Long-Term Outcomes in Patients With Spontaneous Cerebellar Hemorrhage: An International Cohort Study.

BACKGROUND: Spontaneous intracerebral hemorrhage (ICH) in the cerebellum has a poor short-term prognosis, whereas data on the long-term case fatality and recurrent vascular events are sparse. Herewith, we aimed to assess the long-term case fatality and recurrence rate of vascular events after a first cerebellar ICH. METHODS: In this international cohort study, we included patients from 10 hospitals (the United States and Europe from 1997 to 2017) aged ≥18 years with a first spontaneous cerebellar ICH who were discharged alive. Data on long-term case fatality and recurrence of vascular events (recurrent ICH [supratentoria or infratentorial], ischemic stroke, myocardial infarction, or major vascular surgery) were collected for survival analysis and absolute event rate calculation. RESULTS: We included 405 patients with cerebellar ICH (mean age [SD], 72 [13] years, 49% female). The median survival time was 67 months (interquartile range, 23-100 months), with a cumulative survival rate of 34% at 10-year follow-up (median follow-up time per center ranged: 15-80 months). In the 347 patients with data on vascular events 92 events occurred in 78 patients, after initial cerebellar ICH: 31 (8.9%) patients had a recurrent ICH (absolute event rate, 1.8 per 100 patient-years [95% CI, 1.2-2.6]), 39 (11%) had an ischemic stroke (absolute event rate, 2.3 [95% CI, 1.6-3.2]), 13 (3.7%) had a myocardial infarction (absolute event rate, 0.8 [95% CI, 0.4-1.3]), and 5 (1.4%) underwent major vascular surgery (absolute event rate, 0.3 [95% CI, 0.1-0.7]). The median time to a first vascular event during follow-up was 27 months (interquartile range, 8.7-50 months), with a cumulative hazard of 47% at 10 years. CONCLUSIONS: The long-term prognosis of patients who survive a first spontaneous cerebellar ICH is poor and comparable to that of patients who survive a first supratentorial ICH. Further identification of patients at high risk of vascular events following the initial cerebellar ICH is needed. Including patients with cerebellar ICH in randomized controlled trials on secondary prevention of patients with ICH is warranted.

Histopathological Correlates of Lobar Microbleeds in False-Positive Cerebral Amyloid Angiopathy Cases.

OBJECTIVE: A definite diagnosis of cerebral amyloid angiopathy (CAA), characterized by the accumulation of amyloid ß in walls of cerebral small vessels, can only be obtained through pathological examination. A diagnosis of probable CAA during life relies on the presence of hemorrhagic markers, including lobar cerebral microbleeds (CMBs). The aim of this project was to study the histopathological correlates of lobar CMBs in false-positive CAA cases. METHODS: In 3 patients who met criteria for probable CAA during life, but showed no CAA upon neuropathological examination, lobar CMBs were counted on ex vivo 3T magnetic resonance imaging (MRI) and on ex vivo 7T MRI. Areas with lobar CMBs were next sampled and cut into serial sections, on which the CMBs were then identified. RESULTS: Collectively, there were 25 lobar CMBs on in vivo MRI and 22 on ex vivo 3T MRI of the analyzed hemispheres. On ex vivo MRI, we targeted 12 CMBs for sampling, and definite histopathological correlates were retrieved for 9 of them, of which 7 were true CMBs. No CAA was found on any of the serial sections. The "culprit vessels" associated with the true CMBs instead showed moderate to severe arteriolosclerosis. Furthermore, CMBs in false-positive CAA cases tended to be located more often in the juxtacortical or subcortical white matter than in the cortical ribbon. INTERPRETATION: These findings suggest that arteriolosclerosis can generate lobar CMBs and that more detailed investigations into the exact localization of CMBs with respect to the cortical ribbon could potentially aid the diagnosis of CAA during life. ANN NEUROL 2023;94:856-870.

Intensive Blood Pressure Reduction is Associated with Reduced Hematoma Growth in Fast Bleeding Intracerebral Hemorrhage.

