A Causal Classification System for Intracerebral Hemorrhage Subtypes

Connecting the dots: Involvement of methyltransferase-like 3, N6-methyladenosine modification, and ferroptosis in the pathogenesis of intracerebral hemorrhage pathogenesis

Intracerebral hemorrhage is a profoundly detrimental acute cerebrovascular condition with a low overall survival rate and a high post-onset disability rate. Secondary brain injury that ensues post-ICH is the primary contributor to fatality and disability. Hence, the mitigation of brain injury during intracerebral hemorrhage progression has emerged as a crucial aspect of clinical management. N6-methyladenosine is the most pervasive, abundant, and conserved internal co-transcriptional modification of eukaryotic ribonucleic acid and is predominantly expressed in the nervous system. Methyltransferase-like 3 is a key regulatory protein that is strongly associated with the development of the nervous system and numerous neurological diseases. Ferroptosis, a form of iron-associated cell death, is a typical manifestation of neuronal apoptosis in neurological diseases and plays an important role in secondary brain damage following intracerebral hemorrhage. Therefore, this review aimed to elucidate the connection between m6A modification (particularly methyltransferase-like 3) and ferroptosis in the context of intracerebral hemorrhage to provide new insights for future intracerebral hemorrhage management approaches.

Continuous Blood Pressure Indices During the First 72 Hours and Functional Outcome in Patients with Spontaneous Intracerebral Hemorrhage

BACKGROUND

Management of intracerebral hemorrhage (ICH) is challenged by limited therapeutic options and a complex relationship between blood pressure (BP) dynamics, especially BP variability (BPV) and ICH outcome.

METHODS

In an exploratory analysis of prospectively collected data on consecutive patients with nontraumatic ICH between 2015 and 2020, continuous BP accessed via an arterial line extracted from the Intellispace Critical Care and Anesthesia information system (Philips Healthcare) was analyzed over the first 72 h post admission. Arterial lines were used as part of standard clinical practice in the intensive care, ensuring high fidelity and real-time data essential for acute care settings. BPV was assessed through successive variation (SV), standard deviation (SD), and coefficient of variation using all available BP measurements. Multivariate regression models were applied to evaluate the association between BPV indices and functional outcome at 3 months.

RESULTS

Among 261 patients (mean age 69.6 ± 15.2 years, 47.9% female, median National Institutes of Health Stroke Scale [NIHSS] score 6 [interquartile range 2-12]) analyzed, lower systolic BP upon admission (< 140 mm Hg) and lower systolic BPV were significantly associated with favorable outcome, whereas higher diastolic BPV correlated with improved outcomes. In the multivariate analysis, diastolic BPV (SD, SV) within the first 72 h post admission emerged as an independent predictor of good functional outcome (modified Rankin Scale score < 3; odds ratio 1.123, 95% confidence interval CI 1.008-1.184, p = 0.035), whereas systolic BPV (SD) showed a negative association. Patients with better outcomes also exhibited distinct clinical characteristics, including younger age, lower median NIHSS scores, and less prevalence of anticoagulation therapy upon admission.

CONCLUSIONS

This study shows the prognostic value of BPV in the acute phase of ICH. Lower systolic BPV (SD) and higher diastolic BPV (SD, SV) were associated with better functional outcomes, challenging traditional BP management strategies. These findings might help to tailor a personalized BP management in ICH.

Diagnostic accuracy and radiological validation of intracerebral hemorrhage diagnosis in the Swedish Stroke Register (Riksstroke)

BACKGROUND AND PURPOSE

National quality registries for stroke care operate under the assumption that the included patients are correctly diagnosed. We aimed to validate the clinical diagnosis of spontaneous intracerebral hemorrhage (ICH) in Riksstroke (RS) by evaluating radiological data from a large, unselected ICH population.

METHODS

We conducted a retrospective, multicenter study including all ICH patients registered in RS between 2016 and 2020 residing in Skåne County in Sweden (1.41 million inhabitants). Radiological data from first imaging were evaluated for the presence of spontaneous ICH. Other types of bleeds were registered if a spontaneous ICH was not identified on imaging. The radiological evaluation was independently performed by one radiology fellow and one senior neuroradiologist.

