An efficient deep neural network for automatic classification of acute intracranial hemorrhages in brain CT scans.

BACKGROUND: Recent advancements in deep learning models have demonstrated their potential in the field of medical imaging, achieving remarkable performance surpassing human capabilities in tasks such as classification and segmentation. However, these modern state-of-the-art network architectures often demand substantial computational resources, which limits their practical application in resource-constrained settings. This study aims to propose an efficient diagnostic deep learning model specifically designed for the classification of intracranial hemorrhage in brain CT scans. METHOD: Our proposed model utilizes a combination of depthwise separable convolutions and a multi-receptive field mechanism to achieve a trade-off between performance and computational efficiency. The model was trained on RSNA datasets and validated on CQ500 dataset and PhysioNet dataset. RESULT: Through a comprehensive comparison with state-of-the-art models, our model achieves an average AUROC score of 0.952 on RSNA datasets and exhibits robust generalization capabilities, comparable to SE-ResNeXt, across other open datasets. Furthermore, the parameter count of our model is just 3 % of that of MobileNet V3. CONCLUSION: This study presents a diagnostic deep-learning model that is optimized for classifying intracranial hemorrhages in brain CT scans. The efficient characteristics make our proposed model highly promising for broader applications in medical settings.

Detection and classification of intracranial haemorrhage on CT images using a novel deep-learning algorithm.

A novel deep-learning algorithm for artificial neural networks (ANNs), completely different from the back-propagation method, was developed in a previous study. The purpose of this study was to assess the feasibility of using the algorithm for the detection of intracranial haemorrhage (ICH) and the classification of its subtypes, without employing the convolutional neural network (CNN). For the detection of ICH with the summation of all the computed tomography (CT) images for each case, the area under the ROC curve (AUC) was 0.859, and the sensitivity and the specificity were 78.0% and 80.0%, respectively. Regarding ICH localisation, CT images were divided into 10 subdivisions based on the intracranial height. With the subdivision of 41-50%, the best diagnostic performance for detecting ICH was obtained with AUC of 0.903, the sensitivity of 82.5%, and the specificity of 84.1%. For the classification of the ICH to subtypes, the accuracy rate for subarachnoid haemorrhage (SAH) was considerably excellent at 91.7%. This study revealed that our approach can greatly reduce the ICH diagnosis time in an actual emergency situation with a fairly good diagnostic performance.

Identification of Patients with Nontraumatic Intracranial Hemorrhage Using Administrative Claims Data.

INTRODUCTION: Nontraumatic intracranial hemorrhage (ICH) is a neurological emergency of research interest; however, unlike ischemic stroke, has not been well studied in large datasets due to the lack of an established administrative claims-based definition. We aimed to evaluate both explicit diagnosis codes and machine learning methods to create a claims-based definition for this clinical phenotype. METHODS: We examined all patients admitted to our tertiary medical center with a primary or secondary International Classification of Disease version 9 (ICD-9) or 10 (ICD-10) code for ICH in claims from any portion of the hospitalization in 2014-2015. As a gold standard, we defined the nontraumatic ICH phenotype based on manual chart review. We tested explicit definitions based on ICD-9 and ICD-10 that had been previously published in the literature as well as four machine learning classifiers including support vector machine (SVM), logistic regression with LASSO, random forest and xgboost. We report five standard measures of model performance for each approach. RESULTS: A total of 1830 patients with 2145 unique ICD-10 codes were included in the initial dataset, of which 437 (24%) were true positive based on manual review. The explicit ICD-10 definition performed best (Sensitivity = 0.89 (95% CI 0.85-0.92), Specificity = 0.83 (0.81-0.85), F-score = 0.73 (0.69-0.77)) and improves on an explicit ICD-9 definition (Sensitivity = 0.87 (0.83-0.90), Specificity = 0.77 (0.74-0.79), F-score = 0.67 (0.63-0.71). Among machine learning classifiers, SVM performed best (Sensitivity = 0.78 (0.75-0.82), Specificity = 0.84 (0.81-0.87), AUC = 0.89 (0.87-0.92), F-score = 0.66 (0.62-0.69)). CONCLUSIONS: An explicit ICD-10 definition can be used to accurately identify patients with a nontraumatic ICH phenotype with substantially better performance than ICD-9. An explicit ICD-10 based definition is easier to implement and quantitatively not appreciably improved with the additional application of machine learning classifiers. Future research utilizing large datasets should utilize this definition to address important research gaps.