OBJECTIVE: Patients with spontaneous intracerebral hemorrhage (ICH) at the highest risk of hematoma growth are those with the most potential to benefit from anti-expansion treatment. Large clinical trials have not definitively shown a clear benefit of blood pressure (BP) reduction. We aim to determine whether intensive blood pressure reduction could benefit patients with fast bleeding ICH. METHODS: An exploratory analysis of data from the Antihypertensive Treatment of Acute Cerebral Hemorrhage 2 (ATACH-2) randomized controlled trial was performed. In order to capture not just early bleeding (even if a small amount), but the rate of bleeding (ml/hour), we restricted the study to "Fast bleeding ICH," defined as an ICH volume/onset to computed tomography (CT) time >5 ml/hr. Hematoma growth, as defined as an increase of hematoma volume > 33% between baseline and 24 hours. RESULTS: A total of 940 patients were included (mean age = 62.1 years, 61.5% men), of whom 214 (22.8%) experienced hematoma expansion. Of these, 567 (60.3%) met the definition of "fast bleeding" with baseline ICH volume/time to presentation of at least 5 ml/hr. Intensive BP reduction was associated with a significantly lower rate of hematoma growth in fast bleeding patients (20.6% vs 31.0%, p = 0.005). In a subgroup of 266 (46.9%) fast-bleeding patients who received treatment within 2 hours after symptom onset, intensive BP lowering was associated with improved functional independence (odds ratio [OR] = 1.98, 95% confidence interval [CI] = 1.06-3.69, p = 0.031). INTERPRETATION: Our results suggest that early use of intensive BP reduction may reduce hematoma growth and improve outcome in fast bleeding patients. ANN NEUROL 2023.

A Causal Classification System for Intracerebral Hemorrhage Subtypes.

OBJECTIVE: Determining the underlying causes of intracerebral hemorrhage (ICH) is of major importance, because risk factors, prognosis, and management differ by ICH subtype. We developed a new causal CLASsification system for ICH Subtypes, termed CLAS-ICH, based on recent advances in neuroimaging. METHODS: CLAS-ICH defines 5 ICH subtypes: arteriolosclerosis, cerebral amyloid angiopathy, mixed small vessel disease (SVD), other rare forms of SVD (genetic SVD and others), and secondary causes (macrovascular causes, tumor, and other rare causes). Every patient is scored in each category according to the level of diagnostic evidence: (1) well-defined ICH subtype; (2) possible underlying disease; and (0) no evidence of the disease. We evaluated CLAS-ICH in a derivation cohort of 113 patients with ICH from Massachusetts General Hospital, Boston, USA, and in a derivation cohort of 203 patients from Inselspital, Bern, Switzerland. RESULTS: In the derivation cohort, a well-defined ICH subtype could be identified in 74 (65.5%) patients, including 24 (21.2%) with arteriolosclerosis, 23 (20.4%) with cerebral amyloid angiopathy, 18 (15.9%) with mixed SVD, and 9 (8.0%) with a secondary cause. One or more possible causes were identified in 42 (37.2%) patients. Interobserver agreement was excellent for each category (kappa value ranging from 0.86 to 1.00). Despite substantial differences in imaging modalities, we obtained similar results in the validation cohort. INTERPRETATION: CLAS-ICH is a simple and reliable classification system for ICH subtyping, that captures overlap between causes and the level of diagnostic evidence. CLAS-ICH may guide clinicians to identify ICH causes, and improve ICH classification in multicenter studies. ANN NEUROL 2023;93:16-28.

Impaired Kidney Function, Cerebral Small Vessel Disease and Cognitive Disorders: The Framingham Heart Study.

BACKGROUND AND HYPOTHESIS: It remains unclear if the relation of chronic kidney disease (CKD) with cognitive dysfunction is independent of blood pressure (BP). We evaluated kidney function in relation to premorbid BP measurements, cerebral small vessel disease (CSVD) and incident mild cognitive impairment (MCI) and dementia in Framingham Offspring Cohort participants. METHODS: We included Framingham Offspring participants free of dementia, attending an examination during midlife (exam cycle 6, baseline) for ascertainment of kidney function status, with brain MRI late in life (exam cycles 7-9), cognitive outcome data and available interim hypertension and blood pressure assessments. We related CKD (estimated glomerular filtration rate < 60 ml/min/1.73m2) and albuminuria (urine albumin-to-creatinine ratio ≥ 30 mg/g) to CSVD markers and cognitive outcomes using multivariable regression analyses. RESULTS: Among 2604 participants (mean age 67.4 ± 9.2, 64% women, 7% had CKD and 9% albuminuria), albuminuria was independently associated with covert infarcts (adjusted OR, 1.55 [1.00-2.38]; P = 0.049) and incident MCI and dementia (adjusted HR, 1.68 [1.18-2.41]; P = 0.005 and 1.71, [1.11-2.64]; P = 0.015, respectively). CKD was not associated with CSVD markers but was associated with higher risk of incident dementia (HR, 1.53 [1.02-2.29]; P = 0.041), While albuminuria was predictive of the Alzheimer's disease subtype (Adjusted HR = 1.68, [1.03-2.74]; P = 0.04), CKD was predictive of vascular dementia (Adjusted HR, 2.78, [1.16-6.68]; P = 0.023). CONCLUSIONS: Kidney disease was associated with CSVD and cognitive disorders in asymptomatic community dwelling participants. The relation was independent of premorbid BP, suggesting that the link between kidney and brain disease may involve additional mechanisms beyond blood pressure related injury.

