Diffusion-Weighted Imaging Hyperintensities in Subtypes of Acute Intracerebral Hemorrhage: Meta-Analysis

Advances and Future Trends in the Diagnosis and Management of Intracerebral Hemorrhage

Spontaneous intracerebral hemorrhage accounts for approximately 10% to 15% of all strokes in the United States and remains one of the deadliest. Of concern is the increasing prevalence, especially in younger populations. This article reviews the following: epidemiology, risk factors, outcomes, imaging findings, medical management, and updates to surgical management.

Suboptimal Cerebral Perfusion is Associated with Ischemia After Intracerebral Hemorrhage

BACKGROUND

Remote ischemic lesions on diffusion-weighted imaging (DWI) occur in one third of patients with intracerebral hemorrhage (ICH) and are associated with worse outcomes. The etiology is unclear and not solely due to blood pressure reduction. We hypothesized that impaired cerebrovascular autoregulation and hypoperfusion below individualized lower limits of autoregulation are associated with the presence of DWI lesions.

METHODS

This was a retrospective, single-center study of all primary ICH with intraparenchymal pressure monitoring within 10 days from onset and subsequent magnetic resonance imaging. Pressure reactivity index was calculated as the correlation coefficient between mean arterial pressure and intracranial pressure. Optimal cerebral perfusion pressure (CPPopt) is the cerebral perfusion pressure (CPP) with the lowest corresponding pressure reactivity index. The difference between CPP and CPPopt, time spent below the lower limit of autoregulation (LLA), and time spent above the upper limit of autoregulation (ULA) were calculated by using mean hourly physiologic data. Univariate associations between physiologic parameters and DWI lesions were analyzed by using binary logistic regression.

RESULTS

A total of 505 h of artifact-free data from seven patients without DWI lesions and 479 h from six patients with DWI lesions were analyzed. Patients with DWI lesions had higher intracranial pressure (17.50 vs. 10.92 mm Hg; odds ratio 1.14, confidence interval 1.01-1.29) but no difference in mean arterial pressure or CPP compared with patients without DWI lesions. The presence of DWI lesions was significantly associated with a greater percentage of time spent below the LLA (49.85% vs. 14.70%, odds ratio 5.77, confidence interval 1.88-17.75). No significant association was demonstrated between CPPopt, the difference between CPP and CPPopt, ULA, LLA, or time spent above the ULA between groups.

CONCLUSIONS

Blood pressure reduction below the LLA is associated with ischemia after acute ICH. Individualized, autoregulation-informed targets for blood pressure reduction may provide a novel paradigm in acute management of ICH and require further study.

Prevalence of small vessel disease and incidental DWI-positive lesions in patients with aneurysmal subarachnoid hemorrhage versus intracerebral hemorrhage

INTRODUCTION

Aneurysmal subarachnoid hemorrhage (aSAH) and intracerebral hemorrhage (ICH) are main forms of hemorrhagic stroke. Data regarding cerebral small vessel disease (SVD) burden and incidental small lesions on diffusion-weighted imaging (DWI) following aSAH are sparse.

PATIENTS AND METHODS

We retrospectively analyzed a prospective cohort of aSAH and ICH patients with brain MRI within 30 days after onset from March 2015 to January 2023. White matter hyperintensity (WMH), lacune, perivascular space, cerebral microbleed (CMB), total SVD score, and incidental DWI lesions were assessed and compared between aSAH and ICH. Clinical and radiological characteristics associated with small DWI lesions in aSAH were investigated.

RESULTS

We included 180 patients with aSAH (median age [IQR] 53 [47-61] years) and 299 with ICH (63 [53-73] years). DWI lesions were more common in aSAH than ICH (47.8% vs 14.4%, p < 0.001). Higher total SVD score was associated with ICH versus aSAH irrespective of hematoma location, whereas DWI lesions and strictly lobar CMBs were correlated with aSAH. Multivariable analysis showed that shorter time from onset to MRI, anterior circulation aneurysm rupture, CMB ⩾ 5, and total SVD score were associated with DWI lesions in aSAH.

DISCUSSION AND CONCLUSION

Incidental DWI lesions and strictly lobar CMBs were more frequent in aSAH versus ICH whereas ICH had higher SVD burden. Incidental DWI lesions in aSAH were associated with multiple clinical and imaging factors. Longitudinal studies to investigate the dynamic change and prognostic value of the covert hemorrhagic and ischemic lesions in aSAH seem justified.

Diffusion-weighted Imaging Detection of Acute Ischemia Brain Lesions in Spontaneous Intracerebral Hemorrhage Associated with White Matter Hyperintensities, Enlarged Perivascular Spaces and Diabetes Mellitus

OBJECTIVE

Diffusion-weighted imaging (DWI) is commonly detected after spontaneous intracerebral hemorrhage (sICH) and is associated with poor functional outcomes. However, the etiology and significance of DWI lesions remain unclear. Thus, our study aimed to explore the prevalence and risk factors of acute ischemic lesions in sICH and discussed the possible mechanisms.

METHODS

We conducted a retrospective review of a consecutive cohort of 408 patients from June 2013 to October 2019 with sICH, who had brain computed tomography (CT) and magnetic resonance imaging (MRI) within 14 days of symptoms onset. Acute ischemic lesions were assessed on MRI using DWI lesions. We compared the clinical and imaging characteristics of patients with and without DWI lesions. The data were analyzed by univariate and multivariate logistic regression.

