Middle meningeal artery embolization reduces recurrence following surgery for septated chronic subdural hematomas

BACKGROUND

Septated chronic subdural hematomas (cSDH) have high rates of recurrence despite surgical evacuation. Middle meningeal artery embolization (MMAE) has emerged as a promising adjuvant for secondary prevention, yet its efficacy remains ill-defined.

METHODS

This is a retrospective review of septated cSDH cases treated at our institution. The surgery-only group was derived from cases performed before 2018, and the surgery+MMAE group was derived from cases performed 2018 or later. The primary outcome was reoperation rate. Secondary outcomes were recurrence, change in hematoma thickness, and midline shift.

RESULTS

A total of 34 cSDHs in 28 patients (surgery+MMAE) and 95 cSDHs in 83 patients (surgery-only) met the inclusion criteria. No significant difference in baseline characteristics between groups was identified. The reoperation rate was significantly higher in the surgery-only group (n = 16, 16.8%) compared with the surgery+MMAE cohort (n = 0, 0.0%) (p=0.006). A reduced incidence of recurrence (p=0.011) was also seen in the surgery+MMAE group.

CONCLUSIONS

MMAE for septated cSDH was found to be highly effective in preventing recurrence and reoperation. MMAE is an adjunct to surgical evacuation may be of particular benefit in this patient cohort.

Neutrophils and Neutrophil Extracellular Traps Cause Vascular Occlusion and Delayed Cerebral Ischemia After Subarachnoid Hemorrhage in Mice

BACKGROUND

After subarachnoid hemorrhage (SAH), neutrophils are deleterious and contribute to poor outcomes. Neutrophils can produce neutrophil extracellular traps (NETs) after ischemic stroke. Our hypothesis was that, after SAH, neutrophils contribute to delayed cerebral ischemia (DCI) and worse outcomes via cerebrovascular occlusion by NETs.

METHODS

SAH was induced via endovascular perforation, and SAH mice were given either a neutrophil-depleting antibody, a PAD4 (peptidylarginine deiminase 4) inhibitor (to prevent NETosis), DNAse-I (to degrade NETs), or a vehicle control. Mice underwent daily neurological assessment until day 7 and then euthanized for quantification of intravascular brain NETs (iNETs). Subsets of mice were used to quantify neutrophil infiltration, NETosis potential, iNETs, cerebral perfusion, and infarction. In addition, NET markers were assessed in the blood of aneurysmal SAH patients.

RESULTS

In mice, SAH led to brain neutrophil infiltration within 24 hours, induced a pro-NETosis phenotype selectively in skull neutrophils, and caused a significant increase in iNETs by day 1, which persisted until at least day 7. Neutrophil depletion significantly reduced iNETs, improving cerebral perfusion, leading to less neurological deficits and less incidence of DCI (16% versus 51.9%). Similarly, PAD4 inhibition reduced iNETs, improved neurological outcome, and reduced incidence of DCI (5% versus 30%), whereas degrading NETs marginally improved outcomes. Patients with aneurysmal SAH who developed DCI had elevated markers of NETs compared with non-DCI patients.

CONCLUSIONS

After SAH, skull-derived neutrophils are primed for NETosis, and there are persistent brain iNETs, which correlated with delayed deficits. The findings from this study suggest that, after SAH, neutrophils and NETosis are therapeutic targets, which can prevent vascular occlusion by NETs in the brain, thereby lessening the risk of DCI. Finally, NET markers may be biomarkers, which can predict which patients with aneurysmal SAH are at risk for developing DCI.

Cerebrovascular Complications Associated With Iatrogenic Fungal Meningitis Following Surgical Procedures in Mexico

BACKGROUND

The current fungal meningitis outbreak caused by contaminated epidural anesthesia with Fusarium solani among patients who underwent surgical procedures in Matamoros, Mexico remains a cause of concern. Its association with an increased susceptibility for cerebrovascular complications (CVC) has not been reported. This single-center study describes 3 patients with a unique pattern of CVC attributed to fungal meningitis.

METHODS

A retrospective case series of patients diagnosed with fungal meningitis following surgical procedures under contaminated epidural anesthesia who developed a unique pattern of CVC during their hospitalization.

RESULTS

Three female patients (mean age, 35 years) with CVC due to iatrogenic fungal meningitis were included. Positive Fungitell β-D-glucan assay in cerebrospinal fluid was documented in all cases, and F. solani was confirmed by polymerase chain reaction in case 3. All cases were complicated by severe vertebrobasilar circulation vasculopathy and arterial dissections with resultant subarachnoid hemorrhage and intraventricular hemorrhage, ultimately leading to patients' death.

CONCLUSIONS

The death toll from the ongoing fungal meningitis outbreak keeps rising, underscoring the need for early recognition and aggressive treatment. We highlight the risk for vertebrobasilar circulation CVC among these patients. The angioinvasive nature of F. solani is yet to be clarified; however, a clear pattern has been observed. Public health awareness should be raised and a strong response should be pursued.

Subarachnoid Blood Clearance and Aneurysmal Subarachnoid Hemorrhage Outcomes: A Retrospective Review

BACKGROUND

Delayed cerebral ischemia (DCI) continues to be a significant contributor to morbidity and mortality following aneurysmal subarachnoid hemorrhage (aSAH). Subarachnoid blood and its degradation products have been implicated in DCI, and faster blood clearance has been hypothesized to confer better outcomes. This study evaluates the relationship between blood volume and its clearance on DCI (primary outcome) and location at 30 days (secondary outcome) after aSAH.

METHODS

This is a retrospective review of adult patients presenting with aSAH. Hijdra sum scores (HSS) were assessed independently for each computed tomography (CT) scan of patients with available scans on post-bleed days 0-1 and 2-10. This cohort was used to evaluate the course of subarachnoid blood clearance (group 1). A subset of patients in the first cohort with available CT scans on both post-bleed days 0-1 and post-bleed days 3-4 composed the second cohort (group 2). This group was used to evaluate the association between initial subarachnoid blood (measured via HSS post-bleed days 0-1) and its clearance (measured via percentage reduction [HSS %Reduction] and absolute reduction [HSS-Abs-Reduction] in HSS between days 0-1 and 3-4) on outcomes. Univariable and multivariable logistic regression models were used to identify outcome predictors.

RESULTS

One hundred fifty-six patients were in group 1, and 72 patients were in group 2. In this cohort, HSS %Reduction was associated with decreased risk of DCI in univariate (odds ratio [OR] = 0.700 [0.527-0.923], p = 0.011) and multivariable (OR = 0.700 [0.527-0.923], p = 0.012) analyses. Higher HSS %Reduction was significantly more likely to have better outcomes at 30 days in the multivariable analysis (OR = 0.703 [0.507-0.980], p = 0.036). Initial subarachnoid blood volume was associated with outcome location at 30 days (OR = 1.331 [1.040-1.701], p = 0.023) but not DCI (OR = 0.945 [0.780-1.145], p = 0.567).

CONCLUSIONS

Early blood clearance after aSAH was associated with DCI (univariable and multivariable analyses) and outcome location at 30 days (multivariable analysis). Methods facilitating subarachnoid blood clearance warrant further investigation.

Middle meningeal artery embolization of septated chronic subdural hematomas

INTRODUCTION

Middle meningeal artery embolization (MMAE) has emerged as a promising new treatment for patients with chronic subdural hematomas (cSDH). Its efficacy, however, upon the subtype with a high rate of recurrence-septated cSDH-remains undetermined.

METHODS

From our prospective registry of patients with cSDH treated with MMAE, we classified patients based on the presence or absence of septations. The primary outcome was the rate of recurrence of cSDH. Secondary outcomes included a reduction in cSDH thickness, midline shift, and rate of reoperation.

