CT Evolution of Hematoma and Surrounding Hypodensity in a Cadaveric Model of Intracerebral Hemorrhage

Perihematomal Edema After Intracerebral Hemorrhage: An Update on Pathogenesis, Risk Factors, and Therapeutic Advances

Intracerebral hemorrhage (ICH) has one of the worst prognoses among patients with stroke. Surgical measures have been adopted to relieve the mass effect of the hematoma, and developing targeted therapy against secondary brain injury (SBI) after ICH is equally essential. Numerous preclinical and clinical studies have demonstrated that perihematomal edema (PHE) is a quantifiable marker of SBI after ICH and is associated with a poor prognosis. Thus, PHE has been considered a promising therapeutic target for ICH. However, the findings derived from existing studies on PHE are disparate and unclear. Therefore, it is necessary to classify, compare, and summarize the existing studies on PHE. In this review, we describe the growth characteristics and relevant underlying mechanism of PHE, analyze the contributions of different risk factors to PHE, present the potential impact of PHE on patient outcomes, and discuss the currently available therapeutic strategies.

Can perihaematomal radiomics features predict haematoma expansion?

AIM

To evaluate the association between perihaematomal radiomics features and haematoma expansion (HE).

MATERIALS AND METHODS

Clinical and radiological data were collected retrospectively. The 1:1 propensity score matching (PSM) method was used to balance the difference of baseline characteristics between patients with and without HE. Radiomics features were extracted from the intra- and perihaematomal regions. Top HE-associated features were selected using the minimum redundancy, maximum relevancy algorithm. Support vector machine models were used to predict HE. Predictive performance of radiomics features from different regions was evaluated by receiver operating characteristic curve and confusion matrix-derived metrics.

RESULTS

A total of 1,062 patients were enrolled. After PSM analysis, the propensity score-matched cohort (PSM cohort) included 314 patients (HE: n=157; non-HE: n=157). The PSM cohort was distributed into the training (n=218) and the validation cohorts (n=96). The predictive performance of intra- and perihaematomal features were comparable in the training (area under the receiver operating characteristic curve [AUC], 0.751 versus 0.757; p=0.867) and the validation cohorts (AUC, 0.724 versus 0.671; p=0.454). By incorporating intra- and perihaematomal features, the combined model outperformed the single intrahaematomal model in the training cohort (AUC, 0.872 versus 0.751; p<0.001). Decision curve analysis (DCA) further confirmed the clinical usefulness of the combined model.

CONCLUSION

Perihaematomal radiomics features can predict HE. The integration of intra- and perihaematomal signatures may provide additional benefit to the prediction of HE.

Management of intracranial hemorrhage in hemophilia A patients

INTRODUCTION

Intracranial hemorrhage due to head trauma in patients with hemophilia is a major cause of mortality and morbidity. The incidence of central nervous system bleeding in these patients is between 3 and 8%. In this study, we shared our experience on the treatment and follow-up of seven pediatric patients with hemophilia A who had intracranial bleeding due to trauma.

MATERIALS AND METHODS

Between 2010 and 2019, the clinical and radiological findings of seven pediatric patients with hemophilia A with intracranial hemorrhage were retrospectively evaluated in our clinic. One patient underwent operation owing to intracranial hemorrhage, and the other six underwent conservative treatment. Hemoglobin, aPTT (activated partial thromboplastin time), and factor VIII levels were measured at regular intervals. For intracranial hemorrhage follow-up, regular computed tomography (CT) was performed.

RESULTS

All patients visited the emergency department with initial neurological complaints. Further, two of the seven patients died, one was treated with sequelae (cerebral palsy), and the other four were treated without sequelae.

CONCLUSIONS

Early diagnosis and treatment of intracranial hemorrhage is very important in patients with bleeding disorders. Factor VIII replacement should be performed in such patients prior to radiological examinations and consultations. The main objective should be to bring factor VIII levels to normal limits during their treatment and follow-up.

Antihyperthermic treatment decreases perihematomal hypodensity

OBJECTIVE

To investigate the effect on perihematomal hypodensity and outcome of a decrease in body temperature in the first 24 hours in patients with intracerebral hemorrhage (ICH).

METHODS

In this retrospective study on a prospectively registered database, among the 1,100 patients, 795 met all the inclusion criteria. Temperature variations in the first 24 hours and perihematomal hypodensity (PHHD) were recorded. Patients ≥37.5°C were treated with antihyperthermic drugs for at least 48 hours. The main objective was to determine the association among temperature variation, PHHD, and outcome at 3 months.

