Acute hydrocephalus and cerebral perfusion after aneurysmal subarachnoid hemorrhage

Predictive outcome factors in the treatment of subarachnoid hemorrhage with hematoma caused by ruptured anterior circulation aneurysms: A monocentric experience

INTRODUCTION

Intracranial aneurysm (IA) rupture accounts for 3% of strokes and is associated with a concerning mortality rate. Subarachnoid hemorrhage with cerebral hematoma (CSAH) often results in a higher mortality rate; however, the optimal treatment approach remains unclear. This study aims to identify factors predicting poor outcomes and mortality in cases of CSAH due to ruptured aneurysms in the anterior cerebral circulation.

METHODS

This study retrospectively included 102 patients with anterior circulation aneurysm ruptures, treated between 2017 and 2019. A multidisciplinary team determined the treatment strategies. Statistical analyses were performed to assess outcomes.

RESULTS

In the bivariate analysis of CSAH related to anterior circulation aneurysm rupture, significant factors associated with morbidity (mRS >2 at one year follow-up) and mortality were: WFNS score severity, mydriasis, Tako-Tsubo, and the presence of hydrocephalus. In the multivariate analysis, significant factors for mortality were hydrocephalus (p < 0.01) and Tako-Tsubo (p < 0.001), while significant factors for morbidity were hydrocephalus (p < 0.01) and hematoma volume (p = 0.012).

CONCLUSION

Our study analyzed a series of cases involving CSAH from anterior circulation aneurysms. We emphasize the importance of prompt treatment for hydrocephalus and suggest that the diagnosis of Tako-Tsubo should delay but not prevent treatment. Depending on local ethical standards, treatment abstention could be considered in patients with severe WFNS scores, the presence of mydriasis, hematoma >45 mL, and hydrocephalus. Our findings indicate that life-threatening hematomas are best managed surgically, while smaller, non-life-threatening cases may benefit from endovascular treatment, though further randomized trials are needed for validation.

Grading Scores for Identifying Patients at Risk of Delayed Cerebral Ischemia and Neurological Outcome in Spontaneous Subarachnoid Hemorrhage: A Comparison of Receiver Operator Curve Analysis

BACKGROUND

Numerous grading scales were proposed for subarachnoid hemorrhage (SAH) to assess the likelihood of unfavorable neurological outcomes (UO) and the risk of delayed cerebral ischemia (DCI). We aimed to validate the Hemorrhage, Age, Treatment, Clinical Status, and Hydrocephalus (HATCH) score and the VASOGRADE, a simple grading scale for prediction of DCI after aneurysmal SAH.

METHODS

This was a retrospective single-center study of patients with nontraumatic SAH (January 2016 to December 2021) admitted to the intensive care unit. We performed a receiver operating characteristic (ROC) curve analysis to assess the discriminative ability of the HATCH and the VASOGRADE to identify patients who had UO at 3 months (defined as Glasgow Outcome Scale score of 1-3), hospital mortality, and DCI and compared their performance with the World Federation of Neurosurgical Surgeons, the modified Fisher, the Sequential Organ Failure Assessment, and the Acute Physiology and Chronic Health Evaluation II scales. We performed a multivariate logistic regression analysis to assess the association between HATCH and UO at 3 months and between VASOGRADE and DCI.

RESULTS

We included 262 consecutive patients with nontraumatic SAH. DCI was observed in 82 patients (31.3%), whereas 78 patients (29.8%) died during hospital stay and 133 patients (51%) had UO at 3 months. HATCH was independently associated with UO (odds ratio 1.61, 95% confidence interval [CI] 1.36-1.90) and had an area under the ROC curve (AUROC) of 0.83 (95% CI 0.77-0.88), comparable to the Acute Physiology and Chronic Health Evaluation II (AUROC 0.84, 95% CI 0.79-0.89) and Sequential Organ Failure Assessment (AUROC 0.83, 95% CI 0.77-0.88).

CONCLUSIONS

Hemorrhage, Age, Treatment, Clinical Status, and Hydrocephalus and VASOGARDE scores had a good performance to predict UO or in-hospital mortality and DCI, respectively; however, their performance did not outperform nonspecific routinely used scores.

Clinical Outcomes and Predictors of Poor Prognosis in Non-aneurysmal Subarachnoid Hemorrhage: A 10-Year Cohort Analysis

Introduction A large majority of spontaneous subarachnoid hemorrhages (SAH) are attributed to aneurysm rupture, though the cause remains unknown in a notable percentage of cases. Non-aneurysmal SAH (naSAH) is generally thought to follow a more benign clinical course than aneurysmal SAH (aSAH); however, similar complications may occur, and poor outcomes are still possible. Given the limited research on naSAH, this study aims to characterize these patients and correlate clinical and radiographic findings with outcomes. Methods A cohort of 149 patients with naSAH was selected from 2014 to 2023. Outcomes were assessed using the modified Rankin Scale (mRS), categorizing results as favorable (mRS 0-2) or unfavorable (mRS 3-6). Descriptive analysis was conducted, dividing the sample into two groups based on blood distribution on computed tomography scan: pretruncal (pnSAH) and non-pretruncal SAH (npnSAH). Associations between variables were tested, and a multivariable logistic regression was performed to identify significant predictors. Results The mean age was 57.54 years, with 79 males (53.0%) and 70 females (47.0%). A favorable outcome was observed in 133 patients (89.3%). Age, chronic hypertension, anticoagulant, and antiplatelet therapy were significant predictors of poor outcome (p < 0.05). A favorable World Federation of Neurosurgical Societies (WFNS) grade (I-III) was recorded in 88.6% of patients and was significantly associated with outcome (p < 0.05). Among the patients with unfavorable outcomes, 87.5% exhibited a npnSAH pattern. Rebleeding was rare, with only one case (0.7%). Acute hydrocephalus was the primary complication observed in naSAH cases (19.5%). Conclusions Patients with a npnSAH pattern were significantly more likely to experience unfavorable outcomes compared to those with a pnSAH pattern. In multivariate regression analysis, WFNS classification, bleeding pattern (pnSAH vs. npnSAH), and acute hydrocephalus were identified as independent predictors of poor outcomes.

Three-dimensional pseudocontinuous arterial spin labeling with dual postlabeling delay for reflecting cerebral blood flow regulation in patients with hydrocephalus: a retrospective cross-sectional study

Background

Three-dimensional pseudo-continuous arterial spin-labeling (3D pCASL) with dual postlabeling delay (PLD) captures both early and delayed cerebral blood flow (CBF), yet its potential in reflecting blood flow regulation in hydrocephalus patients remains uncertain. This study investigated the hemodynamic characteristics in patients with hydrocephalus and whether the difference in cerebral blood flow using short and long PLDs (ΔCBF = CBFPLD =2.5 s - CBFPLD =1.5 s) could reflect cerebral regulation and further aimed to demonstrate the associations between regional ΔCBF and the degree of ventricular dilatation.

Methods

This retrospective study included consecutive patients with hydrocephalus and control participants attending The Second Affiliated Hospital of Nanchang University from December 2017 to December 2022. The CBF in 18 brain regions was manually delineated by two radiologists. Regional CBF and ΔCBF were compared via covariance analyses. The associations between ΔCBF and the degree of ventricular dilatation were investigated using linear regression analyses and interaction analysis.

Results

In total, 58 patients with communicating hydrocephalus, 57 patients with obstructive hydrocephalus, and 52 controls were analyzed. CBF of the hydrocephalus groups was lower than that of the control group at the shorter PLD. CBF was higher at a longer PLD, with no difference between the hydrocephalus groups and the control group in some regions. The hydrocephalus groups showed a higher ΔCBF compared to the control group. Furthermore, in the left medial watershed (10.6±5.66 vs. 7.01±5.88 mL/100 g/min; P=0.038), communicating hydrocephalus exhibited greater ΔCBF than did obstructive hydrocephalus. ΔCBF of the right posterior external watershed [adjusted β: 0.276; 95% confidence interval (CI): 0.047-0.505; P=0.019] and right parietal cortex (adjusted β: 0.277; 95% CI: 0.056-0.498; P=0.015) in the obstructive hydrocephalus group and ΔCBF of the left internal watershed (adjusted β: 0.274; 95% CI: 0.013-0.536; P=0.040) in the communicating hydrocephalus group were associated with the degree of ventricular dilatation, respectively.

Conclusions

Patients with hydrocephalus showed cerebral regulation in maintaining adequate CBF, resulting in longer arterial transit times. The ability to regulate CBF in brain regions represented by the watershed was associated with the degree of ventricular dilation.

Microcirculatory Impairment and Cerebral Injury in Hydrocephalus and the Effects of Cerebrospinal Fluid Diversion

BACKGROUND AND OBJECTIVES

Hydrocephalus is characterized by progressive enlargement of cerebral ventricles, resulting in impaired microvasculature and cerebral hypoperfusion. This study aimed to demonstrate the microvascular changes in hydrocephalic rats and the effects of cerebrospinal fluid (CSF) release on cerebral blood flow (CBF).