RESULTS

Among 80 patients with 99 cSDHs, the median age was 68 years (IQR 59-77) with 20% females. Twenty-eight cSDHs (35%) had septations identified on imaging. Surgical evacuation with burr holes was performed in 45% and craniotomy in 18.8%. Baseline characteristics between no-septations (no-SEP) and septations (SEP) groups were similar except for median age (SEP vs no-SEP, 72.5 vs. 65.5, p = 0.016). The recurrence rate was lower in the SEP group (SEP vs. no-SEP, 3 vs. 16.7%, p = 0.017) with higher odds of response from MMAE for septated lesions even when controlling for evacuation strategy and antithrombotic use (OR = 0.06, CI [0.006-0.536], p = 0.012). MMAE resulted in higher mean absolute thickness reduction (SEP vs. no-SEP, -8.2 vs. -4.8 mm, p = 0.016) with a similar midline shift change. The rate of reoperation did not differ (6.2 vs. 3.1%, p = 0.65).

CONCLUSION

MMAE appears to be equal to potentially more effective in preventing the recurrence of cSDH in septated lesions. These findings may aid in patient selection.

Neurofibroma of the internal carotid artery cavernous sympathetic plexus: illustrative case

BACKGROUND

Intracranial carotid sympathetic plexus (CSP) nerve sheath tumors have rarely been reported in the literature. This study describes the first reported case of a CSP neurofibroma and the first case of a CSP nerve sheath tumor treated via an endoscopic endonasal approach followed by adjuvant radiosurgery.

OBSERVATIONS

A 53-year-old man presented with 3 days of headaches and diplopia and was found to have a complete left abducens nerve palsy. Computed tomography (CT) revealed a smoothly dilated left carotid canal, CT angiography revealed a superiorly displaced left internal carotid artery (ICA), and magnetic resonance imaging revealed a T2-hyperintense and avidly enhancing lesion in the left cavernous sinus encasing the ICA. The patient underwent subtotal resection via an endoscopic transsphenoidal transcavernous approach followed by Gamma Knife radiosurgery.

LESSONS

Nerve sheath tumors arising from the CSP are extremely rare but need to be considered when assessing unusual cavernous sinus lesions. The clinical presentation is dependent on the anatomical location of the tumor and its relationship to the ICA. The optimal treatment paradigm is unknown.

Acute traumatic dural arteriovenous fistula of the superior sagittal sinus: illustrative case

BACKGROUND

Dural arteriovenous fistulas (dAVFs) are aberrant vascular communications between meningeal arteries and venous sinuses or cortical veins. dAVF pathogenesis is incompletely understood; however, formation likely occurs as a result of angioneogensis.

OBSERVATIONS

A 78-year-old man presented after trauma with basal and cortical subarachnoid hemorrhage (SAH). Computed tomography revealed a parietal bone fracture overlying the superior sagittal sinus (SSS). Catheter angiography performed within 24 hours of the injury demonstrated an SSS dAVF supplied by the middle meningeal artery, adjacent to the fracture.

LESSONS

The authors present the case of an acute traumatic dAVF adjacent to a calvarial fracture. In this case, the authors proprose that the underlying pathogenesis is suggestive of direct vessel injury rather than the pathway commonly associated with this pathology.

Middle Meningeal Artery Embolization for Chronic Subdural Hematomas With Concurrent Antithrombotics

BACKGROUND

Chronic subdural hematoma (CSDH) is an increasingly prevalent disease in the aging population. Patients with CSDH frequently suffer from concurrent vascular disease or develop secondary thrombotic complications requiring antithrombotic treatment.

OBJECTIVE

To determine the safety and impact of early reinitiation of antithrombotics after middle meningeal artery embolization for chronic subdural hematoma.

METHODS

This is a single-institution, retrospective study of patients who underwent middle meningeal artery (MMA) embolizations for CSDH. Patient with or without antithrombotic initiation within 5 days postembolization were compared. Primary outcome was the rate of recurrence within 60 days. Secondary outcomes included rate of reoperation, reduction in CSDH thickness, and midline shift.

RESULTS

Fifty-seven patients met inclusion criteria. The median age was 66 years (IQR 58-76) with 21.1% females. Sixty-six embolizations were performed. The median length to follow-up was 20 days (IQR 14-44). Nineteen patients (33.3%) had rapid reinitiation of antithrombotics (5 antiplatelet, 11 anticoagulation, and 3 both). Baseline characteristics between the no antithrombotic (no-AT) and the AT groups were similar. The recurrence rate was higher in the AT group (no-AT vs AT, 9.3 vs 30.4%, P = .03). Mean absolute reduction in CSDH thickness and midline shift was similar between groups. Rate of reoperation did not differ (4.7 vs 8.7%, P = .61).

CONCLUSION

Rapid reinitiation of AT after MMA embolization for CSDH leads to higher rates of recurrence with similar rates of reoperation. Care must be taken when initiating antithrombotics after treatment of CSDH with MMA embolization.

Targeting Hemoglobin to Reduce Delayed Cerebral Ischemia After Subarachnoid Hemorrhage

Delayed cerebral ischemia (DCI) continues to be a sequela of aneurysmal subarachnoid hemorrhage (aSAH) that carries significant morbidity and mortality. Aside from nimodipine, no therapeutic agents are available to reduce the incidence of DCI. Pathophysiologic mechanisms contributing to DCI are poorly understood, but accumulating evidence over the years implicates several factors. Those have included microvessel vasoconstriction, microthrombosis, oxidative tissue damage, and cortical spreading depolarization as well as large vessel vasospasm. Common to these processes is red blood cell leakage into the cerebrospinal fluids (CSF) and subsequent lysis which releases hemoglobin, a central instigator in these events. This has led to the hypothesis that early blood removal may improve clinical outcome and reduce DCI. This paper will provide a narrative review of the evidence of hemoglobin as an instigator of DCI. It will also elaborate on available human data that discuss blood clearance and CSF drainage as a treatment of DCI. Finally, we will address a recent novel device that is currently being tested, the Neurapheresis CSF Management System™. This is an automated dual-lumen lumbar drainage system that has an option to filter CSF and return it to the patient.

Glyoxal Fixation Is Optimal for Immunostaining of Brain Vessels, Pericytes and Blood-Brain Barrier Proteins

Brain vascular staining is very important for understanding cerebrovascular pathologies. 4% paraformaldehyde is considered the gold standard fixation technique for immunohistochemistry and it revolutionized the examination of proteins in fixed tissues. However, this fixation technique produces inconsistent immunohistochemical staining results due to antigen masking. Here, we test a new fixation protocol using 3% glyoxal and demonstrate that this method improves the staining of the brain vasculature, pericytes, and tight junction proteins compared to 4% paraformaldehyde. Use of this new fixation technique will provide more detailed information about vascular protein expressions, their distributions, and colocalizations with other proteins at the molecular level in the brain vasculature.

Blunt Traumatic Vertebral Artery Injuries: Incidence, Therapeutic Management, and Outcomes

BACKGROUND

Blunt cerebrovascular injury (BCVI) is a term for injuries to the carotid and vertebral arteries (blunt vertebral artery injury [BVAI]) caused by blunt trauma. Computed tomographic angiography is currently the best screening test for BCVI. The subsequent management of any identified vessel injury, however, is not clearly defined.

OBJECTIVE

To describe one of the largest cohorts of isolated vertebral artery injuries and report the evolution of treated and untreated lesions and clinical outcomes of treatment regimens used to reduce the risk of injury-related stroke.

METHODS

The list included patients who presented to or were transferred to a level 1 trauma center and found to have an isolated BVAI. Patients were included if imaging was performed within 24 hours of presentation. Data collected included location and grade of injury, timing and type of initial therapy, follow-up imaging, evolution of the disease, and associated strokes.

RESULTS

A total of 156 patients were included in the analysis. Most patients (135/156) were treated with aspirin alone, 3 with anticoagulation therapy, and 18 did not receive treatment. Three strokes were detected within 24 hours of admission and before treatment initiation. No strokes were detected during the length of the hospitalization for any other patient.

