Migraine or any headaches and white matter hyperintensities and their progression in women and men

BACKGROUND

Cross-sectional and longitudinal studies have been conducted to investigate the association between migraine and any headache and white matter hyperintensities (WMH). However, studies are inconsistent regarding the strength of the association and its clinical significance. The aim of our study was to investigate the association between headache and its subtypes (migraine with aura (MigA+), migraine without aura (MigA-), non-migraine headache (nonMigHA)) and WMH and its course in the population-based 1000BRAINS study using state-of-the-art imaging techniques and migraine classification according to modified international classification of headache disorders.

METHODS

Data from 1062 participants (45% women, 60.9 ± 13.0 years) with ever or never headache (neverHA) and complete quantitative (WMH volume) and qualitative (Fazekas classification) WMH data at first imaging and after 3.7 ± 0.7 years (393 participants) were analyzed. The sex-specific association between headache and its subtypes and WMH volume and its change was evaluated by linear regression, between headache and its subtypes and Fazekas score high vs. low (2-3 vs. 0-1) by log-binomial regression, adjusted for confounders.

RESULTS

The lifetime prevalence of headache was 77.5% (10.5% MigA+, 26.9% MigA-, 40.1% nonMigHA). The median WMH volume was 4005 (IQR: 2454-6880) mm3 in women and 4812 (2842-8445) mm3 in men. Women with any headaches (all headache types combined) had a 1.23 [1.04; 1.45]-fold higher WMH volume than women who reported never having had a headache. There was no indication of higher Fazekas grading or more WMH progression in women with migraine or any headaches. Men with migraine or any headaches did not have more WMH or WMH progression compared to men without migraine or men who never had headache.

CONCLUSIONS

Our study demonstrated no increased occurrence or progression of WMH in participants with mgiraine. But, our results provide some evidence of greater WMH volume in women with headache of any type including migraine. The underlying pathomechanisms and the reasons why this was not shown in men are unclear and require further research.

Aldosterone is Associated with New-onset Cerebrovascular Events in Patients with Hypertension and White Matter Lesions: A cohort study

OBJECTIVE

White matter lesions (WMLs) increase the risk of stroke, stroke recurrence, and death. Higher plasma aldosterone concentration (PAC) increases the risk of stroke, acute myocardial infarction, and hypertension. To evaluate the relationship between PAC and cerebrovascular events in patients with hypertension and WMLs.

METHODS

We conducted a retrospective cohort study that included 1041 participants hospitalized. The outcome was new-onset cerebrovascular events including intracerebral hemorrhage and stroke. A Cox regression model was used to evaluate the relationship between baseline PAC and the risk of cerebrovascular events.

RESULTS

The mean age of participants was 60.9±10.2 years, and 565 (53.4%) were males. The median follow-up duration was 42 months (interquartile range [IQR]: 25-67), and 92 patients experienced new-onset cerebrovascular events. In a multivariate-adjusted model, with PAC as a continuous variable, higher PAC increased the risk of cerebrovascular events; patient risk increased per 1 (hazard ratio [HR: 1.03], 95% confidence interval [CI]: 1.01-1.06, P < 0.01), per 5 (HR: 1.17, 95% CI: 1.06-1.31, P < 0.01), and per 10 ng/dL (HR: 1.41, 95%: 1.14-1.75, P < 0.01) increase in PAC. When PAC was expressed as a categorical variable (quartile: Q1-Q4), patients in Q4 (HR: 2.12, 95% CI: 1.18-3.79, P < 0.05) exhibited an increased risk of cerebrovascular events compared to Q1. Restrictive spline regression showed a linear association between PAC and the risk of new-onset cerebrovascular events after adjusting for all possible variables.

CONCLUSIONS

Our study identified a linear association between PAC and the risk of new-onset cerebrovascular events in patients with hypertension and WMLs.

Deleterious effect of sustained neuroinflammation in pediatric traumatic brain injury

INTRODUCTION

Despite improved management of traumatic brain injury (TBI), it still leads to lifelong sequelae and disability, particularly in children. Chronic neuroinflammation (the so-called tertiary phase), in particular, microglia/macrophage and astrocyte reactivity, is among the main mechanisms suspected of playing a role in the generation of lesions associated with TBI. The role of acute neuroinflammation is now well understood, but its persistent effect and impact on the brain, particularly during development, are not. Here, we investigated the long-term effects of pediatric TBI on the brain in a mouse model.

METHODS

Pediatric TBI was induced in mice on postnatal day (P) 7 by weight-drop trauma. The time course of neuroinflammation and myelination was examined in the TBI mice. They were also assessed by magnetic resonance, functional ultrasound, and behavioral tests at P45.

RESULTS

TBI induced robust neuroinflammation, characterized by acute microglia/macrophage and astrocyte reactivity. The long-term consequences of pediatric TBI studied on P45 involved localized scarring astrogliosis, persistent microgliosis associated with a specific transcriptomic signature, and a long-lasting myelination defect consisting of the loss of myelinated axons, a decreased level of myelin binding protein, and severe thinning of the corpus callosum. These results were confirmed by reduced fractional anisotropy, measured by diffusion tensor imaging, and altered inter- and intra-hemispheric connectivity, measured by functional ultrasound imaging. In addition, adolescent mice with pediatric TBI showed persistent social interaction deficits and signs of anxiety and depressive behaviors.

CONCLUSIONS

We show that pediatric TBI induces tertiary neuroinflammatory processes associated with white matter lesions and altered behavior. These results support our model as a model for preclinical studies for tertiary lesions following TBI.

Association between dietary magnesium intake, inflammation, and neurodegeneration

BACKGROUND

Consistent evidence shows that magnesium (Mg) intake is associated with lower blood pressure (BP), and that lower BP is associated with improved cerebral health. However, recent findings indicate that the positive effect of dietary Mg intake on cerebral health is not mediated by a decrease in BP. As Mg's anti-inflammatory action is a plausible alternative mechanism, the objective of this study was to investigate the associations between Mg intake and inflammation to determine whether it mediates any neuroprotective effect.

METHODS

Participants from the UK Biobank (n = 5775, aged 40-73 years, 54.7% female) were assessed for dietary magnesium using an online food questionnaire, brain and white matter lesion (WML) volumes were segmented with FreeSurfer software, and inflammation markers including high-sensitivity C-reactive protein (hs-CRP), leukocyte, erythrocyte count, and Glycoprotein acetylation (GlycA) were measured using specific laboratory techniques such as immunoturbidimetry, automated cell counting, and nuclear magnetic resonance. Hierarchical linear regression models were performed to investigate the association between dietary Mg, and inflammatory markers and between dietary Mg, brain and WMLs volumes. Mediation analysis was performed to test a possible mediation role of inflammation on the association between dietary Mg and brain and WMLs volumes.

RESULTS

Higher dietary Mg intake was associated with lower inflammation: hs-CRP level (- 0.0497%; 95% confidence interval [CI] - 0.0497%,  - 0.0199%) leukocytes count (- 0.0015%; 95%CI - 0.00151%,  - 0.0011%), and GlycA (- 0.0519%; 95%CI - 0.1298%,  - 0.0129%). Moreover, higher dietary Mg intake was associated with larger grey matter volume (0.010%; 95%CI 0.004%, 0.017%), white matter volume (0.012%; 95%CI 0.003,  0.022) and right hippocampal volume (0.002%; 95%CI 0.0007, -0.0025%). Lower hs-CRP levels mediated the positive association between higher dietary Mg intake and larger grey matter volume.

CONCLUSIONS

The anti-inflammatory effects of dietary Mg intake in the general population, appears to mediate its neuroprotective effect.

Serum Proteomics Identified TAFI as a Potential Molecule Facilitating the Migration of Peripheral Monocytes to Damaged White Matter During Chronic Cerebral Hypoperfusion

Neuroinflammation is assumed as the critical pathophysiologic mechanism of white matter lesions (WMLs), and infiltrated peripheral monocyte-derived macrophages are implicated in the development of neuroinflammation. This study sought to explore the blood molecules that promote the migration of peripheral monocytes to the sites of WMLs. The serum protein expression profiles of patients and Sprague-Dawley rat models with WMLs were detected by data-independent acquisition (DIA) proteomics technique. Compared with corresponding control groups, we acquired 62 and 41 differentially expressed proteins (DEPs) in the serum of patients and model rats with WMLs respectively. Bioinformatics investigations demonstrated that these DEPs were linked to various Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways and Gene Ontology (GO) terms involved in neuroinflammation. Afterward, we identified thrombin-activatable fibrinolysis inhibitor (TAFI) as a shared and overexpressed protein in clinical and animal serum samples, which was further verified by enzyme-linked immunosorbent assay. Additionally, an upregulation of TAFI was also observed in the white matter of rat models, and the inhibition of TAFI impeded the migration of peripheral monocytes to the area of WMLs. In vitro experiments suggested that TAFI could enhance the migration ability of RAW264.7 cells and increase the expression of Ccr2. Our study demonstrates that neuroinflammatory signals can be detected in the peripheral blood of WMLs patients and model rats. TAFI may serve as a potential protein that promotes the migration of peripheral monocytes to WMLs regions, thereby providing a novel molecular target for further investigation into the interaction between the central and peripheral immune systems.

The Impact of Dipyridamole on Disease-Associated Microglia Phenotypic Transformation in White Matter Lesions Induced by Chronic Cerebral Hypoperfusion

White matter lesions (WMLs) resulting from chronic cerebral hypoperfusion (CCH) are the leading cause of vascular dementia (VaD). This study aimed to investigate whether dipyridamole could alleviate WMLs by regulating the phenotype of disease-associated microglia (DAM) through equilibrative nucleoside transporter 2 (ENT2) and adenosine A2A receptor (Adora2a) and to clarify the underlying molecular mechanisms. CCH rat models were constructed to mimic VaD. Morris water maze and Luxol Fast Blue staining were employed to assess cognitive function and quantify the severity of WMLs, respectively. Immunofluorescent staining was performed to analyze the activation of glial cells and the phenotypic transformation of DAM. Additionally, levels of ENT2, proteins in the NF-κB and ERK1/2 pathways and inflammatory cytokines were detected. The results indicated that dipyridamole diminished the activation and proliferation of microglia and astrocytes, increased the expression of myelin basic protein and ameliorated WMLs and cognitive decline in CCH rats. Further study revealed that dipyridamole decreased the expression of ENT2 and inhibited the activation of ERK1/2 and NF-κB signaling pathways, which ultimately converted DAM to anti-inflammatory phenotype and suppressed the levels of TNF-α, IL-1β, IL-6 in WMLs. However, Adora2a inhibitor (SCH58261) attenuated above effects. Our study demonstrates that dipyridamole facilitates the conversion of DAM to the anti-inflammatory phenotype through ENT2/Adora2a pathway and inhibits the activation of ERK1/2 and NF-κB signaling pathways, thereby alleviating neuroinflammation in WMLs. The current findings establish the basis for using dipyridamole to treat VaD.