Validity of cerebrovascular ICD-9-CM codes in healthcare administrative databases. The Umbria Data-Value Project.

BACKGROUND: Validation of administrative databases for cerebrovascular diseases is crucial for epidemiological, outcome, and health services research. The aim of this study was to validate ICD-9 codes for hemorrhagic or ischemic stroke in administrative databases, to use them for a comprehensive assessment of the burden of disease in terms of major outcomes, such as mortality, hospital readmissions, and use of healthcare resources. METHODS: We considered the hospital discharge abstract database of the Umbria Region (890,000 residents). Source population was represented by patients aged >18 discharged from hospital with a diagnosis of hemorrhagic or ischemic stroke between 2012 and 2014 using ICD-9-CM codes in primary position. We randomly selected and reviewed medical charts of cases and non-cases from hospitals. For case ascertainment we considered symptoms and instrumental tests reported in the medical charts. Diagnostic accuracy measures were computed using 2x2 tables. RESULTS: We reviewed 767 medical charts for cases and 78 charts for non-cases. Diagnostic accuracy measures were: subarachnoid hemorrhage: sensitivity (SE) 100% (95% CI: 97%-100%), specificity (SP) 96% (90-99), positive predictive value (PPV) 98% (93-100), negative predictive value (NPV) 100% (95-100); intracerebral hemorrhage: SE 100% (97-100), SP 98% (91-100), PPV 98% (94-100), NPV 100% (95-100); other and unspecified intracranial hemorrhage: SE 100% (97-100), SP 96% (90-99), PPV 98% (93-100), NPV 100% (95-100); ischemic stroke due to occlusion and stenosis of precerebral arteries: SE 99% (94-100), SP 66 (57-75), PPV 70% (61-77), NPV 99% (93-100); occlusion of cerebral arteries: SE 100% (97-100), SP 87% (78-93), PPV 91% (84-95), NPV 100% (95-100); acute, but ill-defined, cerebrovascular disease: SE 100% (97-100), SP 78% (69-86), PPV % 83 (75-89), NPV 100% (95-100). CONCLUSIONS: Case ascertainment for both ischemic and hemorrhagic stroke showed good or high levels of accuracy within the regional healthcare databases in Umbria. This database can confidently be employed for epidemiological, outcome, and health services research related to any type of stroke.

Concurrent Types of Intracranial Hemorrhage are Associated with a Higher Mortality Rate in Adult Patients with Traumatic Subarachnoid Hemorrhage: A Cross-Sectional Retrospective Study.

Traumatic subarachnoid hemorrhage (SAH) is the second most frequent intracranial hemorrhage and a common radiologic finding in computed tomography. This study aimed to estimate the risk of mortality in adult trauma patients with traumatic SAH concurrent with other types of intracranial hemorrhage, such as subdural hematoma (SDH), epidural hematoma (EDH), and intracerebral hemorrhage (ICH), compared to the risk in patients with isolated traumatic SAH. We searched our hospital's trauma database from 1 January, 2009 to 31 December, 2018 to identify hospitalized adult patients ≥20 years old who presented with a trauma abbreviated injury scale (AIS) of ≥3 in the head region. Polytrauma patients with an AIS of ≥3 in any other region of the body were excluded. A total of 1856 patients who had SAH were allocated into four exclusive groups: (Group I) isolated traumatic SAH, n = 788; (Group II) SAH and one diagnosis, n = 509; (Group III) SAH and two diagnoses, n = 493; and (Group IV) SAH and three diagnoses, n = 66. One, two, and three diagnoses indicated occurrences of one, two, or three other types of intracranial hemorrhage (SDH, EDH, or ICH). The adjusted odds ratio with a 95% confidence interval (CI) of the level of mortality was calculated with logistic regression, controlling for sex, age, and pre-existing comorbidities. Patients with isolated traumatic SAH had a lower rate of mortality (1.8%) compared to the other three groups (Group II: 7.9%, Group III: 12.4%, and Group IV: 27.3%, all p < 0.001). When controlling for sex, age, and pre-existing comorbidities, we found that Group II, Group III, and Group IV patients had a 4.0 (95% CI 2.4-6.5), 8.9 (95% CI 4.8-16.5), and 21.1 (95% CI 9.4-47.7) times higher adjusted odds ratio for mortality, respectively, than the patients with isolated traumatic SAH. In this study, we demonstrated that compared to patients with isolated traumatic SAH, traumatic SAH patients with concurrent types of intracranial hemorrhage have a higher adjusted odds ratio for mortality.