RESULTS

Among the enrolled 408 patients, the mean age was 56.8 ± 14.5 years, 68 (16.7%) of them had been diagnosed with diabetes mellitus (DM). DWI lesions were observed in 89 (21.8%) patients, and most of them had a history of lacunar infarctions, which were located in cortical or subcortical. In multivariate logistic regression analysis, DM (odds ratio (OR) 3.962, p <0.001), severe deep white matter hypertensities (DWMH) (OR 2.463, p =0.001) and severe centrum semiovale enlarged perivascular spaces (CSO-EPVS) (OR 2.679, p =0.001) were independently associated with the presence of DWI lesions.

CONCLUSION

In our cohort, we found DM, severe DWMH and severe CSO-EPVS were the independent risk factors in sICH patients with DWI lesions.

Interaction between cerebral small vessel disease, blood pressure, and remote ischemic lesions in acute spontaneous intracerebral hemorrhage

BACKGROUND

Acute blood pressure (BP) reduction is the first-line treatment for acute spontaneous intracerebral hemorrhage (ICH); however, recent research suggests that intensive BP reduction along with cerebral small vessel disease (cSVD) is a risk factor for remote DWI lesions (RDWILs). We aimed to delineate the interplay between cSVD and BP reduction therapy on the risk of RDWILs.

METHODS

We enrolled 303 patients who underwent brain magnetic resonance imaging within 7 days after acute spontaneous ICH. RDWILs were categorized as occurring in borderzone (BZ) or non-BZ areas. We examined the effect of cSVD, acute BP reduction, and their interaction on RDWILs.

RESULTS

RDWILs were observed in 34 (11%) patients (59.8 ± 10.3-years-old, 24% male). RDWILs were associated with a larger acute weighted average mean arterial pressure (MAP) reduction in the initial 24 h after ICH onset and a higher total cerebral microbleed (CMB) count. Intensive MAP changes (odds ratio (OR) per 10 mmHg 1.76, 95% confidence interval (CI) 1.03-3.20), total CMBs burden (OR per 10 CMBs 1.21, 95% CI 1.08-1.39), and presence of lobar CMBs (OR 7.33, 95% CI 1.59-55.6) were risk factors for RDWILs at BZ, but not at non-BZ. Furthermore, a significant interaction was observed between lobar CMBs and MAP reduction on increased risk of RDWILs at BZ (p = 0.030).

CONCLUSION

cSVD modulates the effect of acute BP reduction on the risk of RDWILs. Patients with extensive microangiopathy have a higher risk of developing cerebral ischemic changes in BZ during unstable hemodynamic status.

Relationships of Hemoglobin Concentration, Ischemic Lesions, and Clinical Outcomes in Patients With Intracerebral Hemorrhage

BACKGROUND

Hemoglobin concentration and diffusion-weighted imaging (DWI) ischemic lesions are separately known to be associated with poor intracerebral hemorrhage (ICH) outcomes. While hemoglobin concentrations have known relationships with ischemic stroke, it is unclear whether hemoglobin concentration is associated with DWI ischemic lesions after ICH. We sought to investigate the hypothesis that hemoglobin concentrations would associate with DWI lesions after ICH and further investigated their relationships with clinical outcomes.

METHODS

Supratentorial ICH patients enrolled between 2010 and 2016 to a prospective, multicenter, observational cohort study (ERICH study [Ethnic/Racial Variations of Intracerebral Hemorrhage]) were assessed. Patients from this study with baseline, admission hemoglobin, and hospitalization magnetic resonance imaging were analyzed. Hemoglobin was examined as the primary exposure variable defined as a continuous variable (g/dL). Magnetic resonance imaging DWI ischemic lesion presence was assessed as the primary radiographic outcome. Primary analyses assessed relationships of hemoglobin with DWI lesions. Secondary analyses assessed relationships of DWI lesions with poor 3-month outcomes (modified Rankin Scale score, 4-6). These analyses were performed using separate multivariable logistic regression models adjusting for relevant covariates.

RESULTS

Of 917 patients with ICH analyzed, mean baseline hemoglobin was 13.8 g/dL (±1.9), 60% were deep ICH, and DWI lesions were identified in 27% of the cohort. In our primary analyses, increased hemoglobin, defined as a continuous variable, was associated with DWI lesions (adjusted odds ratio, 1.21 per 1 g/dL change in hemoglobin [95% CI, 1.07-1.37]) after adjusting for sex, race, ICH severity, time to magnetic resonance imaging, and acute blood pressure change. In secondary analyses, DWI lesions were associated with poor 3-month outcomes (adjusted odds ratio, 1.83 [95% CI, 1.24-2.69]) after adjusting for similar covariates.

CONCLUSIONS

We identified novel relationships between higher baseline hemoglobin concentrations and DWI ischemic lesions in patients with ICH. Further studies are required to clarify the role of hemoglobin concentration on both cerebral small vessel disease pathophysiology and ICH outcomes.