METHODS

On postnatal day 21 (P21), male Wistar rats were intracisternally injected with either a kaolin suspension or saline. On P47, Evan's ratio (ER) was measured using MRI. On P49, the arteriolar diameter and vascular density of the pia were quantified using a capillary video microscope. The CBF was measured using laser Doppler flowmetry. The expressions of NeuN and glial fibrillary acidic protein determined by immunochemical staining were correlated with the ER. The CBF and rotarod test performance were recorded before and after CSF release. The expressions of 4-hydroxynonenal (4-HNE) and c-caspase-3 were studied on P56.

RESULTS

Ventriculomegaly was induced to varying degrees, resulting in the stretching and abnormal narrowing of pial arterioles, which regressed with increasing ER. Quantitative analysis revealed significant decreases in the arteriolar diameter and vascular density in the hydrocephalic group compared with those in the control group. In addition, the CBF in the hydrocephalic group decreased to 30%-50% of that in the control group. In hydrocephalus, the neurons appear distorted, and the expression of 4-HNE and reactive astrogliosis increase in the cortex. After CSF was released, improvements in the CBF and rotarod test performance were inversely associated with the ER. In addition, the levels of 4-HNE and c-caspase-3 were further elevated.

CONCLUSION

Rapid ventricular dilatation is associated with severe microvascular distortion, vascular regression, cortical hypoperfusion, and cellular changes that impair the recovery of CBF and motor function after CSF release. Moreover, CSF release may induce reperfusion injury. This pathophysiology should be taken into account when treating hydrocephalus.

Risk Factors and Clinical Significance of Ultra-Long-Term Microischemia After Intracranial Aneurysm Embolization

INTRODUCTION

This study aimed to explore influencing factors and clinical significance of ultra-long-term microischemia following intracranial aneurysm (IA) embolization and establish a theoretical foundation for reducing both the incidence of ultra-long-term microischemia and cognitive dysfunction in patients post embolization.

METHODS

A retrospective analysis was conducted on data from 147 patients who received endovascular treatment for IAs. Patients were categorized into microischemic and control (non-microischemic) groups on the based on the findings of high-resolution magnetic resonance vessel wall imaging (HR-VWI) examinations performed 3 days postoperatively and 6 months postoperatively. Risk factors for the occurrence of ultra-long-term microischemia were determined by univariate analysis and multivariate logistic regression analysis.

RESULTS

Out of 147 patients included in the study, 51 (34.69%) developed microischemia while the remaining 96 (65.31%) did not experience this condition. Analysis revealed that factors such as sex, age, history of underlying diseases (hypertension, diabetes mellitus), aneurysmal site characteristics, the presence or absence of stenosis in the aneurysm-bearing artery, modified Fisher score at admission, Barthel's index at discharge, immunoinflammatory index at 3 days postoperatively and at the 6-month follow-up, the presence or absence of aneurysmal wall enhancement, and the presence or absence of aneurysmal lumen showed no statistically significant differences between the two groups (all P > 0.05). By contrast, variables like in operative time, rupture status of the aneurysm before surgery according to World Federation of Neurologic Surgeons (WFNS) grade, aneurysm size, number of stents used, number of guidewires and catheters used, and Evans index between the two groups were found to have statistically significant disparities between those who developed microischemia and those who did not (P < 0.05). A subsequent multivariate analysis revealed that aneurysm size, Evans index, and the number of stents used were independent risk factors for the occurrence of ultra-long-term microischemia after surgical intervention of aneurysms (P < 0.05). The receiver operating characteristic (ROC) curves of the patients were constructed on the basis of risk factors determined through multivariate logistic regression analysis. Results indicated that aneurysm size (area under ROC curve (AUC) 0.619, sensitivity 94.7%, specificity 17.1%, P = 0.049), Evans index (AUC 0.670, sensitivity 96.4%, specificity 26.8%, P = 0.004), and number of stents (AUC 0.639, sensitivity 44.6%, specificity 90.2%, P < 0.001) effectively predicted the occurrence of microischemia. The incidence of cognitive dysfunction was higher in the microischemic group than in the control group (P < 0.05), and a greater number of microischemic foci was associated with a higher incidence of cognitive dysfunction. The proportion of microschemia foci in the thalamus and basal ganglia in patients with cognitive dysfunction (60.87%) was significantly higher than that in patients without cognitive dysfunction (34.55%) (P < 0.05).

CONCLUSION

Aneurysm size, Evans index > 0.3, and the quantity of stents were independent risk factors for the occurrence of ultra-long-term microischemia after aneurysm embolization and provided good predictive performance. Cognitive dysfunction was closely associated with microischemia, with its severity increasing with an increase in the number of ischemic foci.

Contemporary management of aneurysmal subarachnoid haemorrhage. An update for the intensivist

Aneurysmal subarachnoid haemorrhage (aSAH) is a rare yet profoundly debilitating condition associated with high global case fatality and morbidity rates. The key determinants of functional outcome include early brain injury, rebleeding of the ruptured aneurysm and delayed cerebral ischaemia. The only effective way to reduce the risk of rebleeding is to secure the ruptured aneurysm quickly. Prompt diagnosis, transfer to specialized centers, and meticulous management in the intensive care unit (ICU) significantly improved the prognosis of aSAH. Recently, multimodality monitoring with specific interventions to correct pathophysiological imbalances has been proposed. Vigilance extends beyond intracranial concerns to encompass systemic respiratory and haemodynamic monitoring, as derangements in these systems can precipitate secondary brain damage. Challenges persist in treating aSAH patients, exacerbated by a paucity of robust clinical evidence, with many interventions showing no benefit when tested in rigorous clinical trials. Given the growing body of literature in this field and the issuance of contemporary guidelines, our objective is to furnish an updated review of essential principles of ICU management for this patient population. Our review will discuss the epidemiology, initial stabilization, treatment strategies, long-term prognostic factors, the identification and management of post-aSAH complications. We aim to offer practical clinical guidance to intensivists, grounded in current evidence and expert clinical experience, while adhering to a concise format.

Post-traumatic hydrocephalus: An overview of classification, diagnosis, treatment, and post-treatment imaging evaluation

The syndrome of post-traumatic hydrocephalus (PTH) has been recognized since Dandy's report in 1914. The pathogenesis of PTH has not been fully clarified. At present, it is believed that the obstacles of cerebrospinal fluid (CSF) secretion, absorption and circulation pathways are the reasons for the development of PTH. However, recent studies have also suggested that the osmotic pressure load of CSF and the pathological changes of CSF dynamics are caused by the development of hydrocephalus. Therefore, a better understanding of the definition, classification, diagnostic criteria, treatment, and evaluation of post-treatment effects of PTH is critical for the effective prevention and treatment of PTH. In this paper, we reviewed the classification and diagnosis of PTH and focused on the treatment and the imaging evaluation of post-treatment effects of PTH. This review might provide a judgment criterion for diagnosis of PTH and a basis for the effective prevention and treatment of PTH in the future.

Emergency Medical Management of Aneurysmal Subarachnoid Hemorrhage

Aneurysmal subarachnoid hemorrhage is a medical emergency that necessitates direct transfer to a tertiary referral center specialized in the diagnosis and treatment of this condition. The initial hours after aneurysmal rupture are critical for patients with aneurysmal subarachnoid hemorrhage, both in terms of rebleeding and combating the effect of early brain injury. No good treatment options are available to reduce the risk of rebleeding before aneurysm occlusion. Lowering the blood pressure may reduce the risk of rebleeding but carries a risk of inducing delayed cerebral ischemia or aggravating the consequences of early brain injury. Early brain injury after aneurysmal rupture has an important effect on final clinical outcome. Proper cerebral perfusion is pivotal in these initial hours after aneurysmal rupture but threatened by complications such as neurogenic pulmonary edema and cardiac stunning, or by acute hydrocephalus, which may necessitate early drainage of cerebrospinal fluid.

Morphometric Study of the Initial Ventricular Indices to Predict the Complications and Outcome of Aneurysmal Subarachnoid Hemorrhage

Objective: Acute hydrocephalus is a common complication in patients with aneurysmal subarachnoid hemorrhage (SAH). Several ventricular indices have been introduced to enable measurements of ventricular morphology. Previously, researchers have showed their diagnostic value for various neurological disorders. In this study, we evaluated the association between ventricular indices and the clinical course, occurrence of complications and outcome of SAH. Methods: A total of 745 SAH patients with available early admission computed tomography scans were included in the analyses. Six ventricular indices (bifrontal, bicaudate, ventricular and third ventricle ratios and Evans’ and Huckman’s indices) were measured. Primary endpoints included the occurrence of cerebral infarctions, in-hospital mortality and a poor outcome at 6 months. Secondary endpoints included different adverse events in the course of SAH. Clinically relevant cut-offs for the indices were determined using receiver operating curves. Univariate analyses were performed. Multivariate analyses were conducted on significant findings in a stepwise backward regression model. Results: The higher the values of the ventricular indices were and the older the patient was, the higher the WFNS and Fisher’s scores were, and the lower the SEBES score was at admission. Patients with larger ventricles showed a shorter duration of intracranial pressure increase > 20 mmHg and required decompressive craniectomy less frequently. Ventricular indices were independently associated with the parameters of inflammatory response after SAH (C-reactive protein in serum and interleukin-6 in cerebrospinal fluid and fever). Finally, there were independent correlations between larger ventricles and all the primary endpoints. Conclusions: The lower risk of intracranial pressure increase and absence of an association with vasospasm or systemic infections during SAH, and the poorer outcome in individuals with larger ventricles might be related to a more pronounced neuroinflammatory response after aneurysmal bleeding. These observations might be helpful in the development of specific medical and surgical treatment strategies for SAH patients depending on the initial ventricle measurements.