Novel Anatomic Classification of Spontaneous Thalamic Hemorrhage Classified by Vascular Territory of Thalamus.

BACKGROUND: Spontaneous thalamic hemorrhage has increased in incidence in recent years. Analysis of the characteristics of thalamic hemorrhage was based on the vascular territories of the thalamus. METHODS: Retrospective analysis included 303 consecutive patients with spontaneous thalamic hemorrhage. Thalamic hemorrhage was classified into 4 types: anterior type (supplied mainly by the tuberothalamic artery), medial (mainly paramedian thalamic-subthalamic artery), lateral (mainly thalamogeniculate artery), and posterior (mainly posterior choroidal artery). The baseline characteristics, complications, and functional outcomes were assessed. RESULTS: The anterior type was found in 10 patients (3.3%), the medial type in 47 (15.5%), the lateral type in 230 (75.9%), and the posterior type in 16 (5.3%). Intracerebral hemorrhage volume was smallest in the anterior type, and significantly smaller than in the medial (P = 0.002) and lateral types (P < 0.001). Intraventricular hemorrhage (IVH) or acute hydrocephalus was significantly associated with the medial type (P < 0.01 or P < 0.01, respectively). Non-IVH or non-acute hydrocephalus was significantly associated with the anterior (P < 0.05 or P < 0.05, respectively) and lateral (P < 0.05 or P < 0.05, respectively) types. Emergency surgery was correlated only with the medial type (P < 0.01). The independent predictors of poor outcome were age (odds ratio [OR], 1.07; P = 0.002), admission National Institutes of Health Stroke Scale score (OR, 1.32; P < 0.001), and type of thalamic hemorrhage (OR, 2.08; P = 0.038). CONCLUSIONS: The present study proposed a novel anatomic classification of thalamic hemorrhage according to the major thalamic vascular territories.

Classification of Bleeding Events: Comparison of ECASS III (European Cooperative Acute Stroke Study) and the New Heidelberg Bleeding Classification.

BACKGROUND AND PURPOSE: Intracranial hemorrhage (ICH) after acute ischemic stroke treatments represents a feared complication with possible prognostic implications. In recent years, ICHs were commonly classified according to the ECASS (European Cooperative Acute Stroke Study). To improve the clinical applicability and relevance, the new Heidelberg Bleeding Classification (HBC) has been proposed in 2015. Here, we compared the ECASS and HBC classification with regard to observed events and prognostic relevance. METHODS: A retrospective analysis of a prospectively compiled database of patients with acute ischemic stroke in the anterior circulation who received mechanical thrombectomy between February 2011 and March 2016 was performed. Presence of ICH after mechanical thrombectomy was evaluated on postinterventional computed tomographic imaging. ICHs were specified according to both ECASS III and HBC classification and analyzed with regard to their symptoms and outcome. RESULTS: ICHs were observed in 156 of 768 patients (20.3%). Using ECASS III classification, 101 ICHs could be unambiguously assigned, of which 28 (27.7%; 3.6% of all treated patients) were symptomatic ICHs. Using HBC, 55 additional ICHs could be categorized. Of these total 156 ICHs, 29 (18.6%; 3.8% of all treated patients) were classified as symptomatic according to HBC. CONCLUSIONS: Classification of ICH by ECASS III and HBC criteria show distinct differences. These differences warrant special attention during interpretation and comparison of scientific publications.