RESULTS

Between 2016 and 2020, 1784 ICH cases were registered in RS, of which 1655 (92.8%) had a radiological diagnosis consistent with spontaneous ICH. In the 129 (7.2%) remaining cases, the radiological diagnosis was instead traumatic bleed (n = 80), subarachnoid hemorrhage (n = 15), brain tumor bleed (n = 14), ischemic lesion with hemorrhagic transformation (n = 14), ischemic lesion (n = 3), or no bleed at all (n = 3). There was a higher degree of incorrect coding in the older age groups.

CONCLUSION

At radiological evaluation, 92.8% of ICH diagnoses in RS were consistent with spontaneous ICH, yielding a high rate of agreement that strengthens the validity of the diagnostic accuracy in the register, justifying the use of high coverage quality register data for epidemiological purposes. The most common coding error was traumatic bleeds that were classified as spontaneous ICH.

Heart Rate Variability and Functional Outcomes of Patients with Spontaneous Intracerebral Hemorrhage

BACKGROUND

The relationship between heart rate variability (HRV) changes potentially indicating autonomic dysregulation following spontaneous intracerebral hemorrhage (ICH) and functional outcome has not yet been fully elucidated. This study investigated the effects of HRV during the initial 96 h after admission on 90-day functional outcome in ICH patients.

METHODS

We included patients with spontaneous ICH in a prospective cohort single-center study. Continuous HR data were retrieved from the Intellispace Critical Care and Anesthesia information system (Philips Healthcare) and analyzed within the following time intervals: 0-2, 0-8, 0-12, 0-24, 0-48, 0-72, and 8-16, 16-24, 24-48, 48-72, 72-96 h after admission. HRV was determined from all available HR values by calculating the successive variability (SV), standard deviation (SD), and coefficient of variation (CV). Low HRV was set as SD ≤ 11.4 ms, and high HRV as SD > 11.4 ms. The clinical severity of ICH was assessed using the National Institutes of Health Stroke Scale (NIHSS) and functional outcome using the modified Rankin Scale (mRS). Good functional outcome was defined as mRS 0-2.

RESULTS

The cohort included 261 ICH patients (mean age ± SD 69.6 ± 16.5 years, 48.7% female, median NIHSS 6 (2, 12), median ICH score 1 (0, 2), of whom 106 (40.6%) had good functional outcome. All patients had the lowest HRV at admission, which increased during the first two days. Comparing ICH patients with low HRV (n = 141) and high HRV (n = 118), those with good outcome showed significantly lower HRV during the first three days (0-72 h: HRV SD good outcome 10.6 ± 3.5 ms vs. poor outcome 12.0 ± 4.0 ms; p = 0.004). Logistic regression revealed that advanced age, high premorbid mRS, and high NIHSS at admission were significant predictors of poor functional outcome, while reduced SD of HRV showed a non-significant trend towards good functional outcome (0-72 h: OR 0.898; CI 0.800-1.008; p = 0.067).

CONCLUSIONS

Our results indicate autonomic dysfunction with sympathetic hyperactivity after spontaneous ICH, as reflected by the evidence of the lower HRV in the first days. Initially increased sympathetic tone appears to have a protective effect, as suggested by the comparatively lower HRV in patients with good functional outcome at the first days.

Diagnostic Accuracy of Posterior/Anterior Periventricular WMH Ratio to Differentiate CAA From Hypertensive Arteriopathy

BACKGROUND

Periventricular white matter hyperintensities (PVWMHs) in cerebral amyloid angiopathy (CAA) have been reported posterior predominant using semiautomated segmentation method and logarithmic transformation. We aimed to compare PVWMH extent and posterior/anterior distribution between patients with CAA and patients with hypertensive arteriopathy with radiological tools available in daily practice.

METHODS

We retrospectively analyzed confluent PVWMH directly adjacent to lateral ventricles on axial FLAIR (fluid-attenuated inversion recovery) from 108 patients with CAA and 99 patients with hypertensive arteriopathy presenting with hemorrhage-related symptoms consecutively recruited in our stroke database (Nîmes University Hospital, France) between January 2015 and March 2022. For each of the left (L), right (R), anterior (A), and posterior (P) horns of lateral ventricles, the maximal distance between the outer PVWMH border and ventricle border was measured. The sum of anterior left PVWMH and anterior right PVWMH, and posterior left PVWMH and posterior right PVWMH resulted in anterior and posterior extent, respectively.