Clinical Profile and Outcome in Patients with Spontaneous Subarachnoid Hemorrhage from a South Indian Tertiary Centre: A Prospective Observational Study

Objective Spontaneous subarachnoid hemorrhage (SAH) is a neurological condition that causes significant morbidity and mortality. It is known to have regional differences in its incidence. Indian studies have shown conflicting results about the incidence of aneurysms as the cause of SAH, varying from 35% to 80%. The data available on the epidemiology of spontaneous SAH in the South Indian population are very few. Our study aims to describe the clinical profile of patients presenting with spontaneous SAH to the emergency department in a tertiary center in South India and describe the factors influencing the clinical outcome.

Materials and Methods The study included 75 patients diagnosed with spontaneous SAH in our emergency department. Demographic data, medical history, details about the first medical contact, clinical features at admission, complications during the hospital stay, and interventions underwent were recorded. The study participants were followed-up at 6 weeks after discharge from hospital to assess the neurological outcome based on modified Rankin Scale (mRS) score, using a 9-point questionnaire.

Results Of the 75 patients with spontaneous SAH, the majority were females, and in the age group of 50 to 69 years. The median time to first medical contact was observed to be 2 hours; and SAH was diagnosed at the first medical contact only in 37% of the patients. Hypertension was the most common comorbid condition associated with SAH (53%). Almost 80% of the patients who underwent angiographic studies had aneurysmal SAH (aSAH). Hydrocephalus was the most common complication seen in 37% of the patients, followed by hyponatremia (28%) and vasospasm (25%). At the time of follow-up after 6 weeks, we found that 36% of the patients were having a neurologically favorable outcome with an mRS score of 0 to 2, 8% of patients were having moderate to severe disability (mRS 3 to 5) and were living a dependent life. The mortality rate (mRS 6) was observed to be around 50% (6% lost to follow-up).

Conclusion We observed a relatively higher incidence of aneurysmal rupture among the patients with spontaneous SAH in our region. The misdiagnosis rate at first medical contact was higher. The mortality rate was observed to be around 50% at 6 weeks. Loss of consciousness at ictus, aneurysmal rupture, WFNS grades IV–V, hydrocephalus, vasospasm, hypernatremia, and delayed cerebral ischemia were found to be the mortality predictors in SAH.

White Matter Injury: An Emerging Potential Target for Treatment after Subarachnoid Hemorrhage

Subarachnoid hemorrhage (SAH) refers to vascular brain injury mainly from a ruptured aneurysm, which has a high lifetime risk and imposes a substantial burden on patients, families, and society. Previous studies on SAH mainly focused on neurons in gray matter (GM). However, according to literature reports in recent years, in-depth research on the mechanism of white matter (WM) is of great significance to injury and recovery after SAH. In terms of functional recovery after SAH, all kinds of cells in the central nervous system (CNS) should be protected. In other words, it is necessary to protect not only GM but also WM, not only neurons but also glial cells and axons, and not only for the lesion itself but also for the prevention and treatment of remote damage. Clarifying the mechanism of white matter injury (WMI) and repair after SAH is of great importance. Therefore, this present review systematically summarizes the current research on WMI after SAH, which might provide therapeutic targets for treatment after SAH.

Changes in computed tomography perfusion parameters and maximum contrast enhancement in patients having hydrocephalus with a ventriculoperitoneal shunt: a pilot study

BACKGROUND

Acute hydrocephalus may decrease cerebral perfusion by increasing intracranial pressure. Computed tomography perfusion (CTP) has become a significant adjunct in evaluating regional and global cerebral blood flow (CBF).

PURPOSE

To investigate the changes in cerebral perfusion parameters and maximum contrast enhancement (MCE) in patients with hydrocephalus with ventriculoperitoneal shunt (VPS).

MATERIAL AND METHODS

We performed brain CTP in 45 patients, including those with subarachnoid hemorrhage (SAH)-induced hydrocephalus with VPS (n = 14, G1), hydrocephalus (not related to SAH) with VPS (n = 11, G2), SAH-induced hydrocephalus without VPS (n = 10, G3), and hydrocephalus (not related to SAH) without VPS (n = 10, G4). We measured the cerebral perfusion in the frontal white matter (FWM), centrum semiovale, basal ganglia (BG), and eight cortical lesions of interest and compared the differences in CTP parameters among the groups.

RESULTS

Between the four groups, cerebral blood volume and MCE in the left FWM and CBF in the right FWM increased significantly in G1 and G2 who underwent VP shunt compared to G3 and G4, whereas perfusion significantly reduced in G3 and G4 who did not undergo VP shunt compared to G1 and G2. MCE in the left BG significantly increased in G2 and decreased in G3 and G4. SAH-induced hydrocephalus showed a lower perfusion than hydrocephalus (not related to SAH) in FWM.

CONCLUSIONS

Perfusion changes in patients with hydrocephalus after VP shunt were seen in the FWM and BG, which appears to be the result of the hydrocephalus reducing brain perfusion in the deep part of the brain. We concluded that SAH slows brain perfusion recovery.

Acute hydrocephalus and delayed cerebral infarction after aneurysmal subarachnoid hemorrhage

BACKGROUND

Delayed cerebral infarction (DCIn) following aneurysmal subarachnoid hemorrhage (aSAH) is a major cause of morbi-mortality; yet, the causes for DCIn remain incompletely understood.

OBJECTIVE

We tested the hypothesis that acute hydrocephalus could be related to the occurrence of DCIn, independently of the occurrence and severity of vasospasm.

METHODS

Radiological and clinical data of patients treated at a single large volume academic center for aSAH between 2017 and 2019 were retrospectively analyzed. DCIn was defined as imaging stigma of cerebral infarction visible on 6-week imaging follow-up after aSAH. Hydrocephalus was defined on baseline imaging as a relative bicaudate index above 1. Cerebral vasospasm was defined by reduction of artery diameter in comparison with initial diameter. We used uni- and multivariable models to test the associations between these variables, hydrocephalus and DCIn.

RESULTS

Of 164 included patients, vasospasm occurred in 58 patients (35.4%), and DCIn in 47 (28.7%). Acute hydrocephalus was present in 85 patients (51.8%) on baseline CT. No relation was found between acute hydrocephalus and delayed cerebral infarction in our multivariate analysis (adjusted OR: 1.20 95% CI [0.43-3.37]; p = 0.732). Only vasospasm occurrence was independently associated with DCIn (adjusted OR: 10.97 95% CI [4.60-26.01]).

CONCLUSION

Our study did not show an association between acute hydrocephalus and DCIn after aSAH, after adjustment for the presence and severity of cerebral vasospasm.

Acute paraparesis syndrome after ruptured anterior communicating artery aneurysm

Here, we describe a series of 7 patients who presented with acute paraparesis due to anterior communicating artery aneurysm rupture. This study aimed to assess the clinical and radiological factors associated with acute paraparesis syndrome caused by subarachnoid hemorrhage (SAH).Between June 2005 and December 2012, our institution consecutively treated 210 patients with anterior communicating aneurysm rupture within 24 hours after ictus. We divided the patients into 2 groups based on the presence (n = 7) and absence (n = 203) of acute paraparesis after anterior communicating aneurysm rupture.Diffusion-weighted magnetic resonance imaging revealed high intensity in the medial aspects of the bilateral frontal lobes in 3 patients. The mean third ventricular distance at the time of admission was 9.2 mm (range, 8-12.5 mm), and the mean bicaudate distance was 33.9 mm (range, 24-39 mm). There was a significant difference in the bicaudate distance (P = .001) and third ventricle distance (P = .001) between the 2 groups. Acute hydrocephalus and global cerebral edema (GCE) were confirmed radiologically in all patients in the acute paraparesis group. The presence of acute hydrocephalus (P = .001) and GCE (P = .003) were significantly different between the groups.Acute paraparesis syndrome after SAH is transient and gradually improves if the patient does not develop severe vasospasm. The present study demonstrates that acute paraparesis after SAH is associated with acute hydrocephalus and GCE.

Bumetanide lowers acute hydrocephalus in a rat model of subarachnoid hemorrhage

BACKGROUND

Subarachnoid hemorrhage (SAH) can lead to acute hydrocephalus (AH). AH pathophysiology is classically attributed to an obstruction of the arachnoid granulations by blood. Recent findings in rodents suggest that after intraventricular hemorrhage, AH is related to cerebrospinal fluid (CSF) hypersecretion by the choroid plexus (CP), as it can be reduced by intracerebroventricular (ICV) injection of bumetanide.

OBJECTIVE

Here, we investigated if and how CSF hypersecretion and/or CSF outflow disorders contribute to post-SAH hydrocephalus.

METHODS

Ninety-four Wistar rats were used. SAH was induced by the endovascular perforation technique. The presence of AH was confirmed by magnetic resonance imaging (MRI), and rats with AH were randomly assigned to 4 groups: control group, superior sagittal sinus (SSS) thrombosis to block CSF reabsorption, ICV injection of saline, and ICV injection of bumetanide to decrease CSF secretion. Clinical outcome was evaluated with a neuroscore. A second MRI was performed 24 h later to evaluate the ventricular volume.