RESULTS

The decrease in temperature in the first 24 hours increased the possibility of good outcome 11-fold. Temperature decrease, lower PHHD volume, and a good outcome were observed in 31.8% of the patients who received antihyperthermic treatment.

CONCLUSION

The administration of early antihyperthermic treatment in patients with spontaneous ICH with a basal axillary temperature ≥37.5°C resulted in good outcome in a third of the treated patients.

Hematoma Hounsfield units and expansion of intracerebral hemorrhage: A potential marker of hemostatic clot contraction

BACKGROUND

Clot contraction reinforces hemostasis by providing an impermeable barrier and contractile force. Since computed tomography attenuation of intracerebral hemorrhage is largely determined by the density of red blood cells, clot contraction can be reflected in an increase of Hounsfield unit (HU) of hematoma.

AIMS

We hypothesized that hematoma expansion is inversely associated with mean HU of intracerebral hemorrhage at presentation.

METHODS

Eighty-nine consecutive spontaneous intracerebral hemorrhage patients with onset to first computed tomography within 24 h were included. Hematomas were segmented using semiautomated planimetry to measure the volume and mean HU. Hematoma expansion was defined as an increase in hematoma volume by over 33% or 6 mL. Multivariable logistic regression was performed for hematoma expansion. The discrimination power of mean HU for hematoma expansion was assessed using C-statistic.

RESULTS

The computed tomography attenuation of hematoma at presentation was 57.5 ± 3.3 HU and the volume was 16.9 ± 23.2 mL. Hematoma expansion occurred in 37.1% of patients. The computed tomography attenuation of hematoma was lower in patients with hematoma expansion than with no expansion (55.7 ± 2.9 HU vs. 58.6 ± 3.1 HU, p-value < 0.01). Multivariable logistic regression revealed that the mean HU of hematoma was inversely associated with hematoma expansion (adjusted odds ratio, 0.64; 95% confidence interval, 0.51-0.80). The C-statistic of the model with four known predictors increased from 0.66 to 0.84 after incorporating mean HU (p-value < 0.01).

CONCLUSIONS

Intracerebral hemorrhage with lower mean HU of hematoma at presentation is more likely to undergo hematoma expansion. This finding suggests the potential presence of clot contraction process that reinforces hemostasis in intracerebral hemorrhage.

Standards for Detecting, Interpreting, and Reporting Noncontrast Computed Tomographic Markers of Intracerebral Hemorrhage Expansion

Significant hematoma expansion (HE) affects one-fifth of people within 24 hours after acute intracerebral hemorrhage (ICH), and its prevention is an appealing treatment target. Although the computed tomography (CT)-angiography spot sign predicts HE, only a minority of ICH patients receive contrast injection. Conversely, noncontrast CT (NCCT) is used to diagnose nearly all ICH, so NCCT markers represent a widely available alternative for prediction of HE. However, different NCCT signs describe similar features, with lack of consensus on the optimal image acquisition protocol, assessment, terminology, and diagnostic criteria. In this review, we propose practical guidelines for detecting, interpreting, and reporting NCCT predictors of HE. ANN NEUROL 2019;86:480-492.

Early hematoma retraction in intracerebral hemorrhage is uncommon and does not predict outcome

Background

Clot retraction in intracerebral hemorrhage (ICH) has been described and postulated to be related to effective hemostasis and perihematoma edema (PHE) formation. The incidence and quantitative extent of hematoma retraction (HR) is unknown. Our aim was to determine the incidence of HR between baseline and time of admission. We also tested the hypothesis that patients with HR had higher PHE volume and good prognosis.

Methods

This was a retrospective single-centre study in which serial planimetric volume measurements of the total hematoma volume (parenchymal (IPH) and intraventricular (IVH)) and PHE were performed in ICH patients with baseline non-contrast computed tomography (CT) completed within 6 hours of onset and follow-up CT 24 (±12) hours from symptom onset. HR was defined as a decrease in volume of >3ml or >15%, and hematoma expansion (HE) as an increase of >6ml or >30%. All other patients were categorized as stable hematoma (HS). Good outcome was defined as modified Rankin Scale (mRS) 0–2 at 90 days.

Results

A total of 136 patients (mean age = 69.3±13.39 years, 58.1% male) were included. Median (interquartile range) baseline total hematoma volume was 14.96 (7.80, 31.88) ml. HR >3ml and >15% occurred in 6 (4.4%) and 8 (5.9%) patients, respectively. Neither definition of HR was associated with follow-up PHE (p>0.297) or good outcome (p>0.249). IVH was the only independent predictor of HR (p<0.0241).

Conclusions

Early HR is rare and associated with IVH, but not with PHE or clinical outcome. There was no relationship between HR, PHE, and patient prognosis. Therefore, HR is unlikely to be a useful endpoint in clinical ICH studies.