Serum neurofilament light and white matter characteristics in the general population: a longitudinal analysis

Neurofilament light polypeptide (NfL) is a component of the neuronal cytoskeleton and particularly abundant in large-caliber axons. When axonal injury occurs, NfL is released and reaches the cerebrospinal fluid and the blood. Associations between NfL and white matter alterations have previously been observed in studies based on patients with neurological diseases. The current study aimed to explore the relationship between serum NfL (sNfL) and white matter characteristics in a population-based sample. The cross-sectional associations between sNfL as dependent variable, fractional anisotropy (FA), and white matter lesion (WML) volume were analyzed with linear regression models in 307 community-dwelling adults aged between 35 and 65 years. These analyses were repeated with additional adjustment for the potential confounders age, sex, and body mass index (BMI). Longitudinal associations over a mean follow-up of 5.39 years were analyzed with linear mixed models. The unadjusted cross-sectional models yielded significant associations between sNfL, WML volume, and FA, respectively. However, after the adjustment for confounders, these associations did not reach significance. In the longitudinal analyses, the findings corroborated the baseline findings showing no significant associations between sNfL and white matter macrostructure and microstructure beyond the effects of age. In synopsis with previous studies in patients with acute neurological diseases showing a significant association of sNfL with white matter changes beyond the effects of age, the present results based on a sample from the general population suggest the perspective that changes in sNfL reflect age-related effects that also manifest in altered white matter macrostructure and microstructure.

Neddylation in the chronically hypoperfused corpus callosum: MLN4924 reduces blood-brain barrier injury via ERK5/KLF2 signaling

Blood-brain barrier (BBB) breakdown and cerebrovascular dysfunction may contribute to the pathology in white matter lesions and consequent cognitive decline caused by cerebral hypoperfusion. Neddylation is the process of attaching a ubiquitin-like molecule NEDD8 (neuronal precursor cell-expressed developmentally downregulated protein 8) to specific targets. By modifying protein substrates, neddylation plays critical roles in various important biological processes. However, whether neddylation influences the pathogenesis of hypoperfused brain remains unclear. In the present study, cerebral hypoperfusion-induced white matter lesions were produced by bilateral common carotid artery stenosis in mice. The function of the neddylation pathway, BBB integrity, cerebrovascular dysfunction, myelin density in the corpus callosum and cognitive function were determined. We show that NEDD8 conjugation aberrantly amplified in microvascular endothelium in the corpus callosum following cerebral hypoperfusion. MLN4924, a small-molecule inhibitor of NEDD8-activating enzyme currently in clinical trials, preserved BBB integrity, attenuated glial activation and enhanced oligodendrocyte differentiation, and reduced hypoperfusion-induced white matter lesions in the corpus callosum and thus improved cognitive performance via inactivating cullin-RING E3 ligase (CRL). Administration of MLN4924 caused the accumulation of ERK5 and KLF2. The ERK5 inhibitor BIX 02189, down-regulated MLN4924-induced activation of KLF2 and reversed MLN4924-mediated increase in pericyte coverage and junctional proteins. Furthermore, BIX 02189 blocked MLN4924-afforded protection against BBB disruption and white matter lesions in the corpus callosum. Collectively, our results revealed that neddylation impairs vascular function and thus exacerbated the pathology of hypoperfused brain and that inhibition of neddylation with MLN4924 may offer novel therapeutic opportunities for cerebral hypoperfusion-associated cognitive impairment.

Natural products and their derivatives alleviating cerebral white matter lesions

White matter lesions (WMLs), characterized by focal demyelination or myelination disorders, are commonly present in cerebral small vessel disease and various neurological diseases. Multiple etiologies lead to WMLs. However, there is no specific therapy or effective drugs for relieving WMLs. Natural products and their derivatives originate from bacterial, fungal, plant, and marine animal sources, many of which have multiple therapeutic targets. Compared to single target compounds, natural products and their derivatives are promising to be developed as better drugs to attenuate WMLs. Thus, this review attempts to summarize the status of natural products and their derivatives (2010-to date) alleviating cerebral white matter lesions for the discovery of new drugs.

Identification of demyelinating lesions and application of McDonald criteria when confronted with white matter lesions on brain MRI

INTRODUCTION

White matter lesions (WML) on magnetic resonance imaging (MRI) are common in clinical practice. When analyzing WML, radiologists sometimes propose a pathophysiological mechanism to explain the observed MRI abnormalities, which can be a source of anxiety for patients. In some cases, discordance may appear between the patient's clinical symptoms and the identification of the MRI-appearing WML, leading to extensive diagnostic work-up. To avoid misdiagnosis, the analysis of WML should be standardized, and a consensual MRI reading approach is needed.

OBJECTIVE

To analyze the MRI WML identification process, associated diagnosis approach, and misinterpretations in physicians involved in WML routine practice.

METHODS

Through a survey distributed online to practitioners involved in WML diagnostic work-up, we described the leading causes of MRI expertise misdiagnosis and associated factors: clinical experience, physicians' subspecialty and location of practice, and type of device used to complete the survey. The survey consisted of sixteen T2-weighted images MRI analysis, from which ten were guided (binary response to lesion location identification), four were not shown (multiple possible answers), and two were associated with dissemination in space (DIS) McDonald criteria application. Two independent, experienced practitioners determined the correct answers before the participants' completion.

RESULTS

In total, 364 participants from the French Neuro Radiological (SFNR), French Neurological (SFN), and French Multiple Sclerosis (SFSEP) societies completed the survey entirely. According to lesion identification, 34.3% and 16.9% of the participants correctly identified juxtacortical and periventricular lesions, respectively, whereas 56.3% correctly identified non-guided lesions. Application of the 2017 McDonald's DIS criteria was correct for 35.3% of the participants. According to the global survey scoring, factors independently associated with correct answers in multivariate analysis were MS-expert subspecialty (P<0.001), young clinical practitioners (P=0.02), and the use of a computer instead of a smartphone to perform WML analysis (P=0.03).

CONCLUSION

Our results highlight the difficulties regarding WML analysis in clinical practice and suggest that radiologists and neurologists should rely on each other to ensure the diagnosis of multiple sclerosis and related disorders and limit misdiagnoses.

Cerebrovascular integrity affects gradients of aging-related dopamine D1 differences in the striatum

Extant research suggest aging-related losses of different dopaminergic markers, including presynaptic dopamine transporters as well as post-synaptic DA receptors. Given the central role of DA in neurocognitive functions, maintenance of a healthy DA system may be a key to mitigate age-related cognitive decline. Mechanisms behind DA losses in aging are however largely uncharted. Past research documented an association between dopaminergic integrity and cerebrovascular health (via white matter lesion volumes). However, it remains unclear whether proximity to lesions affected the spatial patterns of age-related D1DR differences within the striatum, and whether such differences are related to mnemonic function. Here, a large cohort of middle-aged to older healthy participants (age = 40-80 years, n = 119, 50 % women) was assessed for D1-receptor (D1DR) availability with positron emission tomography using [11C]SCH23390, and for white matter lesions using FLAIR-MRI. We found evidence for variations in degree of age-related differences along the ventro-dorsal axis, with more pronounced differences in the dorsal caudate. Further analyses revealed an association between distance to lesions and extent of D1DR losses in the caudate. Furthermore, D1DR differences in dorsal caudate (proximal to lesions) was more strongly associated with memory performance. In conclusion, the present findings suggest that maintenance of cerebrovascular health may be a key factor in promoting successful dopaminergic and memory aging.

Chronic cerebral hypoperfusion: a critical feature in unravelling the etiology of vascular cognitive impairment

Vascular cognitive impairment (VCI) describes a wide spectrum of cognitive deficits related to cerebrovascular diseases. Although the loss of blood flow to cortical regions critically involved in cognitive processes must feature as the main driver of VCI, the underlying mechanisms and interactions with related disease processes remain to be fully elucidated. Recent clinical studies of cerebral blood flow measurements have supported the role of chronic cerebral hypoperfusion (CCH) as a major driver of the vascular pathology and clinical manifestations of VCI. Here we review the pathophysiological mechanisms as well as neuropathological changes of CCH. Potential interventional strategies for VCI are also reviewed. A deeper understanding of how CCH can lead to accumulation of VCI-associated pathology could potentially pave the way for early detection and development of disease-modifying therapies, thus allowing preventive interventions instead of symptomatic treatments.

Frequency specificity in the amplitude of low frequency oscillations in patients with white matter lesions

Previous studies have reported that patients with white matter lesions (WMLs) have abnormal spontaneous brain activity in the resting state. However, the spontaneous neuronal activity of specific frequency bands in WMLs patients is unknown. Here, we included 16 WMLs patients and 13 gender and age-matched healthy controls (HCs) underwent resting-state magnetic resonance imaging (rs-fMRI) scan and studied the specificity of the amplitude of low-frequency fluctuations (ALFF) in WMLs patients in the slow-5 (0.01-0.027 Hz), slow-4 (0.027-0.073 Hz), and typical (0.01-0.08 Hz) frequency bands. In addition, ALFF values of different frequency bands were extracted as classification features and support vector machines (SVM) were used to classify WMLs patients. In all three frequency bands, significant increases in ALFF values in WMLs patients were observed in the cerebellum. In the slow-5 band, the ALFF values of the left anterior cingulate and paracingulate gyri (ACG), and the right precentral gyrus, rolandic operculum and inferior temporal gyrus in WMLs patients were lower than those in HCs. In the slow-4 band, ALFF values were lower in WMLs patients than in HCs at the left ACG, the right median cingulate and paracingulate gyri, parahippocampal gyrus, caudate nucleus, and the bilateral lenticular nucleus, putamen. In the SVM classification model, the classification accuracy of slow-5, slow-4 and typical frequency bands is 75.86%, 86.21% and 72.41%, respectively. The results indicate that the ALFF abnormalities in WMLs patients have frequency specificity, and the ALFF abnormalities in the slow-4 frequency band may serve as imaging markers for WMLs.