RESULTS

Fifty percent of rats that survived SAH induction had AH. Their ventricular volume correlated well to the functional outcome after 24 h (r = 0.803). In rats with AH, 24 h later, ventricular volume remained equally increased in the absence of any further procedure. Similarly, ICV injection of saline or SSS thrombosis had no impact on the ventricular volume. However, ICV injection of bumetanide reduced AH by 35.9% (p = 0.002).

CONCLUSION

In rodents, post-SAH hydrocephalus is may be due to hypersecretion of CSF by the CP, as it is limited by ICV injection of bumetanide. However, we cannot exclude other mechanisms involved in post-SAH acute hydrocephalus.

Spontaneous angiogram-negative subarachnoid hemorrhage: a retrospective single center cohort study

Background

Spontaneous angiogram-negative subarachnoid hemorrhage (SAH) is considered a benign illness with little of the aneurysmal SAH-related complications. We describe the clinical course, SAH-related complications, and outcome of patients with angiogram-negative SAH.

Methods

We retrospectively reviewed all adult patients admitted to a neurosurgical intensive care unit during 2004–2018 due to spontaneous angiogram-negative SAH. Our primary outcome was a dichotomized Glasgow Outcome Scale (GOS) at 3 months. We assessed factors that associated with outcome using multivariable logistic regression analysis.

Results

Of the 108 patients included, 84% had a favorable outcome (GOS 4–5), and mortality was 5% within 1 year. The median age was 58 years, 51% were female, and 93% had a low-grade SAH (World Federation of Neurosurgical Societies grading I–III). The median number of angiograms performed per patient was two. Thirty percent of patients showed radiological signs of acute hydrocephalus, 28% were acutely treated with an external ventricular drain, 13% received active vasospasm treatment and 17% received a permanent shunt. In the multivariable logistic regression model, only acute hydrocephalus associated with unfavorable outcome (odds ratio = 4.05, 95% confidence interval = 1.05–15.73). Two patients had a new bleeding episode.

Conclusion

SAH-related complications such as hydrocephalus and vasospasm are common after angiogram-negative SAH. Still, most patients had a favorable outcome. Only acute hydrocephalus was associated with unfavorable outcome. The high rate of SAH-related complications highlights the need for neurosurgical care in these patients.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00701-021-05069-7.

CSF Secretion Is Not Altered by NKCC1 Nor TRPV4 Antagonism in Healthy Rats

Background: Cerebrospinal fluid (CSF) secretion can be targeted to reduce elevated intracranial pressure (ICP). Sodium-potassium-chloride cotransporter 1 (NKCC1) antagonism is used clinically. However, supporting evidence is limited. The transient receptor potential vanilloid-4 (TRPV4) channel may also regulate CSF secretion and ICP elevation. We investigated whether antagonism of these proteins reduces CSF secretion. Methods: We quantified CSF secretion rates in male Wistar rats. The cerebral aqueduct was blocked with viscous mineral oil, and a lateral ventricle was cannulated. Secretion rate was measured at baseline and after antagonist administration. Acetazolamide was administered as a positive control to confirm changes in CSF secretion rates. Results: Neither NKCC1, nor TRPV4 antagonism altered CSF secretion rate from baseline, n = 3, t(2) = 1.14, p = 0.37, and n = 4, t(3) = 0.58, p = 0.6, respectively. Acetazolamide reduced CSF secretion by ~50% across all groups, n = 7, t(6) = 4.294, p = 0.005. Conclusions: Acute antagonism of NKCC1 and TRPV4 proteins at the choroid plexus does not reduce CSF secretion in healthy rats. Further investigation of protein changes and antagonism should be explored in neurological disease where increased CSF secretion and ICP are observed before discounting the therapeutic potential of protein antagonism at these sites.

Hydrocephalus Following Experimental Subarachnoid Hemorrhage in Rats with Different Aerobic Capacity

Low aerobic capacity is considered to be a risk factor for stroke, while the mechanisms underlying the phenomenon are still unclear. The current study looked into the impacts of different aerobic capacities on early brain injury in a subarachnoid hemorrhage (SAH) model using rats bred for high and low aerobic capacity (high-capacity runners, HCR; low-capacity runners, LCR). SAH was modeled with endovascular perforation in HCR and LCR rats. Twenty-four hours after SAH, the rats underwent behavioral testing and MRI, and were then euthanized. The brains were used to investigate ventricular wall damage, blood-brain barrier breakdown, oxidative stress, and hemoglobin scavenging. The LCR rats had worse SAH grades (p < 0.01), ventricular dilatation (p < 0.01), ventricular wall damage (p < 0.01), and behavioral scores (p < 0.01). The periventricular expression of HO-1 and CD163 was significantly increased in LCR rats (p < 0.01 each). CD163-positive cells were co-localized with HO-1-positive cells. The LCR rats had greater early brain injuries than HCR rats. The LCR rats had more serious SAH and extensive ventricular wall damage that evolved more frequently into hydrocephalus. This may reflect changes in iron handling and neuroinflammation.

Optimal timing and safety of the external ventricular drainage in patients with high-grade aneurysmal subarachnoid hemorrhage treated with endovascular coiling

The presented retrospective analysis has evaluated the optimal timing and safety of external ventricular drainage (EVD) for acute hydrocephalus after aneurysmal subarachnoid hemorrhage (aSAH). The study cohort comprised 102 patients, 49 of whom underwent EVD at 3-120 h (mean, 16 h) after the clinical onset of aSAH, either before (N = 27) or after (N = 22) ruptured aneurysm coiling. Among those treated with EVD, favorable and fair outcomes at discharge (modified Rankin Scale [mRS] scores 0-3) were noted in 14 (29%) and unfavorable (mRS scores 4-6) in 35 (71%). The former was more common among women (P = 0.019) and patients without chronic arterial hypertension (P = 0.028). The cut-off value for optimal timing of EVD was defined at 13 h after the onset of aSAH. Favorable and fair outcomes were more frequent after early (≤13 h; N = 30) than late (>13 h; N = 19) EVD (40% vs. 11%; P = 0.026), whereas did not differ significantly between those in whom such procedure was done before or after ruptured aneurysm coiling (19% vs. 41%; P = 0.083). In the entire study cohort, 2 patients had re-rupture of the aneurysm, and while both of them were treated with EVD, neither case of complication was directly associated with the procedure and, in fact, preceded it. In conclusion, EVD for management of acute hydrocephalus in patients with high-grade aSAH should be preferably applied within 13 h after the clinical onset of stroke, which may be considered sufficiently safe regardless whether it is performed before or after ruptured aneurysm coiling.

Risk factors of chronic shunt dependent hydrocephalus following aneurysmal subarachnoid haemorrhage

BACKGROUND

Acute and delayed hydrocephalus are common sequelae following aneurysmal subarachnoid haemorrhage.

AIMS

To identify factors that may influence cerebrospinal fluid diversion either temporarily or permanently in order to guide clinical judgement.

METHODS

Patients treated in our unit between 01/2014 until 12/2017 with aneurysmal SAH were retrospectively analysed to identify significant factors predisposing to CSF diversion.

RESULTS

242 patients were analysed (180F, 62M) with mean age 56 years over 36 months. 31 % patients had EVD inserted and 12 % received shunts. 19 patients had EVDs prior to their shunt. 11.8 % patients received serial lumbar puncture. Higher WFNS (P<0.05) and Fisher grade (P<0.05) were associated with increased rates of EVD insertion and shunting. Higher WFNS and Fisher scores were observed within posterior circulation aneurysms. Lower GCS and higher WFNS had significant correlation towards early shunting (P<0.05). EVD infection predisposes to higher rates of shunt conversion (P<0.05). Factors predisposing to post aneurysmal subarachnoid haemorrhage hydrocephalus and CSF drainage included aneurysm location in posterior circulation (P<0.05), increasing relative need of EVD insertion by 185 % and shunting by 240 %. Basilar tip aneurysms had even higher incidence of shunting (42 % of all posterior circulation aneurysms). Posterior circulation aneurysms had significantly higher risk of requiring EVD insertion, with 48 % of aneurysms in the posterior circulation compared to 25 % in the anterior circulation requiring EVDs (P<0.05). Incidence of posterior circulation aneurysms increases with age (>50(P<0.05)).

CONCLUSION

Our study demonstrated factors that may predict chronic post aneurysmal subarachnoid haemorrhage hydrocephalus (PASHH) in patients that will ultimately need timely intervention.

Acute communicating hydrocephalus caused by extravasation of digital subtraction angiography contrast medium: a case report and literature review

With the increasing use of endovascular technology in the treatment of various conditions, there has been an inevitable rise in cases with extravasation of contrast medium. We present a case in which extravasation of a large quantity of contrast medium resulted in acute communicating hydrocephalus. A 78-year-old woman came to the hospital because of abnormal right-sided limb movement, and was diagnosed with occlusion of the left internal carotid artery. The patient underwent timely intra-arterial mechanical thrombectomy. Postoperative computed tomography (CT) examination revealed a high-density shadow of the left basal ganglia and left frontal lobe. Twelve hours later, the patient fell into a coma. Repeat head CT indicated acute hydrocephalus with no evidence of obstruction. The patient underwent emergency external ventricular drainage, and the drainage fluid was observed to be clear. The patient regained consciousness after the procedure and the drainage tube was removed 4 days later. The patient had no recurrence of hydrocephalus. The mechanisms and treatment of this condition are discussed.