Evolution of Traumatic Parenchymal Intracranial Hematomas (ICHs): Comparison of Hematoma and Edema Components

This study seeks to quantitatively assess evolution of traumatic ICHs over the first 24 h and investigate its relationship with functional outcome. Early expansion of traumatic intracranial hematoma (ICH) is common, but previous studies have focused on the high density (blood) component. Hemostatic therapies may increase the risk of peri-hematoma infarction and associated increased cytotoxic edema. Assessing the magnitude and evolution of ICH and edema represented by high and low density components on computerized tomography (CT) may be informative for designing therapies targeted at traumatic ICH. CT scans from participants in the COBRIT (Citicoline Brain Injury Trial) study were analyzed using MIPAV software. CT scans from patients with non-surgical intraparenchymal ICHs at presentation and approximately 24 h later (±12 h) were selected. Regions of high density and low density were quantitatively measured. The relationship between volumes of high and low density were compared to several outcome measures, including Glasgow Outcome Score-Extended (GOSE) and Disability Rating Score (DRS). Paired scans from 84 patients were analyzed. The median time between the first and second scan was 22.79 h (25%ile 20.11 h; 75%ile 27.49 h). Over this time frame, hematoma and edema volumes increased >50% in 34 (40%) and 46 (55%) respectively. The correlation between the two components was low (r = 0.39, p = 0.002). There was a weak correlation between change in edema volume and GOSE at 6 months (r = 0.268, p = 0.037), change in edema volume and DRS at 3 and 6 months (r = -0.248, p = 0.037 and r = 0.358, p = 0.005, respectively), change in edema volume and COWA at 6 months (r = 0.272, p = 0.049), and between final edema volume and COWA at 6 months (r = 0.302, p = 0.028). To conclude, both high density and low density components of traumatic ICHs expand significantly in the first 2 days after TBI. In our study, there does not appear to be a relationship between hematoma volume or hematoma expansion and functional outcome, while there is a weak relationship between edema expansion and functional outcome.

Natural History of Perihematomal Edema and Impact on Outcome After Intracerebral Hemorrhage

BACKGROUND AND PURPOSE

Edema may worsen outcome after intracerebral hemorrhage (ICH). We assessed its natural history, factors influencing growth, and association with outcome.

METHODS

We estimated edema volumes in ICH patients from the Helsinki ICH study using semiautomated planimetry. We assessed the correlation between edema extension distance (EED) and time from ICH onset, creating an edema growth trajectory model up to 3 weeks. We interpolated expected EED at 72 hours and identified clinical and imaging characteristics associated with faster edema growth. Association of EED and mortality was assessed using logistic regression adjusting for predictors of ICH outcome.

RESULTS

From 1013 consecutive patients, 861 were included. There was a strong inverse correlation between EED growth rate (cm/d) and time from onset (days): EED growth=0.162*days exp(-0.927), R²=0.82. Baseline factors associated with larger than expected EED were older age (71 versus 68; P=0.002), higher National Institutes of Health Stroke Scale score (14 versus 8; P<0.001), and lower Glasgow Coma scale score (13 versus 15; P<0.001), larger ICH volume (19.7 versus 12.7 mL; P<0.001), larger initial EED (0.42 versus 0.30; P<0.001), irregularly shaped hematoma (55% versus 42%; P<0.001), and higher glucose (7.6 versus 6.9 mmol/L; P=0.001). Patients with faster edema growth had more midline shift (50% versus 31%; P<0.001), herniation (12% versus 4%; P<0.001), and higher 6-month (46% versus 26%; P<0.001) mortality. In the logistic regression model, higher-than-expected EED was associated with 6-month mortality (odds ratio, 1.60; 95% confidence interval, 1.04-2.46; P=0.032).

CONCLUSIONS

Edema growth can be readily monitored and is an independent determinant of mortality after ICH, providing an important treatment target for strategies to improve patient outcome.

Intracerebral Hemorrhage: Perihemorrhagic Edema and Secondary Hematoma Expansion: From Bench Work to Ongoing Controversies

Intracerebral hemorrhage (ICH) is a medical emergency, which often leads to severe disability and death. ICH-related poor outcomes are due to primary injury causing structural damage and mass effect and secondary injury in the perihemorrhagic region over several days to weeks. Secondary injury after ICH can be due to hematoma expansion (HE) or a consequence of repair pathway along the continuum of neuroinflammation, neuronal death, and perihemorrhagic edema (PHE). This review article is focused on PHE and HE and will cover the animal studies, related human studies, and clinical trials relating to these mechanisms of secondary brain injury in ICH patients.