Hypertension control after intracerebral hemorrhage among varying small vessel disease etiologies.

INTRODUCTION: Intracerebral hemorrhage (ICH) is attributable to cerebral small vessel disease (cSVD), which includes cerebral amyloid angiopathy (CAA) and hypertensive-cSVD (HTN-cSVD). HTN-cSVD includes patients with strictly deep ICH/microbleeds and mixed location ICH/microbleeds, the latter representing a more severe form of HTN-cSVD. We test the hypothesis that more severe forms of HTN-cSVD are related to worse hypertension control in long-term follow-up after ICH. METHODS: From consecutive non-traumatic ICH patients admitted to a tertiary care center, we classified the ICH as CAA, strictly deep ICH/microbleeds, and mixed-location ICH/microbleeds. CSVD burden was quantified using a validated MRI-based score (range: 0-6 points). We created a multivariable (linear mixed effects) model adjusting for age, sex, race, year of inclusion, hypertension, and antihypertensive medication usage to investigate the association of average systolic blood pressure (SBP) during follow-up with cSVD etiology/severity. RESULTS: 796 ICH survivors were followed for a median of 48.8 months (IQR 41.5-60.4). CAA-related ICH survivors (n = 373) displayed a lower median SBP (138 mmHg, IQR 133-142 mmHg) compared to those of strictly deep ICH (n = 222, 141 mmHg, IQR 136-143 mmHg, p = 0.04), and mixed location ICH/microbleeds (n = 201, 142 mmHg, IQR 135-144 mmHg, p = 0.02). In the multivariable analysis, mixed location ICH/microbleeds (effect: + 3.8 mmHg, SE: 1.3 mmHg, p = 0.01) and increasing cSVD severity (+ 1.8 mmHg per score point, SE: 0.8 mmHg, p = 0.03) were associated with higher SBP in follow-up. CONCLUSION: CSVD severity and subtype predicts long-term hypertension control in ICH patients.

Poststroke Disability: Association Between Sex and Patient-Reported Outcomes.

BACKGROUND: Ischemic stroke (IS) is a leading cause of long-term disability with sex-specific differences in outcomes. Identifying the influential factors that contribute to sex-specific disparities in stroke outcomes, therefore, holds potential to develop individualized interventions for reducing long-term disability. Further, investigating the association between sex and Patient-Reported Outcome Measures (PROMs) provides additional information on the individual impact and heterogeneity of IS. We aimed to identify sex-specific differences in stroke outcomes and relationship with PROMs in IS patients with 3-month follow-up. METHODS: Between February 2017 and February 2020, a total of 410 patients admitted with IS to the Massachusetts General Hospital, in Boston, were enrolled in this prospective cohort. At 3-month poststroke, patients were assessed for Barthel Index, modified Rankin Scale, and PROM-10 questionnaires. T scores for physical and mental health were determined from the summing of PROM-10 responses in each domain. Regression analysis was performed to identify sex-specific determinants of functional and patient-reported outcomes. RESULTS: At baseline, 242 participants were male (mean age, 65 years) and 168 were female (mean age, 70 years). Groups had similar rates of cardiovascular risk factors, admission National Institutes of Health Stroke Scale, and discharge modified Rankin Scale. At follow-up, male participants were more likely to have better rates of T Physical and Barthel Index. In regression analysis, PROMs T Physical (odds ratio, 1.06; P=0.01), Barthel Index (odds ratio, 1.06; P=0.01), and modified Rankin Scale score of ≥2 (odds ratio, 2.60; P=0.01) were associated with female sex. Female sex was also associated with lower scores for PROMs Physical subcomponents and with patient-reported general health and emotional problems. CONCLUSIONS: Women have worse outcomes after ischemic stroke, including objective measures of functional disability and patient-reported outcomes. Incorporating PROMs into IS outcome measures may offer additional insight into sex-specific differences in stroke recovery and outcomes.

Association of Depression Onset and Treatment With Blood Pressure Control After Intracerebral Hemorrhage.