CONCLUSION

Our data demonstrate that the risk of stroke after cervical vertebral artery injury is low, and aspirin as a prophylactic is efficacious in grade I and IV injuries. There are limited data regarding grade II and grade III injuries. The benefit of early interval imaging follow-up is unclear and warrants investigation.

Failed endovascular therapy for acute internal carotid artery occlusion from pituitary apoplexy: illustrative case

BACKGROUND

Large pituitary adenomas can rarely cause compression of the cavernous internal carotid artery (ICA) due to chronic tumor compression or invasion. Here, the authors present a case of pituitary apoplexy causing acute bilateral ICA occlusion with resultant stroke. Our middle-aged patient presented with sudden vision loss and experienced rapid deterioration requiring intubation. Computed tomography (CT) angiography revealed a large pituitary mass causing severe stenosis of the bilateral ICAs. CT perfusion revealed a significant perfusion delay in the anterior circulation. The patient was taken for cerebral angiography, and balloon angioplasty was attempted with no improvement in arterial flow. Resection of the tumor was then performed, with successful restoration of blood flow. Despite restoration of luminal patency, the patient experienced bilateral ICA infarcts.

OBSERVATIONS

Pituitary apoplexy can present as an acute stroke due to flow-limiting carotid compression. Balloon angioplasty is ineffective for the treatment of this type of compression. Surgical removal of the tumor restores the flow and luminal caliber of the ICA.

LESSONS

Pituitary apoplexy can be a rare presentation of acute stroke and should be managed with immediate surgical decompression rather than attempted angioplasty in order to restore blood flow and prevent the development of cerebral ischemia.

Endoscopic Third Ventriculostomy for Hydrocephalus Secondary to Extraventricular Obstruction in Thalamic Hemorrhage: A Case Series

BACKGROUND

Intracranial hemorrhage carries significant morbidity and mortality, particularly if associated with hydrocephalus. Management of hydrocephalus includes temporary external ventricular drainage, with or without shunting. Thalamic location is an independent predictor of mortality and increases the likelihood of shunt dependence.

OBJECTIVE

To determine whether endoscopic third ventriculostomy (ETV) can avoid the need for shunt placement and expedite recovery.

METHODS

We prospectively identified thalamic intracranial hemorrhage patients who developed acute hydrocephalus requiring cerebrospinal fluid diversion by extraventricular drain placement from November 2017 to February 2019. Patients who failed an extraventricular drain clamping trial were then evaluated for eligibility for an ETV procedure. Patients who underwent ETV were then followed up for the development of hydrocephalus, need for shunting, and length of stay in the intensive care unit.

RESULTS

Eight patients (7 males, 1 female) were prospectively enrolled. All patients underwent an ETV successfully. None of the patients required shunting. ETV was performed despite the presence of other factors that would have prevented shunt placement, including fever, leukocytosis, and gastrostomy tube placement. Seven patients who underwent ETV were evaluated at 3-mo follow-up and did not require shunting.

CONCLUSION

ETV is a safe and effective technique for the management of hydrocephalus resulting from an extraventricular obstruction in thalamic hemorrhage. It can avoid the need for permanent shunting in this patient population. Larger studies should be conducted to validate and further analyze this intervention.

A safer endovascular technique for pre-operative embolization of juvenile nasopharyngeal angiofibroma: avoiding the pitfalls of external carotid artery - internal carotid artery anastomoses

Intra-arterial embolization of juvenile nasopharyngeal angiofibroma (JNA) prior to surgical resection is the preferred approach to minimize blood loss during surgical resection of the tumor. However, the presence of external carotid artery–internal carotid artery (ECA-ICA) anastomoses may hinder complete tumor embolization due to the associated risk for embolic complications. Here, we evaluate the use of a balloon-assisted embolization (BAE) technique in the treatment of JNA. We conducted a retrospective review of JNA patients who underwent tumor embolization with injection of Onyx in a single session between 2013–2018. All cases displayed tumor arterial supply from ECA and ICA circulations on 2-D catheter angiograms. Procedural and surgical outcome data were analyzed. Results are given as mean±standard deviation (range). Among 9 patients with JNA, all were males and mean age was 14.1±6.3 years (range, 9–29 years). The mean tumor volume embolization was 84.4±12.4% (range, 60–100%) and in 89% patients ≥80% of tumor volume embolization was achieved. There were no embolization-related complications reported. During surgical resection of the tumor there was a low average surgical blood loss of 722±651.5 mL (range, 50–2,000 mL) and the mean procedure time was 282.6±85.4 mins (range, 151–403 mins). In this series, the BAE technique showed to be a safe and effective approach to achieve successful tumor embolization while avoiding embolic complications and effectively reducing the risk for blood loss during surgical resection.

Dural Ectasia in Neurofibromatosis 1: Case Series, Management, and Review

BACKGROUND

The natural history and management of dural ectasia in Neurofibromatosis 1 (NF1) is still largely unknown. Dural ectasias are one of the common clinical manifestations of NF1; however, the treatment options for dural ectasias remain unstudied.

OBJECTIVE

To investigate the natural history, diagnosis, management, and outcome of the largest case series of patients with NF1-associated dural ectasia to date.

METHODS

Records from our NF1 clinic were reviewed to identify NF1 patients with computed tomography or magnetic resonance imaging evidence of dural ectasia(s) to determine their clinical course. Demographics, symptoms, radiographic and histopathologic findings, treatment, and clinical course were assessed.

RESULTS

Thirty-four of 37 patients were managed without surgery. Of the 18 initially asymptomatic patients, 5 (27.8%) progressed to symptoms attributable to a dural ectasia (onset of 2.7% per patient-year). Three patients required surgical intervention because of extraspinal mass effect. All 3 initially improved but had symptom recurrence within 2 yr. Reoperation involved shunt placement for cerebrospinal fluid (CSF) diversion. On imaging review, 26 (76.5%) of the nonsurgical patients harbored an associated nearby plexiform neurofibroma. Pathology of one surgical case revealed dural infiltration by diffuse neurofibroma.

CONCLUSION

Using the largest NF1-associated dural ectasia group to date, we report the first symptom-onset rate for nonsurgical patients. In the few cases requiring surgery for decompression, primary resection, and patching of ectasias failed, subsequently requiring CSF shunting. We demonstrate imaging evidence of nearby plexiform neurofibroma in a majority of cases, which, when combined with histopathology, provides a novel explanation for the formation of dural ectasias.

Embolization of carotid-cavernous fistulas: A technical note on simultaneous balloon protection of the internal carotid artery

A carotid-cavernous fistula (CCF) is an abnormal connection between the carotid circulation and the cavernous sinus. Treatment of CCFs often consists of obliteration of the fistula by a transarterial or transvenous endovascular approach using embolic agents. However, fistula embolization is often halted due to the potential embolic complications that may arise from the retrograde flow of the embolic agents into the arterial circulation, which often leads to the development of fistula recurrence. Moreover, retreatment of a CCF recurrence is challenging and more complex approaches may be required. In this technical note, we describe our experience with CCF embolization in 25 patients treated at a single center. We utilized a transvenous approach for CCF embolization with simultaneous balloon occlusion of the internal carotid artery during the infusion of the embolic material into the fistula. In our series, this simultaneous protection of the internal carotid artery showed to be a safe technique to prevent embolic complications and to achieve successful obliteration of the fistula. On follow-up, 2 cases presented a recurrence, one due to technical difficulties and the other related to an undetected vascular injury. In conclusion, this technique provides a safe approach in the treatment of CCFs by decreasing the risk of embolic complications and increasing the effectiveness of the embolic agents in accomplishing the obliteration of the CCF.

Atorvastatin Treatment of Cavernous Angiomas with Symptomatic Hemorrhage Exploratory Proof of Concept (AT CASH EPOC) Trial

BACKGROUND

More than a million Americans harbor a cerebral cavernous angioma (CA), and those who suffer a prior symptomatic hemorrhage have an exceptionally high rebleeding risk. Preclinical studies show that atorvastatin blunts CA lesion development and hemorrhage through inhibiting RhoA kinase (ROCK), suggesting it may confer a therapeutic benefit.