Stroke Epidemiology in an Australian Rural Cohort (SEARCH).

Background Stroke rates in Australia and New Zealand have been declining since 1990 but all studies have been completed in large urban centers. Aim We report the first Australasian stroke incidence study in a rural population. Methods The authors applied the principle of complete ascertainment, used the WHO standard definition of stroke and classified ischemic stroke by the TOAST criteria. Data were collected from five rural centers defined by postcode of residence, over a 2-year period with 12 months of follow up of all cases. Results There were 217 strokes in 215 individuals in a population of 96,036 people, over 2 years, giving a crude attack rate of 113 per 100,000 per year. The 181 first-ever strokes (83% of total), standardized to the WHO world population, occurred at a rate of 50/100,000 (95% CI: 43-58). The 28-day fatality for first-ever strokes was 24% (95% CI: 18-31) and 77% (95% CI: 71-83) were classified as ischemic (140/181), 15% (95% CI: 10-21) intracerebral hemorrhage, 3% (95% CI: 1-6) due to subarachnoid hemorrhage and 5% (95% CI: 2-9) were unknown. A high proportion of first-ever ischemic strokes (44%) were cardioembolic, mostly (77%) due to atrial arrhythmias. Of the 38 with known atrial arrhythmias prior to stroke, only six (16%) were therapeutically anticoagulated. Conclusions This rural companion study of a recent Australian urban stroke incidence study confirms the downward trend of stroke incidence in Australia, and reiterates that inadequate anticoagulation of atrial arrhythmia remains a preventable cause of ischemic stroke.

Fetal intracranial hemorrhage: sonographic criteria and merits of prenatal diagnosis.

PURPOSE: To determine the sonographic criteria for diagnosis of fetal intracranial hemorrhage (ICH), using both gray scale ultrasound, and tomographic ultrasound imaging (TUI). MATERIALS AND METHODS: A prospective multicenter study, recruiting patients at risk of fetal ICH over four years. All cases with fetal ICH had serial ultrasound assessments, including TUI, fetal and postnatal MRIs. RESULTS: Twenty-one patients were diagnosed with fetal ICH, two cases had extracerebral (subdural) hemorrhage, 16 cases had intracerebral (intraventricular) hemorrhage and three cases had combined hemorrhage. The mean gestational age at which they were diagnosed was 29.8 ± 5.2 weeks. Seventy-six percent of cases had no identifiable risk factors. IUGR was associated with 57.9% of cases. Using grey scale ultrasound, we demonstrated clear cut sonographic criteria for diagnosis of fetal ICH. TUI enabled us to detect some midline cerebral lesions not detected by grey scale 2D ultrasound alone. Fetal and postnatal MRI confirmed those findings. CONCLUSION: Ultrasonography can be used in the detection, classification and monitoring the progression of various types of ICH. TUI is an additional diagnostic tool that might help to detect the exact size, and extent of those lesions. Fetal MRI is not superior, but might aid in the diagnosis.

Introducing the Big Knowledge to Use (BK2U) challenge.

The purpose of the Big Data to Knowledge initiative is to develop methods for discovering new knowledge from large amounts of data. However, if the resulting knowledge is so large that it resists comprehension, referred to here as Big Knowledge (BK), how can it be used properly and creatively? We call this secondary challenge, Big Knowledge to Use. Without a high-level mental representation of the kinds of knowledge in a BK knowledgebase, effective or innovative use of the knowledge may be limited. We describe summarization and visualization techniques that capture the big picture of a BK knowledgebase, possibly created from Big Data. In this research, we distinguish between assertion BK and rule-based BK (rule BK) and demonstrate the usefulness of summarization and visualization techniques of assertion BK for clinical phenotyping. As an example, we illustrate how a summary of many intracranial bleeding concepts can improve phenotyping, compared to the traditional approach. We also demonstrate the usefulness of summarization and visualization techniques of rule BK for drug-drug interaction discovery.

Intracranial Hemorrhage in the Neonate.

