emergence of WMH. We also found, similar to other studies, that WMH risk factors had low explanatory power for WMH, making it unclear which factors lead to WMH.

Patients with Mild Traumatic Brain Injury Recruited from Both Hospital and Primary Care Settings: A Controlled Longitudinal Magnetic Resonance Imaging Study

With an emphasis on traumatic axonal injury (TAI), frequency and evolution of traumatic intracranial lesions on 3T clinical magnetic resonance imaging (MRI) were assessed in a combined hospital and community-based study of patients with mild traumatic brain injury (mTBI). The findings were related to post-concussion symptoms (PCS) at 3 and 12 months. Prospectively, 194 patients (16–60 years of age) were recruited from the emergency departments at a level 1 trauma center and a municipal outpatient clinic into the Trondheim mTBI follow-up study. MRI was acquired within 72 h (n = 194) and at 3 (n = 165) and 12 months (n = 152) in patients and community controls (n = 78). The protocol included T2, diffusion weighted imaging, fluid attenuated inversion recovery (FLAIR), and susceptibility weighted imaging (SWI). PCS was assessed with British Columbia Post Concussion Symptom Inventory in patients and controls. Traumatic lesions were present in 12% on very early MRI, and in 5% when computed tomography (CT) was negative. TAI was found in 6% and persisted for 12 months on SWI, whereas TAI lesions on FLAIR disappeared or became less conspicuous on follow-up. PCS occurred in 33% of patients with lesions on MRI and in 19% in patients without lesions at 3 months (p = 0.12) and in 21% with lesions and 14% without lesions at 12 months (p = 0.49). Very early MRI depicted cases of TAI in patients with mTBI with microbleeds persisting for 12 months. Patients with traumatic lesions may have a more protracted recovery, but the study was underpowered to detect significant differences for PCS because of the low frequency of trauma-related MRI lesions.

Aging and Brain Atrophy in Multiple Sclerosis

BACKGROUND AND PURPOSE

Brain atrophy accelerates at the age of 60 in healthy individuals (HI) and at disease onset in multiple sclerosis (MS) patients. Whether there is an exacerbating effect of aging superimposed on MS-related brain atrophy is unknown. We estimated the aging effect on lateral ventricular volume (LVV) and whole brain volume (WBV) changes in MS patients.

METHODS

1,982 MS patients (mean follow-up: 4.8 years) and 351 HI (mean follow-up: of 3.1 years), aged from 20 to 79 years old (yo), were collected retrospectively. Percent LVV change (PLVVC) and percent brain volume change (PBVC) on 1.5T and 3T MRI scanners (median of 3.9 scans per subject) were calculated. These were determined between all-time points and subjects were divided in six-decade age groups. MRI differences between age groups were calculated using analysis of covariance (ANCOVA).

RESULTS

Compared to HI, at first MRI, MS patients had significantly increased LVV in the age groups: 30-39 yo, 40-49 yo, 50-59 yo, 60-69 yo (all P < .0001), and 70-79 yo (P = .029), and decreased WBV in the age groups: 20-29 yo (P = .024), 30-39 yo (P = .031), 40-49 yo, and 50-59 yo (all P < .0001). Annualized PLVVC was significantly different between the age groups 20-59 and 60-79 yo in MS patients (P = .005) and HI (P < .0001), as was for PBVC in MS patients (P = .001), but not for HI (P = .521). There was a significant aging interaction effect in the annualized PLVVC (P = .001) between HI and MS patients, which was not observed for the annualized PBVC (P = .380).

CONCLUSIONS

Development of brain atrophy manifests progressively in MS patients, and occurs with a different pattern, as compared to aging HI. PLVVC increased across age in HI as compared to MS, while PBVC decreased across ages in both HI and MS.

Endothelial damage, vascular bagging and remodeling of the microvascular bed in human microangiopathy with deep white matter lesions

White matter lesions (WMLs) are a common manifestation of small vessel disease (SVD) in the elderly population. They are associated with an enhanced risk of developing gait abnormalities, poor executive function, dementia, and stroke with high mortality. Hypoperfusion and the resulting endothelial damage are thought to contribute to the development of WMLs. The focus of the present study was the analysis of the microvascular bed in SVD patients with deep WMLs (DWMLs) by using double- and triple-label immunohistochemistry and immunofluorescence. Simultaneous visualization of collagen IV (COLL4)-positive membranes and the endothelial glycocalyx in thick sections allowed us to identify endothelial recession in different types of string vessels, and two new forms of small vessel/capillary pathology, which we called vascular bagging and ghost string vessels. Vascular bags were pouches and tubes that were attached to vessel walls and were formed by multiple layers of COLL4-positive membranes. Vascular bagging was most severe in the DWMLs of cases with pure SVD (no additional vascular brain injury, VBI). Quantification of vascular bagging, string vessels, and the density/size of CD68-positive cells further showed widespread pathological changes in the frontoparietal and/or temporal white matter in SVD, including pure SVD and SVD with VBI, as well as a significant effect of the covariate age. Plasma protein leakage into vascular bags and the white matter parenchyma pointed to endothelial damage and basement membrane permeability. Hypertrophic IBA1-positive microglial cells and CD68-positive macrophages were found in white matter areas covered with networks of ghost vessels in SVD, suggesting phagocytosis of remnants of string vessels. However, the overall vessel density was not altered in our SVD cohort, which might result from continuous replacement of vessels. Our findings support the view that SVD is a progressive and generalized disease process, in which endothelial damage and vascular bagging drive remodeling of the microvasculature.