OBJECTIVE

To evaluate whether atorvastatin produces a difference compared to placebo in lesional iron deposition as assessed by quantitative susceptibility mapping (QSM) on magnetic resonance imaging in CAs that have demonstrated a symptomatic hemorrhage in the prior year. Secondary aims shall assess effects on vascular permeability, ROCK activity in peripheral leukocytes, signal effects on clinical outcomes, adverse events, and prespecified subgroups.

METHODS

The phase I/IIa placebo-controlled, double-blinded, single-site clinical trial aims to enroll 80 subjects randomized 1-1 to atorvastatin (starting dose 80 mg PO daily) or placebo. Dosing shall continue for 24-mo or until reaching a safety endpoint.

EXPECTED OUTCOMES

The trial is powered to detect an absolute difference of 20% in the mean percent change in lesional QSM per year (2-tailed, power 0.9, alpha 0.05). A decrease in QSM change would be a signal of potential benefit, and an increase would signal a safety concern with the drug.

DISCUSSION

With firm mechanistic rationale, rigorous preclinical discoveries, and biomarker validations, the trial shall explore a proof of concept effect of a widely used repurposed drug in stabilizing CAs after a symptomatic hemorrhage. This will be the first clinical trial of a drug aimed at altering rebleeding in CA.

Trial Readiness in Cavernous Angiomas With Symptomatic Hemorrhage (CASH)

BACKGROUND

Brain cavernous angiomas with symptomatic hemorrhage (CASH) are uncommon but exact a heavy burden of neurological disability from recurrent bleeding, for which there is no proven therapy. Candidate drugs to stabilize the CASH lesion and prevent rebleeding will ultimately require testing of safety and efficacy in multisite clinical trials. Much progress has been made in understanding the epidemiology of CASH, and novel biomarkers have been linked to the biological mechanisms and clinical activity in lesions. Yet, the ability to enroll and risk-stratify CASH subjects has never been assessed prospectively at multiple sites. Biomarkers and other outcomes have not been evaluated for their sensitivity and reliability, nor have they been harmonized across sites.

OBJECTIVE

To address knowledge gaps and establish a research network as infrastructure for future clinical trials, through the Trial Readiness grant mechanism, funded by National Institute of Neurological Disorders and Stroke/National Institutes of Health.

METHODS

This project includes an observational cohort study to assess (1) the feasibility of screening, enrollment rates, baseline disease categorization, and follow-up of CASH using common data elements at multiple sites, (2) the reliability of imaging biomarkers including quantitative susceptibility mapping and permeability measures that have been shown to correlate with lesion activity, and (3) the rates of recurrent hemorrhage and change in functional status and biomarker measurements during prospective follow-up.

EXPECTED OUTCOMES

We propose a harmonized multisite assessment of enrollment rates of CASH, baseline features relevant to stratification in clinical trials, and follow-up assessments of functional outcomes in relation to clinical bleeds. We introduce novel biomarkers of vascular leak and hemorrhage, with firm mechanistic foundations, which have been linked to clinical disease activity. We shall test their reliability and validity at multiple sites, and assess their changes over time, with and without clinical rebleeds, hence their fitness as outcome instruments in clinical trials.

DISCUSSION

The timing cannot be more opportune, with therapeutic targets identified, exceptional collaboration among researchers and the patient community, along with several drugs ready to benefit from development of a path to clinical testing using this network in the next 5 years.

Subclinical imaging changes in cerebral cavernous angiomas during prospective surveillance

OBJECTIVE

The purpose of this study was to systematically assess asymptomatic changes (ACs), including subclinical hemorrhage, growth, or new lesion formation (NLF) during longitudinal follow-up of cerebral cavernous angiomas (CAs), and to correlate these with symptomatic hemorrhage (SH) during the same period and with clinical features of the disease.

METHODS

One hundred ninety-two patients were included in this study, among 327 consecutive patients with CA, prospectively identified between September 2009 and February 2019. Included patients had undergone clinical and MRI follow-up, in conjunction with institutional review board-approved biomarker studies, and harbored ≥ 1 CA with a maximum diameter of ≥ 5 mm on T2-weighted MRI. Rates of AC and SH per lesion-year and patient-year were assessed using prospectively articulated criteria. In multifocal/familial cases, rates of NLF were also assessed.

RESULTS

There were no differences in demographic or disease features among cases included or excluded in the study cohort, except for a higher proportion of included patients with CCM3 mutation. Follow-up was 411 patient-years (2503 lesion-years). The rate of AC was higher than the rate of SH (12.9% vs 7.5% per patient-year, and 2.1% vs 1.2% per lesion-year, both p = 0.02). Patients presenting with a prior history of SH had a higher rate of AC than those with other forms of presentation (19.7% and 8.2% per patient-year, respectively; p = 0.003). A higher rate of NLF on T2-weighted MRI (p = 0.03) was observed in patients with prior SH. Three of 6 solitary/sporadic and 2 of 28 multifocal/familial patients underwent resection of the lesion after AC.

CONCLUSIONS

Rates of AC are greater than SH during prospective follow-up of CAs, and greater in cases with prior SH. AC may be a more sensitive biomarker of lesional activity, and a more efficient surrogate outcome in clinical trials than SH. Patients experiencing an AC are more likely to undergo a surgical intervention when CAs are solitary/sporadic than when they are multifocal/familial.

Symptomatic Hemorrhagic Complications in Clot Lysis: Evaluation of Accelerated Resolution of Intraventricular Hemorrhage Phase III Clinical Trial (CLEAR III): A Posthoc Root-Cause Analysis

BACKGROUND

As intraventricular thrombolysis for intraventricular hemorrhage (IVH) has developed over the last 2 decades, hemorrhagic complications have remained a concern despite general validation of its safety in controlled trials in the Clot Lysis: Evaluation of Accelerated Resolution of Intraventricular Hemorrhage Phase III (CLEAR-IVH) program.

OBJECTIVE

To analyze factors associated with symptomatic bleeding following IVH with and without thrombolysis in conjunction with the recently completed CLEAR III trial.

METHODS

We reviewed safety reports on symptomatic bleeding events reported during the first year after randomization among subjects enrolled in the CLEAR III trial. Clinical and imaging data were retrieved through the trial database as part of ongoing quality and safety monitoring. A posthoc root-cause analysis was performed to identify potential factors predisposing to rebleeding in each case. Cases were classified according to onset of rebleeding (during dosing, early after dosing and delayed), the pattern of bleeding, and treatment rendered (alteplase vs saline).

RESULTS

Twenty subjects developed a secondary symptomatic intracranial hemorrhage constituting 4% of subjects. Symptomatic rebleeding events occurred during the dosing protocol (n = 9, 67% alteplase), early after the protocol (n = 5, 40% alteplase), and late (n = 6, 0% alteplase). Catheter-related hemorrhages were the most common (n = 7, 35%) followed by expansion or new intraventricular (n = 6, 30%) and intracerebral (n = 5, 25%) hemorrhages. Symptomatic hemorrhages during therapy resulted from a combination of treatment- and patient-related factors and were at most partially attributable to alteplase. Rebleeding after the dosing protocol primarily reflected patients' risk factors.

CONCLUSION

Intraventricular thrombolysis marginally increases the overall risk of symptomatic hemorrhagic complications after IVH, and only during the treatment phase.