Intracranial hemorrhage is a serious cause of morbidity and mortality in the neonate. Subgaleal, subdural, subarachnoid, and intraventricular hemorrhage have varying pathophysiology, but each can have serious long-term consequences. This article reviews the pathophysiology, presentation, and outcomes for intracranial hemorrhage in the newborn, as well as potential therapeutic interventions.

Associated Aneurysms in Infratentorial Arteriovenous Malformations: Role of Aneurysm Size and Comparison with Supratentorial Lesions.

BACKGROUND: The natural history and treatment of brain arteriovenous malformations (AVMs) is the object of ongoing debates and discussions. To capture the entirety of these complex lesions, associated vascular pathologies, such as associated aneurysms (AAs), have to be implemented in future risk stratification models, as they are believed to represent additional risk factors for intracranial hemorrhage. The present study aims to determine AA characteristics in posterior fossa AVMs and to compare with AAs accompanying supratentorial AVMs, with special focus on aneurysm size. METHODS: Patients with cerebral AVMs, treated in our department between 1990 and 2013, were analyzed retrospectively. Only patients with flow-related AAs of the feeding arteries were evaluated. Thus, patients harboring intranidal, venous or remote aneurysms were excluded. RESULTS: Of 485 patients with cerebral AVM, 76 patients harbored an AVM of the posterior fossa. Among those, 22 individuals exhibited a total of 35 AAs (n = 8 patients with multiple AAs). Most common location of AAs was the posterior inferior cerebellar artery (n = 20, 57%) and mean AA diameter was 7.9 mm (SD 5.5). In the subgroup of patients with a single AA, mean aneurysm size in posterior fossa AVMs was with 7.8 mm (SD 6.0; range 2-25 mm) significantly larger than the mean size of AAs with supratentorial AVMs (4.8 mm, SD 3.0; range 2-20 mm; p = 0.048). Intracranial hemorrhage was found in 18 of 22 patients (82%) with infratentorial AVMs, and of these, 11 patients suffered from aneurysm rupture. In 14 patients bearing a single AA, 8 (57%) had sustained hemorrhage from aneurysm rupture. The mean diameter of AAs was as supposed in the ruptured group with 9.8 mm (SD 6.9; range 4-25 mm) significantly larger than in the unruptured AA group exhibiting a mean of 5.0 mm (SD 3.3; range 2-10 mm; p = 0.038). Patients with posterior fossa AVMs and AAs were significantly older as compared to those patients with supratentorial lesions (57.1, SD 12.6 vs. 45.8 years, SD 15.9 years; p = 0.004), which was also evident in the subgroup of patients with single AAs (55.2, SD 11.7 vs. 45.8 years, SD 14.9 years; p = 0.038). CONCLUSIONS: AAs of posterior fossa AVMs are larger in diameter than aneurysms accompanying supratentorial AVMs. AA size influences risk for hemorrhage, which, together with the high number of hemorrhagic events in posterior fossa AVMs, justifies treating these pathologies. The higher age of patients with AVMs of the posterior fossa might be one reason for larger AAs in this cohort, when compared to patients with supratentorial AVMs and AAs.

SLAM: Stereotactic Radiosurgery of Large Arteriovenous Malformations: Meta-analysis of Hemorrhage in High-Grade Pollock-Flickinger Arteriovenous Malformations.