Activation of epiplexus macrophages in hydrocephalus caused by subarachnoid hemorrhage and thrombin

Aims

We have found that hydrocephalus development in spontaneously hypertensive rats was associated with activation of epiplexus cells. The current study examined whether epiplexus cell activation occurs in a rat subarachnoid hemorrhage (SAH), whether activation would be greater in a subset of rats that developed hydrocephalus and the potential role of thrombin in epiplexus cell activation.

Methods

There were two parts in this study. First, an endovascular perforation was performed in rats to induce SAH. Second, rats received an intraventricular infusion of either thrombin or saline. Magnetic resonance imaging was used to measure the ventricular volumes. Immunofluorescence and immunohistochemistry were used to study epiplexus cell activation.

Results

Iba‐1, OX‐6, and CD68 were expressed in the epiplexus cells of the choroid plexus in sham‐operated rats. SAH increased Iba‐1 and CD68 immunoreactivity in epiplexus cells in addition to an increase in Iba‐1‐positive cell soma size. Those effects were greater in rats that developed hydrocephalus. Intraventricular thrombin mimicked the effects of SAH on epiplexus cell activation and hydrocephalus.

Conclusion

This study supports the concept that epiplexus cell activation is associated with hydrocephalus development. Epiplexus cell activation may be in response to thrombin production after hemorrhage, and it may be a therapeutic target.

Cerebrospinal fluid dynamics and intracranial pressure elevation in neurological diseases

The fine balance between the secretion, composition, volume and turnover of cerebrospinal fluid (CSF) is strictly regulated. However, during certain neurological diseases, this balance can be disrupted. A significant disruption to the normal CSF circulation can be life threatening, leading to increased intracranial pressure (ICP), and is implicated in hydrocephalus, idiopathic intracranial hypertension, brain trauma, brain tumours and stroke. Yet, the exact cellular, molecular and physiological mechanisms that contribute to altered hydrodynamic pathways in these diseases are poorly defined or hotly debated. The traditional views and concepts of CSF secretion, flow and drainage have been challenged, also due to recent findings suggesting more complex mechanisms of brain fluid dynamics than previously proposed. This review evaluates and summarises current hypotheses of CSF dynamics and presents evidence for the role of impaired CSF dynamics in elevated ICP, alongside discussion of the proteins that are potentially involved in altered CSF physiology during neurological disease. Undoubtedly CSF secretion, absorption and drainage are important aspects of brain fluid homeostasis in maintaining a stable ICP. Traditionally, pharmacological interventions or CSF drainage have been used to reduce ICP elevation due to over production of CSF. However, these drugs are used only as a temporary solution due to their undesirable side effects. Emerging evidence suggests that pharmacological targeting of aquaporins, transient receptor potential vanilloid type 4 (TRPV4), and the Na+-K+-2Cl- cotransporter (NKCC1) merit further investigation as potential targets in neurological diseases involving impaired brain fluid dynamics and elevated ICP.

Ischemic Lesions in Acute and Subacute Perimesencephalic Subarachnoid Hemorrhage

OBJECTIVE

Perimesencephalic hemorrhage (PMH) is a subtype of nonaneurysmal subarachnoid hemorrhage (SAH). In patients with aneurysmal SAH, the occurrence of acute ischemic lesions is associated with severity and poor outcome. We investigated the frequency of ischemic lesions on DWI in patients with PMH and compared it with the frequency of ischemic lesions in patients with aneurysmal SAH.

SUBJECTS AND METHODS

From a prospective cohort of 80 patients with acute spontaneous SAH, we included 15 patients with PMH and 39 patients with aneurysmal SAH who were matched on the basis of their clinical condition (World Federation of Neurological Societies grade 1 or 2). MRI was performed less than 72 hours after SAH, 8-10 days after SAH, or at both points in time. The number and distribution of lesions previously seen on DWI that were also seen on a second MRI examination were assessed. Nonparametric tests were used to compare groups.

RESULTS

Early acute ischemic lesions (those identified < 72 hours after SAH) were found in 46.2% of patients with PMH and in 62.9% of patients with aneurysmal SAH. No significant differences in the number of acute ischemic lesions between groups were noted less than 72 hours after SAH (median, 0.5 lesion [interquartile range {IQR}, two lesions] in patients with PMH vs one lesion [IQR, three lesions] in patients with aneurysmal SAH [p = 0.48] or 8-10 days after SAH (median, 0.5 lesion [IQR, four lesions] in patients with PMH vs 1.5 lesions [IQR, three lesions] in patients with aneurysmal SAH [p = 0.26]). However, 58.3% of patients with aneurysmal SAH had new infarcts at 8-10 days, compared with 7.1% of patients with PMH. Patients with PMH had diffuse ischemic lesions, whereas patients with aneurysmal SAH in the anterior circulation had mainly supratentorial lesions.

CONCLUSION

Early ischemic lesions appeared on DWI both in patients with PMH and in patients with aneurysmal SAH. The number of lesions increased during the time window for vasospasm, mainly in patients with aneurysmal SAH. Further studies are required to better understand the pathophysiologic mechanisms behind early ischemia in patients with PMH and their impact on prognosis.

Prospective Multicenter Study of Changes in MTT after Aneurysmal SAH and Relationship to Delayed Cerebral Ischemia in Patients with Good- and Poor-Grade Admission Status

BACKGROUND AND PURPOSE

Patients with aneurysmal SAH and good clinical status at admission are considered at a lower risk for delayed cerebral ischemia. Prolonged MTT may be associated with an increased risk. It is unclear whether this is dependent on clinical status. Our purpose was to determine whether increased MTT within 3 days of aneurysmal SAH compared with baseline is associated with a higher risk of delayed cerebral ischemia in patients with good (World Federation of Neurosurgical Societies I-III) versus poor (World Federation of Neurosurgical Societies IV-V) admission status.

MATERIALS AND METHODS

This prolonged MTT was a multicenter, prospective cohort investigation of 87 patients with aneurysmal SAH. MTT was measured at admission before aneurysm treatment (MTT1) and following repair (MTT2) within 3 days of admission; MTT_diff was calculated as the difference between MTT2 and MTT1. Changes in MTT across time were assessed with repeated measures analyses. Risk of delayed cerebral ischemia or death was determined with multivariate logistic regression analysis.

RESULTS

In patients with a good grade (n = 49), MTT was prolonged in patients who developed delayed cerebral ischemia, with MTT_diff significantly greater (0.82 ± 1.5) compared with those who did not develop delayed cerebral ischemia (-0.14 ± 0.98) (P = .03). Prolonged MTT was associated with a significantly higher risk of delayed cerebral ischemia or death (OR = 3.1; 95% CI, 1.3-7.4; P = .014) on multivariate analysis. In patients with poor grades (n = 38), MTT_diff was not greater in patients who developed delayed cerebral ischemia; MTT1 was significantly prolonged compared with patients with a good grade.

CONCLUSIONS

Patients in good clinical condition following aneurysmal SAH but with increasing MTT in the first few days after aneurysmal SAH are at high risk of delayed cerebral ischemia and warrant close clinical monitoring.

Effect of Intracranial Pressure Control on Improvement of Cerebral Perfusion After Acute Subarachnoid Hemorrhage: A Comparative Angiography Study Based on Temporal Changes of Intracranial Pressure and Systemic Pressure

OBJECTIVE

Increased intracranial pressure (ICP) is a well-known complication after aneurysmal subarachnoid hemorrhage (aSAH). This study focused on the different temporal changes in ICP, mean arterial pressure, and cerebral perfusion pressure at the early stage of aSAH, throughout aneurysm embolization, and their effects on improvement in angiographic perfusion patterns.

METHODS

Twenty-seven patients with aSAH were evaluated who underwent coiling and cerebrospinal fluid (CSF) drainage. Diagnostic angiography was performed to confirm the presence and location of the vascular lesion. The transit time of the capillary filling phase was defined as a surrogate of cerebral perfusion. Capillary filling transit times were compared before and after CSF drainage. Univariate and multivariate analyses were performed to identify associations between different physical parameters and capillary filling transit times.

RESULTS

By univariate analysis, average capillary transit time before CSF drainage had a significant correlation with initial ICP (P = 0.0004; R² = 0.398) but not systemic pressure (mean arterial pressure or cerebral perfusion pressure). Improvement in capillary filling pattern (i.e., a decrease in angiographic capillary transit time after CSF drainage) was seen in patients with high initial ICP and correlated with ICP difference after ventricular drainage (P = 0.0001 and P < 0.0001, respectively). Using multivariate regression analysis, improved control in postprocedural ICP levels significantly correlated with angiographic evidence of improved cerebral perfusion (P = 0.0243).

CONCLUSIONS

Decreasing ICP by CSF drainage strongly correlated with improved cerebral microcirculation after aSAH. Further development of ICP control protocols that can provide better ICP management of patients with aSAH is warranted.