Transcriptome clarifies mechanisms of lesion genesis versus progression in models of Ccm3 cerebral cavernous malformations

Cerebral cavernous malformations (CCMs) are dilated capillaries causing epilepsy and stroke. Inheritance of a heterozygous mutation in CCM3/PDCD10 is responsible for the most aggressive familial form of the disease. Here we studied the differences and commonalities between the transcriptomes of microdissected lesional neurovascular units (NVUs) from acute and chronic in vivo Ccm3/Pdcd10ECKO mice, and cultured brain microvascular endothelial cells (BMECs) Ccm3/Pdcd10ECKO.We identified 2409 differentially expressed genes (DEGs) in acute and 2962 in chronic in vivo NVUs compared to microdissected brain capillaries, as well as 121 in in vitro BMECs with and without Ccm3/Pdcd10 loss (fold change ≥ |2.0|; p < 0.05, false discovery rate corrected). A functional clustered dendrogram generated using the Euclidean distance showed that the DEGs identified only in acute in vivo NVUs were clustered in cellular proliferation gene ontology functions. The DEGs only identified in chronic in vivo NVUs were clustered in inflammation and immune response, permeability, and adhesion functions. In addition, 1225 DEGs were only identified in the in vivo NVUs but not in vitro BMECs, and these clustered within neuronal and glial functions. One miRNA mmu-miR-3472a was differentially expressed (FC = - 5.98; p = 0.07, FDR corrected) in the serum of Ccm3/Pdcd10+/- when compared to wild type mice, and this was functionally related as a putative target to Cand2 (cullin associated and neddylation dissociated 2), a DEG in acute and chronic lesional NVUs and in vitro BMECs. Our results suggest that the acute model is characterized by cell proliferation, while the chronic model showed inflammatory, adhesion and permeability processes. In addition, we highlight the importance of extra-endothelial structures in CCM disease, and potential role of circulating miRNAs as biomarkers of disease, interacting with DEGs. The extensive DEGs library of each model will serve as a validation tool for potential mechanistic, biomarker, and therapeutic targets.

Biomarkers of cavernous angioma with symptomatic hemorrhage

BACKGROUNDCerebral cavernous angiomas (CAs) with a symptomatic hemorrhage (CASH) have a high risk of recurrent hemorrhage and serious morbidity.METHODSEighteen plasma molecules with mechanistic roles in CA pathobiology were investigated in 114 patients and 12 healthy subjects. The diagnostic biomarker of a CASH in the prior year was derived as that minimizing the Akaike information criterion and validated using machine learning, and was compared with the prognostic CASH biomarker predicting bleeding in the subsequent year. Biomarkers were longitudinally followed in a subset of cases. The biomarkers were queried in the lesional neurovascular unit (NVU) transcriptome and in plasma miRNAs from CASH and non-CASH patients.RESULTSThe diagnostic CASH biomarker included a weighted combination of soluble CD14 (sCD14), VEGF, C-reactive protein (CRP), and IL-10 distinguishing CASH patients with 76% sensitivity and 80% specificity (P = 0.0003). The prognostic CASH biomarker (sCD14, VEGF, IL-1β, and sROBO-4) was confirmed to predict a bleed in the subsequent year with 83% sensitivity and 93% specificity (P = 0.001). Genes associated with diagnostic and prognostic CASH biomarkers were differentially expressed in CASH lesional NVUs. Thirteen plasma miRNAs were differentially expressed between CASH and non-CASH patients.CONCLUSIONShared and unique biomarkers of recent symptomatic hemorrhage and of future bleeding in CA are mechanistically linked to lesional transcriptome and miRNA. The biomarkers may be applied for risk stratification in clinical trials and developed as a tool in clinical practice.FUNDINGNIH, William and Judith Davis Fund in Neurovascular Surgery Research, Be Brave for Life Foundation, Safadi Translational Fellowship, Pritzker School of Medicine, and Sigrid Jusélius Foundation.

Phenotypic characterization of murine models of cerebral cavernous malformations

Cerebral cavernous malformations (CCMs) are clusters of dilated capillaries that affect around 0.5% of the population. CCMs exist in two forms, sporadic and familial. Mutations in three documented genes, KRIT1(CCM1), CCM2, and PDCD10(CCM3), cause the autosomal dominant form of the disease, and somatic mutations in these same genes underlie lesion development in the brain. Murine models with constitutive or induced loss of respective genes have been applied to study disease pathobiology and therapeutic manipulations. We aimed to analyze the phenotypic characteristic of two main groups of models, the chronic heterozygous models with sensitizers promoting genetic instability, and the acute neonatal induced homozygous knockout model. Acute model mice harbored a higher lesion burden than chronic models, more localized in the hindbrain, and largely lacking iron deposition and inflammatory cell infiltrate. The chronic model mice showed a lower lesion burden localized throughout the brain, with significantly greater perilesional iron deposition, immune B- and T-cell infiltration, and less frequent junctional protein immunopositive endothelial cells. Lesional endothelial cells in both models expressed similar phosphorylated myosin light chain immunopositivity indicating Rho-associated protein kinase activity. These data suggest that acute models are better suited to study the initial formation of the lesion, while the chronic models better reflect lesion maturation, hemorrhage, and inflammatory response, relevant pathobiologic features of the human disease.

Comprehensive transcriptome analysis of cerebral cavernous malformation across multiple species and genotypes

The purpose of this study was to determine important genes, functions, and networks contributing to the pathobiology of cerebral cavernous malformation (CCM) from transcriptomic analyses across 3 species and 2 disease genotypes. Sequencing of RNA from laser microdissected neurovascular units of 5 human surgically resected CCM lesions, mouse brain microvascular endothelial cells, Caenorhabditis elegans with induced Ccm gene loss, and their respective controls provided differentially expressed genes (DEGs). DEGs from mouse and C. elegans were annotated into human homologous genes. Cross-comparisons of DEGs between species and genotypes, as well as network and gene ontology (GO) enrichment analyses, were performed. Among hundreds of DEGs identified in each model, common genes and 1 GO term (GO:0051656, establishment of organelle localization) were commonly identified across the different species and genotypes. In addition, 24 GO functions were present in 4 of 5 models and were related to cell-to-cell adhesion, neutrophil-mediated immunity, ion transmembrane transporter activity, and responses to oxidative stress. We have provided a comprehensive transcriptome library of CCM disease across species and for the first time to our knowledge in Ccm1/Krit1 versus Ccm3/Pdcd10 genotypes. We have provided examples of how results can be used in hypothesis generation or mechanistic confirmatory studies.

Abstract 63: Plasma Biomarkers of Cavernous Angioma With Symptomatic Hemorrhage (CASH)

Introduction: Cerebral cavernous angiomas with a documented symptomatic hemorrhage (CASH) are associated with an exceptionally high risk of recurrent hemorrhage and serious morbidity. It is unclear if peripheral blood plasma biomarkers implicated in disease biology can differentiate CASH, and whether the same or different biomarkers can distinguish cases who would rebleed.

Methods: Eighteen plasma molecules with postulated mechanistic roles in this disease were quantified in 114 patients and 12 healthy subjects. The best biomarker combination differentiating CASH in the prior year (+/- 30 days) was derived by minimizing the Akaike Information Criterion (AIC), and was validated using statistical and machine-learning simulations. This was compared to the biomarker predicting bleeding in the subsequent year (+/- 30 days), and both explanatory and predictive biomarkers were followed longitudinally in a subset of cases.

Results: Nine plasma molecules had significantly different levels expressed in CASH patients (p<0·05, FDR corrected). The best biomarker (AIC=75·9) included a weighted combination of 4 of these (sCD-14, VEGF, CRP, and IL-10), and distinguished CASH patients with 76% sensitivity and 80% specificity (p=0·0003). A weighed combination of two of these compounds (sCD14 and VEGF) and two others (IL-1β and sROBO-4) predicted which patients would bleed in the subsequent year with 83% sensitivity and 93% specificity (p=0·001). The CASH biomarker increased in recovering patients (p=0·01), while the predictive biomarker decreased after a bleed (p=0·01). No significant change over time was observed in stable subjects in either biomarker.

Conclusions: Our results suggest shared and unique biomarkers of recent symptomatic hemorrhage and of future bleeding in cavernous angiomas. This may be applied for risk stratification in clinical trials, and potentially developed as a tool in clinical practice.

