Blood pressure and sodium: association with MRI markers in cerebral small vessel disease

Dietary salt intake and hypertension are associated with increased risk of cardiovascular disease including stroke. We aimed to explore the influence of these factors, together with plasma sodium concentration, in cerebral small vessel disease (SVD). In all, 264 patients with nondisabling cortical or lacunar stroke were recruited. Patients were questioned about their salt intake and plasma sodium concentration was measured; brain tissue volume and white-matter hyperintensity (WMH) load were measured using structural magnetic resonance imaging (MRI) while diffusion tensor MRI and dynamic contrast-enhanced MRI were acquired to assess underlying tissue integrity. An index of added salt intake (P = 0.021), pulse pressure (P = 0.036), and diagnosis of hypertension (P = 0.0093) were positively associated with increased WMH, while plasma sodium concentration was associated with brain volume (P = 0.019) but not with WMH volume. These results are consistent with previous findings that raised blood pressure is associated with WMH burden and raise the possibility of an independent role for dietary salt in the development of cerebral SVD

Application of Texture Analysis to Study Small Vessel Disease and Blood–Brain Barrier Integrity

artículo 327Evaluamos el uso alternativo del análisis de textura para evaluar el papel de la barrera hematoencefálica (BBB) en la enfermedad de pequeños vasos (SVD). Utilizamos imágenes de resonancia magnética cerebral de 204 pacientes con accidente cerebrovascular, adquiridas antes y 20 minutos después de la administración intravenosa de gadolinio. Segmentamos tejidos, hiperintensidades de la materia blanca (WMH) y aplicamos puntuaciones visuales validadas. Medimos las características de la textura en todos los tejidos antes y después del contraste y utilizamos ANCOVA para evalúe el efecto de los indicadores de SVD en el cambio anterior / posterior al contraste, Kruskal-Wallis para determinar la importancia entre los grupos de pacientes y los modelos lineales mixtos para las variaciones anteriores / posteriores al contraste en el líquido cefalorraquídeo (LCR) con puntuaciones Fazekas. El aumento de la "homogeneidad" textural en los tejidos normales con mayor presencia de indicadores de la EVP fue consecuentemente más evidente que en los tejidos anormales. La “homogeneidad” textural aumentó con la edad, las puntuaciones de los espacios perivasculares de los ganglios basales (p <0,01) y las puntuaciones de la EVP (p <0,05) y fue significativamente mayor en los pacientes hipertensos (p <0,002) y el ictus lacunar (p = 0,04). La hipertensión (74% de los pacientes), la carga de WMH (mediana = 1.5 ± 1.6% del volumen intracraneal) y la edad (media = 65.6 años, SD = 11.3) predijeron el cambio pre / post-contraste en la sustancia blanca normal, WMH e índice Lesión de trazo. Señal CSF Incremento con el aumento de SVD post-contraste. Un patrón general consistente de aumento de la homogeneidad de la textura "con el aumento de la SVD y el cambio posterior al contraste en el LCR con el aumento de WMH sugiere que el análisis de textura puede ser útil para el estudio de la integridad de BBB.S

Blood-brain barrier failure as a core mechanism in cerebral small vessel disease and dementia: evidence from a cohort study

Introduction: Small vessel disease (SVD) is a common contributor to dementia. Subtle blood-brain barrier (BBB) leakage may be important in SVD-induced brain damage. Methods: We assessed imaging, clinical variables, and cognition in patients with mild (i.e., nondisabling) ischemic lacunar or cortical stroke. We analyzed BBB leakage, interstitial fluid, and white matter integrity using multimodal tissue-specific spatial analysis around white matter hyperintensities (WMH). We assessed predictors of 1 year cognition, recurrent stroke, and dependency. Results: In 201 patients, median age 67 (range 34–97), BBB leakage, and interstitial fluid were higher in WMH than normal-appearing white matter; leakage in normal-appearing white matter increased with proximity to WMH (P , .0001), with WMH severity (P 5 .033), age (P 5 .03), and hypertension (P , .0001). BBB leakage in WMH predicted declining cognition at 1 year. Discussion: BBB leakage increases in normal-appearing white matter with WMH and predicts worsening cognition. Interventions to reduce BBB leakage may prevent SVD-associated dementia

Rationale, design and methodology of the image analysis protocol for studies of patients with cerebral small vessel disease and mild stroke

Rationale: Cerebral small vessel disease (SVD) is common in ageing and patients with dementia and stroke. Its manifestations on magnetic resonance imaging (MRI) include white matter hyperintensities, lacunes, microbleeds, perivascular spaces, small subcortical infarcts, and brain atrophy. Many studies focus only on one of these manifestations. A protocol for the differential assessment of all these features is, therefore, needed. Aims: To identify ways of quantifying imaging markers in research of patients with SVD and operationalize the recommendations from the STandards for ReportIng Vascular changes on nEuroimaging guidelines. Here, we report the rationale, design, and methodology of a brain image analysis protocol based on our experience from observational longitudinal studies of patients with nondisabling stroke. Design: The MRI analysis protocol is designed to provide quantitative and qualitative measures of disease evolution including: acute and old stroke lesions, lacunes, tissue loss due to stroke, perivascular spaces, microbleeds, macrohemorrhages, iron deposition in basal ganglia, substantia nigra and brain stem, brain atrophy, and white matter hyperintensities, with the latter separated into intense and less intense. Quantitative measures of tissue integrity such as diffusion fractional anisotropy, mean diffusivity, and the longitudinal relaxation time are assessed in regions of interest manually placed in anatomically and functionally relevant locations, and in others derived from feature extraction pipelines and tissue segmentation methods. Morphological changes that relate to cognitive deficits after stroke, analyzed through shape models of subcortical structures, complete the multiparametric image analysis protocol. Outcomes: Final outcomes include guidance for identifying ways to minimize bias and confounds in the assessment of SVD and stroke imaging biomarkers. It is intended that this information will inform the design of studies to examine the underlying pathophysiology of SVD and stroke, and to provide reliable, quantitative outcomes in trials of new therapies and preventative strategies