BACKGROUND: Blood pressure (BP) control represents a crucial intervention to improve long-term outcomes following spontaneous intracerebral hemorrhage (ICH). However, fewer than half of ICH survivors achieve target treatment goals. ICH survivors are also at very high risk for poststroke depression, which may contribute to inadequate BP control. We, therefore, sought to determine whether depressive symptoms after ICH are associated with inadequate BP control. We also investigated whether associations between depression after ICH and BP measurements were mediated by treatment with selective serotonin reuptake inhibitors or norepinephrine-serotonin reuptake inhibitors antidepressants. METHODS: We leveraged data from a single-center longitudinal study of ICH conducted at Massachusetts General Hospital (Boston, MA) between 2006 and 2018. We collected data from semiautomated review of electronic health records, baseline and follow-up interviews, and computed tomography imaging. Information on BP measurements, depression diagnoses, antidepressants medication use, and medical visits were collected longitudinally and analyzed using mixed effects models. Primary outcomes included systolic and diastolic BP measurements during long-term follow-up after ICH. RESULTS: We included 1243 consecutive ICH patients without pre-stroke depression history. Of these, 721 (58%) were diagnosed with incident depression over a median follow-up time of 52.8 months (interquartile range, 42.1-60.5). Depression onset was associated with subsequent increase in systolic (+8.3 mm Hg, SE, 2.4 mm Hg, P=0.012) and diastolic (+4.4 mm Hg, SE, 1.2 mm Hg) BP measurements. Resolution of depressive symptoms was associated with subsequent decrease in systolic (-5.9 mm Hg, SE, 1.4 mm Hg, P=0.031) and diastolic (-3.4 mm Hg, SE, 1.1 mm Hg, P=0.041) BP measurements. We also found associations between higher systolic BP measurements and use of selective serotonin reuptake inhibitor and noradrenaline-serotonin reuptake inhibitor antidepressants, independent of whether depression symptoms were active or not (all P<0.05). CONCLUSIONS: ICH survivors displayed increasing BP values after receiving a diagnosis of depression, followed by decreasing values among those experiencing resolution of depressive symptoms. Use of selective serotonin reuptake inhibitor and noradrenaline-serotonin reuptake inhibitor antidepressants was independently associated with higher systolic BP measurements. Clinicians ought to closely monitor BP for ICH survivors being treated for depression, especially using selective serotonin reuptake inhibitor and noradrenaline-serotonin reuptake inhibitor. Future studies will also be required to investigate the mechanisms underlying these associations.

Blood Pressure Control Targets and Risk of Cardiovascular and Cerebrovascular Events After Intracerebral Hemorrhage.

BACKGROUND: Intracerebral hemorrhage (ICH) survivors are at high risk for recurrent stroke and cardiovascular events. Blood pressure (BP) control represents the most potent intervention to lower these risks, but optimal treatment targets in this patient population remain unknown. We sought to determine whether survivors of ICH achieving more intensive BP control than current guideline recommendations (systolic BP <130 mmHg and diastolic BP <80 mmHg) were at lower risk of major adverse cardiovascular and cerebrovascular events and mortality. METHODS: We analyzed data for 1828 survivors of spontaneous ICH from 2 cohort studies. Follow-up BP measurements were recorded 3 and 6 months after ICH, and every 6 months thereafter. Outcomes of interest were major adverse cardiovascular and cerebrovascular events (recurrent ICH, incident ischemic stroke, myocardial infarction), vascular mortality (defined as mortality attributed to recurrent ICH, ischemic stroke, or myocardial infarction), and all-cause mortality. RESULTS: During a median follow-up of 46.2 months, we observed 166 recurrent ICH, 68 ischemic strokes, 69 myocardial infarction, and 429 deaths. Compared with survivors of ICH with systolic BP 120 to 129 mmHg, participants who achieved systolic BP <120 mmHg displayed reduced risk of recurrent ICH (adjusted hazard ratio [AHR], 0.74 [95% CI, 0.59-0.94]) and major adverse cardiovascular and cerebrovascular events (AHR, 0.69 [95% CI, 0.53-0.92]). All-cause mortality (AHR, 0.76 [95% CI, 0.57-1.03]) and vascular mortality (AHR, 0.68 [95% CI, 0.45-1.01]) did not differ significantly. Among participants aged >75 years or with modified Rankin Scale score 4 to 5, systolic BP <120 mmHg was associated with increased all-cause mortality (AHR, 1.38 [95% CI, 1.02-1.85] and AHR, 1.36 [95% CI, 1.03-1.78], respectively), but not vascular mortality. We found no differences in outcome rates between survivors of ICH with diastolic BP <70 versus 70 to 79 mmHg. CONCLUSIONS: Targeting systolic BP <120 mmHg in select groups of survivors of ICH could result in decreased major adverse cardiovascular and cerebrovascular events risk without increasing mortality. Our findings warrant investigation in dedicated randomized controlled trials.

Sex Differences in Onset and Progression of Cerebral Amyloid Angiopathy.