Patients with cranial dural arteriovenous fistulas may benefit from expanded hypercoagulability and cancer screening

OBJECTIVE

Cranial dural arteriovenous fistulas (DAVFs) have been associated with dural sinus occlusion, and previous reports have suggested the association of hypercoagulability with some cases. But the prevalence of a hypercoagulable state has not been systematically analyzed in conjunction with laboratory markers and clinical manifestations, including history of thromboembolism or systemic malignancy. The authors hypothesize that laboratory or clinical evidence of a hypercoagulable state, including cancer, is commonly identifiable in consecutively identified patients with DAVFs, with implications for clinical management.

METHODS

The retrospective cohort study included all patients older than 17 years with cranial DAVFs diagnosed at University of Chicago Medicine during a 6-year period, whose medical records and imaging results were reviewed for objective laboratory or clinical evidence of a hypercoagulable state, including malignancy. Each case was analyzed for implications on clinical management. Data were analyzed in relation to a systematic review of the literature on this association.

RESULTS

Fifteen (88%) of 17 cases of DAVFs had laboratory (n = 8) or clinical evidence of a hypercoagulable state (thromboembolism [n = 8] or cancer [n = 6]). This hypercoagulability or cancer impacted clinical care in all 15 cases.

CONCLUSIONS

An underlying hypercoagulable state manifested by laboratory testing or clinically, including cancer, is staggeringly common. It is important to recognize this association, along with its impact on the management of the DAVFs and systemic diseases.

Spontaneous Healing of a Ruptured Blood Blister-Like Aneurysm

BACKGROUND

Blood blister-like aneurysms (BBAs) are an uncommon group of arterial aneurysms with a high risk of rupture, progression, and repeat rupture. The best intervention is unclear; however, their clinical behavior typically requires urgent intervention. We describe a BBA managed conservatively with complete resolution found at follow-up.

CASE DESCRIPTION

A 50-year-old woman presented with a Hunt-Hess grade 2, Fisher grade 3 subarachnoid hemorrhage (SAH). Computed tomography (CT) revealed mild hydrocephalus with a thick basal SAH that was eccentric to the left. The findings from CT angiography were negative. Digital subtraction arteriography (DSA) revealed a focal protuberance along the dorsal surface of the left ophthalmic segment that was concerning for a dorsal variant BBA. Repeat angiography 48 hours later demonstrated receding of the ectasia, with replacement by a <1-mm defect resembling a dorsal vessel surface fenestration. DSA 7 days after her presentation showed further healing. At 6 weeks, DSA showed no residual abnormality.

CONCLUSIONS

DSA remains an important imaging study for the detection of small aneurysms, because CT angiography might not have sufficient resolution. Our unique case provides strong evidence that BBAs represent a parent artery focal dissection. BBAs can remodel over time, usually with enlargement and repeat rupture if untreated. It is possible, as we have demonstrated, that some small lesions presenting with SAH might spontaneously heal without intervention.

Unique Contribution of Haptoglobin and Haptoglobin Genotype in Aneurysmal Subarachnoid Hemorrhage

Survivors of cerebral aneurysm rupture are at risk for significant morbidity and neurological deficits. Much of this is related to the effects of blood in the subarachnoid space which induces an inflammatory cascade with numerous downstream consequences. Recent clinical trials have not been able to reduce the toxic effects of free hemoglobin or improve clinical outcome. One reason for this may be the inability to identify patients at high risk for neurologic decline. Recently, haptoglobin genotype has been identified as a pertinent factor in diabetes, sickle cell, and cardiovascular disease, with the Hp 2-2 genotype contributing to increased complications. Haptoglobin is a protein synthesized by the liver that binds free hemoglobin following red blood cell lysis, and in doing so, prevents hemoglobin induced toxicity and facilitates clearance. Clinical studies in patients with subarachnoid hemorrhage indicate that Hp 2-2 patients may be a high-risk group for hemorrhage related complications and poor outcome. We review the relevance of haptoglobin in subarachnoid hemorrhage and discuss the effects of genotype and expression levels on the known mechanisms of early brain injury (EBI) and cerebral ischemia after aneurysm rupture. A better understanding of haptoglobin and its role in preventing hemoglobin related toxicity should lead to novel therapeutic avenues.

Surgical Performance in Minimally Invasive Surgery Plus Recombinant Tissue Plasminogen Activator for Intracerebral Hemorrhage Evacuation Phase III Clinical Trial

BACKGROUND

Minimally invasive thrombolytic evacuation of intracerebral hematoma is being investigated in the ongoing phase III clinical trial of Minimally Invasive Surgery plus recombinant Tissue plasminogen activator for Intracerebral hemorrhage Evacuation (MISTIE III).

OBJECTIVE

To assess the accuracy of catheter placement and efficacy of hematoma evacuation in relation to surgical approach and surgeon experience.

METHODS

We performed a trial midpoint interim assessment of 123 cases that underwent the surgical procedure. Accuracy of catheter placement was prospectively assessed by the trial Surgical Center based on prearticulated criteria. Hematoma evacuation efficacy was evaluated based on absolute volume reduction, percentage hematoma evacuation, and reaching the target end-of-treatment volume of <15 mL. One of 3 surgical trajectories was used: anterior (A), posterior (B), and lobar (C). Surgeons were classified based on experience with the MISTIE procedure as prequalified, qualified with probation, and fully qualified.

RESULTS

The average hematoma volume was 49.7 mL (range 20.0-124), and the mean evacuation rate was 71% (range 18.4%-99.8%). First placed catheters were 58% in good position, 28% suboptimal (but suitable to dose), and 14% poor (requiring repositioning). Posterior trajectory (B) was associated with significantly higher rates of poor placement (35%, P = .01). There was no significant difference in catheter placement accuracy among surgeons of varying experience. Hematoma evacuation efficacy was not significantly different among the 3 surgical approaches or different surgeons' experience.

CONCLUSION

Ongoing surgical education and quality monitoring in MISTIE III have resulted in consistent rates of hematoma evacuation despite technical challenges with the surgical approaches and among surgeons of varying experience.

Features of the Chaperone Cellular Network Revealed through Systematic Interaction Mapping

A comprehensive view of molecular chaperone function in the cell was obtained through a systematic global integrative network approach based on physical (protein-protein) and genetic (gene-gene or epistatic) interaction mapping. This allowed us to decipher interactions involving all core chaperones (67) and cochaperones (15) of Saccharomyces cerevisiae. Our analysis revealed the presence of a large chaperone functional supercomplex, which we named the naturally joined (NAJ) chaperone complex, encompassing Hsp40, Hsp70, Hsp90, AAA+, CCT, and small Hsps. We further found that many chaperones interact with proteins that form foci or condensates under stress conditions. Using an in vitro reconstitution approach, we demonstrate condensate formation for the highly conserved AAA+ ATPases Rvb1 and Rvb2, which are part of the R2TP complex that interacts with Hsp90. This expanded view of the chaperone network in the cell clearly demonstrates the distinction between chaperones having broad versus narrow substrate specificities in protein homeostasis.

Plasma Biomarkers of Inflammation and Angiogenesis Predict Cerebral Cavernous Malformation Symptomatic Hemorrhage or Lesional Growth

RATIONALE

The clinical course of cerebral cavernous malformations is highly unpredictable, with few cross-sectional studies correlating proinflammatory genotypes and plasma biomarkers with prior disease severity.

OBJECTIVE

We hypothesize that a panel of 24 candidate plasma biomarkers, with a reported role in the physiopathology of cerebral cavernous malformations, may predict subsequent clinically relevant disease activity.