RESULTS

Compared with hypertensive arteriopathy, patients with CAA were older (median, 77 versus 71; P=0.0010) and less frequently male (46% versus 64%; P=0.012) and had less frequent hypertension (45% versus 63%; P=0.013) and more chronic hemorrhages (P<0.0001). CAA showed slightly more extensive anterior right PVWMH (median, 6.50 versus 5.90 mm; P=0.034), far more extensive (all P<0.0001) posterior left PVWMH (median, 13.95 versus 6.95 mm), posterior right PVWMH (median, 14.15 versus 5.45 mm), posterior (median, 27.95 versus 13.00 mm), and total (median, 39.60 versus 24.65 mm) PVWMH, and higher posterior/anterior ratios (median, 1.82 versus 1.01). Age-/sex-adjusted model predicting CAA incorporating total PVWMH extent and posterior/anterior ratios for the given score (-4.3683+0.0268×PVWMH-T+0.3749×posterior/anterior PVWMH ratio+0.0394×age+0.3046 when female) showed highest area under the curve (0.76 [0.70-0.83]), with a 72% [62.50-80.99] sensitivity and 76% [67.18-84.12] specificity. Values above the optimal threshold of 0.22 for the score showed a crude relative risk of 2.75 (2.26-2.37; P<0.0001).

CONCLUSIONS

Severe posterior PVWMH and high posterior/anterior PVWMH ratio assessed by radiological tools used in daily practice are associated with probable CAA versus hypertensive arteriopathy.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT05486897.

Associations of Cerebral Small Vessel Disease and Chronic Kidney Disease in Patients With Acute Intracerebral Hemorrhage: A Cross-Sectional Study

BACKGROUND AND OBJECTIVES

Chronic kidney disease (CKD) may be associated with the pathogenesis and phenotype of cerebral small vessel disease (SVD), which is the commonest cause of intracerebral hemorrhage (ICH). The purpose of this study was to investigate the associations of CKD with ICH neuroimaging phenotype, volume, and location, total burden of small vessel disease, and its individual components.

METHODS

In 2 cohorts of consecutive patients with ICH evaluated with MRI, we investigated the frequency and severity of CKD based on established Kidney Disease Improving Global Outcomes criteria, requiring estimated glomerular filtration rate (eGFR) measurements <60 mL/min/1.732 ≥ 3 months apart to define CKD. MRI scans were rated for ICH neuroimaging phenotype (arteriolosclerosis, cerebral amyloid angiopathy, mixed location SVD, or cryptogenic ICH) and the presence of markers of SVD (white matter hyperintensities [WMHs], cerebral microbleeds [CMBs], lacunes, and enlarged perivascular spaces, defined according to the STandards for ReportIng Vascular changes on nEuroimaging criteria). We used multinomial, binomial logistic, and ordinal logistic regression models adjusted for age, sex, hypertension, and diabetes to account for possible confounding caused by shared risk factors of CKD and SVD.

RESULTS

Of 875 patients (mean age 66 years, 42% female), 146 (16.7%) had CKD. After adjusting for age, sex, and comorbidities, patients with CKD had higher rates of mixed SVD than those with eGFR >60 (relative risk ratio 2.39, 95% CI 1.16-4.94, p = 0.019). Severe WMHs, deep microbleeds, and lacunes were more frequent in patients with CKD, as was a higher overall SVD burden score (odds ratio 1.83 for each point on the ordinal scale, 95% CI 1.31-2.56, p < 0.001). Patients with eGFR ≤30 had more CMBs (median 7 [interquartile range 1-23] vs 2 [0-8] for those with eGFR >30, p = 0.007).

DISCUSSION

In patients with ICH, CKD was associated with SVD burden, a mixed SVD phenotype, and markers of arteriolosclerosis. Our findings indicate that CKD might independently contribute to the pathogenesis of arteriolosclerosis and mixed SVD, although we could not definitively account for the severity of shared risk factors. Longitudinal and experimental studies are, therefore, needed to investigate causal associations. Nevertheless, stroke clinicians should be aware of CKD as a potentially independent and modifiable risk factor of SVD.