BACKGROUND: The prognosis of arteriovenous malformations (AVMs) after treatment has been predicted largely by 2 grading scales: the Spetzler-Martin and Pollock-Flickinger. Although there are studies that examine the rate of hemorrhage with the Spetzler-Martin scale, there have not been studies examining hemorrhage in which the Pollock-Flickinger score was used. The annual hemorrhage rate after radiosurgery of Pollock-Flickinger AVM scores >2 is analyzed. METHODS: Literature search for radiosurgery of large AVMs from January 1, 2000 to June 1, 2014 was conducted. Articles were examined for individual patient data and aggregate patient data that reported hemorrhage rates and mortality. Patients were only included if they had an AVM score ≥2. RESULTS: Annual AVM hemorrhage rate after radiosurgery for all patients (n = 673) was 3.22% (99.3 hemorrhages, 3080.5 follow-up years, 95% confidence interval [95% CI] 2.64%-3.89%). Mortality rate from hemorrhage was 40.08% (95% CI 31.21%-49.90%). A total of 203 patients presented with hemorrhage and 395 did not. In patients with first-time hemorrhage, the annual hemorrhage rate was 3.53% (95% CI 2.66%-4.77%). The annual hemorrhage rate of those with hemorrhagic presentation was 6.10% (95% CI 4.65%-8.07%). The odds ratio comparing re-hemorrhage rate versus first-time hemorrhage is 1.768 (95% CI 1.1571-2.7014, P = 0.0084). Complete obliteration of all AVMs was equal to 33.27% (95% CI, 29.25%-37.54%). CONCLUSIONS: The annual hemorrhage rate in AVMs with scores >2 treated with radiosurgery was comparable with baseline rupture rates reported for untreated AVMs. With further stratification by hemorrhagic versus nonhemorrhagic presentation, the subsequent annual hemorrhage rates are similar to their respective natural histories. Considering the mortality rate from hemorrhage at 40.08% (95% CI, 35.54%-44.62%), the consequences of radiosurgical treatment of large AVMs is significantly worse than the reported 10%-30% fatality rate from hemorrhage of an untreated AVM. Additionally, the overall mortality rate was 6.24% however the percentage of mortalities from hemorrhage was 97.62%.

Validity of international classification of disease codes to identify ischemic stroke and intracranial hemorrhage among individuals with associated diagnosis of atrial fibrillation.

BACKGROUND: Because of its association with death and disability, stroke is a focus of outcomes in atrial fibrillation (AF) research. International Classification of Disease-Ninth Revision (ICD-9) edition codes are commonly used to identify stroke in research, particularly in large administrative data. We sought to assess the validity of ICD-9 codes in stroke case ascertainment and for AF across 3 institutions. METHODS AND RESULTS: Participating centers included Boston Medical Center (safety net hospital), Geisinger Health System (rural Pennsylvania), and the University of Alabama (academic center in the southeastern stroke belt). ICD-9 codes for ischemic stroke (433-434, 436) and intracranial hemorrhage (430-432) identified 1812 stroke cases with an associated code for AF (427.31) from 2006 to 2010. Cases were vetted through chart review with final adjudication by a stroke neurologist. Review considered 94.2% of ICD-9 identified stroke cases valid with decreased accuracy for concurrent AF diagnosis (82.28%) and stroke attributable to AF (72.8%). Among events with "without infarction" modifiers, 7.2% were valid strokes. ICD-9 stroke code accuracy did not differ by stroke type or site. Stroke code 434 displayed higher accuracy than 433 (94.4% versus 85.2%; P<0.01), and primary stroke codes were more accurate than nonprimary codes (97.2% versus 83.7%; P<0.0001). CONCLUSIONS: Using ICD-9 stroke and AF codes to identify patients with stroke plus AF resulted in inaccuracies. Given the expanded financial and policy implications of patient-oriented research, conclusions derived solely from administrative data without validation of outcome events should be interpreted with caution.

The prediction of 30-day mortality in patients with primary pontine hemorrhage: a scoring system comparison.

BACKGROUND AND PURPOSE: Owing to its low morbidity but high mortality, no accurate scoring system focuses on primary pontine hemorrhage (PPH) has been established. We aim to compare the performances of the Acute Physiology and Chronic Health Evaluation (APACHE) II and the Simplified Acute Physiology Score (SAPS) II with the ICH score in predicting the 30-day mortality in patients with PPH. METHODS: We conducted a retrospective analysis of patients admitted with a diagnosis of PPH to a university-affiliated hospital in southern China from May 2000 to June 2011. Data related to patient demographics and that necessary to calculate APACHE II, SAPS II, and ICH score were recorded. Performances of these scoring systems were presented as calibration and discrimination, which were measured by the Hosmer-Lemeshow goodness-of-fit test and the area under the receiver operating characteristic (ROC) curve, respectively. RESULTS: Among 75 patients with PPH finally included, 31 (41.3%) died within 30 days. SAPS II (χ(2) = 6.57, P = 0.682) had the best calibration, followed by APACHE II (χ(2) = 8.06, P = 0.428) and ICH score (χ(2) = 4.94, P = 0.176). Furthermore, in terms of area under the ROC curve, APACHE II (0.919) was more discriminative than SAPS II (0.890) and ICH score (0.844). CONCLUSIONS: In predicting 30-day mortality in patients with PPH, SAPS II has the best calibration, while APACHE II has the highest discrimination. The ICH score, which is easier and simpler to calculate, should be modified for PPH.