Aquaporin-4 IgG antibodies: predictors of positivity and their relationship with neuropsychiatric disorders and white matter lesions in Juvenile systemic lupus erythematosus

BACKGROUND

This study aimed to describe the prevalence of the various clinical features and severity of juvenile systemic lupus erythematosus (jSLE) and to assess predictors of AQP4-Ab positivity in jSLE. In addition, we assessed the relationship of AQP4-Abs with neuropsychiatric disorders and white matter lesions in jSLE.

METHOD

For 90 patients with jSLE, demographic data, clinical manifestations, and treatments received were recorded, and all of the patients were underwent clinical examinations, including assessments for the neurological manifestations of jSLE and neuropsychiatric disorders; Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) score evaluations; laboratory investigations, including serum AQP4-Ab assays; and 1.5 Tesla brain MRI. Echocardiography and renal biopsy were performed for the indicated patients.

RESULT

Fifty-six patients (62.2%) tested positive for AQP4-Abs. These patients were more likely to have higher disease activity scores (p < 0.001); discoid lesions (p = 0.039); neurological disorders (p = 0.001), mainly psychosis and seizures (p = 0.009 and p = 0.032, respectively); renal and cardiac involvement (p = 0.004 and p = 0.013, respectively); lower C3 levels (p = 0.006); white matter hyperintensities (p = 0.008); and white matter atrophy (p = 0.03) than patients who were negative for AQP4-Abs. Furthermore, AQP4-Ab-positive patients were more likely to have received cyclophosphamide (p = 0.028), antiepileptic drugs (p = 0.032) and plasma exchange therapy (p = 0.049).

CONCLUSION

jSLE patients with higher severity scores, neurological disorders, or white matter lesions could develop antibodies against AQP4. We recommend more studies for systematic screening of AQP4-Ab positivity in jSLE patients to confirm its relationship with neurological disorders.

The spatio-temporal relationship between concurrent lesion and brain atrophy changes in early multiple sclerosis: A post-hoc analysis of the REFLEXION study

BACKGROUND

White matter (WM) lesions and brain atrophy are present early in multiple sclerosis (MS). However, their spatio-temporal relationship remains unclear.

METHODS

Yearly magnetic resonance images were analysed in 387 patients with a first clinical demyelinating event (FCDE) from the 5-year REFLEXION study. Patients received early (from baseline; N = 258; ET) or delayed treatment (from month-24; N = 129; DT) with subcutaneous interferon beta-1a. FSL-SIENA/VIENA were used to provide yearly percentage volume change of brain (PBVC) and ventricles (PVVC). Yearly total lesion volume change (TLVC) was determined by a semi-automated method. Using linear mixed models and voxel-wise analyses, we firstly investigated the overall relationship between TLVC and PBVC and between TLVC and PVVC in the same follow-up period. Analyses were then separately performed for: the untreated period of DT patients (first two years), the first year of treatment (year 1 for ET and year 3 for DT), and a period where patients had received at least 1 year of treatment (stable treatment; ET: years 2, 3, 4, and 5; DT: years 4 and 5).

RESULTS

Whole brain: across the whole study period, lower TLVC was related to faster atrophy (PBVC: B = 0.046, SE = 0.013, p < 0.001; PVVC: B = -0.466, SE = 0.118, p < 0.001). Within the untreated period of DT patients, lower TLVC was related to faster atrophy (PBVC: B = 0.072, SE = 0.029, p = 0.013; PVVC: B = -0.917, SE = 0.306, p = 0.003). A similar relationship was found within the first year of treatment of ET patients (PBVC: B = 0.081, SE = 0.027, p = 0.003; PVVC: B = -1.08, SE = 0.284, p < 0.001), consistent with resolving oedema and pseudo-atrophy. Voxel-wise: overall, higher TLVC was related to faster ventricular enlargement. Lower TLVC was related to faster widespread atrophy in year 1 in both ET (first year of treatment) and DT (untreated) patients. In the second untreated year of DT patients and within the stable treatment period of ET patients (year 4), faster periventricular and occipital lobe atrophy was associated with higher TLVC.

CONCLUSIONS

WM lesion changes and atrophy occurred simultaneously in early MS. Spatio-temporal correspondence of these two processes involved mostly the periventricular area. Within the first year of the study, in both treatment groups, faster atrophy was linked to lower lesion volume changes, consistent with higher shrinking and disappearing lesion activity. This might reflect the pseudo-atrophy phenomenon that is probably related to the therapy driven (only in ET patients, as they received treatment from baseline) and "natural" (both ET and DT patients entered the study after a FCDE) resolution of oedema. In an untreated period and later on during stable treatment, (real) atrophy was related to higher lesion volume changes, consistent with increased new and enlarging lesion activity.

Low neighborhood deprivation buffers against hippocampal neurodegeneration, white matter hyperintensities, and poorer cognition

There is increasing recognition that socioeconomic inequalities contribute to disparities in brain and cognitive health in older adults. However, whether neighborhood socioeconomic status (SES) buffers individuals with low individual SES against neurodegeneration, cerebrovascular disease, and poorer cognitive function is not well understood. Here, we evaluated whether neighborhood deprivation (Townsend deprivation index) interacted with individual SES (composite household income and education levels) on hippocampus volume, regional cortical thickness, white matter hyperintensities, and cognition in 19,638 individuals (mean age = 54.8) from the UK Biobank. We found that individuals with low individual SES had the smallest hippocampal volumes, greatest white matter hyperintensity burden, and poorest cognition if they were living in high deprivation neighborhoods but that these deleterious effects on brain and cognitive function were attenuated if they were living in low deprivation neighborhoods (p for interactions < .05). While neighborhood deprivation did not interact with individual SES to influence regional cortical thickness, higher neighborhood deprivation was independently associated with lower cortical thickness in 16 regions (false discovery rate q < .05). Across multiple brain indices and cognitive function analyses, we found converging evidence suggesting that low neighborhood deprivation may have a neuroprotective effect against neurodegeneration, cerebrovascular pathology, and cognitive impairment, particularly in vulnerable individuals with low household income and education levels.

How relevant are cerebral white matter lesions in the D313Y variant of the α-galactosidase A gene? Neurological, cardiological, laboratory, and MRI data of 21 patients within a follow-up of 3 years

BACKGROUND

Fabry disease is an inherited metabolic disorder with various symptoms. Neurological manifestations are small fiber neuropathy, cerebral white matter lesions (WML), megadolicho basilar artery, and stroke. The relevance of the D313Y variant in the galactosidase alpha gene is controversially discussed.

OBJECTIVES

We aimed at elucidating the implications of this differential diagnosis of multiple sclerosis (MS), focussing on the analysis of WML over time and correlations with other markers.

METHODS

We reviewed retrospectively the clinical, laboratory, and magnetic resonance imaging data of 21 carriers of the D313Y variant at a single German outpatient clinic for MS between 2004 and 2021.

RESULTS

In our cohort (15 females, 6 males), mean age at diagnosis was 44.1 ± 16.3 years, and mean follow-up duration was 3.1 ± 3.9 years. WML were rated on both, the Fazekas scale and the age-related white matter changes rating scale, and were of variable interindividual extent. Follow-up imaging showed virtually no progress. WML did not correlate with the severity of clinical findings or lysoGb3 levels. Symptomatic carriers of the variant are characterized by an almost complete lack of internal organ manifestations and laboratory findings, usually associated with Fabry disease.

CONCLUSION

WML in carriers of the D313Y variant do not seem to be suitable for assessing or predicting the (para-) clinical status. Concerning MS patients, the variant and its clinical signs can be a differential diagnosis, but also a co-factor. Imaging and cerebrospinal fluid findings facilitate the distinction between both entities.

Selective emergence of antibody-secreting cells in the multiple sclerosis brain

BACKGROUND

Although distinct brain-homing B cells have been identified in multiple sclerosis (MS), it is unknown how these further evolve to contribute to local pathology. We explored B-cell maturation in the central nervous system (CNS) of MS patients and determined their association with immunoglobulin (Ig) production, T-cell presence, and lesion formation.

METHODS

Ex vivo flow cytometry was performed on post-mortem blood, cerebrospinal fluid (CSF), meninges and white matter from 28 MS and 10 control brain donors to characterize B cells and antibody-secreting cells (ASCs). MS brain tissue sections were analysed with immunostainings and microarrays. IgG index and CSF oligoclonal bands were measured with nephelometry, isoelectric focusing, and immunoblotting. Blood-derived B cells were cocultured under T follicular helper-like conditions to evaluate their ASC-differentiating capacity in vitro.

FINDINGS

ASC versus B-cell ratios were increased in post-mortem CNS compartments of MS but not control donors. Local presence of ASCs associated with a mature CD45^low phenotype, focal MS lesional activity, lesional Ig gene expression, and CSF IgG levels as well as clonality. In vitro B-cell maturation into ASCs did not differ between MS and control donors. Notably, lesional CD4⁺ memory T cells positively correlated with ASC presence, reflected by local interplay with T cells.

INTERPRETATION

These findings provide evidence that local B cells at least in late-stage MS preferentially mature into ASCs, which are largely responsible for intrathecal and local Ig production. This is especially seen in active MS white matter lesions and likely depends on the interaction with CD4⁺ memory T cells.

FUNDING

Stichting MS Research (19-1057 MS; 20-490f MS), National MS Fonds (OZ2018-003).

Assessing the association between white matter lesions and Parkinson's disease

BACKGROUND

The association between white matter (WM) lesions and Parkinson's disease (PD) was not fully established. We therefore applied Mendelian randomization (MR) analyses to identify the causal effect between white matter lesions and PD.