Comparison of cerebral perfusion in perimesencephalic subarachnoid hemorrhage and aneurysmal subarachnoid hemorrhage

PURPOSE

Perimesencephalic hemorrhage (PMH) is a benign subtype of nonaneurysmal subarachnoid hemorrhage (SAH). We aimed to investigate if cerebral perfusion in PMH is less affected than in aneurysmal SAH (aSAH).

METHODS

From a prospective cohort of 80 patients with spontaneous SAH, we included PMH patients (n = 15) and selected aSAH patients (n = 39) with similar clinical grade at admission (World Federation of Neurosurgeons Scale-WFNS I/II). Computed tomography (CT) perfusion was performed at < 72 h and/or at 8-10 days. Cerebral perfusion parameter values were compared between groups with nonparametric tests. Subgroup analyses compared PMH and aSAH patients stratified according to aneurysmal location (anterior or posterior circulation) and blood burden (Fisher grade).

RESULTS

At < 72 h, no significant differences in perfusion parameters were found between PMH and aSAH patients. At 8-10 days, PMH patients had lower MTT than aSAH patients, and a trend for higher CBF. PMH patients had higher CBF and CBV at < 72 h when compared to posterior circulation aSAH patients. When compared to aSAH patients with similar blood burden, PMH patients had higher CBF and lower MTT at < 72 h, and lower MTT at 8-10 days.

CONCLUSION

PMH patients had better cerebral perfusion compared to patients with aSAH, particularly during the vasospasm time window. After stratifying for the amount of blood, PMH patients also had better cerebral perfusion in the first 72 h after SAH. These results are in line with the better clinical presentation and prognosis of PMH, and possibly with a different etiology.

Apolipoprotein E ε4: A Possible Risk Factor of Intracranial Pressure and White Matter Perfusion in Good-Grade Aneurysmal Subarachnoid Hemorrhage Patients at Early Stage

Aneurysmal subarachnoid hemorrhage (aSAH) is a devastating and complicated disease with significant morbidity and mortality. Previous studies have shown that genetic susceptibility may play an important role in the outcome of a given individual with aSAH. This study evaluates the potential association in effects of the APOE allele on the early brain injury (EBI) in light of elevated intracranial pressure (ICP) and cerebral perfusion disorders in a consecutive series of non-comatose Chinese patients with aSAH. A total of 122 patients with aSAH (54 males and 68 females) were enrolled in this study. Demographic and clinical data were collected. We measured ICP before microsurgical clipping or endovascular coiling during the first 72 h after aneurysm rupture. Computed tomography perfusion (CTP) examination in patients was performed before treatment. The distributions of APOE genotypes and alleles matched Hardy–Weinberg law (p > 0.05). In this study, 68 patients (55.7%) had a normal ICP, whereas 54 (44.3%) had an elevated ICP. Fourteen of 21 patients with APOE ε4 had an elevated ICP, which was significantly different from those without APOE ε4 (p = 0.03). The patients with the ε4 allele had a higher incidence of elevated ICP [p = 0.009, 95% confidence interval (CI) = 1.481–15.432, odds ratio = 4.780] than those without this allele. For CTP measurements, a lower mean cerebral blood flow (difference, −4.74; 95% CI, 0.53–8.94 s, p = 0.03), longer mean transit time (difference, 0.47; 95% CI, −0.87 to −0.78, p = 0.02), and time-to-peak (difference, 2.29; 95% CI, −3.64 to −0.93 s, p = 0.02) were observed in patients with ε4 allele than in those without in the internal capsule regions. In conclusion, the APOE ε4 allele predisposes patients to elevated ICP and perfusion disorders in white matter regions during the first 72 h after aSAH. The presence of an APOE ε4 allele plays an important role in the EBI response to aSAH.

Hydrocephalus after Subarachnoid Hemorrhage: Pathophysiology, Diagnosis, and Treatment

Hydrocephalus (HCP) is a common complication in patients with subarachnoid hemorrhage. In this review, we summarize the advanced research on HCP and discuss the understanding of the molecular originators of HCP and the development of diagnoses and remedies of HCP after SAH. It has been reported that inflammation, apoptosis, autophagy, and oxidative stress are the important causes of HCP, and well-known molecules including transforming growth factor, matrix metalloproteinases, and iron terminally lead to fibrosis and blockage of HCP. Potential medicines for HCP are still in preclinical status, and surgery is the most prevalent and efficient therapy, despite respective risks of different surgical methods, including lamina terminalis fenestration, ventricle-peritoneal shunting, and lumbar-peritoneal shunting. HCP remains an ailment that cannot be ignored and even with various solutions the medical community is still trying to understand and settle why and how it develops and accordingly improve the prognosis of these patients with HCP.

MRI Characterization in the Acute Phase of Experimental Subarachnoid Hemorrhage

A number of mechanisms have been proposed for the early brain injury after subarachnoid hemorrhage (SAH). In this study, we investigated the radiographic characteristics and influence of gender on early brain injury after experimental SAH. SAH was induced by endovascular perforation in male and female rats. Magnetic resonance imaging was performed in a 7.0-T Varian MR scanner at 24 h after SAH. The occurrence and size of T2 lesions, ventricular dilation, and white matter injury (WMI) were determined on T2-weighted images (T2WI). The effects of SAH on heme oxygenase-1 and fibrin/fibrinogen were examined by Western blotting and immunohistochemistry. SAH severity was assessed using a MRI grading system, and neurological function was evaluated according to a modified Garcia's scoring system. T2 hyperintensity areas and enlarged ventricles were observed in T2WI coronal sections 24 h after SAH. The overall incidence of T2 lesions, WMI, and hydrocephalus was 54, 20, and 63%, respectively. Female rats had a higher incidence of T2 hyperintensity lesions and hydrocephalus, as well as larger T2 lesion volumes and higher average ventricular volume. SAH rats graded at 3-4 (our previously validated MRI grading scale) had larger T2 lesion volumes, more hydrocephalus, and worse neurological function compared with those graded at 0-2. In conclusion, T2 lesion, WMI, and hydrocephalus were the most prevalent MRI characteristics 24 h after experimental SAH. The T2 lesion area matched with fibrinogen/fibrin positive staining in the acute phase of SAH. SAH induced more severe brain injury in females compared to males in the acute phase of SAH.

Prognostic Assessment of Aneurysmal Subarachnoid Patients with WFNS Grade V by CT Perfusion on Arrival

BACKGROUND

The prognosis of patients with aneurysmal subarachnoid hemorrhage (aSAH) depends on their condition on arrival at the hospital. However, a small number of patients recover from an initially poor condition. We investigated the correlation between quantitative measures of computed tomography (CT) perfusion (CTP) on arrival and the outcomes of patients with World Federation of Neurosurgical Society (WFNS) grade V aSAH.

METHODS

We performed plain CT, CTP, and CT angiography (CTA) in all patients with aSAH on arrival. Aneurysms were surgically obliterated in patients with stable vital signs and the presence of a brain stem response. We measured the average mean transit time (aMTT) and compared it with the modified Rankin Scale (mRS) score at 1 month. Regions of interest were identified as 24 areas in the bilateral anterior, middle, and posterior cerebral artery territories and 2 areas in the basal ganglia.

RESULTS

A total of 57 patients were treated between 2007 and 2014. None of the 21 patients with aMTT >6.385 seconds achieved a favorable outcome, whereas 8 of the 36 patients with aMTT <6.385 seconds did achieve a favorable outcome (P = 0.015). Furthermore, comparing the number of areas showing a mean transit time (MTT) >7.0 seconds among the aforementioned 8 areas and mRS, favorable outcomes were not seen in 24 patients with more than 2 such areas (P = 0.009).

CONCLUSION

We cannot expect a favorable outcome for patients with WFNS grade V aSAH with aMTT >6.385 seconds or more than 2 of 8 areas with MTT >7.0 seconds.

The Effect of Gender on Acute Hydrocephalus after Experimental Subarachnoid Hemorrhage

Acute hydrocephalus is a common complication of subarachnoid hemorrhage (SAH). We investigated the effect of gender on acute hydrocephalus development in a rat SAH model. SAH was induced in adult male and female Sprague-Dawley rats using endovascular perforation. Sham rats underwent the same procedure without perforation. Magnetic resonance imaging (MRI) was performed 24 h after SAH to determine ventricular volume. Hydrocephalus was defined as a ventricular volume that was more than 3 standard deviations from the mean value in sham-operated animals. After MRI, animals were euthanized and the extent of SAH was assessed using a modified grading system. No sham animals died. Mortality rates after SAH induction in male and female animals were 27 and 22 %, respectively. SAH induced significant ventricular enlargement compared with sham-operated rats (p < 0.01). The T2* hypointensity volume in the ventricle (used to assess intraventricular blood) was correlated with ventricular volume after SAH (r = 0.33, p < 0.05). The incidence of acute hydrocephalus 24 h after SAH was greater in female (75 %) than in male animals (47 %, p < 0.05) and the relative changes in ventricular volume were significantly larger in female than in male rats (292 ± 150 % vs 216 ± 127 % of sham-operated animals, respectively, p < 0.05). The increased hydrocephalus occurred even though SAH severity grade and ventricular T2* hypointensity volumes were not significantly different between male and female animals. Our data demonstrate that gender influences acute hydrocephalus development in a rat SAH model. Future studies should determine the role of estrogen in SAH-induced hydrocephalus.