METHODS AND RESULTS

Plasma biomarkers were assessed in nonfasting peripheral venous blood collected from consecutive cerebral cavernous malformation subjects followed for 1 year after initial sample collection. A first cohort (N=49) was used to define the best model of biomarker level combinations to predict a subsequent symptomatic lesional hemorrhagic expansion within a year after the blood sample. We generated the receiver operating characteristic curves and area under the curve for each biomarker individually and each weighted linear combination of relevant biomarkers. The best model to predict lesional activity was selected as that minimizing the Akaike information criterion. In this cohort, 11 subjects experienced symptomatic lesional hemorrhagic expansion (5 bleeds and 10 lesional growths) within a year after the blood draw. Subjects had lower soluble CD14 (cluster of differentiation 14; P=0.05), IL (interleukin)-6 (P=0.04), and VEGF (vascular endothelial growth factor; P=0.0003) levels along with higher plasma levels of IL-1β (P=0.008) and soluble ROBO4 (roundabout guidance receptor 4; P=0.03). Among the 31 weighted linear combinations of these 5 biomarkers, the best model (with the lowest Akaike information criterion value, 25.3) was the weighted linear combination including soluble CD14, IL-1β, VEGF, and soluble ROBO4, predicting a symptomatic hemorrhagic expansion with a sensitivity of 86% and specificity of 88% (area under the curve, 0.90; P<0.0001). We then validated our best model in the second sequential independent cohort (N=28).

CONCLUSIONS

This is the first study reporting a predictive association between plasma biomarkers and subsequent cerebral cavernous malformation disease clinical activity. This may be applied in clinical prognostication and stratification of cases in clinical trials.

A Report of 2 Cases of Brainstem Hemorrhage After Suboccipital Craniectomy for Chiari Decompression

BACKGROUND AND IMPORTANCE

Decompression surgery for Chiari malformation is known to have very low procedure-related complications. There has been no report of post-Chiari malformation decompression surgery development of brainstem hemorrhage. We report 2 post-Chiari decompression surgery brainstem hemorrhage cases with 2-yr follow-up.

CLINICAL PRESENTATION

Two cases were reviewed in which patients underwent uncomplicated suboccipital craniectomy with expansive autologous pericranium duraplasty for Chiari decompression. Postoperatively, both patients awoke with hemibody sensory and motor deficits. Immediate postoperative magnetic resonance imaging revealed a small hemorrhage within the dorsal medulla in both cases. Follow-up imaging shows resolution along with near complete clinical recovery of deficits.

CONCLUSION

These cases demonstrate a rare postdecompression surgery-related complication in Chiari malformation. We hypothesize that these hemorrhages may occur from the rapid drainage of cerebrospinal fluid resulting in a loss of positive pressure, allowing a low-pressure hemorrhage to occur. Given that these hemorrhages are of low pressure, recovery is excellent.

Abstract 75: Plasma Biomarkers of Inflammation and Angiogenesis Predict Cerebral Cavernous Malformation Symptomatic Hemorrhage or Lesional Growth

Introduction: The clinical course of cerebral cavernous malformations (CCMs) is highly unpredictable, with a limited number of cross sectional studies correlating pro-inflammatory genotypes and plasma biomarkers with prior disease severity. We hereby hypothesize that a panel of plasma biomarkers, with reported role in the physiopathology of CCM, may predict subsequent clinically relevant disease activity.

Methods: This was a single-site prospective observational cohort study, without planned intervention. Non-fasting peripheral venous blood samples from 55 patients (25 with sporadic and 30 with familial CCM) were collected. Twenty-four plasma biomarkers were quantified and analyzed regarding their predictive association with the occurrence of a symptomatic hemorrhage or lesional growth within a year following the blood sample. We generated the receiver operating characteristic (ROC) curves and area under curves (AUC) for each biomarker individually and for each weighted linear combination of relevant biomarkers. The best model to predict lesional activity was selected as that minimizing the Akaike Information Criterion (AIC), representing parsimonious model offering the best fit to the data with the fewest number of predictors.

Results: Eleven patients experienced lesional activity events (5 symptomatic bleeds and 10 lesional growths) within a year after the blood draw. These patients had lower levels of CD14 (p=0.05), IL6 (p=0.04), ROBO4 (p=0.03) and VEGF (p=0.0003), along with higher IL1β (p=0.008) plasma levels. Among the 35 weighted linear combinations of these 5 biomarkers, the best model (with the lowest AIC value=25.3), was the combination including CD14, IL1β, VEGF and ROBO4, predicting a symptomatic bleed or lesional growth with a sensitivity of 86% and specificity of 88% (AUC=0.90, p<0.0001).

Conclusion: This is the first study reporting a predictive association between plasma biomarkers and subsequent CCM disease clinical activity. This may be applied in clinical prognostication, and in the stratification of cases in clinical trials.

Thrombospondin1 (TSP1) replacement prevents cerebral cavernous malformations

KRIT1 mutations are the most common cause of cerebral cavernous malformation (CCM). Acute Krit1 gene inactivation in mouse brain microvascular endothelial cells (BMECs) changes expression of multiple genes involved in vascular development. These changes include suppression of Thbs1, which encodes thrombospondin1 (TSP1) and has been ascribed to KLF2- and KLF4-mediated repression of Thbs1 In vitro reconstitution of TSP1 with either full-length TSP1 or 3TSR, an anti-angiogenic TSP1 fragment, suppresses heightened vascular endothelial growth factor signaling and preserves BMEC tight junctions. Furthermore, administration of 3TSR prevents the development of lesions in a mouse model of CCM1 (Krit1ECKO ) as judged by histology and quantitative micro-computed tomography. Conversely, reduced TSP1 expression contributes to the pathogenesis of CCM, because inactivation of one or two copies of Thbs1 exacerbated CCM formation. Thus, loss of Krit1 function disables an angiogenic checkpoint to enable CCM formation. These results suggest that 3TSR, or other angiogenesis inhibitors, can be repurposed for TSP1 replacement therapy for CCMs.

CSF inflammatory response after intraventricular hemorrhage

OBJECTIVE

To investigate the temporal pattern and relevant associations of CSF inflammatory measures after intraventricular hemorrhage (IVH).

METHODS

We analyzed prospectively collected CSF cell counts and protein and glucose levels from participants in the Clot Lysis Evaluation of Accelerated Resolution of IVH phase III (CLEAR III) trial. Corrected leukocyte count and cell index were calculated to adjust for CSF leukocytes attributable to circulating blood. Data were chronologically plotted. CSF inflammatory measures (daily, mean, median, maximum, and cases with highest quartile response) were correlated with initial IVH volume, IVH clearance rate, thrombolytic treatment, bacterial infection, and adjudicated clinical outcome at 30 and 180 days.

RESULTS

A total of 11,376 data points of CSF results from 464 trial participants were analyzed. Measures of CSF inflammatory response evolved during the resolution of IVH. This was significantly more pronounced with initial IVH volume exceeding 20 mL. Intraventricular alteplase was associated with a significantly augmented inflammatory response compared to saline, even after correcting for initial IVH volume. There was an association but nonpredictive correlation of CSF inflammation measures with culture-positive CSF bacterial infection. None of the CSF inflammatory measures, including cases with upper quartile inflammatory response, was associated with a significant detrimental effect on 30 or 180 days functional outcome or mortality after multivariate adjustment for measures of disease severity.

CONCLUSIONS

Aseptic CSF inflammation after IVH is primarily dependent on the volume of initial bleed. Thrombolysis intensifies the inflammatory response, with no apparent detrimental effect on clinical outcome.

CLINICALTRIALSGOV IDENTIFIER

NCT00784134.

