Role of small acute hyperintense lesions in long-term progression of cerebral small vessel disease and clinical outcome: a 14-year follow-up study.

BACKGROUND: Small hyperintense lesions are found on diffusion-weighted imaging (DWI) in patients with sporadic small vessel disease (SVD). Their exact role in SVD progression remains unclear due to their asymptomatic and transient nature. The main objective is to investigate the role of DWI+lesions in the radiological progression of SVD and their relationship with clinical outcomes. METHODS: Participants with SVD were included from the Radboud University Nijmegen Diffusion tensor MRI Cohort. DWI+lesions were assessed on four time points over 14 years. Outcome measures included neuroimaging markers of SVD, cognitive performance and clinical outcomes, including stroke, all-cause dementia and all-cause mortality. Linear mixed-effect models and Cox regression models were used to examine the outcome measures in participants with a DWI+lesion (DWI+) and those without a DWI+lesion (DWI-). RESULTS: DWI+lesions were present in 45 out of 503 (8.9%) participants (mean age: 66.7 years (SD=8.3)). Participants with DWI+lesions and at least one follow-up (n=33) had higher white matter hyperintensity progression rates (ß=0.36, 95% CI=0.05 to 0.68, p=0.023), more incident lacunes (incidence rate ratio=2.88, 95% CI=1.80 to 4.67, p<0.001) and greater cognitive decline (ß=-0.03, 95% CI=-0.05 to -0.01, p=0.006) during a median follow-up of 13.2 (IQR: 8.8-13.8) years compared with DWI- participants. No differences were found in risk of all-cause mortality, stroke or dementia. CONCLUSION: Presence of a DWI+lesion in patients with SVD is associated with greater radiological progression of SVD and cognitive decline compared with patients without DWI+lesions.

Short-Term and Long-Term Risk of Recurrent Vascular Event by Cause After Ischemic Stroke in Young Adults.

Importance: Cause of ischemic stroke in young people is highly variable; however, the risk of recurrence is often presented with all subtypes of stroke grouped together in classification systems such as the Trial of ORG (danaparoid sodium [Orgaran]) 10172 in Acute Stroke Treatment (TOAST) criteria, which limits the ability to individually inform young patients with stroke about their risk of recurrence. Objective: To determine the short-term and long-term risk of recurrent vascular events after ischemic stroke at a young age by stroke cause and to identify factors associated with recurrence. Design, Setting, and Participants: This cohort study used data from the Observational Dutch Young Symptomatic Stroke Study, a prospective, multicenter, hospital-based cohort study, conducted at 17 hospitals in the Netherlands between 2013 and 2021. Eligible participants included 30-day survivors of an initial, neuroimaging-proven ischemic stroke (aged 18-49 years). Data analysis was conducted from June to July 2023. Exposure: Diagnosis of a first-ever, ischemic stroke via neuroimaging. Main Outcome and Measures: The primary outcome was short-term (within 6 months) and long-term (within 5 years) recurrence risk of any vascular event, defined as fatal or nonfatal recurrent ischemic stroke, transient ischemic attack, myocardial infarction, and revascularization procedure. Predefined characteristics were chosen to identify factors associated with risk of recurrence (cause of stroke, age, sex, stroke severity, and cardiovascular health factors). Results: A total of 1216 patients (median [IQR] age, 44.2 [38.4-47.7] years; 632 male [52.0%]; 584 female [48.0%]) were included, with a median (IQR) follow-up of 4.3 (2.6-6.0) years. The 6-month risk of any recurrent ischemic event was 6.7% (95% CI, 5.3%-8.1%), and the 5-year risk was 12.2% (95% CI, 10.2%-14.2%)The short-term risk was highest for patients with cervical artery dissections (13.2%; 95% CI, 7.6%-18.7%). Other factors associated with a recurrent short-term event were atherothrombotic stroke, rare causes of stroke, and hypertension. The long-term cumulative risk was highest for patients with atherothrombotic stroke (22.7%; 95% CI, 10.6%-34.7%) and lowest for patients with cryptogenic stroke (5.8%; 95% CI, 3.0%-8.5%). Cardioembolic stroke was associated with a recurrent long-term event, as were diabetes and alcohol abuse. Conclusions and Relevance: The findings of this cohort study of 1216 patients with an ischemic stroke at a young age suggest that the risk of recurrent vascular events was high and varied by cause of stroke both for short-term and long-term follow-up, including causes that remained concealed when combined into 1 category in the routinely used TOAST criteria. This knowledge will allow for more personalized counseling of young patients with stroke.