Stroke

Stroke affects up to one in five people during their lifetime in some high-income countries, and up to almost one in two in low-income countries. Globally, it is the second leading cause of death. Clinically, the disease is characterised by sudden neurological deficits. Vascular aetiologies contribute to the most common causes of ischaemic stroke, including large artery disease, cardioembolism, and small vessel disease. Small vessel disease is also the most frequent cause of intracerebral haemorrhage, followed by macrovascular causes. For acute ischaemic stroke, multimodal CT or MRI reveal infarct core, ischaemic penumbra, and site of vascular occlusion. For intracerebral haemorrhage, neuroimaging identifies early radiological markers of haematoma expansion and probable underlying cause. For intravenous thrombolysis in ischaemic stroke, tenecteplase is now a safe and effective alternative to alteplase. In patients with strokes caused by large vessel occlusion, the indications for endovascular thrombectomy have been extended to include larger core infarcts and basilar artery occlusion, and the treatment time window has increased to up to 24 h from stroke onset. Regarding intracerebral haemorrhage, prompt delivery of bundled care consisting of immediate anticoagulation reversal, simultaneous blood pressure lowering, and prespecified stroke unit protocols can improve clinical outcomes. Guided by underlying stroke mechanisms, secondary prevention encompasses pharmacological, vascular, or endovascular interventions and lifestyle modifications.

Deep learning-assisted detection and segmentation of intracranial hemorrhage in noncontrast computed tomography scans of acute stroke patients: a systematic review and meta-analysis

BACKGROUND

Deep learning (DL)-assisted detection and segmentation of intracranial hemorrhage stroke in noncontrast computed tomography (NCCT) scans are well-established, but evidence on this topic is lacking.

MATERIALS AND METHODS

PubMed and Embase databases were searched from their inception to November 2023 to identify related studies. The primary outcomes included sensitivity, specificity, and the Dice Similarity Coefficient (DSC); while the secondary outcomes were positive predictive value (PPV), negative predictive value (NPV), precision, area under the receiver operating characteristic curve (AUROC), processing time, and volume of bleeding. Random-effect model and bivariate model were used to pooled independent effect size and diagnostic meta-analysis data, respectively.

RESULTS

A total of 36 original studies were included in this meta-analysis. Pooled results indicated that DL technologies have a comparable performance in intracranial hemorrhage detection and segmentation with high values of sensitivity (0.89, 95% CI: 0.88-0.90), specificity (0.91, 95% CI: 0.89-0.93), AUROC (0.94, 95% CI: 0.93-0.95), PPV (0.92, 95% CI: 0.91-0.93), NPV (0.94, 95% CI: 0.91-0.96), precision (0.83, 95% CI: 0.77-0.90), DSC (0.84, 95% CI: 0.82-0.87). There is no significant difference between manual labeling and DL technologies in hemorrhage quantification (MD 0.08, 95% CI: -5.45-5.60, P =0.98), but the latter takes less process time than manual labeling (WMD 2.26, 95% CI: 1.96-2.56, P =0.001).

CONCLUSION

This systematic review has identified a range of DL algorithms that the performance was comparable to experienced clinicians in hemorrhage lesions identification, segmentation, and quantification but with greater efficiency and reduced cost. It is highly emphasized that multicenter randomized controlled clinical trials will be needed to validate the performance of these tools in the future, paving the way for fast and efficient decision-making during clinical procedure in patients with acute hemorrhagic stroke.

Neuro-imaging in intracerebral hemorrhage: updates and knowledge gaps

Intracerebral hemorrhage (ICH) is characterized by hematoma development within the brain's parenchyma, contributing significantly to the burden of stroke. While non-contrast head computed tomography (CT) remains the gold standard for initial diagnosis, this review underscores the pivotal role of magnetic resonance imaging (MRI) in ICH management. Beyond diagnosis, MRI offers invaluable insights into ICH etiology, prognosis, and treatment. Utilizing echo-planar gradient-echo or susceptibility-weighted sequences, MRI demonstrates exceptional sensitivity and specificity in identifying ICH, aiding in differentiation of primary and secondary causes. Moreover, MRI facilitates assessment of hemorrhage age, recognition of secondary lesions, and evaluation of perihematomal edema progression, thus guiding tailored therapeutic strategies. This comprehensive review discusses the multifaceted utility of MRI in ICH management, highlighting its indispensable role in enhancing diagnostic accuracy as well as aiding in prognostication. As MRI continues to evolve as a cornerstone of ICH assessment, future research should explore its nuanced applications in personalized care paradigms.