METHODS

We performed a bidirectional two-sample Mendelian randomization (MR) study to investigate the association between three WM phenotypes-white matter hyperintensities (WMH, N = 18,381), fractional anisotropy (FA, N = 17,673), and mean diffusivity (MD, N = 17,467)-with PD (N = 482,730) using summary statistics from genome-wide association studies (GWAS). The inverse variance weighted (IVW), weighted median, MR-Egger, and MR-PRESSO methods were used to evaluate the causal estimate.

RESULTS

Significant evidence was suggested that higher MD was associated with a higher PD risk (OR = 1.049, 95% CI = 1.018-1.081, p = 0.022) when the outlier was removed using MR-PRESSO method. Moreover, genetically predicted PD was associated with a lower WMH load (IVW β = - 0.047, 95% CI = - 0.085 to - 0.009, p = 0.016) and a higher FA (β = 0.185, 95% CI = 0.021-0.349, p = 0.027). No evidence of pleiotropy was found using MR-Egger intercept.

CONCLUSION

Our findings provided genetic support that white matter microstructural integrity lesions might increase the risk of PD. However, genetically predicted PD was potentially associated with a lower load of white matter lesions.

SERS "hot spot" enhance-array assay for misfolded SOD1 correlated with white matter lesions and aging

Misfolding of superoxide dismutase-1 (SOD1) has been correlated with many neurodegenerative diseases, such as Amyotrophic lateral sclerosis's and Alzheimer's among others. However, it is unclear whether misfolded SOD1 plays a role in another neurodegenerative disease of white matter lesions (WMLs). In this study, a sensitive and specific method based on SERS technique was proposed for quantitative detection of misfolded SOD1 content in WMLs. To fabricate the double antibodysandwich substrates for SERS detection, gold nanostars modified with capture antibody were immobilized on glass substrates to prepare active SERS substrates, and then SERS probes conjugated with a Raman reporter and a specific target antibody were coupled with active SERS substrates. This SERS substrates had been employed for quantitative detection of misfolded SOD1 levels in WMLs and exhibited excellent stability, reliability, and accuracy. Moreover, experimental results indicated that the level of misfolded SOD1 increased with the increase in age and the degree of WMLs. Hence, misfolded SOD1 may be a potential blood marker for WMLs and aging. Meanwhile, SERS-based gold nanostars have great clinical application potential in the screening, diagnosis and treatment of WMLs.

Minimizing the effect of white matter lesions on deep learning based tissue segmentation for brain volumetry

Automated methods for segmentation-based brain volumetry may be confounded by the presence of white matter (WM) lesions, which introduce abnormal intensities that can alter the classification of not only neighboring but also distant brain tissue. These lesions are common in pathologies where brain volumetry is also an important prognostic marker, such as in multiple sclerosis (MS), and thus reducing their effects is critical for improving volumetric accuracy and reliability. In this work, we analyze the effect of WM lesions on deep learning based brain tissue segmentation methods for brain volumetry and introduce techniques to reduce the error these lesions produce on the measured volumes. We propose a 3D patch-based deep learning framework for brain tissue segmentation which is trained on the outputs of a reference classical method. To deal more robustly with pathological cases having WM lesions, we use a combination of small patches and a percentile-based input normalization. To minimize the effect of WM lesions, we also propose a multi-task double U-Net architecture performing end-to-end inpainting and segmentation, along with a training data generation procedure. In the evaluation, we first analyze the error introduced by artificial WM lesions on our framework as well as in the reference segmentation method without the use of lesion inpainting techniques. To the best of our knowledge, this is the first analysis of WM lesion effect on a deep learning based tissue segmentation approach for brain volumetry. The proposed framework shows a significantly smaller and more localized error introduced by WM lesions than the reference segmentation method, that displays much larger global differences. We also evaluated the proposed lesion effect minimization technique by comparing the measured volumes before and after introducing artificial WM lesions to healthy images. The proposed approach performing end-to-end inpainting and segmentation effectively reduces the error introduced by small and large WM lesions in the resulting volumetry, obtaining absolute volume differences of 0.01 ± 0.03% for GM and 0.02 ± 0.04% for WM. Increasing the accuracy and reliability of automated brain volumetry methods will reduce the sample size needed to establish meaningful correlations in clinical studies and allow its use in individualized assessments as a diagnostic and prognostic marker for neurodegenerative pathologies.

Comparing myelin-sensitive magnetic resonance imaging measures and resulting g-ratios in healthy and multiple sclerosis brains

The myelin concentration and the degree of myelination of nerve fibers can provide valuable information on the integrity of human brain tissue. Magnetic resonance imaging (MRI) of myelin-sensitive parameters can help to non-invasively evaluate demyelinating diseases such as multiple sclerosis (MS). Several different myelin-sensitive MRI methods have been proposed to determine measures of the degree of myelination, in particular the g-ratio. However, variability in underlying physical principles and different biological models influence measured myelin concentrations, and consequently g-ratio values. We therefore investigated similarities and differences between five different myelin-sensitive MRI measures and their effects on g-ratio mapping in the brains of both MS patients and healthy volunteers. We compared two different estimates of the myelin water fraction (MWF) as well as the inhomogeneous magnetization transfer ratio (ihMTR), magnetization transfer saturation (MTsat), and macromolecular tissue volume (MTV) in 13 patients with MS and 14 healthy controls. In combination with diffusion-weighted imaging, we derived g-ratio parameter maps for each of the five different myelin measures. The g-ratio values calculated from different myelin measures varied strongly, especially in MS lesions. While, compared to normal-appearing white matter, MTsat and one estimate of the MWF resulted in higher g-ratio values within lesions, ihMTR, MTV, and the second MWF estimate resulted in lower lesion g-ratio values. As myelin-sensitive measures provide rough estimates of myelin content rather than absolute myelin concentrations, resulting g-ratio values strongly depend on the utilized myelin measure and model used for g-ratio mapping. When comparing g-ratio values, it is, thus, important to utilize the same MRI methods and models or to consider methodological differences. Particular caution is necessary in pathological tissue such as MS lesions.

Right hemispheric white matter hyperintensities improve the prediction of spatial neglect severity in acute stroke

White matter hyperintensities (WMH) are frequently observed in brain scans of elderly people. They are associated with an increased risk of stroke, cognitive decline, and dementia. However, it is unknown yet if measures of WMH provide information that improve the understanding of poststroke outcome compared to only state-of-the-art stereotaxic structural lesion data. We implemented high-dimensional machine learning models, based on support vector regression, to predict the severity of spatial neglect in 103 acute right hemispheric stroke patients. We found that (1) the additional information of right hemispheric or bilateral voxel-based topographic WMH extent indeed yielded a significant improvement in predicting acute neglect severity (compared to the voxel-based stroke lesion map alone). (2) Periventricular WMH appeared more relevant for prediction than deep subcortical WMH. (3) Among different measures of WMH, voxel-based maps as measures of topographic extent allowed more accurate predictions compared to the use of traditional ordinally assessed visual rating scales (Fazekas-scale, Cardiovascular Health Study-scale). In summary, topographic WMH appear to be a valuable clinical imaging biomarker for predicting the severity of cognitive deficits and bears great potential for rehabilitation guidance of acute stroke patients.

The spatio-temporal relationship between white matter lesion volume changes and brain atrophy in clinically isolated syndrome and early multiple sclerosis

BACKGROUND

White matter lesions and brain atrophy are both present early in multiple sclerosis. However, the spatio-temporal relationship between atrophy and lesion processes remains unclear.

METHODS

Yearly magnetic resonance images were analyzed in 392 patients with clinically isolated syndrome from the 5-year REFLEX/REFLEXION studies. Patients received early treatment (from baseline; N = 262) or delayed treatment (from month-24; N = 130) with subcutaneous interferon beta-1a. Global and central atrophy were assessed using FSL-SIENA to provide yearly percentage volume change of brain and ventricles, respectively. Yearly total lesion volume change was calculated by subtracting the sum of the negative lesion volume change (disappearing + shrinking) from the positive lesion volume change (new + enlarging) for each yearly interval, as determined by an in-house developed semi-automated method. Using linear mixed models, during the period where patients had received ≥1 year of treatment, we investigated whether total lesion volume change was associated with percentage brain volume change or percentage ventricular volume change in the next year, and vice versa.

RESULTS

Higher total lesion volume change was related to significantly faster global atrophy (percentage brain volume change) in the next year (B = - 0.113, SE = 0.022, p < 0.001). In patients receiving early treatment only, total lesion volume change was also associated with percentage ventricular volume change in the next year (B = 1.348, SE = 0.181, p < 0.001). Voxel-wise analyses showed that in patients receiving early treatment, higher total lesion volume change in years 2, 3, and 4 was related to faster atrophy in the next year, and in year 4 this relationship was stronger in patients receiving delayed treatment. Interestingly, faster atrophy was related to higher total lesion volume change in the next year (percentage brain volume change: B = - 0.136, SE = 0.062, p = 0.028; percentage ventricular volume change: B = 0.028, SE = 0.008, p < 0.001).

CONCLUSIONS

Higher lesion volume changes were associated with faster atrophy in the next year. Interestingly, there was also an association between faster atrophy and higher lesion volume changes in the next year.

Sensitivity of portable low-field magnetic resonance imaging for multiple sclerosis lesions

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Paired, same-day, 3T and 64mT MRI studies were analyzed in 33 MS patients.

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64mT MRI showed 94% sensitivity for detecting any lesions in 3T confirmed cases.

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The diameter of the smallest detected lesion was larger at 64mT compared to 3T.

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Total lesion volume estimates were strongly correlated between 3T and 64mT scans.

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Portable low-field MRI detects white matter lesions, but smaller lesions may be missed.