Differential impact of white matter hyperintensities on long-term outcomes in ischemic stroke patients with large artery atherosclerosis

BACKGROUND

The presence of white matter hyperintensity (WMH) is related to poor long-term outcomes in stroke patients. However, the long-term outcome is unknown in patients with both large artery atherosclerosis (LAA) and WMH.

METHODS

We investigated the impact of WMH on long-term outcome in patients with LAA. Consecutive patients in a prospective stroke registry were included. Patients were followed for a median of 7.7 years (interquartile range, 5.6-9.7). The degree of WMH was assessed by Fazekas grade on fluid-attenuated inversion recovery images. Total WMH burden was calculated by summation of Fazekas scores in periventricular and deep white matter. Severe WMH was defined as total burden score ≥ 3.

RESULTS

Among 2529 patients, 639 patients (25.3%) were classified with the LAA subtype. After applying exclusion criteria, the data from 538 patients were analyzed. The mean patient age was 65.7 ± 10.3 years. Severe WMHs were found in 243 patients (45.2%). During follow-up, 200 patients (37.2%) died. Cox regression analysis showed that LAA patients with severe WMH had a 1.50-fold (95% CI, 1.12-2.00, p = 0.007) higher death rate compared to those without. In the older age group (≥65 years), Cox regression revealed that patients with severe WMH had a 1.75-fold (95% CI, 1.15-2.65, p = 0.008) higher 5-year death rate, whereas the younger age group did not have this association.

CONCLUSION

The degree of WMH might be a surrogate marker for long-term outcome in patients with LAA. Atherosclerotic burdens in both small and large arteries might impact long-term prognosis in ischemic stroke patients.

Early Age-Related Functional Connectivity Decline in High-Order Cognitive Networks

As the world ages, it becomes urgent to unravel the mechanisms underlying brain aging and find ways of intervening with them. While for decades cognitive aging has been related to localized brain changes, growing attention is now being paid to alterations in distributed brain networks. Functional connectivity magnetic resonance imaging (fcMRI) has become a particularly useful tool to explore large-scale brain networks; yet, the temporal course of connectivity lifetime changes has not been established. Here, an extensive cross-sectional sample (21-85 years old, N = 887) from a public fcMRI database was used to characterize adult lifespan connectivity dynamics within and between seven brain networks: the default mode, salience, dorsal attention, fronto-parietal control, auditory, visual and motor networks. The entire cohort was divided into young (21-40 years, mean ± SD: 25.5 ± 4.8, n = 543); middle-aged (41-60 years, 50.6 ± 5.4, n = 238); and old (61 years and above, 69.0 ± 6.3, n = 106) subgroups. Correlation matrices as well as a mixed model analysis of covariance indicated that within high-order cognitive networks a considerable connectivity decline is already evident by middle adulthood. In contrast, a motor network shows increased connectivity in middle adulthood and a subsequent decline. Additionally, alterations in inter-network interactions are noticeable primarily in the transition between young and middle adulthood. These results provide evidence that aging-related neural changes start early in adult life.

First evidence for glial pathology in late life minor depression: S100B is increased in males with minor depression

Minor depression is diagnosed when a patient suffers from 2 to 4 depressive symptoms for at least 2 weeks. Though minor depression is a widespread phenomenon, its pathophysiology has hardly been studied. To get a first insight into the pathophysiological mechanisms underlying this disorder we assessed serum levels of biomarkers for plasticity, glial and neuronal function: brain-derived neurotrophic factor (BDNF), S100B and neuron specific enolase (NSE). 27 subjects with minor depressive episode and 82 healthy subjects over 60 years of age were selected from the database of the Leipzig population-based study of civilization diseases (LIFE). Serum levels of BDNF, S100B and NSE were compared between groups, and correlated with age, body-mass index (BMI), and degree of white matter hyperintensities (score on Fazekas scale). S100B was significantly increased in males with minor depression in comparison to healthy males, whereas other biomarkers did not differ between groups (p = 0.10–0.66). NSE correlated with Fazekas score in patients with minor depression (r_s = 0.436, p = 0.048) and in the whole sample (r_s = 0.252, p = 0.019). S100B correlated with BMI (r_s = 0.246, p = 0.031) and with age in healthy subjects (r_s = 0.345, p = 0.002). Increased S100B in males with minor depression, without alterations in BDNF and NSE, supports the glial hypothesis of depression. Correlation between white matter hyperintensities and NSE underscores the vascular hypothesis of late life depression.