Uncommon Causes of Nontraumatic Intracerebral Hemorrhage

Nontraumatic intracerebral hemorrhage is an important health issue. Although common causes such as hypertension and cerebral amyloid angiopathy predominantly affect the elderly, there exists a spectrum of uncommon etiologies that contribute to the overall incidence of intracerebral hemorrhage. The identification of these rare causes is essential for targeted clinical management, informed prognostication, and strategic secondary prevention where relevant. This topical review explores the uncommon intracerebral hemorrhage causes and provides practical clues for their clinical and imaging identification. By expanding the clinician's differential diagnosis, this review aims to bridge the gap between standard intracerebral hemorrhage classification systems and the nuanced reality of clinical practice.

Advances in Cerebral Small Vessel Disease: Sandra E. Black Lecture to the Canadian Neurological Sciences Federation

Cerebral small vessel diseases (CSVDs) are among the most common age-related pathologies of the brain. Arteriolosclerosis and cerebral amyloid angiopathy (CAA) are the most common CSVDs. In addition to causing stroke and dementia, CSVDs can have diverse covert radiological manifestations on computed tomography and magnetic resonance imaging including lacunes, T2-weighted white matter hyperintensities, increased density of visible perivascular spaces, microbleeds and cortical superficial siderosis. Because they cannot be visualized directly, research on the pathophysiology of CSVD has been difficult. However, advances in quantitative imaging methods, including physiological imaging such as measurement of cerebrovascular reactivity and increased vascular permeability, are beginning to allow investigation of the early effects of CSVD in living people. Furthermore, genomics, metabolomics and proteomics have the potential to illuminate previously unrecognized pathways to CSVD that could be important targets for new clinical trials.

The Hemorrhagic Side of Primary Angiitis of the Central Nervous System (PACNS)

Primary Angiitis of the Central Nervous System (PACNS) is a rare cerebrovascular disease involving the arteries of the leptomeninges, brain and spinal cord. Its diagnosis can be challenging, and the current diagnostic criteria show several limitations. Among the clinical and neuroimaging manifestations of PACNS, intracranial bleeding, particularly intracerebral hemorrhage (ICH), is poorly described in the available literature, and it is considered infrequent. This review aims to summarize the available data addressing this issue with a dedicated focus on the clinical, neuroradiological and neuropathological perspectives. Moreover, the limitations of the actual data and the unanswered questions about hemorrhagic PACNS are addressed from a double point of view (PACNS subtyping and ICH etiology). Fewer than 20% of patients diagnosed as PACNS had an ICH during the course of the disease, and in cases where ICH was reported, it usually did not occur at presentation. As trigger factors, both sympathomimetic drugs and illicit drugs have been proposed, under the hypothesis of an inflammatory response due to vasoconstriction in the distal cerebral arteries. Most neuroradiological descriptions documented a lobar location, and both the large-vessel PACNS (LV-PACNS) and small-vessel PACNS (SV-PACNS) subtypes might be the underlying associated phenotypes. Surprisingly, amyloid beta deposition was not associated with ICH when histopathology was available. Moreover, PACNS is not explicitly included in the etiological classification of spontaneous ICH. This issue has received little attention in the past, and it could be addressed in future prospective studies.

CADMUS: A Novel MRI-Based Classification of Spontaneous Intracerebral Hemorrhage Associated With Cerebral Small Vessel Disease

BACKGROUND AND OBJECTIVES

Cerebral small vessel disease (SVD) is the major cause of intracerebral hemorrhage (ICH). There is no comprehensive, easily applicable classification of ICH subtypes according to the presumed underlying SVD using MRI. We developed an MRI-based classification for SVD-related ICH.