Magnetic resonance imaging (MRI) is a fundamental tool in the diagnosis and management of neurological diseases such as multiple sclerosis (MS). New portable, low-field strength, MRI scanners could potentially lower financial and technical barriers to neuroimaging and reach underserved or disabled populations, but the sensitivity of these devices for MS lesions is unknown. We sought to determine if white matter lesions can be detected on a portable 64mT scanner, compare automated lesion segmentations and total lesion volume between paired 3T and 64mT scans, identify features that contribute to lesion detection accuracy, and explore super-resolution imaging at low-field. In this prospective, cross-sectional study, same-day brain MRI (FLAIR, T1w, and T2w) scans were collected from 36 adults (32 women; mean age, 50 ± 14 years) with known or suspected MS using Siemens 3T (FLAIR: 1 mm isotropic, T1w: 1 mm isotropic, and T2w: 0.34–0.5 × 0.34–0.5 × 3–5 mm) and Hyperfine 64mT (FLAIR: 1.6 × 1.6 × 5 mm, T1w: 1.5 × 1.5 × 5 mm, and T2w: 1.5 × 1.5 × 5 mm) scanners at two centers. Images were reviewed by neuroradiologists. MS lesions were measured manually and segmented using an automated algorithm. Statistical analyses assessed accuracy and variability of segmentations across scanners and systematic scanner biases in automated volumetric measurements. Lesions were identified on 64mT scans in 94% (31/33) of patients with confirmed MS. The average smallest lesions manually detected were 5.7 ± 1.3 mm in maximum diameter at 64mT vs 2.1 ± 0.6 mm at 3T, approaching the spatial resolution of the respective scanner sequences (3T: 1 mm, 64mT: 5 mm slice thickness). Automated lesion volume estimates were highly correlated between 3T and 64mT scans (r = 0.89, p < 0.001). Bland-Altman analysis identified bias in 64mT segmentations (mean = 1.6 ml, standard error = 5.2 ml, limits of agreement = –19.0–15.9 ml), which over-estimated low lesion volume and under-estimated high volume (r = 0.74, p < 0.001). Visual inspection revealed over-segmentation was driven venous hyperintensities on 64mT T2-FLAIR. Lesion size drove segmentation accuracy, with 93% of lesions > 1.0 ml and all lesions > 1.5 ml being detected. Using multi-acquisition volume averaging, we were able to generate 1.6 mm isotropic images on the 64mT device. Overall, our results demonstrate that in established MS, a portable 64mT MRI scanner can identify white matter lesions, and that automated estimates of total lesion volume correlate with measurements from 3T scans.

Dose-response association between plasma homocysteine and white matter lesions in patients with hypertension: a case-control study

White matter lesions (WMLs) are common MRI changes that are indicative of cerebral small vessel disease (CSVD). Elevated plasma homocysteine (Hcy) levels are related to an increased risk of vascular disease. We aimed to analyze the relationship between Hcy levels and WMLs in patients with hypertension. A total of 1961 patients with WMLs and 15,463 patients without WMLs were matched at a 1:1 ratio by age and sex. Hyperhomocysteinemia (HHcy) was defined as an abnormally high level (>15 µmol/l) of Hcy in a plasma sample. In total, 1888 (WML group) and 1888 (No-WMLs group) patients were enrolled, with 51.6% of the sample being male and a mean age of 63 years. Multivariate logistic regression analysis showed a significant association between a higher level of plasma Hcy and a higher prevalence of WMLs (OR 1.03 95% CI, 1.02-1.04) when the Hcy level was used as a continuous variable. Patients with Hcy levels of 15-20 µmol/l (OR 1.54, 95% CI 1.31-1.81) and >20 µmol/l (OR 1.51, 95% CI 1.26-1.82) also had a significantly higher risk of WMLs than patients with Hcy levels <15 µmol/l. Multivariable-adjusted spline regression models showed that the risk of WMLs started to increase only in patients with Hcy levels above 13.85 µmol/l (P < 0.001). In subgroup analyses of WMLs, there was no significant interaction between the Hcy group and subgroup heterogeneity for the prevalence of WMLs (P > 0.05). Our study found a dose-response association between plasma homocysteine levels, especially a Hcy level >13.85 µmol/l, and the prevalence of WMLs, implying that lowering Hcy levels might be a target for prevention.

Test-retest reliability of arterial spin labelling for cerebral blood flow in older adults with small vessel disease

Cerebral small vessel disease (SVD) is common in older people and is associated with lacunar stroke, white matter hyperintensities (WMH) and vascular cognitive impairment. Cerebral blood flow (CBF) is reduced in SVD, particularly within white matter.Here we quantified test-retest reliability in CBF measurements using pseudo-continuous arterial spin labelling (pCASL) in older adults with clinical and radiological evidence of SVD (N=54, mean (SD): 66.9 (8.7) years, 15 females/39 males). We generated whole-brain CBF maps on two visits at least 7 days apart (mean (SD): 20 (19), range 7-117 days).Test-retest reliability for CBF was high in all tissue types, with intra-class correlation coefficient [95%CI]: 0.758 [0.616, 0.852] for whole brain, 0.842 [0.743, 0.905] for total grey matter, 0.771 [0.636, 0.861] for deep grey matter (caudate-putamen and thalamus), 0.872 [0.790, 0.923] for normal-appearing white matter (NAWM) and 0.780 [0.650, 0.866] for WMH (all p<0.001). ANCOVA models indicated significant decline in CBF in total grey matter, deep grey matter and NAWM with increasing age and diastolic blood pressure (all p<0.001). CBF was lower in males relative to females (p=0.013 for total grey matter, p=0.004 for NAWM).We conclude that pCASL has high test-retest reliability as a quantitative measure of CBF in older adults with SVD. These findings support the use of pCASL in routine clinical imaging and as a clinical trial endpoint.All data come from the PASTIS trial, prospectively registered at: https://eudract.ema.europa.eu (2015-001235-20, registered 13/05/2015), http://www.clinicaltrials.gov (NCT02450253, registered 21/05/2015).

Differential spatial distribution of white matter lesions in Parkinson's and Alzheimer's diseases and cognitive sequelae

White Matter Lesions (WML) are a radiological finding common in aged subjects. We explored the impact of WML on underlying neurodegenerative processes. We focused on the impact of WML on two neurodegenerative diseases with different pathology. In this cross-sectional study of 137 subjects (78 female, 59 men, mean age 67.2; 43-87 years), we compared WML in healthy controls (HC; n = 55), patients with Alzheimer's disease and amnestic Mild Cognitive Impairment (aMCI), and Parkinson's disease patients with normal cognition and with MCI. Subjects with AD and aMCI were treated as one group (n = 40), subjects with PD and PDMCI were another group (n = 42). MRI T2_FLAIR sequences were analyzed. WML were divided into periventricular (pWML) or subcortical (sWML) depending on their distance from the ventricles. Subjects from the AD + aMCI group, had a significantly greater volume of WML than both HC and the PD + PDMCI group. The volume of WML was greater in the PD + PDMCI than in HC but the difference was not significant. In AD + aMCI subjects, sWML and not pWML were related to a decrease in global cognitive functioning despite greater volume of pWML. In PD + PDMCI, pWML correlate with decline in executive functions and working memory. In HC, pWML correlated with the multidomain decrease corresponding with the aging. This points to a difference between normal aging and pathological aging due to AD and PD brain pathology. The WML location together with underlying disease related neurodegeneration may play a role in determining the effect of WML on cognition. Our results suggest that the impact of WML is not uniform in all patients; rather, their volume, location and cognitive effect may be disease-specific.

White matter lesions may be an early marker for age-related cognitive decline

BACKGROUND

Research suggests that cerebral small vessel disease (CSVD), amyloid, and pTau contribute to age-related cognitive decline. It remains unknown how these factors relate to one another and how they jointly contribute to cognitive decline in normal aging. This project examines the association between these factors and their relationship to cognitive decline in cognitively unimpaired older adults without subjective cognitive decline.

METHODS

A total of 230 subjects with cerebrospinal fluid (CSF) Aß42, CSF pTau181, white matter lesions (WMLs) used as a proxy of CSVD, and cognitive scores from the Alzheimer's Disease Neuroimaging Initiative were included. Associations between each factor and cognitive score were investigated using regression models. Furthermore, relationships between the three pathologies were also examined using regression models.

RESULTS

At baseline, there was an inverse association between WML load and Aß42 (t = -4.20, p <.001). There was no association between WML load and pTau (t = 0.32, p = 0.75), nor with Aß42 and pTau (t = 0.51, p =.61). Correcting for age, sex and education, baseline WML load was associated with baseline ADAS-13 scores (t = 2.59, p =.01) and lower follow-up executive functioning (t = -2.84, p =.005). Baseline Aß42 was associated with executive function at baseline (t = 3.58, p<.004) but not at follow-up (t = 1.05, p = 0.30), nor with ADAS-13 at baseline (t = -0.24, p = 0.81) or follow-up (t = 0.09, p = 0.93). Finally, baseline pTau was not associated with any cognitive measure at baseline or follow-up.

CONCLUSION

Both baseline Aß42 and WML load are associated with some baseline cognition scores, but only baseline WML load is associated with follow-up executive functioning. This finding suggests that WMLs may be one of the earliest clinical manifestations that contributes to future cognitive decline in cognitively healthy older adults. Given that healthy older adults with WMLs exhibit declines in cognitive functioning, they may be less resilient to future pathology increasing their risk for cognitive impairment due to dementia than those without WMLs.

The enigma of vascular depression in old age: a critical update

Depression is common in older individuals and is associated with high disability and increased mortality, yet the factors predicting late-life depression (LLD) are poorly understood. The relationship between of depressive disorder, age- and disease-related processes have generated pathogenic hypotheses and provided new treatment options. LLD syndrome is often related to a variety of vascular mechanisms, in particular hypertension, cerebral small vessel disease, white matter lesions, subcortical vascular impairment, and other processes (e.g., inflammation, neuroimmune regulatory dysmechanisms, neurodegenerative changes, amyloid accumulation) that may represent etiological factors by affecting frontolimbic and other neuronal networks predisposing to depression. The "vascular depression" hypothesis suggests that cerebrovascular disease (CVD) and vascular risk factors may predispose, induce or perpetuate geriatric depressive disorders. It is based on the presence of various cerebrovascular risk factors in many patients with LLD, its co-morbidity with cerebrovascular lesions, and the frequent development of depression after stroke. Other findings related to vascular depression are atrophy of the medial temporal cortex or generalized cortical atrophy that are usually associated with cognitive impairment. Other pathogenetic hypotheses of LLD, such as metabolic or inflammatory ones, are briefly discussed. Treatment planning should consider there may be a modest response to antidepressants, but several evidence-based and novel treatment options for LLD exist, such as electroconvulsive therapy, transcranial magnetic stimulation, neurobiology-based psychotherapy, as well as antihypertension and antiinflammatory drugs. However, their effectiveness needs further investigation, and new methodologies for prevention and treatment of depression in older individuals should be developed.