BACKGROUND: Cerebral Amyloid Angiopathy (CAA) disease course is highly variable even in hereditary forms. Sex may be a possible modifying factor. We investigated biological sex differences in clinical disease course and magnetic resonance imaging-markers in sporadic (sCAA) and Dutch-type hereditary CAA (D-CAA). METHODS: Patients with D-CAA and sCAA were included from hospital and research databases of the Leiden University Medical Center (2012-2020) and Massachusetts General Hospital (1994-2012). Key outcomes were: sex differences in symptomatic intracerebral hemorrhage (sICH) onset, recurrence and survival (analyzed using Kaplan Meier survival and regression analyses), and sex differences in magnetic resonance imaging-markers in D-CAA (explored using scatterplots), and in sCAA (investigated using regression analysis). RESULTS: We included 136 patients with D-CAA (mean age 57 years, 56% women, 64% with previous sICH) and 370 patients with sCAA (mean age 76 years, 51% women, all with previous sICH). Men and women with D-CAA did not differ for sICH onset (median age 54 in men and 56 in women [P=0.13]). Men with D-CAA had a slightly higher number of sICH compared with women (median 2 versus 1; adjusted RR, 1.5 [95% CI, 1.1-1.9]) and a shorter interval between the first and second sICH (median 1.8 years for men and 3.1 years for women, P=0.02). Men with sCAA had their first sICH at an earlier age (median 75 versus 78 years, respectively, P=0.003) and more lobar microbleeds (median 1 versus 0, P=0.022) compared with women with sCAA. No substantial differences were found in the other magnetic resonance imaging markers. Survival after first sICH was comparable between sexes for D-CAA (P=0.12) and sCAA (P=0.23). CONCLUSIONS: Men with CAA seem to have an earlier onset (sCAA) and more hemorrhagic disease course (sCAA and D-CAA) compared with women. Future studies are necessary to confirm these findings and determine the underlying role of sex-related factors.

Using Noncontrast Computed Tomography to Improve Prediction of Intracerebral Hemorrhage Expansion.

BACKGROUND: Noncontrast computed tomography hypodensities are a validated predictor of hematoma expansion (HE) in intracerebral hemorrhage and a possible alternative to the computed tomography angiography (CTA) spot sign but their added value to available prediction models remains unclear. We investigated whether the inclusion of hypodensities improves prediction of HE and compared their added value over the spot sign. METHODS: Retrospective analysis of patients admitted for primary spontaneous intracerebral hemorrhage at the following 8 university hospitals in Boston, US (1994-2015, prospective), Hamilton, Canada (2010-2016, retrospective), Berlin, Germany (2014-2019, retrospective), Chongqing, China (2011-2015, retrospective), Pavia, Italy (2017-2019, prospective), Ferrara, Italy (2010-2019, retrospective), Brescia, Italy (2020-2021, retrospective), and Bologna, Italy (2015-2019, retrospective). Predictors of HE (hematoma growth >6 mL and/or >33% from baseline to follow-up imaging) were explored with logistic regression. We compared the discrimination of a simple prediction model for HE based on 4 predictors (antitplatelet and anticoagulant treatment, baseline intracerebral hemorrhage volume, and onset-to-imaging time) before and after the inclusion of noncontrast computed tomography hypodensities, using receiver operating characteristic curve and De Long test for area under the curve comparison. RESULTS: A total of 2465 subjects were included, of whom 664 (26.9%) had HE and 1085 (44.0%) had hypodensities. Hypodensities were independently associated with HE after adjustment for confounders in logistic regression (odds ratio, 3.11 [95% CI, 2.55-3.80]; P<0.001). The inclusion of noncontrast computed tomography hypodensities improved the discrimination of the 4 predictors model (area under the curve, 0.67 [95% CI, 0.64-0.69] versus 0.71 [95% CI, 0.69-0.74]; P=0.025). In the subgroup of patients with a CTA available (n=895, 36.3%), the added value of hypodensities remained statistically significant (area under the curve, 0.68 [95% CI, 0.64-0.73] versus 0.74 [95% CI, 0.70-0.78]; P=0.041) whereas the addition of the CTA spot sign did not provide significant discrimination improvement (area under the curve, 0.74 [95% CI, 0.70-0.78]). CONCLUSIONS: Noncontrast computed tomography hypodensities provided a significant added value in the prediction of HE and appear a valuable alternative to the CTA spot sign. Our findings might inform future studies and suggest the possibility to stratify the risk of HE with good discrimination without CTA.

Peak Width of Skeletonized Mean Diffusivity: A Neuroimaging Marker for White Matter Injury.