Trigger factors in patients with a patent foramen ovale-associated stroke: A case-crossover study.

BACKGROUND: Patent foramen ovale (PFO) is a congenital anatomical variant which is associated with strokes in young adults. Contrary to vascular risk factors and atherosclerosis, a PFO is present from birth. However, it is completely unknown how an anatomical structure that is already present at birth in a large proportion of the population can convert into a PFO that causes stroke in a few. Recent studies reported a significant association between certain trigger factors and ischemic stroke in young adults. This study aims to investigate these triggers in PFO-associated stroke. METHODS: The ODYSSEY study, a multicenter prospective cohort study between 2013 and 2021, included patients aged 18-49 years experiencing their first-ever ischemic event. Participants completed a questionnaire about exposure to potential trigger factors. A case-crossover design was used to assess the relative risks (RR) with 95% confidence intervals (95% CI). The primary outcome was the RR of potential trigger factors for PFO-associated stroke. RESULTS: Overall, 1043 patients completed the questionnaire and had an ischemic stroke, of which 124 patients had a PFO-associated stroke (median age 42.1 years, 45.2% men). For patients with PFO-associated stroke, the RR was 26.0 (95% CI 8.0-128.2) for fever, 24.2 (95% CI 8.5-68.7) for flu-like disease, and 3.31 (95% CI 2.2-5.1) for vigorous exercise. CONCLUSION: In conclusion, flu-like disease, fever, and vigorous exercise may convert an asymptomatic PFO into a stroke-causing PFO in young adults. DATA ACCESS STATEMENT: The raw and anonymized data used in this study can be made available to other researchers on request. Written proposals can be addressed to the corresponding author and will be assessed by the ODYSSEY investigators for appropriateness of use, and a data sharing agreement in accordance with Dutch regulations will be put in place before data are shared.

The Hyperintense study: Assessing the effects of induced blood pressure increase and decrease on MRI markers of cerebral small vessel disease: Study rationale and protocol.

Background: Neuroimaging markers of cerebral small vessel disease (SVD) are common in older individuals, but the pathophysiological mechanisms causing these lesions remain poorly understood. Although hypertension is a major risk factor for SVD, the direct causal effects of increased blood pressure are unknown. The Hyperintense study is designed to examine cerebrovascular and structural abnormalities, possibly preceding SVD, in young adults with hypertension. These patients undergo a diagnostic work-up that requires patients to temporarily discontinue their antihypertensive agents, often leading to an increase in blood pressure followed by a decrease once effective medication is restarted. This allows examination of the effects of blood pressure increase and decrease on the cerebral small vessels. Methods: Hyperintense is a prospective observational cohort study in 50 hypertensive adults (18-55 years) who will temporarily discontinue antihypertensive medication for diagnostic purposes. MRI and clinical data is collected at four timepoints: before medication withdrawal (baseline), once antihypertensives are largely or completely withdrawn (T = 1), when patients have restarted medication (T = 2) and reached target blood pressure and 1 year later (T = 3). The 3T MRI protocol includes conventional structural sequences and advanced techniques to assess various aspects of microvascular integrity, including blood-brain barrier function using Dynamic Contrast Enhanced MRI, white matter integrity, and microperfusion. Clinical assessments include motor and cognitive examinations and blood sampling. Discussion: The Hyperintense study will improve the understanding of the pathophysiological mechanisms following hypertension that may cause SVD. This knowledge can ultimately help to identify new targets for treatment of SVD, aimed at prevention or limiting disease progression.