The influence of white matter lesions on the electric field in transcranial electric stimulation

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Sensitivity analysis allows the simulation of tDCS with uncertain conductivities.

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White matter lesions (WML) have no global influence on the electric field in tDCS.

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In subjects with a high lesion load, a local influence can be observed.

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In low to medium lesion load subjects, explicit modeling of WML is not required.

Background

Transcranial direct current stimulation (tDCS) is a promising tool to enhance therapeutic efforts, for instance, after a stroke. The achieved stimulation effects exhibit high inter-subject variability, primarily driven by perturbations of the induced electric field (EF). Differences are further elevated in the aging brain due to anatomical changes such as atrophy or lesions. Informing tDCS protocols by computer-based, individualized EF simulations is a suggested measure to mitigate this variability.

Objective

While brain anatomy in general and specifically atrophy as well as stroke lesions are deemed influential on the EF in simulation studies, the influence of the uncertainty in the change of the electrical properties of the white matter due to white matter lesions (WMLs) has not been quantified yet.

Methods

A group simulation study with 88 subjects assigned into four groups of increasing lesion load was conducted. Due to the lack of information about the electrical conductivity of WMLs, an uncertainty analysis was employed to quantify the variability in the simulation when choosing an arbitrary conductivity value for the lesioned tissue.

Results

The contribution of WMLs to the EF variance was on average only one tenth to one thousandth of the contribution of the other modeled tissues. While the contribution of the WMLs significantly increased (p≪.01) in subjects exhibiting a high lesion load compared to low lesion load subjects, typically by a factor of 10 and above, the total variance of the EF didnot change with the lesion load.

Conclusion

Our results suggest that WMLs do not perturb the EF globally and can thus be omitted when modeling subjects with low to medium lesion load. However, for high lesion load subjects, the omission of WMLs may yield less robust local EF estimations in the vicinity of the lesioned tissue. Our results contribute to the efforts of accurate modeling of tDCS for treatment planning.

Relationship between Helicobacter pylori infection and white matter lesions in patients with migraine

Background/aim

White matter lesions (WML) are more frequently observed in migraine patients than in the average population. Associations between Helicobacter pylori (H. pylori) infection and different extraintestinal pathologies have been identified. Here, we aimed to investigate the association between H. pylori infection and WML in patients diagnosed with episodic migraine.

Materials and methods

A retrospective study was conducted with 526 subjects with a diagnosis of episodic migraine. Hyperintensity of WML had been previously evaluated in these patients with brain magnetic resonance imaging (MRI) examinations. Previous endoscopic gastric biopsy histopathological examination of the same patients and reports on H. pylori findings were recorded. The demographic characteristics of the patients, such as age, gender and chronic systemic diseases such as hypertension and diabetes mellitus (DM) were recorded. Statistical evaluation was made.

Results

Evaluation was made among 526 migraine patients who met the inclusion criteria, comprising 397 (75.5%) females and 129 (24.5%) males with a mean age of 45.57 ± 13.46 years (range, 18–69 years). WML was detected on brain MRI in 178 (33.8%) patients who were also positive for H. pylori (p <  0.05). Subjects who are H. pylori-positive with migraine, WML were observed at a 2.5-fold higher incidence on brain MRI (odds ratio: 2.562, 95% CI 1.784–3.680). WML was found to be more significant in patients with hypertension and migraine than those without (p <  0.001). Older age was also found to be associated with WML (OR = 1.07, 95% CI: 0.01–0.04, p <  0.001). The age (p <  0.001), H. pylori (p <  0.001), hypertension (p <  0.001), and hypertension + DM (p <  0.05), had significant associations in predicting WML according to the multivariate logistic regression analysis. The presence of hypertension had a higher odds ratio value than the other variables.

Conclusion

It was concluded that H. pylori infection, as a chronic infection, can be considered a risk factor in developing WML in subjects with migraine.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-022-02715-0.

White Matter and Alzheimer's Disease: A Bidirectional Mendelian Randomization Study

INTRODUCTION

Observational studies have indicated widespread comorbidity of white matter (WM) lesions and Alzheimer's disease (AD) in the elderly, but the causality and direction of their relationship remained unclear. Our study aims to examine the bidirectional causal relationship between WM change and AD using a genetically informed method.

METHODS

We performed a bidirectional two-sample mendelian randomization (MR) study to investigate the correlation of three WM phenotypes-white matter hyperintensities (WMH, N = 18,381), fractional anisotropy (FA, N = 17,673), and mean diffusivity (MD, N = 17,467)-with AD (N = 63,926) using summary statistics from genome-wide association studies (GWAS). The inverse variance weighted method (IVW) was used to evaluate the causal estimate and alternative methods to test the heterogeneity, horizontal pleiotropy, and outliers.

RESULTS

There was no significant causal evidence of WM MRI markers on AD across all MR methods. We identified significant evidence of causal effects of AD on the risk of WMH (OR 1.06, 95% CI 1.03-1.10, p < 0.01). The same direction of effects was observed in MR-Egger, weighted median, and weighted mode analysis. Besides, we also observed a risk causal relationship between AD with MD in MR-Egger, weighted median, and weighted mode-based methods (MR-Egger OR 1.38, 95% CI 1.07-1.79, p = 0.02; weighted median OR 1.21, 95% CI 1.02-1.45, p = 0.03; weighted mode-based OR 1.32, 95% CI 1.14-1.53, p < 0.01). However, the general significance of the causal effect of AD on WMH and MD disappeared when we removed the single nucleotide polymorphisms (SNPs) near the APOE regions, revealing that the ability of AD to increase the risk of white matter damage might be mediated by APOE to some extent. Unfortunately, we did not observe significant causal evidence of AD on FA across all MR analyses.

CONCLUSIONS

In this bidirectional MR study, we did not observe that WM injuries were associated with a higher risk of AD. Likewise, genetically predicted AD did not result in a causal effect on white matter damage. However, our research revealed that underlying mechanisms linking AD and white matter lesions might be related to the SNPs near APOE regions.

Having a stimulating lifestyle is associated with maintenance of white matter integrity with age

Brain maintenance refers to the fact that some older adults experience few age-related changes in the brain, which helps maintain their cognition. The goal of this study was to assess maintenance of white matter integrity by testing whether reserve proxies, measuring factors associated to a stimulating lifestyle, affect the maintenance of white matter integrity. Another goal was to measure whether maintenance of white matter integrity explains inter-individual differences in working memory (WM). Forty-one cognitively healthy older adults received a structural magnetic resonance imaging (MRI) examination to measure white matter lesions. They completed an n-back WM task with different loads (1- & 2-back), along with a questionnaire on their lifestyle. There was a positive association between age and volume of white matter lesions. This association was no longer found in those with higher scores on reserve proxies. In addition, smaller volumes of white matter lesions were associated with better performance than expected for age in the 1-back WM task. Better WM is associated with the maintenance of white matter integrity in older adults, which in turn is linked to measures reflecting a stimulating lifestyle throughout life.

Different patterns of white matter lesions among patent foramen ovale, atherosclerotic cerebral small vessel disease and cerebral venous thrombosis

None of studies are available on the predictive ability of white matter lesions (WMLs) among patent foramen ovale (PFO), atherosclerotic cerebral small vessel disease (aCSVD) and cerebral venous thrombosis (CVT). Herein, we aimed to uncover the difference of the WML patterns among the three disease entities in a real-world setting to provide clinical references for predicting probable WML etiologies. We retrospectively reviewed data from consecutive patients with imaging-confirmed PFO, aCSVD, or CVT enrolled from 2014 through 2020. WMLs presented on fluid-attenuated inversion recovery (FLAIR) maps were compared among the three groups based on visual evaluation, Fazekas and modified Scheltens scales. Propensity score matching (PSM) was implemented to correct age and hypertension differences among groups. A total of 401 patients were entered into final analysis, including PFO (n = 112, 46.5 ± 12.8 years), aCSVD (n = 177, 61.6 ± 11.8 years) and CVT (n = 112, 37.4 ± 11.4 years) groups. In this study, WMLs occurred in all of the involved patients in the three groups (100%), which were independent to age, symptom onset and disease durations. On visual evaluation, PFO-WMLs were multiple spots distributed asymmetrically around bilateral subcortex and peri-ventricles. aCSVD-WMLs were dots or sheets distributed symmetrically in subcortex and peri-ventricles, and often coexisted with lacunar infarctions. CVT-WMLs were cloud-like around bilateral peri-ventricles, and enabled to attenuate after recanalization. Fazekas and modified Scheltens scores of PFO-WML vs. aCSVD-WML were significantly different even after being matched by 1:2 PSM (all p < 0.05), meaning that the WML burden in aCSVD was considerably heavier than that in PFO. WML patterns induced by PFO, aCSVD and CVT were obviously different, and were therefore of great clinical significance to preliminarily predict and differentiate the three diseases entities.

Xi-Xian-Tong-Shuan capsule alleviates vascular cognitive impairment in chronic cerebral hypoperfusion rats by promoting white matter repair, reducing neuronal loss, and inhibiting the expression of pro-inflammatory factors

BACKGROUND

While the number of cases of vascular cognitive impairment caused by chronic cerebral hypoperfusion (CCH) has been increasing every year, there are currently no clinically effective treatment methods. At present, Xi-Xian-Tong-Shuan capsule is predominantly used in patients with acute cerebral ischemia; however, its protective effect on CCH has rarely been reported.

OBJECTIVE

To explore the underlying mechanisms by which Xi-Xian-Tong-Shuan capsule alleviates cognitive impairment caused by CCH.