Intraventricular Injection of Noncellular Cerebrospinal Fluid from Subarachnoid Hemorrhage Patient into Rat Ventricles Leads to Ventricular Enlargement and Periventricular Injury

Early brain injury and hydrocephalus (HCP) are important mediators of poor outcome in subarachnoid hemorrhage (SAH) patients. We aim to understand the development of HCP and subependymal cellular injury after intraventricular injection of noncellular human SAH cerebrospinal fluid (CSF) into rat ventricles. Two-hundred microliters of noncellular CSF from SAH patients or normal controls were injected into the right lateral ventricle of seven adult male Sprague-Dawley rats. Propidium iodide (PI) was simultaneously injected to detect necrotic cellular death. Rats were then sacrificed 24 h after surgery and the brain specimens were cut and stained for heme oxygenase 1 (HO-1), an oxidative stress marker. We found that the ventricular area at the bregma level in the CSF injection group was significantly larger than that in the control group (p < 0.05). The periventricular tissue in the CSF injection group had significantly more necrotic cell death as well as HO-1 expression as compared with the control group (p < 0.05). In conclusion, injection of SAH patients' CSF into the rat ventricle leads to HCP as well as subependymal injury compared with injection of control CSF.

Expression of transferrin in hematoma brain tissue at different stages after intra cerebral hemorrhage in rats

OBJECTIVE

To explore the expression of transferrin (Tf) and transferrin receptor (TfR) in hematoma brain tissue at different stage after intracerebral hemorrhage (ICH) in rats.

METHODS

ICH rats model were established by collagenase method, and rats were sacrificed at 24 h, 72 h, 7 d and 14 d after operation. The levels of Tf and TfR in different periods of rats were detected by immunohistochemical method, and correlation between two groups was analyzed.

RESULTS

Tf, TfR-positive cells at each time after operation in observation group were significantly higher than that in control group (P < 0.05). Tf, TfR-positive cells began to increase from 24 h after the operation and reached the peak 72 h-7 d after surgery, but then gradually decreased. Tf was mainly expressed in nucleus and cytoplasm of neurons and glial cells around the hematoma, but TfR was mainly expressed in nucleus and cytoplasm of neurons and choroid plexus endothelial cells. Correlation analysis showed that the Tf-positive cell was significantly positively correlated with TfR-positive cell expression (r = 0.447, P = 0.022).

CONCLUSIONS

Tf and TfR were important transporters in brain tissue excessive load iron transport after ICH, and detecting the expression levels of the two indicators can provide a reference for prognosis treatment in ICH.

Evaluating CT Perfusion Deficits in Global Cerebral Edema after Aneurysmal Subarachnoid Hemorrhage

BACKGROUND AND PURPOSE

Global cerebral edema is an independent predictor of mortality and poor outcomes after aneurysmal SAH. Global cerebral edema, a complex disease process, is thought to be associated with an altered cerebral autoregulatory response. We studied the association between cerebral hemodynamics and early global cerebral edema by using CTP.

MATERIALS AND METHODS

We retrospectively studied consecutive patients with aneurysmal SAH with admission CTP performed at days 0-3. Two neuroradiologists classified global cerebral edema and hydrocephalus on NCCT performed concurrently with CTP. Global cerebral edema was defined as diffuse effacement of the sulci and/or basal cisterns or diffuse disruption of the cerebral gray-white matter junction. CTP was postprocessed into CBF and MTT maps by using a standardized method. Quantitative analysis of CTP was performed by using standard protocol with ROI sampling of the cerebral cortex. The Fisher exact test, Mann-Whitney test, and independent-samples t test were used to determine statistical associations.

RESULTS

Of the 45 patients included, 42% (19/45) had global cerebral edema and 58% (26/45) did not. Patient groups with and without global cerebral edema were well-matched for demographic and clinical data. Patients with global cerebral edema were more likely to have qualitative global CTP deficits than those without global cerebral edema (P = .001) with an OR = 13.3 (95% CI, 2.09-138.63). Patients with global cerebral edema also had a very strong trend toward statistical significance, with reduced quantitative CBF compared with patients without global cerebral edema (P = .064).

CONCLUSIONS

Global perfusion deficits are significantly associated with global cerebral edema in the early phase after aneurysmal SAH, supporting the theory that hemodynamic disturbances occur in global cerebral edema.

The value of perfusion computed tomography (PCT) imaging after aneurysmal subarachnoid hemorrhage: a review of the current data

BACKGROUND AND PURPOSE

The estimation of the extent of early brain injury (EBI) and sensitive detection of delayed cerebral ischemia (DCI) remains a major challenge in the context of aneurysmal subarachnoid hemorrhage (aSAH). Cerebral perfusion computed tomography (PCT) imaging is increasingly used as an additional diagnostic tool to monitor early brain injury as well as delayed cerebral ischemia after aSAH. Here, we review the current literature as well as the resulting implications and illustrate our institutional experience with PCT imaging in this context.

METHODS

The current literature on PCT imaging for SAH was identified based on a search of the PubMed database. Patient cohorts were dichotomized according to the time of PCT after ictus into early PCT (<72 h after ictus) and subsequent PCT (>72 h after ictus). The specific aspects and findings of PCT at different times are compared and discussed.

RESULTS

Sixteen relevant publications were identified, nine of which focused on early PCT and seven on subsequent PCT diagnostics after aSAH. Early PCT provided relevant details on the extent of EBI and identified patients at risk for developing DCI, whereas subsequent PCT imaging facilitated the monitoring and detection of DCI.

CONCLUSIONS

The present review demonstrates that PCT imaging is able to detect EBI as well as DCI in patients experiencing aSAH. As a consequence, this technique should be routinely implemented in monitoring strategies for this patient population.

Aneurysmal subarachnoid hemorrhage: pathobiology, current treatment and future directions

Aneurysmal subarachnoid hemorrhage is the most devastating form of stroke. Many pathological mechanisms ensue after cerebral aneurysm rupture, including hydrocephalus, apoptosis of endothelial cells and neurons, cerebral edema, loss of blood-brain barrier, abnormal cerebral autoregulation, microthrombosis, cortical spreading depolarization and macrovascular vasospasm. Although studied extensively through experimental and clinical trials, current treatment guidelines to prevent delayed cerebral ischemia is limited to oral nimodipine, maintenance of euvolemia, induction of hypertension if ischemic signs occur and endovascular therapy for patients with continued ischemia after induced hypertension. Future investigations will involve agents targeting vasodilation, anticoagulation, inhibition of apoptosis pathways, free radical neutralization, suppression of cortical spreading depolarization and attenuation of inflammation.

Near-infrared transillumination back scattering sounding--new method to assess brain microcirculation in patients with chronic carotid artery stenosis

Purpose

The purpose of the study was to assess the responses of pial artery pulsation (cc-TQ) and subarachnoid width (sas-TQ) to acetazolamide challenge in patients with chronic carotid artery stenosis and relate these responses to changes in peak systolic velocity (PSV), cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT) and time to peak response (TTP).

Methods

Fifteen patients with carotid artery stenosis ≥90% on the ipsilateral side and <50% on the contralateral side were enrolled into the study. PSV was assessed using colour-coded duplex sonography, CBF, CBV, MTT and TTP with perfusion computed tomography, cc-TQ and sas-TQ with near-infrared transillumination/backscattering sounding (NIR-T/BSS).

Results

Based on the ipsilateral/contralateral cc-TQ ratio after acetazolamide challenge two groups of patients were distinguished: the first group with a ratio ≥1 and the second with a ratio <1. In the second group increases in CBF and CBV after the acetazolamide test were significantly higher in both hemispheres (ipsilateral: +33.0%±8.1% vs. +15.3%±4.4% and +26.3%±6.6% vs. +14.3%±5.1%; contralateral: +26.8%±7.0% vs. +17.6%±5.6% and +20.0%±7.3% vs. +10.0%±3.7%, respectively), cc-TQ was significantly higher only on the ipsilateral side (+37.3%±9.3% vs. +26.6%±8.6%) and the decrease in sas-TQ was less pronounced on the ipsilateral side (−0.7%±1.5% vs. −10.2%±1.5%), in comparison with the first group. The changes in sas-TQ following the acetazolamide test were consistent with the changes in TTP.

Conclusions

The ipsilateral/contralateral cc-TQ ratio following acetazolamide challenge may be used to distinguish patient groups characterized by different haemodynamic parameters. Further research on a larger group of patients is warranted.

Cerebral CT Perfusion in Patients with Perimesencephalic and Those with Aneurysmal Subarachnoid Hemorrhage

Background

The cause of perimesencephalic hemorrhage is unknown, but a venous source is suggested. If perimesencephalic hemorrhage is of venous origin, less elevation of the intracranial pressure and less perfusion deficits are expected than after aneurysmal subarachnoid hemorrhage.

Aims

We compared perfusion in the acute stage after perimesencephalic hemorrhage and aneurysmal subarachnoid hemorrhage.

Methods

We included 45 perimesencephalic hemorrhage patients and 45 aneurysmal subarachnoid hemorrhage patients, who were matched on clinical condition at admission and underwent computerized tomographic scanning <72 h after subarachnoid hemorrhage. Cerebral blood flow was assessed in 12 predefined regions of interest. Differences in cerebral blood flow values with corresponding 95% confidence intervals were calculated. Sub-group analyses were performed stratified on comparable amounts of blood and location of blood (posterior circulation aneurysms and additionally in infratentorial and supratentorial aneurysms).