METHODS

We performed a retrospective study in the prospectively collected Swiss Stroke Registry (SSR, 2013-2019) and the Stroke InvestiGation in North And central London (SIGNAL) cohort. Patients with nontraumatic, SVD-related ICH and available MRI within 3 months were classified as Cerebral Amyloid angiopathy (CAA), Deep perforator arteriopathy (DPA), Mixed CAA-DPA, or Undetermined SVD using hemorrhagic and nonhemorrhagic MRI markers (CADMUS classification). The primary outcome was inter-rater reliability using Gwet's AC1. Secondary outcomes were recurrent ICH/ischemic stroke at 3 months according to the CADMUS phenotype. We performed Firth penalized logistic regressions and competing risk analyses.

RESULTS

The SSR cohort included 1,180 patients (median age [interquartile range] 73 [62-80] years, baseline NIH Stroke Scale 6 [2-12], 45.6% lobar hematoma, systolic blood pressure on admission 166 [145-185] mm Hg). The CADMUS phenotypes were as follows: mixed CAA-DPA (n = 751 patients, 63.6%), undetermined SVD (n = 203, 17.2%), CAA (n = 154, 13.1%), and DPA (n = 72, 6.3%), with a similar distribution in the SIGNAL cohort (n = 313). Inter-rater reliability was good (Gwet's AC1 for SSR/SIGNAL 0.69/0.74). During follow-up, 56 patients had 57 events (28 ICH, 29 ischemic strokes). Three-month event rates were comparable between the CADMUS phenotypes.

DISCUSSION

CADMUS, a novel MRI-based classification for SVD-associated ICH, is feasible and reproducible and may improve the classification of ICH subtypes in clinical practice and research.

Intracerebral haemorrhage

Intracerebral haemorrhage (ICH) is a dramatic condition caused by the rupture of a cerebral vessel and the entry of blood into the brain parenchyma. ICH is a major contributor to stroke-related mortality and dependency: only half of patients survive for 1 year after ICH, and patients who survive have sequelae that affect their quality of life. The incidence of ICH has increased in the past few decades with shifts in the underlying vessel disease over time as vascular prevention has improved and use of antithrombotic agents has increased. The pathophysiology of ICH is complex and encompasses mechanical mass effect, haematoma expansion and secondary injury. Identifying the causes of ICH and predicting the vital and functional outcome of patients and their long-term vascular risk have improved in the past decade; however, no specific treatment is available for ICH. ICH remains a medical emergency, with prevention of haematoma expansion as the key therapeutic target. After discharge, secondary prevention and management of vascular risk factors in patients remains challenging and is based on an individual benefit-risk balance evaluation.

Acute Spontaneous Lobar Cerebral Hemorrhages Present a Different Clinical Profile and a More Severe Early Prognosis than Deep Subcortical Intracerebral Hemorrhages-A Hospital-Based Stroke Registry Study

Acute spontaneous intracerebral hemorrhage (ICH) is the most severe stroke subtype, with a high risk of death, dependence, and dementia. Knowledge about the clinical profile and early outcomes of ICH patients with lobar versus deep subcortical brain topography remains limited. In this study, we investigated the effects of ICH topography on demographics, cerebrovascular risk factors, clinical characteristics, and early outcomes in a sample of 298 consecutive acute ICH patients (165 with lobar and 133 with subcortical hemorrhagic stroke) available in a single-center-based stroke registry over 24 years. The multiple logistic regression analysis shows that variables independently associated with lobar ICH were early seizures (OR 6.81, CI 95% 1.27−5.15), chronic liver disease (OR 4.55, 95% CI 1.03−20.15), hemianopia (OR 2.55, 95% CI 1.26−5.15), headaches (OR 1.90, 95% CI 1.90, 95% IC 1.06−3.41), alcohol abuse (>80 gr/day) (OR 0−10, 95% CI 0.02−0,53), hypertension (OR 0,41, 95% CI 0.23−0−70), sensory deficit (OR 0.43, 95% CI 0.25−0.75), and limb weakness (OR: 0.47, 95% CI 0.24−0.93). The in-hospital mortality was 26.7% for lobar and 16.5% for subcortical ICH. The study confirmed that the clinical spectrum, prognosis, and early mortality of patients with ICH depend on the site of bleeding, with a more severe early prognosis in lobar intracerebral hemorrhage.