METHODS

A model of CCH was established in specific-pathogen-free (SPF)-grade male Sprague-Dawley (SD) rats using bilateral common carotid artery occlusion (BCCAO). Xi-Xian-Tong-Shuan capsules were intragastrically administered for 42 days after the BCCAO surgery. We then assessed for changes in cognitive function, expression levels of pro-inflammatory factors, and coagulation function as well as for the presence of white matter lesions and neuronal loss. One-way ANOVA and Tukey's test were used to analyze the experimental data.

RESULTS

The rats showed significant cognitive dysfunction after the BCCAO surgery along with white matter lesions, a loss of neurons, and elevated levels of inflammatory factors, all of which were significantly reversed after intervention with Xi-Xian-Tong-Shuan capsules.

CONCLUSION

Xi-Xian-Tong-Shuan capsules can ameliorate vascular cognitive impairment in CCH rats by preventing damage of white matter, reducing neuronal loss, and inhibiting the expression of pro-inflammatory factors. Our study provides a new reference for the clinical treatment of chronic cerebral ischemia with Xi-Xian-Tong-Shuan capsules.

Uncertainty of leukoencephalopathies: a case report

BACKGROUND

Adult-onset leukoencephalopathies are a group of heterogeneous disorders characterized by white matter abnormalities. Leukoencephalopathy is usually encountered in children, but here we report a case with adult-onset leukoencephalopathy. Also, we explore this concept of uncertainty in medicine by discussing the approach to this case that has multiple possible etiologies.

CASE PRESENTATION

A 70-year-old Caucasian male presented with a subacute onset of cognitive impairment and mood disturbances associated with behavioral changes. Neuroimaging demonstrated high-intensity lesions involving cerebral white matter. Progressive dementia and cognitive decline followed. Multiple possible etiologies are discussed based on the patient presentation and risk factors.

CONCLUSION

Adult-onset leukoencephalopathy can become a diagnostic challenge. Certain approaches need to be developed to explore the uncertainty of such conditions and to improve diagnostic yield.

Hippocampal and non-hippocampal correlates of physically active lifestyle and their relation to episodic memory in older adults

Aging is associated with compromised neurocognition. While aerobic exercise has been linked with cognitive resilience, findings regarding its relationship with brain morphology are inconsistent. Furthermore, the biological underpinnings of the relationship between aerobic activity and memory in the aging human brain are unclear. To investigate these issues, we examined hippocampal and non-hippocampal structural correlates of aerobically active lifestyle and cardiorespiratory fitness in older adults. We then examined structural pathways which may potentially mediate the association between active lifestyle and memory. Fifty participants (aged 65-80) underwent structural and diffusion MRI, memory evaluation, were examined for active lifestyle and cardiorespiratory fitness. Morphological features of the hippocampus and fornix, white matter lesions, and brain atrophy were assessed. Active lifestyle and cardiorespiratory fitness correlated with all neurocognitive measures. An exploratory mediation analysis revealed hippocampal and white matter lesions pathways linking active lifestyle and cardiorespiratory fitness with memory. Our results support a neuroprotective role of aerobic exercise on the aging brain and suggest plausible morphological pathways that may underlie the relationship between aerobic exercise and memory.

Influence of white matter lesions on the prognosis of acute cardioembolic stroke without reperfusion therapy

Background

Few studies have investigated the influence of white matter lesions (WMLs) on the prognosis of acute cardioembolic stroke (CES). We aimed to explore the role of WMLs in predicting 3-month prognosis of CES without reperfusion therapy.

Methods

A number of 251 acute CES patients without reperfusion therapy at a single center were retrospectively recruited. The severity of WMLs was evaluated by Fazekas scale and patients were divided into mild WMLs group (188 cases, Fazekas ≤ 2 points) and moderate to severe WMLs group (63 cases, Fazekas ≥ 3 points) accordingly. General data and clinical features of the two groups were compared. Functional outcomes of patients were followed up for 3 months using the modified Rankin scale (mRS) and patients were divided into poor outcome group (mRS ≥ 3) and favorable outcome group (mRS ≤ 2). The effect of WMLs on the prognosis was identified by binary logistic regression.

Results

Patients in moderate to severe WMLs group were older (P < 0.001). Also, they had higher baseline National Institutes of Health Stroke Scale (NIHSS) score (P < 0.001) and elevated incidence of asymptomatic cerebral hemorrhage (P = 0.040) and stroke associated pneumonia (P = 0.001) than those in mild WMLs group. At 3 months, there were 100 cases in the poor outcome group. Patients in poor outcome group had higher baseline NIHSS score, increased proportion of moderate to severe WMLs, and elevated incidence of stroke associated pneumonia than those in favorable outcome group (P < 0.001). Binary logistic regression analysis showed that moderate to severe WMLs (odds ratio [OR] = 4.105, 95 % confidence interval [CI] = 1.447–11.646), baseline NIHSS score (OR = 1.368, 95 % CI = 1.240–1.511), and stroke-associated pneumonia (OR = 4.840, 95 %CI = 1.889–12.400) were independent risk factors for poor outcome.

Conclusions

Moderate to severe WMLs is an independent risk factor for prognosis of CES patients without reperfusion therapy.

Voxel-wise and spatial modelling of binary lesion masks: Comparison of methods with a realistic simulation framework

OBJECTIVES

White matter lesions are a very common finding on MRI in older adults and their presence increases the risk of stroke and dementia. Accurate and computationally efficient modelling methods are necessary to map the association of lesion incidence with risk factors, such as hypertension. However, there is no consensus in the brain mapping literature whether a voxel-wise modelling approach is better for binary lesion data than a more computationally intensive spatial modelling approach that accounts for voxel dependence.

METHODS

We review three regression approaches for modelling binary lesion masks including mass-univariate probit regression modelling with either maximum likelihood estimates, or mean bias-reduced estimates, and spatial Bayesian modelling, where the regression coefficients have a conditional autoregressive model prior to account for local spatial dependence. We design a novel simulation framework of artificial lesion maps to compare the three alternative lesion mapping methods. The age effect on lesion probability estimated from a reference data set (13,680 individuals from the UK Biobank) is used to simulate a realistic voxel-wise distribution of lesions across age. To mimic the real features of lesion masks, we propose matching brain lesion summaries (total lesion volume, average lesion size and lesion count) across the reference data set and the simulated data sets. Thus, we allow for a fair comparison between the modelling approaches, under a realistic simulation setting.

RESULTS

Our findings suggest that bias-reduced estimates for voxel-wise binary-response generalized linear models (GLMs) overcome the drawbacks of infinite and biased maximum likelihood estimates and scale well for large data sets because voxel-wise estimation can be performed in parallel across voxels. Contrary to the assumption of spatial dependence being key in lesion mapping, our results show that voxel-wise bias-reduction and spatial modelling result in largely similar estimates.

CONCLUSIONS

Bias-reduced estimates for voxel-wise GLMs are not only accurate but also computationally efficient, which will become increasingly important as more biobank-scale neuroimaging data sets become available.

Carotid Atherosclerosis and Longitudinal Changes of MRI Visual Rating Measures in Stroke Survivors: A Seven-Year Follow-Up Study

OBJECTIVES

We aimed to assess longitudinal changes in MRI measures of brain atrophy and white matter lesions in stroke and transient ischemic attack (TIA) survivors, and explore whether carotid stenosis predicts progression of these changes, assessed by visual rating scales.

MATERIALS AND METHODS

All patients with a first-ever stroke or TIA admitted to Bærum Hospital, Norway, in 2007/2008, were invited in the acute phase and followed for seven years. Carotid ultrasound was performed during the hospital stay. Carotid stenosis was defined as ≥50% narrowing of lumen. MRI was performed one and seven years after the index event and analyzed according to the visual rating scales Fazekas scale (0-3), Medial Temporal Lobe Atrophy (MTLA) (0-4) score, and Global Cortical Atrophy (GCA) scale (0-3). Patients with MRI scans at both time points were included in this sub-study.

RESULTS

Of 227 patients recruited, 76 had both MRI examinations. Mean age 73.9±10.6, 41% women, and 9% had ≥50% carotid stenosis. Mean Fazekas scale was 1.7±0.9 and 1.8±1.0, mean MTLA score 1.0 ±1.0 and 1.7±1.0, and mean GCA scale score 1.4±0.7 and 1.4±0.6 after one and seven years, respectively. 71% retained the same Fazekas scale score, while 21% showed progression. Deterioration in GCA scale was seen in 20% and increasing MTLA score in 57%. Carotid stenosis was not associated with progression on Fazekas score, MTLA score or GCA scale.

CONCLUSIONS

Three out of five showed progression on the MTLA score. Carotid stenosis was not associated with longitudinal change of visual rating scales.

Association of Left Ventricular Hypertrophy and Atrial Fibrillation with Hemorrhagic Evolution of Small Vessel Disease

OBJECTIVES

Cerebral small vessel disease (SVD) is often associated with hypertension and may evolve towards intracerebral hemorrhage (ICH) or lacunar ischemic stroke. However, the factors favoring the evolution towards ICH or lacunar stroke are not well understood.

MATERIALS AND METHODS

This retrospective study included 326 consecutive patients (71.1±13.2 years, 38% women): 143 with deep ICH and 183 with lacunar lesions (LL) <2 cm, which were visible in a deep location on brain CT scan. Among LL patients, 143 had a small-artery occlusion (SAO) stroke according to the TOAST classification. Clinical characteristics plus laboratory and neuroradiological variables of these patients had been prospectively collected and a subgroup underwent echocardiography.

RESULTS

In multivariate analysis, ICH patients (97% hypertensive), compared to SAO patients (89% hypertensive), had greater left ventricular wall thickness (LVWT; OR 4.15, 95%CI 1.64-10.53, for those with LVWT ≥ 1.4 cm, 70% of whom were hemorrhagic) and lower prevalence of white matter lesions (OR 0.30, 95%CI 0.13-0.70), ever smokers (OR 0.39, 95%CI 0.18-0.82) and diabetics (OR 0.29, 95% CI 0.10-0.84). Moreover, ICH patients had a greater prevalence of atrial fibrillation than LL patients (OR 3.14, 95%CI 1.11-8.93), and so they were more often anticoagulated.

CONCLUSIONS

Most SVD patients were hypertensive, but those evolving towards ICH were characterized by organ damage at the cardiac level (increase in LVWT and atrial fibrillation), while those evolving towards lacunar stroke were characterized by a higher prevalence of smokers and diabetics, and by organ damage at the cerebral level (white matter lesions).