A leading cause of white matter (WM) injury in older individuals is cerebral small vessel disease (SVD). Cerebral SVD is the most prevalent vascular contributor to cognitive impairment and dementia. Therapeutic progress for cerebral SVD and other WM disorders depends on the development and validation of neuroimaging markers suitable as outcome measures in future interventional trials. Diffusion-tensor imaging (DTI) is one of the best-suited MRI techniques for assessing the extent of WM damage in the brain. But the optimal method to analyze individual DTI data remains hindered by labor-intensive and time-consuming processes. Peak width of skeletonized mean diffusivity (PSMD), a recently developed fast, fully automated DTI marker, was designed to quantify the WM damage secondary to cerebral SVD and reflect related cognitive impairment. Despite its promising results, knowledge about PSMD is still limited in the radiologic community. This focused review provides an overview of the technical details of PSMD while synthesizing the available data on its clinical and neuroimaging associations. From a critical expert viewpoint, the authors discuss the limitations of PSMD and its current validation status as a neuroimaging marker for vascular cognitive impairment. Finally, they point out the gaps to be addressed to further advance the field.

Vessels Sing Their ARIAs: The Role of Vascular Amyloid in the Age of Aducanumab.

We review the implications of the recently approved aducanumab amyloid-ß immunotherapy for treating Alzheimer disease with comorbid cerebral amyloid angiopathy. In clinical trials, amyloid-ß immunotherapy has been associated with a high rate of amyloid-related imaging abnormalities, potentially driven by coexisting cerebral amyloid angiopathy. Therefore, immunotherapy's efficacy in patients may be modified by coexisting cerebrovascular pathology. We discuss the contributions of cerebral amyloid angiopathy on the development of amyloid-related imaging abnormalities and propose strategies to identify cerebral amyloid angiopathy in patients considered for immunotherapy.

Cerebral Small Vessel Disease and Depression Among Intracerebral Hemorrhage Survivors.

BACKGROUND AND PURPOSE: Intracerebral hemorrhage (ICH) is an acute manifestation of cerebral small vessel disease (CSVD), usually cerebral amyloid angiopathy or hypertensive arteriopathy. CSVD-related imaging findings are associated with increased depression incidence in the general population. Neuroimaging may, therefore, provide insight on depression risk among ICH survivors. We sought to determine whether CSVD CT and magnetic resonance imaging markers are associated with depression risk (before and after ICH), depression remission, and effectiveness of antidepressant treatment. METHODS: We analyzed data from the single-center longitudinal ICH study conducted at Massachusetts General Hospital. Participants underwent CT and magnetic resonance imaging imaging and were followed longitudinally. We extracted information for neuroimaging markers of CSVD subtype and severity. Outcomes of interest included pre-ICH depression, new-onset depression after ICH, resolution of depressive symptoms, and response to antidepressant treatment. RESULTS: We followed 612 ICH survivors for a median of 47.2 months. Multiple CSVD-related markers were associated with depression risk. Survivors of cerebral amyloid angiopathy-related lobar ICH were more likely to be diagnosed with depression before ICH (odds ratio, 1.68 [95% CI, 1.14-2.48]) and after ICH (sub-hazard ratio, 1.52 [95% CI, 1.12-2.07]), less likely to achieve remission of depressive symptoms (sub-hazard ratio, 0.69 [95% CI, 0.51-0.94]), and to benefit from antidepressant therapy (P=0.041). Cerebral amyloid angiopathy disease burden on magnetic resonance imaging was associated with depression incidence and treatment resistance (interaction P=0.037), whereas hypertensive arteriopathy disease burden was only associated with depression incidence after ICH. CONCLUSIONS: CSVD severity is associated with depression diagnosis, both before and after ICH. Cerebral amyloid angiopathy-related ICH survivors are more likely to experience depression (both before and after ICH) than patients diagnosed with hypertensive arteriopathy-related ICH, and more likely to report persistent depressive symptoms and display resistance to antidepressant treatment.

Contrast agent-free state-of-the-art magnetic resonance imaging on cerebral small vessel disease - Part 2: Diffusion tensor imaging and functional magnetic resonance imaging.

Cerebral small vessel disease (cSVD) has been widely studied using conventional magnetic resonance imaging (MRI) methods, although the association between MRI findings and clinical features of cSVD is not always concordant. We assessed the additional contribution of contrast agent-free, state-of-the-art MRI techniques, particularly diffusion tensor imaging (DTI) and functional magnetic resonance imaging (fMRI), to understand brain damage and structural and functional connectivity impairment related to cSVD. We performed a review following the PICOS worksheet and Search Strategy, including 152 original papers in English, published from 2000 to 2022. For each MRI method, we extracted information about their contributions regarding the origins, pathology, markers, and clinical outcomes in cSVD. In general, DTI studies have shown that changes in mean, radial, and axial diffusivity measures are related to the presence of cSVD. In addition to the classical deficit in executive functions and processing speed, fMRI studies indicate connectivity dysfunctions in other domains, such as sensorimotor, memory, and attention. Neuroimaging metrics have been correlated with the diagnosis, prognosis, and rehabilitation of patients with cSVD. In short, the application of contrast agent-free, state-of-the-art MRI techniques has provided a complete picture of cSVD markers and tools to explore questions that have not yet been clarified about this clinical condition. Longitudinal studies are desirable to look for causal relationships between image biomarkers and clinical outcomes.