Histopathology of Cerebral Microinfarcts and Microbleeds in Spontaneous Intracerebral Hemorrhage

In patients with spontaneous intracerebral hemorrhage caused by different vasculopathies, cerebral microinfarcts have the same aspect on MRI and the same applies to cerebral microbleeds. It is unclear what pathological changes underlie these cerebral microinfarcts and cerebral microbleeds. In the current study, we explored the histopathological substrate of these lesions by investigating the brain tissue of 20 patients (median age at death 77 years) who died from ICH (9 lobar, 11 non-lobar) with a combination of post-mortem 7-T MRI and histopathological analysis. We identified 132 CMIs and 204 CMBs in 15 patients on MRI, with higher numbers of CMIs in lobar ICH patients and similar numbers of CMBs. On histopathology, CMIs and CMBs were in lobar ICH more often located in the superficial than in the deep layers of the cortex, and in non-lobar ICH more often in the deeper layers. We found a tendency towards more severe CAA scores in lobar ICH patients. Other histopathological characteristics were comparable between lobar and non-lobar ICH patients. Although CMIs and CMBs were found in different segments of the cortex in lobar ICH compared to non-lobar ICH patients, otherwise similar histopathological features of cortical CMIs and CMBs distant from the ICH suggest shared pathophysiological mechanisms in lobar and non-lobar ICH caused by different vasculopathies.

Can novel CT-and MR-based neuroimaging biomarkers further improve the etiological diagnosis of lobar intra-cerebral hemorrhage?

Lobar hematomas represent around half of all supratentorial hemorrhages and have high mortality and morbidity. Their management depends on the underlying cause. Apart from local causes such as vascular malformation, which are rare and can usually be easily excluded thanks to imaging, the vast majority of lobar hematomas equally frequently result from either hypertensive arteriolopathy (HA) or cerebral amyloid angiopathy (CAA). Distinguishing between CAA and HA is important for prognostication (risk of recurrence nearly sevenfold higher in the former), for decision-making regarding, e.g., antithrombotic therapies (for other indications) and for clinical trials of new therapies. Currently, a non-invasive diagnosis of probable CAA can be made using the MR-based modified Boston criteria, which have excellent specificity but moderate sensitivity against histopathological reference, leading to the clinically largely irrelevant diagnosis of "possible CAA". Furthermore, the Boston criteria cannot be applied when both lobar and deep MRI hemorrhagic markers are present, a not uncommon situation. Here we propose to test whether new CT and MR-based imaging biomarkers, namely finger-like projections of the hematoma and adjacent subarachnoid hemorrhage on acute-stage CT or MRI, and remote punctate diffusion-weighted imaging ischemic lesions on acute or subacute-stage MRI, have the potential to improve the performance of the Boston criteria. Furthermore, we also propose to test whether clinical-radiological biomarkers may also allow a positive diagnosis of HA to be made in lobar hematomas, which, if feasible, would not only further reduce the prevalence of "possible CAA" but also permit a diagnosis of HA and/or CAA to be made in the presence of mixed deep and lobar MRI hemorrhagic markers.

Changes in Cerebral Blood Flow and Diffusion-Weighted Imaging Lesions After Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) is a common subtype of stroke and places a great burden on the family and society with a high mortality and disability rate and a poor prognosis. Many findings from imaging and pathologic studies have suggested that cerebral ischemic lesions visualized on diffusion-weighted imaging (DWI) in patients with ICH are not rare and are generally considered to be associated with poor outcome, increased risk of recurrent (ischemic and hemorrhagic) stroke, cognitive impairment, and death. In this review, we describe the changes in cerebral blood flow (CBF) and DWI lesions after ICH and discuss the risk factors and possible mechanisms related to the occurrence of DWI lesions, such as cerebral microangiopathy, cerebral atherosclerosis, aggressive early blood pressure lowering, hyperglycemia, and inflammatory response. We also point out that a better understanding of cerebral DWI lesions will be a key step toward potential therapeutic interventions to improve long-term recovery for patients with ICH.

Diffusion-weighted imaging hyperintensities during the chronic stage of intracerebral hemorrhage with surgery: A new clinical situation or post-surgery artifact?

Background and objective

Diffusion-weighted imaging (DWI) hyperintensities were occasionally seen at previous hematoma in patients several months after intracerebral hemorrhage with surgery. Whether they are newly occurred clinical situations or post-surgery changes is unknown. This study aims to investigate the prevalence and possible mechanisms for this phenomenon.

Methods

We retrospectively reviewed the MRI database for intracerebral hemorrhage with surgery after 3 months of disease onset in our hospital. We also prospectively performed repeated multimodal MRI scans for two patients at the chronic stage after surgery for intracerebral hemorrhage.

Results

We found that 14 out of 23 patients (60.9%) had DWI hyperintensities at the site of previous hematoma 3 months after intracerebral hemorrhage with surgery. All the DWI lesions were hyperintense on T1- and T2-weighted imaging, most of which appeared long and narrow in shape. The DWI lesions were usually located adjacent to the thin wall of the previous hematoma cavity close to the lateral ventricle. They were more associated with the basal ganglia hemorrhage than with the lobar hemorrhage (P = 0.02) and were more frequently seen for those with intraventricular hemorrhage than without (P = 0.02). Prospectively repeated MRI exams of two patients revealed unchanged DWI hyperintensity during the 18- and 2-month follow-up, respectively.

Conclusion

The DWI lesions at previous hematoma were commonly seen in patients after surgery for intracerebral hemorrhage at the chronic stage which would persist for years. We hypothesized a possible mechanism by which extracellular methemoglobin “islands” are formed with delayed or no absorption by macrophages from adjacent thin residual brain tissue. Unnecessary further examinations and treatment would be avoided by realizing this imaging phenomenon.