Pre-stroke cognitive impairment is associated with vascular imaging pathology: a prospective observational study

BACKGROUND

Chronic brain pathology and pre-stroke cognitive impairment (PCI) is predictive of post-stroke dementia. The aim of the current study was to measure pre-stroke neurodegenerative and vascular disease burden found on brain MRI and to assess the association between pre-stroke imaging pathology and PCI, whilst also looking for potential sex differences.

METHODS

This prospective brain MRI cohort is part of the multicentre Norwegian cognitive impairment after stroke (Nor-COAST) study. Patients hospitalized with acute ischemic or hemorrhagic stroke were included from five participating stroke units. Visual rating scales were used to categorize baseline MRIs (N = 410) as vascular, neurodegenerative, mixed, or normal, based on the presence of pathological imaging findings. Pre-stroke cognition was assessed by interviews of patients or caregivers using the Global Deterioration Scale (GDS). Stroke severity was assessed with the National Institute of Health Stroke Scale (NIHSS). Univariate and multiple logistic regression analyses were performed to investigate the association between imaging markers, PCI, and sex.

RESULTS

Patients' (N = 410) mean (SD) age was 73.6 (±11) years; 182 (44%) participants were female, the mean (SD) NIHSS at admittance was 4.1 (±5). In 68% of the participants, at least one pathological imaging marker was found. Medial temporal lobe atrophy (MTA) was present in 30% of patients, white matter hyperintensities (WMH) in 38% of patients and lacunes in 35% of patients. PCI was found in 30% of the patients. PCI was associated with cerebrovascular pathology (OR 2.5; CI = 1.4 to 4.5, p = 0.001) and mixed pathology (OR 3.4; CI = 1.9 to 6.1, p = 0.001) but was not associated with neurodegeneration (OR 1.0; CI = 0.5 to 2.2; p = 0.973). Pathological MRI markers, including MTA and lacunes, were more prevalent among men, as was a history of clinical stroke prior to the index stroke. The OR of PCI for women was not significantly increased (OR 1.2; CI = 0.8 to 1.9; p = 0.3).

CONCLUSIONS

Pre-stroke chronic brain pathology is common in stroke patients, with a higher prevalence in men. Vascular pathology and mixed pathology are associated with PCI. There were no significant sex differences for the risk of PCI.

TRIAL REGISTRATION

NCT02650531 , date of registration: 08.01.2016.

A unique case of progressive hemifacial microsomia or Parry-Romberg syndrome associated with limb and brain anomalies with normal neurological findings: A review of the literature

In this report, we describe an unusual case of progressive hemifacial atrophy or Parry-Romberg syndrome in a 10-year-old girl with progressive hemifacial microsomia and limb anomalies who had brain magnetic resonance imaging (MRI) findings of white matter hyper-intensities. Patients typically present with neurological manifestations such as epilepsy, facial pain, and migraines and ophthalmological symptoms in conjunction with white matter lesions. The patient demonstrated normal cognition and psychomotor development despite the presence of white matter lesions in her frontal lobe that is commonly associated with neurological symptoms. This report brings attention to the complicated relationship between facial, limb and brain imaging findings in Parry-Romberg syndrome and differentiates it from hemifacial microsomia syndrome.

Changes in brain functional connectivity and cognition related to white matter lesion burden in hypertensive patients from SPRINT

PURPOSE

Hypertension is a risk factor for cognitive impairment; however, the mechanisms leading to cognitive changes remain unclear. In this cross-sectional study, we evaluate the impact of white matter lesion (WML) burden on brain functional connectivity (FC) and cognition in a large cohort of hypertensive patients from the Systolic Blood Pressure Intervention Trial (SPRINT) at baseline.

METHODS

Functional networks were identified from baseline resting state functional MRI scans of 660 SPRINT participants using independent component analysis. WML volumes were calculated from structural MRI. Correlation analyses were carried out between mean FC of each functional network and global WML as well as WML within atlas-defined white matter regions. For networks of interest, voxel-wise-adjusted correlation analyses between FC and regional WML volume were performed. Multiple variable linear regression models were built for cognitive test performance as a function of network FC, followed by mediation analysis.

RESULTS

Mean FC of the default mode network (DMN) was negatively correlated with global WML volume, and regional WML volume within the precuneus. Voxel-wise correlation analyses revealed that regional WML was negatively correlated with FC of the DMN's left lateral temporal region. FC in this region of the DMN was positively correlated to performance on the Montreal Cognitive Assessment and demonstrated significant mediation effects. Additional networks also demonstrated global and regional WML correlations; however, they did not demonstrate an association with cognition.

CONCLUSION

In hypertensive patients, greater WML volume is associated with lower FC of the DMN, which in turn is related to poorer cognitive test performance.

TRIAL REGISTRATION

NCT01206062.

Transcriptome Sequencing Identifies Potential Biomarker for White Matter Lesions Diagnosis in the Hypertension Population

Hypertension is confirmed to be one of the major risk factors of leukoaraiosis (LA). However, the pathogenesis of LA is not completely understood and there is no reliable indicator for the early diagnosis of LA in the hypertensive population. This study was designed to explore the potential biomarker for LA diagnosis in patients with hypertension. And it serves as the basis for the further study of LA mechanism. In this study, This study included 110 subjects, including 50 in the LA group and 60 in the control group. First, we performed transcriptome sequencing and quantitative PCR (qPCR) in four samples from the LA group, and three from the control group (seven people) to identify relevant long non-coding RNAs (long ncRNAs or lncRNA). The 103 samples were used for qPCR validation of relevant lncRNAs and the results were consistent with the sequencing. In-depth bioinformatics analysis were performed on differentially expressed (DE) lncRNAs and mRNAs. Go-functional enrichment analysis was performed on DE mRNAs. Some DE mRNA were enriched to biological processes associated with LA, And some lncRNAs related to DE mRNAs were traceable through cis/trans analysis, suggesting that they might be regulated in some way. Additionally, potential biomarkers for LA diagnosis in the hypertension population were identified via RT-qPCR and receive operating characteristic curve (ROC) analysis of lncRNA. One lncRNA, AC020928.1, has been demonstrated to be potential biomarkers for LA diagnosis in the hypertension population. The results of the present study indicated that the lncRNA may have an important role in the pathogenesis of LA and may be a novel target for further research. As the relationship between lncRNAs and LA is just beginning to be unraveled, their specific mechanisms require further investigation.

Reduction in pericyte coverage leads to blood-brain barrier dysfunction via endothelial transcytosis following chronic cerebral hypoperfusion

Background

Chronic cerebral hypoperfusion (CCH) is the leading cause of cerebral small vessel disease (CSVD). CCH is strongly associated with blood–brain barrier (BBB) dysfunction and white matter lesions (WMLs) in CSVD. However, the effects of CCH on BBB integrity and components and the cellular and molecular mechanisms underlying the effects of BBB dysfunction remain elusive. Whether maintaining BBB integrity can reverse CCH-induced brain damage has also not been explored.

Methods

In this study, we established a rat model of CSVD via permanent bilateral common carotid artery occlusion (2VO) to mimic the chronic hypoperfusive state of CSVD. The progression of BBB dysfunction and components of the BBB were assessed using immunostaining, Western blotting, transmission electron microscopy (TEM) and RNA sequencing. We also observed the protective role of imatinib, a tyrosine kinase inhibitor, on BBB integrity and neuroprotective function following CCH. The data were analyzed using one-way or two-way ANOVA.

Results

We noted transient yet severe breakdown of the BBB in the corpus callosum (CC) following CCH. The BBB was severely impaired as early as 1 day postoperation and most severely impaired 3 days postoperation. BBB breakdown preceded neuroinflammatory responses and the formation of WMLs. Moreover, pericyte loss was associated with BBB impairment, and the accumulation of serum protein was mediated by increased endothelial transcytosis in the CC. RNA sequencing also revealed increased transcytosis genes expression. BBB dysfunction led to brain damage through regulation of TGF-β/Smad2 signaling. Furthermore, imatinib treatment ameliorated serum protein leakage, oligodendrocyte progenitor cell (OPC) activation, endothelial transcytosis, microglial activation, and aberrant TGF-β/Smad2 signaling activation.

Conclusions

Our results indicate that reduced pericyte coverage leads to increased BBB permeability via endothelial transcytosis. Imatinib executes a protective role on the BBB integrity via inhibition of endothelial transcytosis. Maintenance of BBB integrity ameliorates brain damage through regulation of TGF-β/Smad2 signaling following CCH; therefore, reversal of BBB dysfunction may be a promising strategy for CSVD treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12987-021-00255-2.

Patterns of white matter hyperintensities associated with cognition in middle-aged cognitively healthy individuals

White matter hyperintensities (WMH) are commonly detected in the brain of elderly individuals and have been associated with a negative impact on multiple cognitive domains. We aim to investigate the impact of global and regional distribution of WMH on episodic memory and executive function in middle-aged cognitively unimpaired participants [N = 561 (45–75 years)] enriched for Alzheimer’s disease risk factors. WMH were automatically segmented from FLAIR, T1 and FSE MR images. WMH load was calculated both globally and regionally. At each cerebral lobe, regional WMH load was measured at four equidistant layers extending from the lateral ventricles to juxtacortical areas. Cognition was measured by The Memory Binding Test (MBT) and WAIS-IV subtests. Global composite z-scores were calculated for the two cognitive domains. Association between global and regional WMH measurements were sought against cognitive measures, both in global composite scores and in individual subtests. We adjusted cognition and WMH burden for the main sociodemographic (age, sex and education) and genetic factors (APOE-ε4). Memory and executive function were significantly associated with global WMH load. Regionally, lower executive performance was mainly associated with higher deep WMH load in frontal areas and, to a lower degree, in occipital, parietal and temporal regions. Lower episodic memory performance was correlated with higher WMH burden in deep frontal and occipital areas. Our novel methodological approach of regional analysis allowed us to reveal the association between cognition and WMH in strategic brain locations. Our results suggest that, even a small WMH load can impact cognition in cognitively unimpaired middle-aged subjects.