Results

Cerebral blood flow was higher in perimesencephalic hemorrhage patients (mean: 63·8) than in aneurysmal subarachnoid hemorrhage patients (mean: 55·9; difference of means: −7·9 [95% confidence interval: −10·7 to −5·2]) and also in the sub-group with comparable amounts of blood (mean cerebral blood flow: 56·4; difference of means: −7·4 [95% confidence interval: −10·4 to −4·3]). Cerebral blood flow was comparable with perimesencephalic hemorrhage patients for the sub-group with posterior circulation aneurysms (difference of means: −0·7 [95% confidence interval: −5·2 to 3·8]); however, differences diverged after stratifying posterior circulation aneurysms into supratentorial (difference of means −3·9 [95% confidence interval: −9·3 to 1·4]) and infratentorial aneurysms (difference of means 3·0 [95% confidence interval: −2·8 to 8·8]).

Conclusion

Perimesencephalic hemorrhage patients have a higher cerebral blood flow than aneurysmal subarachnoid hemorrhage patients. The findings of this study further support a venous origin of bleeding in perimesencephalic hemorrhage patients. Future studies should further elaborate on cerebral blood flow in posterior circulation aneurysms.

CT evaluation of lateral ventricular dilatation after subarachnoid hemorrhage: baseline bicaudate index values [correction of balues]

OBJECTIVES

To define baseline bicaudate index (BCI) values in patients with subarachnoid hemorrhage (SAH).

METHODS

We reviewed the clinical and radiological information on consecutive adult patients admitted with acute SAH to our hospital between 1 January 2002 and 1 January 2008. Patients without diagnosis of acute hydrocephalus were entered into this study. Age-stratified BCI values were calculated.

RESULTS

Our study cohort comprised 108 patients (66 women, 61%). The clinical status at presentation was excellent with a median score of 1 on the World Federation of Neurological Surgeons Scale. Cisternal blood burden was mild to moderate with a median Hijdra score of 17 (out of 30). The upper limits of normal (ninety-fifth percentile) for BCI were 0·12 at age 45 years and under, 0·14 at 55 years, 0·16 at 65 years, and 0·17 thereafter.

CONCLUSION

Albeit not perfect, the BCI is a commonly used linear measure of the lateral ventricular size. We present baseline BCI values in a cohort of patients with acute SAH. A diagnosis of hydrocephalus can be made when the BCI value exceeds the upper limit of normal for age.

Subarachnoid hemorrhage-induced hydrocephalus in rats

BACKGROUND AND PURPOSE

Hydrocephalus is an important complication of subarachnoid hemorrhage (SAH). We investigated the occurrence of acute hydrocephalus in a rat SAH model.

METHODS

SAH was induced by endovascular perforation in adult male Sprague-Dawley rats (n=36). Sham rats (n=8) underwent the same procedure without perforation. MRI was performed 24 hours after SAH and the volume of the ventricular system and extent of T2* hypointensity lesions were measured. We defined hydrocephalus as ventricular volume > +3 SDs above the mean in sham animals. SAH grade was determined and brains were used for histology, immunohistochemistry, Perls staining, and Western blot analysis. Ventricular wall damage was defined as percentage of ependymal surface disruption.

RESULTS

All surviving rats (n=27) after SAH had ventricular enlargement (33.6 ± 4.7 versus 13.5 ± 1.4 mm(3) in sham animals, P<0.01). Ventricular volume correlated with SAH severity (r=0.48; P<0.05). Out of 27 SAH rats, 12 demonstrated hydrocephalus and all had intraventricular blood accumulation. Rats with hydrocephalus had more severe ventricular wall damage (7.4 ± 1.2%) than the sham animals (0.6 ± 0.2%; P<0.01) and rats without hydrocephalus (1.1 ± 0.2%; P<0.01). Periventricular iron deposition was observed and heme oxygenase-1 and Iba-1 expression were markedly increased in hydrocephalus rats.

CONCLUSIONS

SAH causes ventricular enlargement in a rat endovascular perforation model, with hydrocephalus occurring in 44% of animals at 24 hours. Rats with hydrocephalus had more severe SAH, intraventricular hemorrhage, and greater ventricular wall damage.

Aggressive CSF diversion reverses delayed cerebral ischemia in aneurysmal subarachnoid hemorrhage: a case report

BACKGROUND

External ventricular drain (EVD) placement temporarily provides cerebrospinal fluid (CSF) diversion and is indicated in patients with aneurysmal subarachnoid hemorrhage (aSAH) to relieve hydrocephalus.

METHODS

Case report.

RESULTS

A 56-year-old woman was admitted to our hospital with aSAH complicated by acute hydrocephalus. An EVD was placed and set to 15 mmHg. After nearly 72 h, she clinically deteriorated. A computed tomography (CT) perfusion scan showed hypoperfusion in the watershed regions in both hemispheres and CT angiogram showed mild segmental arterial narrowings. After the EVD was lowered to 5 mmHg, the radiologic perfusion abnormalities and clinical symptoms resolved.

CONCLUSIONS

We postulate a mechanism by which CSF diversion could decrease the risk of delayed cerebral ischemia after aSAH: CSF drainage at low levels of intracranial pressure (e.g., 5 mmHg) could improve blood flow in the microcirculation, and thus improve tissue perfusion.

The importance of early brain injury after subarachnoid hemorrhage

Aneurysmal subarachnoid hemorrhage (aSAH) is a medical emergency that accounts for 5% of all stroke cases. Individuals affected are typically in the prime of their lives (mean age 50 years). Approximately 12% of patients die before receiving medical attention, 33% within 48 h and 50% within 30 days of aSAH. Of the survivors 50% suffer from permanent disability with an estimated lifetime cost more than double that of an ischemic stroke. Traditionally, spasm that develops in large cerebral arteries 3-7 days after aneurysm rupture is considered the most important determinant of brain injury and outcome after aSAH. However, recent studies show that prevention of delayed vasospasm does not improve outcome in aSAH patients. This finding has finally brought in focus the influence of early brain injury on outcome of aSAH. A substantial amount of evidence indicates that brain injury begins at the aneurysm rupture, evolves with time and plays an important role in patients' outcome. In this manuscript we review early brain injury after aSAH. Due to the early nature, most of the information on this injury comes from animals and few only from autopsy of patients who died within days after aSAH. Consequently, we began with a review of animal models of early brain injury, next we review the mechanisms of brain injury according to the sequence of their temporal appearance and finally we discuss the failure of clinical translation of therapies successful in animal models of aSAH.

Metamorphosis of subarachnoid hemorrhage research: from delayed vasospasm to early brain injury

Delayed vasospasm that develops 3–7 days after aneurysmal subarachnoid hemorrhage (SAH) has traditionally been considered the most important determinant of delayed ischemic injury and poor outcome. Consequently, most therapies against delayed ischemic injury are directed towards reducing the incidence of vasospasm. The clinical trials based on this strategy, however, have so far claimed limited success; the incidence of vasospasm is reduced without reduction in delayed ischemic injury or improvement in the long-term outcome. This fact has shifted research interest to the early brain injury (first 72 h) evoked by SAH. In recent years, several pathological mechanisms that activate within minutes after the initial bleed and lead to early brain injury are identified. In addition, it is found that many of these mechanisms evolve with time and participate in the pathogenesis of delayed ischemic injury and poor outcome. Therefore, a therapy or therapies focused on these early mechanisms may not only prevent the early brain injury but may also help reduce the intensity of later developing neurological complications. This manuscript reviews the pathological mechanisms of early brain injury after SAH and summarizes the status of current therapies.

Diagnostic threshold values of cerebral perfusion measured with computed tomography for delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

BACKGROUND AND PURPOSE

Early diagnosis of delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage is critical but difficult. We analyzed diagnostic threshold values of CT perfusion for use in detection of DCI in patients with subarachnoid hemorrhage.

METHODS

We prospectively enrolled patients with subarachnoid hemorrhage with CT perfusion on admission and at time of clinical deterioration or after 1 week if no deterioration occurred. The gold standard was the clinical diagnosis of DCI based on all clinical, laboratory, and imaging data except CT perfusion. Patients with failed imaging (n=6) and other causes of deterioration (n=45) were excluded for the current study. We measured CT perfusion values, including cerebral blood volume, blood flow, mean transit time (MTT), and time to peak in predefined regions of interest and then compared absolute perfusion and perfusion asymmetry for patients with and without DCI. Diagnostic threshold values for DCI were evaluated and sensitivity and specificity calculated for optimal thresholds.

RESULTS

Of 85 eligible patients with subarachnoid hemorrhage, 50 had DCI; 35 patients with no clinical deterioration comprised the reference group. Cerebral blood flow was significantly lower, MTT higher, and perfusion asymmetry larger in patients with DCI. We found that largest absolute MTT and the MTT difference between hemispheres were good diagnostic tests. Diagnostic threshold values with optimal sensitivity and specificity were an MTT of 5.9 seconds and an MTT difference of 1.1 second.

CONCLUSIONS

Thresholds for absolute MTT values and between-hemisphere MTT differences on CT perfusion can distinguish between patients with delayed cerebral ischemia and clinically stable patients.