One-Year Outcome Trajectories and Factors Associated with Functional Recovery Among Survivors of Intracerebral and Intraventricular Hemorrhage With Initial Severe Disability

Importance

Patients who survive severe intracerebral hemorrhage (ICH) and intraventricular hemorrhage (IVH) typically have poor functional outcome in the short term and understanding of future recovery is limited.

Objective

To describe 1-year recovery trajectories among ICH and IVH survivors with initial severe disability and assess the association of hospital events with long-term recovery.

Design, Setting, and Participants

This post hoc analysis pooled all individual patient data from the Clot Lysis: Evaluating Accelerated Resolution of Intraventricular Hemorrhage phase 3 trial (CLEAR-III) and the Minimally Invasive Surgery Plus Alteplase for Intracerebral Hemorrhage Evacuation (MISTIE-III) phase 3 trial in multiple centers across the US, Canada, Europe, and Asia. Patients were enrolled from August 1, 2010, to September 30, 2018, with a follow-up duration of 1 year. Of 999 enrolled patients, 724 survived with a day 30 modified Rankin Scale score (mRS) of 4 to 5 after excluding 13 participants with missing day 30 mRS. An additional 9 patients were excluded because of missing 1-year mRS. The final pooled cohort included 715 patients (71.6%) with day 30 mRS 4 to 5. Data were analyzed from July 2019 to January 2022.

Exposures

CLEAR-III participants randomized to intraventricular alteplase vs placebo. MISTIE-III participants randomized to stereotactic thrombolysis of hematoma vs standard medical care.

Main Outcomes and Measures

Primary outcome was 1-year mRS. Patients were dichotomized into good outcome at 1 year (mRS 0 to 3) vs poor outcome at 1 year (mRS 4 to 6). Multivariable logistic regression models assessed associations between prospectively adjudicated hospital events and 1-year good outcome after adjusting for demographic characteristics, ICH and IVH severity, and trial cohort.

Results

Of 715 survivors, 417 (58%) were male, and the overall mean (SD) age was 60.3 (11.7) years. Overall, 174 participants (24.3%) were Black, 491 (68.6%) were White, and 49 (6.9%) were of other races (including Asian, Native American, and Pacific Islander, consolidated owing to small numbers); 98 (13.7%) were of Hispanic ethnicity. By 1 year, 129 participants (18%) had died and 308 (43%) had achieved mRS 0 to 3. In adjusted models for the combined cohort, diabetes (adjusted odds ratio [aOR], 0.50; 95% CI, 0.26-0.96), National Institutes of Health Stroke Scale (aOR, 0.93; 95% CI, 0.90-0.96), severe leukoaraiosis (aOR, 0.30; 95% CI, 0.16-0.54), pineal gland shift (aOR, 0.87; 95% CI, 0.76-0.99]), acute ischemic stroke (aOR, 0.44; 95% CI, 0.21-0.94), gastrostomy (aOR, 0.30; 95% CI, 0.17-0.50), and persistent hydrocephalus by day 30 (aOR, 0.37; 95% CI, 0.14-0.98) were associated with lack of recovery. Resolution of ICH (aOR, 1.82; 95% CI, 1.08-3.04) and IVH (aOR, 2.19; 95% CI, 1.02-4.68) by day 30 were associated with recovery to good outcome. In the CLEAR-III model, cerebral perfusion pressure less than 60 mm Hg (aOR, 0.30; 95% CI, 0.13-0.71), sepsis (aOR, 0.05; 95% CI, 0.00-0.80), and prolonged mechanical ventilation (aOR, 0.96; 95% CI, 0.92-1.00 per day), and in MISTIE-III, need for intracranial pressure monitoring (aOR, 0.35; 95% CI, 0.12-0.98), were additional factors associated with poor outcome. Thirty-day event-based models strongly predicted 1-year outcome (area under the receiver operating characteristic curve [AUC], 0.87; 95% CI, 0.83-0.90), with significantly improved discrimination over models using baseline severity factors alone (AUC, 0.76; 95% CI, 0.71-0.80; P < .001).

Conclusions and Relevance

Among survivors of severe ICH and IVH with initial poor functional outcome, more than 40% recovered to good outcome by 1 year. Hospital events were strongly associated with long-term functional recovery and may be potential targets for intervention. Avoiding early pessimistic prognostication and delaying prognostication until after treatment may improve ability to predict future recovery.

Clinical neuroimaging in intracerebral haemorrhage related to cerebral small vessel disease: contemporary practice and emerging concepts

INTRODUCTION

About 80% of all non-traumatic intracerebral haemorrhage (ICH) are caused by the sporadic cerebral small vessel diseases deep perforator arteriopathy (DPA, also termed hypertensive arteriopathy or arteriolosclerosis) and cerebral amyloid angiopathy (CAA), though these frequently co-exist in older people. Contemporary neuroimaging (MRI and CT) detects an increasing spectrum of haemorrhagic and non-haemorrhagic imaging biomarkers of small vessel disease which may identify the underlying arteriopathies.

AREAS COVERED

We discuss biomarkers for cerebral small vessel disease subtypes in ICH, and explore their implications for clinical practice and research.