Contrast-agent-free state-of-the-art MRI on cerebral small vessel disease-part 1. ASL, IVIM, and CVR.

Cerebral small vessel disease (cSVD), a common cause of stroke and dementia, is traditionally considered the small vessel equivalent of large artery occlusion or rupture that leads to cortical and subcortical brain damage. Microvessel endothelial dysfunction can also contribute to it. Brain imaging, including MRI, is useful to show the presence of lesions of several types, although the association between conventional MRI measures and clinical features of cSVD is not always concordant. We assessed the additional contribution of contrast-agent-free, state-of-the-art MRI techniques such as arterial spin labeling (ASL), diffusion tensor imaging, functional MRI, and intravoxel incoherent motion (IVIM) applied to cSVD in the existing literature. We performed a review following the PICO Worksheet and Search Strategy, including original papers in English, published between 2000 and 2022. For each MRI method, we extracted information about their contributions, in addition to those established with traditional MRI methods and related information about the origins, pathology, markers, and clinical outcomes in cSVD. This paper presents the first part of the review, which includes 37 studies focusing on ASL, IVIM, and cerebrovascular reactivity (CVR) measures. In general, they have shown that, in addition to white matter hyperintensities, alterations in other neuroimaging parameters such as blood flow and CVR also indicate the presence of cSVD. Such quantitative parameters were also related to cSVD risk factors. Therefore, they are promising, noninvasive tools to explore questions that have not yet been clarified about this clinical condition. However, protocol standardization is essential to increase their clinical use.

Perivascular space dilation is associated with vascular amyloid-ß accumulation in the overlying cortex.

Perivascular spaces (PVS) are compartments surrounding cerebral blood vessels that become visible on MRI when enlarged. Enlarged PVS (EPVS) are commonly seen in patients with cerebral small vessel disease (CSVD) and have been suggested to reflect dysfunctional perivascular clearance of soluble waste products from the brain. In this study, we investigated histopathological correlates of EPVS and how they relate to vascular amyloid-ß (Aß) in cerebral amyloid angiopathy (CAA), a form of CSVD that commonly co-exists with Alzheimer's disease (AD) pathology. We used ex vivo MRI, semi-automatic segmentation and validated deep-learning-based models to quantify EPVS and associated histopathological abnormalities. Severity of MRI-visible PVS during life was significantly associated with severity of MRI-visible PVS on ex vivo MRI in formalin fixed intact hemispheres and corresponded with PVS enlargement on histopathology in the same areas. EPVS were located mainly around the white matter portion of perforating cortical arterioles and their burden was associated with CAA severity in the overlying cortex. Furthermore, we observed markedly reduced smooth muscle cells and increased vascular Aß accumulation, extending into the WM, in individually affected vessels with an EPVS. Overall, these findings are consistent with the notion that EPVS reflect impaired outward flow along arterioles and have implications for our understanding of perivascular clearance mechanisms, which play an important role in the pathophysiology of CAA and AD.

Cerebellar atrophy and its implications on gait in cerebral amyloid angiopathy.

OBJECTIVE: Recent data suggest that cerebral amyloid angiopathy (CAA) causes haemorrhagic lesions in cerebellar cortex as well as subcortical cerebral atrophy. However, the potential effect of CAA on cerebellar tissue loss and its clinical implications have not been investigated. METHODS: Our study included 70 non-demented patients with probable CAA, 70 age-matched healthy controls (HCs) and 70 age-matched patients with Alzheimer's disease (AD). The cerebellum was segmented into percent of cerebellar subcortical volume (pCbll-ScV) and percent of cerebellar cortical volume (pCbll-CV) represented as percent (p) of estimated total intracranial volume. We compared pCbll-ScV and pCbll-CV between patients with CAA, HCs and those with AD. Gait velocity (metres/second) was used to investigate gait function in patients with CAA. RESULTS: Patients with CAA had significantly lower pCbll-ScV compared with both HC (1.49±0.1 vs 1.73±0.2, p<0.001) and AD (1.49±0.1 vs 1.66±0.24, p<0.001) and lower pCbll-CV compared with HCs (6.03±0.5 vs 6.23±0.6, p=0.028). Diagnosis of CAA was independently associated with lower pCbll-ScV compared with HCs (p<0.001) and patients with AD (p<0.001) in separate linear regression models adjusted for age, sex and presence of hypertension. Lower pCbll-ScV was independently associated with worse gait velocity (ß=0.736, 95% CI 0.28 to 1.19, p=0.002) in a stepwise linear regression analysis including pCbll-CV along with other relevant variables. INTERPRETATION: Patients with CAA show more subcortical cerebellar atrophy than HC or patients with AD and more cortical cerebellar atrophy than HCs. Reduced pCbll-ScV correlated with lower gait velocity in regression models including other relevant variables. Overall, this study suggests that CAA causes cerebellar injury, which might contribute to gait disturbance.