The correlation between hematoma volume and outcome in ruptured posterior fossa arteriovenous malformations indicates the importance of surgical evacuation of hematomas.

AIM: The correlation between hematoma volume and outcome in ruptured arteriovenous malformations (AVM) with accompanying posterior fossa hematoma was retrospectively evaluated. MATERIAL AND METHODS: Microsurgery operations were performed on 127 patients with intracranial AVM between January 1998 and January 2009 at our clinic. Fifteen (11.8%) patients were identified as suffering from posterior fossa AVM, and twelve of these patients presented with a cerebellar hematoma. All patients were clinically evaluated according to the following criteria: modified Rankin Scale (mRS) prior to surgery, Spetzler-Martin grade (SMG) of the AVMs, hematoma volume prior to surgery, and mRS following surgery. RESULTS: Postoperative mRS scores were significantly lower than preoperative scores (p=0.0001). Postoperative outcomes were concordant with the SMG of the AVMs (r=0.67, p=0.033), hematoma volume (r=0.537, p=0.072) and preoperative mRS scores (r=0.764, p=0.004). These analyses show that the postoperative mRS score is strongly correlated with a preoperative mRS score, hematoma volume and SMG. CONCLUSION: Posterior fossa AVMs present an increased risk for hemorrhage and for increased morbidity and mortality. Cases with hematoma should be operated on an urgent basis. We conclude that hematoma volume is a factor that impacts postoperative results and prognosis. SMG and preoperative mRS scores were also correlated with outcome.

Hemorrhagic manifestations of reversible cerebral vasoconstriction syndrome: frequency, features, and risk factors.

BACKGROUND AND PURPOSE: Reversible cerebral vasoconstriction syndrome (RCVS), characterized by severe headaches and reversible constriction of cerebral arteries, may be associated with ischemic and hemorrhagic strokes. The aim of this study was to describe the frequency, patterns, and risk factors of intracranial hemorrhages in RCVS. METHODS: We analyzed prospective data on 89 consecutive patients with RCVS, of which 8 were postpartum and 46 used vasoactive substances. Standard bivariate and multivariate statistical tests were applied to compare patients with and without hemorrhage. RESULTS: Thirty patients (34%), of which 5 were postpartum and 12 used vasoactive substances, developed at least 1 type of intracranial hemorrhage, including cortical subarachnoid (n = 27), intracerebral (n = 11), and subdural hemorrhage (n=2). Patients with hemorrhage had an older age (46.6 versus 41.6 years, P = 0.049) and were more frequently females (90% versus 51%, P = 0.0017) or were migrainers (43% versus 19%, P = 0.022) than those without hemorrhage. Multivariate testing identified 2 independent risk factors of hemorrhage in RCVS: female gender (OR, 4.05; 95% CI, 1.46 to 11.2) and migraine (OR, 2.34; 95% CI, 1.06 to 5.18). Patients with hemorrhage had a greater risk of persistent focal deficits (30% versus 2%, P = 0.0002), cerebral infarction (13% versus 2%, P = 0.039), posterior reversible encephalopathy syndrome (17% versus 3%, P = 0.041) at the acute stage, and of inability to resume normal activities at 6 months (27% versus 0%, P < 0.0001). CONCLUSIONS: In RCVS, women and migrainers seem to be at higher risk of intracranial hemorrhage. Overall, intracranial hemorrhages are frequent in RCVS and are associated with a more severe clinical spectrum.