EXPERT OPINION

ICH is not a single disease, but results from a defined range of vascular pathologies with important implications for prognosis and treatment. The terms "primary" and "hypertensive" ICH are poorly defined and should be avoided, as they encourage incomplete investigation and classification. Imaging-based criteria for CAA will show improved diagnostic accuracy, but specific imaging biomarkers of DPA are needed. Ultra-high-field 7T-MRI using structural and quantitative MRI may provide further insights into mechanisms and pathophysiology of small vessel disease. We expect neuroimaging biomarkers and classifications to allow personalized treatments (e.g. antithrombotic drugs) in clinical practice and to improve patient selection and monitoring in trials of targeted therapies directed at the underlying arteriopathies.

Diffusion-Weighted Lesions After Intracerebral Hemorrhage: Associated MRI Findings

The current study aimed to investigate whether diffusion-weighted imaging-positive (DWI+) lesions after acute intracerebral hemorrhage (ICH) are associated with underlying small vessel disease (SVD) or linked to the acute ICH. We included patients ≥18 years with spontaneous ICH confirmed on neuroimaging and performed 3T MRIs after a median of 11 days (interquartile range [IQR] 6–43). DWI+ lesions were assessed in relation to the hematoma (perihematomal vs. distant and ipsilateral vs. contralateral). Differences in clinical characteristics, ICH characteristics, and MRI markers of SVD between participants with or without DWI+ lesions were investigated using non-parametric tests. We observed 54 DWI+ lesions in 30 (22%) of the 138 patients (median age [IQR] 65 [55–73] years; 71% men, 59 lobar ICH) with available DWI images. We found DWI+ lesions ipsilateral (54%) and contralateral (46%) to the ICH, and 5 (9%) DWI+ lesions were located in the immediate perihematomal region. DWI+ lesion presence was associated with probable CAA diagnosis (38 vs. 15%, p = 0.01) and larger ICH volumes (37 [8–47] vs. 12 [6–24] ml, p = 0.01), but not with imaging features of SVD. Our findings suggest that DWI+ lesions after ICH are a feature of both the underlying SVD and ICH-related mechanisms.

Diffusion-Weighted Imaging Hyperintensities in Acute and Subacute-Phase Intracerebral Hemorrhage

OBJECTIVE

Diffusion-weighted imaging hyperintensities are observed in intracerebral hemorrhage patients at times and might be associated with unfavorable functional outcomes. However, the suitable time to evaluate diffusion-weighted imaging hyperintensities to influence stroke outcome remains unclear. This study investigated the associations between acute and sub-acute diffusion-weighted imaging hyperintensities and functional outcomes among patients with acute intracerebral hemorrhage.

METHODS

Diffusion-weighted imaging hyperintensities were evaluated within 24 h (acute phase) and at 14 ± 5 days (sub-acute phase). An unfavorable functional outcome was a score of 5-6 on the modified Rankin Scale at 3 months.

RESULTS

Among 268 intracerebral hemorrhage patients, diffusion-weighted imaging hyperintensities in the acute phase were observed in 32 (11.9%). Among 227 patients who underwent a second magnetic resonance imaging in the sub-acute phase, diffusion-weighted imaging hyperintensities were observed in 57 (25.1%). Multivariable analysis revealed that the baseline intracerebral hemorrhage volume, history of stroke, and severe white matter lesions were associated with sub-acute diffusion-weighted imaging hyperintensities. The patients with unfavorable outcomes (n = 37) had a higher frequency of sub-acute diffusion-weighted imaging hyperintensities than those without (n = 190) (51.4% vs. 20.0%, P < 0.001); the frequencies of acute diffusion-weighted imaging hyperintensities were not significantly different between the groups (13.5% vs. 10.0%, P = 0.559). Sub-acute diffusion-weighted imaging hyperintensities were independently associated with unfavorable outcomes after adjusting for confounding factors (Odds Ratio, 3.35, 95% CI 1.20-9.35, P = 0.021).

CONCLUSION

The rate of sub-acute diffusion-weighted imaging hyperintensities was higher than acute diffusion-weighted imaging hyperintensities among acute intracerebral hemorrhage patients and likely to be associated with unfavorable outcomes.

The Influence of Diffusion Weighted Imaging Lesions on Outcomes in Patients with Acute Spontaneous Intracerebral Hemorrhage

BACKGROUND/OBJECTIVE

Diffusion weighted imaging (DWI) lesions have been well described in patients with acute spontaneous intracerebral hemorrhage (sICH). However, there are limited data on the influence of these lesions on sICH functional outcomes. We conducted a prospective observational cohort study with blinded imaging and outcomes assessment to determine the influence of DWI lesions on long-term outcomes in patients with acute sICH. We hypothesized that DWI lesions are associated with worse modified Rankin Scale (mRS) at 3 months after hospital discharge.

METHODS

Consecutive sICH patients meeting study criteria were consented for an magnetic resonance imaging (MRI) scan of the brain and evaluated for remote DWI lesions by neuroradiologists blinded to the patients' hospital course. Blinded mRS outcomes were obtained at 3 months. Logistic regression was used to determine significant factors (p < 0.05) associated with worse functional outcomes defined as an mRS of 4-6. The generalized estimating equation (GEE) approach was used to investigate the effect of DWI lesions on dichotomized mRS (0-3 vs 4-6) longitudinally.