Inactivated COVID-19 vaccine induced acute stroke-like focal neurologic symptoms: a case series.

BACKGROUND: A subgroup of individuals experienced stroke-like symptoms after receiving an inactivated COVID-19 vaccine. We present clinical characteristics, neuroimaging, and outcome of these patients. METHODS: Medical personals who had neurological symptoms after receiving inactivated COVID-19 vaccine were enrolled. Clinical, laboratory investigation and neuroimaging were collected. Subjects were prospectively followed-up on clinical and neuroimaging to detect brain parenchymal or cerebrovascular abnormality. RESULTS: Nineteen out of 385 subjects (4.9%) developed neurological symptoms after vaccination. There was a female predominance (89.5%) with mean age of 34 ± 7.5 years. Majority of patients (52.6%) had symptoms within 60 min after vaccination. The most common neurological symptoms were numbness (94.7%) followed by headache (52.6%) and weakness (47.4%). The most common neurological signs were sensory deficit (79%) followed by motor weakness (52.6%) and tongue deviation (26.3%). Recurrent headache was observed in most patients (89.5%) during followed up. Serial brain imaging was done in all patients with median follow-up interval of 18 days. There was no evidence of acute brain infarction in any of the patients, 84.2% had no vascular abnormality, 15.8% had transient focal narrowing of cerebral vessels. Outcome was favorable, modified ranking scale 0-1 for all patients at 4 weeks after vaccination. CONCLUSIONS: Transient focal neurological symptoms and deficits can be found after COVID-19 vaccination. However, benefit to stop COVID-19 pandemic by vaccination is outweighed by these seemingly reversible side effects. The pathophysiology underlined these phenomena should be further investigated.

COVID-19 related acute necrotizing encephalopathy with extremely high interleukin-6 and RANBP2 mutation in a patient with recently immunized inactivated virus vaccine and no pulmonary involvement.

BACKGROUND: We report the first case of COVID-19 associated acute necrotizing encephalopathy (ANE) without pulmonary disease in a patient with an extremely high interleukin-6 (IL-6) level and Ran Binding Protein 2 (RANBP2) mutation. CASE PRESENTATION: A 29-year-old woman recently immunized with inactivated viral vaccine-BBIBP32-CorV (Sinopharm) presented with alteration of consciousness. Her body temperature was 37° Celsius, blood pressure 42/31 mmHg, heart rate 130 bpm, respiratory rate 20 per minute, and oxygen saturation 98%. Respiratory examination was unremarkable. Neurological examination revealed stupor but preserved brainstem reflexes. Non-contrast computerized tomography of the brain showed symmetrical hypodense lesions involving bilateral thalami and cerebellar hemispheres characteristic of ANE. No pulmonary infiltration was found on chest radiograph. SARS-CoV-2 was detected by PCR; whole genome sequencing later confirmed the Delta variant. RANBP2 gene analysis revealed heterozygous Thr585Met mutation. Serum IL-6 was 7390 pg/mL. Urine examination showed pyelonephritis. Her clinical course was complicated by seizure, septic shock, acute kidney injury, and acute hepatic failure. She later developed coma and passed away in 6 days. CONCLUSIONS: ANE is caused by cytokine storm leading to necrosis and hemorrhage of the brain. IL-6 was deemed as a prognostic factor and a potential treatment target of ANE in previous studies. RANBP2 missense mutation strongly predisposes this condition by affecting mitochondrial function, viral entry, cytokine signaling, immune response, and blood-brain barrier maintenance. Also, inactivated vaccine has been reported to precipitate massive production of cytokines by antibody dependent enhancement (ADE). The true incidence of COVID-19 associated ANE is not known as were the predictors of its development. We proposed these potential two factors (RANBP2 mutation and ADE) that could participate in the pathogenesis of ANE in COVID-19 apart from SARS-CoV2 infection by itself. Further study is needed to confirm this hypothesis, specifically in the post-vaccination period. Role of RANBP2 mutation and its application in COVID-19 and ANE should be further elaborated.