RESULTS

DWI lesions were found in 60 of 121 patients (49.6%). The presence of a DWI lesion was associated with increased odds for an mRS of 4-6 at 3 months (OR 5.987, 95% CI 1.409-25.435, p = 0.015) in logistic regression. Using the GEE model, patients with a DWI lesion were less likely to recover over time between 14 days/discharge and 3 months (p = 0.005).

CONCLUSIONS

DWI lesions are common in primary sICH, occurring in almost half of our cohort. Our data suggest that DWI lesions are associated with worse mRS at 3 months in good grade sICH and are predictive of impaired recovery after hospital discharge. Further research into the pathophysiologic mechanisms underlying DWI lesions may lead to novel treatment options that may improve outcomes associated with this devastating disease.

Callosal Diffusion-Restriction in Patients with Intracranial Hemorrhage

OBJECTIVE

We aim to report the incidence and clinical characteristics of patients who were found to have diffusion restricting lesions of the corpus callosum (CC) on Diffusion-weighted imaging (DWI) on magnetic resonance imaging (MRI) following intracranial hemorrhage (ICH).

DESIGN/METHODS

A retrospective cross-sectional analysis was performed of medical records of all adult patients admitted to a single tertiary center with a primary diagnosis of ICH and received nicardipine infusion over a 2-year period. Patients without MRI brain available or patients who underwent digital subtraction angiography (DSA) prior to MRI were excluded. ICH and intraventricular hemorrhage (IVH) volumes and scores were calculated. MRI brain scans were evaluated for presence and locations of DWI lesions.

RESULTS

Among 162 patients who met inclusion criteria, 6 patients (4%, median age 53, range 37-71, 100% male, 33% white) were found to have DWI lesions in the CC with a median ICH volume of 17ml (range 1-105ml). The ICH locations were lobar (n=3), deep (n=2) and cerebellum (n=1). All patients (100%) had intraventricular hemorrhage (IVH) with median IVH volume of 25ml (range 2.7-55ml). Four patients were on levetiracetam. No identifiable infections or metabolic abnormalities were found among these patients. All but one patient had normal DSA. Follow up MRI was only available in one patient and showed no reversibility at 14 days.

CONCLUSION

Although rare, diffusion restricting corpus callosum lesions can be seen in patients with ICH, especially in patients with IVH. The etiology and clinical significance of these lesions remains unknown and warrant further research.

Comparison of Diagnostic Effects of T2-Weighted Imaging, DWI, SWI, and DTI in Acute Cerebral Infarction

Objective: To achieve precision medicine, the use of imaging methods to help the clinical detection of cerebral infarction is conducive to the clinical development of a treatment plan and increase of the cure rate and improvement of the prognosis of patients.Methods: In this work, T2-weighted imaging (T2WI), diffusion-weighted imaging (DWI), susceptibility-weighted imaging (SWI), and diffusion tensor imaging (DTI) examinations were performed on 34 patients with clinically diagnosed cerebral infarction to measure the difference in signal intensity between the lesion and its mirror area and make a comparative analysis by means of the Student-Newman-Keuls method.Results: The detection rate of T2WI was 79% (27/34), the detection rate of DWI was 97% (33/34), the detection rate of SWI was 88% (30/34), and the detection rate of DTI was 94% (32/34).Conclusion: The imaging performance was in the order DWI > DTI > SWI > T2WI for the diagnosis of cerebral infarction, and combined imaging is better than single imaging.

Timing of diffusion weighted imaging lesions in spontaneous intracerebral hemorrhage

INTRODUCTION

Diffusion weighted imaging (DWI) lesions are common after spontaneous intracerebral hemorrhage (sICH). However, their timing relative to a patient's admission to the hospital is unknown. The purpose of this study is to estimate the timing of new DWI lesions after admission for acute sICH.

MATERIAL AND METHODS

Select patients enrolled in a single center prospective study examining the prevalence DWI lesions in acute primary sICH received two MRI scans of the brain after admission. The presence of a new DWI lesion between MRI scans was defined as a new DWI event. A lognormal parametric model was used to estimate the median time (50% percentile) to develop a new DWI lesion.

RESULTS

Among the 121 participants enrolled in the study, 63 (52%) had two brain MRIs. The median time from admission to 1st MRI was 1 day (IQR 1.2, range 0.1-8.4). The median time between the 2 MRI scans was 2.1 (IQR 2.9, range 0.02-17.4) days. 30.2% (n = 19) of participants developed a new DWI lesion between MRI scans. The estimated median time from 1st MRI to new DWI event was 6.3 days (95% CI, 4.1 to 9.6).

DISCUSSION AND CONCLUSION

Accounting for time from admission to 1st MRI, we found that 50% of new DWI lesions occurred by 7.3 days after sICH admission. Pathophysiologic changes in sICH during this time frame need to be studied in order to elucidate a mechanism for DWI lesions.

cnm-Positive Streptococcus mutans and diffusion-weighted imaging hyperintensities in acute intracerebral hemorrhage

BACKGROUND

Strains of Streptococcus mutans expressing the cell surface collagen-binding protein, Cnm, encoded by cnm (cnm-positive S. mutans), are associated with hypertensive intracerebral hemorrhage (ICH) and the occurrence of cerebral microbleeds (CMBs). Small diffusion-weighted imaging (DWI) hyperintensities in patients with acute ICH are also associated with CMBs. However, the association between cnm-positive S. mutans and DWI hyperintensities is unclear. Hence, this study aimed to investigate the association between cnm-positive S. mutans and DWI hyperintensities in patients with acute ICH.

METHODS

Patients with acute ICH were prospectively registered at three hospitals. Dental plaque specimens were collected within 4 days after admission, and cnm-positive S. mutans was detected using the polymerase chain reaction. Magnetic resonance imaging at 14 ± 5 days after admission was used to evaluate DWI hyperintensities and CMBs.

RESULTS

A total of 197 patients were enrolled in this study. cnm-positive S. mutans was detected in 30 patients (15.2%), and DWI hyperintensities were observed in 56 patients (28.4%). Patients with cnm-positive S. mutans had a higher frequency of DWI hyperintensities (50.0% vs 24.6%; p = 0.008) and a higher number of CMBs (5.5 vs 1.5; p < 0.001) than those without cnm-positive S. mutans. Multivariable logistic analysis revealed that the presence of cnm-positive S. mutans was independently associated with DWI hyperintensities (OR 2.38; 95% CI 1.01-5.61; p = 0.047) after adjusting for several confounding factors.

CONCLUSION

This study found an association between the presence of cnm-positive S. mutans and DWI hyperintensities in patients with acute ICH.

Diffusion-Weighted Imaging Lesions After Intracerebral Hemorrhage and Risk of Stroke: A MISTIE III and ATACH-2 Analysis

BACKGROUND AND PURPOSE

Punctate ischemic lesions noted on diffusion-weighted imaging (DWI) are associated with poor functional outcomes after intracerebral hemorrhage (ICH). Whether these lesions increase long-term risk of stroke is poorly understood.

METHODS

We pooled individual patient data from the ATACH-2 trial (Antihypertensive Treatment of Acute Cerebral Hemorrhage) and the MISTIE III trial (Minimally Invasive Surgery Plus Alteplase for Intracerebral Hemorrhage Evacuation Phase 3). We included subjects with a magnetic resonance imaging scan. The exposure was a DWI lesion. The primary outcome was any stroke, defined as a composite of ischemic stroke or recurrent ICH, whereas secondary outcomes were incident ischemic stroke and recurrent ICH. Using multivariate Cox regression analysis, we evaluated the risk of stroke.

RESULTS

Of 505 patients with ICH with magnetic resonance imaging, 466 were included. DWI lesions were noted in 214 (45.9%) subjects, and 34 incident strokes (20 ischemic stroke and 14 recurrent ICH) were observed during a median follow-up of 324 days (interquartile range, 91-374). Presence of a DWI lesion was associated with a 6.9% (95% CI, 2.2-11.6) absolute increase in risk of all stroke (hazard ratio, 2.6 [95% CI, 1.2-5.7]). Covariate adjustment with Cox regression models also demonstrated this increased risk. In the secondary analyses, there was an increased risk of ischemic stroke (hazard ratio, 3.5 [95% CI, 1.1-11.0]) but not recurrent ICH (hazard ratio, 1.7 [95% CI, 0.6-5.1]).

CONCLUSIONS

In a heterogeneous cohort of patients with ICH, presence of a DWI lesion was associated with a 2.5-fold heightened risk of stroke among ICH survivors. This elevated risk persisted for ischemic stroke but not for recurrent ICH.

Cerebral Microembolism in Intracerebral Hemorrhage: A Prospective Case-Control Study

BACKGROUND

Small and remote acute ischemic lesions may occur in up to one-third of patients with spontaneous intracerebral hemorrhage (ICH). Possible mechanisms include cerebral embolism, small vessel disease, blood pressure variability and others. The embolic mechanism has not been adequately studied. Using transcranial Doppler (TCD), we assessed the incidence of spontaneous microembolic signals (MESs) in patients with acute ICH.

METHODS

Twenty acute ICH patients were prospectively evaluated within 48 h of hospital admission. Clinical and imaging data were collected. Continuous TCD monitoring was performed in both middle cerebral arteries for a one-hour period on days 1, 3 and 7 of hospital admission. Monitoring was performed in the emergency room, ICU or ward, according to patient location. We compared the frequency and risk factors for MES in patients with ICH and in 20 age- and gender-matched controls without history of ischemic or hemorrhagic stroke.

RESULTS

The mean age was 57.5 ± 14.1 years, and 60% were male. MESs were detected in 7 patients with ICH and in one control patient without ICH (35% vs 5%, p = 0.048). The frequency of MES on day 1 was 15% (3 of 20 patients), on day 3, 26% (5 of 19 patients) and on day 7, 37.5% (3 of 8 patients). Among patients with ICH, those with MES had a tendency to higher frequencies of dyslipidemia (83% vs 33%, p = 0.13) and lobar location of hemorrhages (71% vs 30%, p = 0.15). Two out of 6 patients with ICH who also underwent MRI had remote DWI lesions, of whom one showed MES on TCD.

CONCLUSION

Micro-embolic signals occur in over one-third of patients with ICH. Further research is needed to identify the sources of cerebral microembolism and their relationship with small acute infarcts in ICH.

Beyond the brain: Extra-axial pathology on diffusion weighted imaging in neuroimaging

Diffusion-weighted imaging (DWI) has a central role in the assessment of the brain parenchyma, particularly in the context of acute stroke. However, the applications of DWI extend far beyond the brain parenchyma and include the assessment of the extra-axial structures of the head and neck that are included in routine brain imaging. In this pictorial review, the added-value of DWI over other conventional sequences is illustrated through discussion of a broad range of disorders affecting the vasculature, skull, orbits, nasal cavity and salivary glands. This article highlights the requirement for all structures, both intra- and extra-axial, to be carefully reviewed on DWI.

Early elevated neutrophil-to-lymphocyte ratio associated with remote diffusion-weighted imaging lesions in acute intracerebral hemorrhage

AIMS

To explore the relationship between the circulating neutrophil-to-lymphocyte ratio (NLR) and the remote diffusion-weighted imaging lesions (R-DWILs) after spontaneous intracerebral hemorrhage (ICH).

METHODS

Consecutive patients with spontaneous ICH were prospectively collected from November 2016 to May 2018 and retrospectively analyzed. We included subjects who presented within 24 hours after symptom onset and were free of detectable infections on admission or in hospital. Blood samples were obtained at 24-48 hours after ICH ictus, while all complete MRI scans were performed at 5-8 days. R-DWILs were defined as focal hyperintensities remote from the site of the ICH or the peri-hematoma regions. NLR was calculated by dividing the absolute neutrophil counts by the absolute lymphocyte counts. Multivariate binary logistic regression models were generated to evaluate the relationship between NLR and R-DWILs.

RESULTS

One hundred sixty-three subjects met eligibility criteria (age 62.3 ± 13.6 years, 60.7% males), of whom 31(19.0%) experienced R-DWILs. Higher circulating NLR was documented in patients with R-DWILs. With the best cutoff value of 6.01, elevated NLR was independently associated with the presence of R-DWILs (OR = 3.170, 95% CI 1.306-7.697, P = .011) in the bivariate logistic regression analysis with adjustment for age, sex, atrial fibrillation, previous ischemic stroke/TIA, SBP on admission, hematoma volume, and IVH.

CONCLUSIONS

This study provides significant evidence of the association between circulating NLR and R-DWILs in spontaneous ICH patients. Patients with NLR > 6.01 at 24-48 hours after ICH ictus should be paid more attention to when evaluating R-DWILs.

Premature vascular disease in young adult stroke: a pathology-based case series

INTRODUCTION

The prevalence of modifiable vascular risk factors is increasing in young adults and may contribute to the growing frequency of stroke in this population. The neuropathology and end-organ damage profile of young adult stroke patients with clinically advanced atherosclerosis or arteriosclerosis has not been studied.

METHODS

This retrospective study included patients aged 18-60 years admitted to our hospital from 1995 to 2017 with recurrent ischemic or hemorrhagic strokes, fatal stroke, or stroke associated with advanced small vessel disease (SVD) on brain MRI, who had no evidence for structural, genetic, inflammatory, or infectious etiology for stroke, and had adequate pathological materials available for analysis. The presence of atherosclerosis, arteriolosclerosis, left ventricular hypertrophy, and nephrosclerosis was evaluated.

RESULTS

Twelve patients (mean age 47 ± 9 years, range 31-57 years, 67% male) met inclusion criteria. Four had fatal intracerebral hemorrhage (ICH), three had recurrent non-fatal ICH, one had ICH with advanced SVD on MRI, and four had recurrent ischemic strokes including two with transient ischemic attacks. Pathological studies showed moderate/severe atherosclerosis in 64% and moderate/severe arteriolosclerosis in 42% of patients. Pathological data to evaluate end-organ damage were available for nine patients; eight showed left ventricular hypertrophy and all showed nephrosclerosis.

CONCLUSION

Young adult stroke patients with recurrent stroke, fatal stroke, or SVD on imaging have advanced atherosclerosis and arteriolosclerosis-related pathological changes in multiple organ systems. Aggressive control of atherosclerosis risk factors is warranted even in young individuals.

Incident Cerebral Microbleeds After Intracerebral Hemorrhage

Background and Purpose—

The frequency and prognostic implications of incident cerebral microbleeds (CMB), defined as development of one or more new CMB, after intracerebral hemorrhage (ICH) is unclear. Therefore, we performed a systematic review and meta-analysis to investigate the frequency and prognostic implications of incident CMB after ICH.

Methods—

We searched Ovid Medline and Embase in May 2018 for longitudinal studies of adults who underwent brain magnetic resonance imaging at 2 or more times after ICH. We calculated the pooled proportion of adults with incident CMB and sought associations between incident CMB and clinical outcomes (death, recurrent ICH, or new ischemic stroke). We planned subgroup analyses to investigate clinical variables associated with incident CMB.

Results—

We identified 2354 publications, of which we included 4 cohort studies involving 349 patients. The pooled proportion of adults with at least one new CMB during a mean 27 months follow-up (SD 20 months) was ≈40% (95% CI, 30%–50%). In one study, as the number of incident CMB increased (0 versus 1–3 new CMB versus ≥4 new CMB) the risk of recurrent symptomatic lobar ICH increased (hazard ratio 3.0; 95% CI, 1.2–7.3). No study reported on outcomes of incident ischemic stroke or death.

Conclusions—

Incident CMB occurs in ≈40% of adults after ICH. The association of incident CMB with recurrent lobar ICH needs confirmation and their association with death and ischemic stroke investigation.