Plasma Biomarkers of Inflammation Reflect Seizures and Hemorrhagic Activity of Cerebral Cavernous Malformations

The clinical course of cerebral cavernous malformations (CCMs) is highly variable. Based on recent discoveries implicating angiogenic and inflammatory mechanisms, we hypothesized that serum biomarkers might reflect chronic or acute disease activity. This single-site prospective observational cohort study included 85 CCM patients, in whom 24 a priori chosen plasma biomarkers were quantified and analyzed in relation to established clinical and imaging parameters of disease categorization and severity. We subsequently validated the positive correlations in longitudinal follow-up of 49 subjects. Plasma levels of matrix metalloproteinase-2 and intercellular adhesion molecule 1 were significantly higher (P = 0.02 and P = 0.04, respectively, FDR corrected), and matrix metalloproteinase-9 was lower (P = 0.04, FDR corrected) in patients with seizure activity at any time in the past. Vascular endothelial growth factor and endoglin (both P = 0.04, FDR corrected) plasma levels were lower in patients who had suffered a symptomatic bleed in the prior 3 months. The hierarchical clustering analysis revealed a cluster of four plasma inflammatory cytokines (interleukin 2, interferon gamma, tumor necrosis factor alpha, and interleukin 1 beta) separating patients into what we designated "high" and "low" inflammatory states. The "high" inflammatory state was associated with seizure activity (P = 0.02) and more than one hemorrhagic event during a patient's lifetime (P = 0.04) and with a higher rate of new hemorrhage, lesion growth, or new lesion formation (P < 0.05) during prospective follow-up. Peripheral plasma biomarkers reflect seizure and recent hemorrhagic activity in CCM patients. In addition, four clustered inflammatory biomarkers correlate with cumulative disease aggressiveness and predict future clinical activity.

Quantitative susceptibility mapping as a monitoring biomarker in cerebral cavernous malformations with recent hemorrhage

BACKGROUND

Quantitative Susceptibility Mapping (QSM) MRI allows accurate assessment of iron content in cerebral cavernous malformations (CCM), and a threshold increase by 6% in QSM has been shown to reflect new symptomatic hemorrhage (SH) in previously stable lesions.

PURPOSE/HYPOTHESIS

It is unclear how lesional QSM evolves in CCMs after recent SH, and whether this could serve as a monitoring biomarker in clinical trials aimed at preventing rebleeding in these lesions.

STUDY TYPE

This is a prospective observational cohort study.

POPULATION

16 CCM patients who experienced a SH within the past year, whose lesion was not resected or irradiated.

FIELD STRENGTH/SEQUENCE

The data acquisition was performed using QSM sequence implemented on a 3T MRI system ASSESSMENT: The lesional QSM assessments at baseline and yearly during 22 patient-years of follow-up were performed by a trained research staff including imaging scientists.

STATISTICAL TESTS

Biomarker changes were assessed in relation to clinical events. Clinical trial modeling was performed using two-tailed tests of time-averaged difference (assuming within-patient correlation of 0.8, power = 0.9 and alpha = 0.1) to detect 20%, 30% or 50% effects of intervention on clinical and biomarkers event rates during two years of follow-up.

RESULTS

The change in mean lesional QSM of index hemorrhagic lesions was +7.93% per patient-year in the whole cohort. There were 5 cases (31%) of recurrent SH or lesional growth, and twice as many instances (62%) with a threshold (6%) increase in QSM. There were no instances of SH hemorrhage or lesional growth without an associated threshold increase in QSM during the same epoch.

LEVEL OF EVIDENCE

1 Technical Efficacy: Stage 4 J. Magn. Reson. Imaging 2018;47:1133-1138.

Applications of Tissue Engineering in Joint Arthroplasty: Current Concepts Update

Research in tissue engineering has undoubtedly achieved significant milestones in recent years. Although it is being applied in several disciplines, tissue engineering's application is particularly advanced in orthopedic surgery and in degenerative joint diseases. The literature is full of remarkable findings and trials using tissue engineering in articular cartilage disease. With the vast and expanding knowledge, and with the variety of techniques available at hand, the authors aimed to review the current concepts and advances in the use of cell sources in articular cartilage tissue engineering.

Endothelial TLR4 and the microbiome drive cerebral cavernous malformations

Cerebral cavernous malformations (CCMs) are a cause of stroke and seizure for which no effective medical therapies yet exist. CCMs arise from the loss of an adaptor complex that negatively regulates MEKK3-KLF2/4 signalling in brain endothelial cells, but upstream activators of this disease pathway have yet to be identified. Here we identify endothelial Toll-like receptor 4 (TLR4) and the gut microbiome as critical stimulants of CCM formation. Activation of TLR4 by Gram-negative bacteria or lipopolysaccharide accelerates CCM formation, and genetic or pharmacologic blockade of TLR4 signalling prevents CCM formation in mice. Polymorphisms that increase expression of the TLR4 gene or the gene encoding its co-receptor CD14 are associated with higher CCM lesion burden in humans. Germ-free mice are protected from CCM formation, and a single course of antibiotics permanently alters CCM susceptibility in mice. These studies identify unexpected roles for the microbiome and innate immune signalling in the pathogenesis of a cerebrovascular disease, as well as strategies for its treatment.

Patient-reported outcome following nonsurgical management of type II odontoid process fractures in adults

Background:

Transverse (type II) odontoid process fracture is among the most commonly encountered cervical spine fractures. Nonsurgical management through external immobilization is occasionally preferred to surgical management but is criticized for its higher rates of failure and lower patient satisfaction. Our aim is to analyze patient-reported outcomes in patients who underwent nonsurgical treatment for type II odontoid fractures.

Methods:

We identified patients >18-year-old who underwent external immobilization as a treatment for isolated type II odontoid fracture between 2007 and 2012. We collected demographic parameters, clinical presentation, mode of injury, imaging studies and modality and duration of treatment (soft collar, halo-vest, or both). Patients were contacted by telephone to participate in a 15-min survey addressing their recovery including their subjective rate of return to preinjury level of functioning.

Results:

Fifteen patients met the inclusion/exclusion criteria and participated in our survey. Patients were followed up for an average of 19 months after injury. Overall mean age was 61 years. Injury followed a mechanical fall or a road traffic accident in 11 and 4 cases, respectively. External immobilization was achieved by halo vest only in nine patients, soft collar only in two patients (13%), and through a sequential combination in the remaining 4 (27%). This was deployed for a mean of 7.8 months. Radiological studies at the last follow-up showed bony healing (27%), fibrous nonunion (60%), and persistent instability (13%). Patients reported gradual recovery of function throughout the 1^st year after injury with levels above 70% of preinjury functioning achieved by 13% of patients at 6 months, 33% at 9 months, and 47% at 12 months. Overall satisfaction with nonsurgical management was 68%.

Conclusion:

In selected patients with type II odontoid fractures, external immobilization represents a good option with acceptable course of recovery.

Demographic Risk Factors for Vascular Lesions as Etiology of Intraventricular Hemorrhage in Prospectively Screened Cases

BACKGROUND

Spontaneous intraventricular hemorrhage (IVH) is associated with high rates of morbidity and mortality despite critical care and other advances. An important step in clinical management is to confirm/rule out an underlying vascular lesion, which influences further treatment, potential for further bleeding, and prognosis. Our aim is to compare demographic and clinical characteristics between IVH patients with and without an underlying vascular lesion, and among cohorts with different vascular lesions.

METHODS

We analyzed prospectively collected data of IVH patients screened for eligibility as part of the Clot Lysis: Evaluation Accelerated Resolution of IVH Phase III (CLEAR III) clinical trial. The trial adopted a structured screening process to systematically exclude patients with an underlying vascular lesion as the etiology of IVH. We collected age, sex, ethnicity, and primary diagnosis on these cases and vascular lesions were categorized prospectively as aneurysm, vascular malformation (arteriovenous malformation, dural arteriovenous fistula, and cavernoma), Moyamoya disease, or other vascular lesion. We excluded cases <18 or >80 years of age. Baseline characteristics were compared between the CLEAR group (IVH screened without vascular lesion) and the group of IVH patients screened and excluded from CLEAR because of an identified vascular lesion. We further analyzed the differential demographic and clinical characteristics among subcohorts with different vascular lesions.

RESULTS

A total of 10,538 consecutive IVH cases were prospectively screened for the trial between 2011 and 2015. Out of these, 496 cases (4.7%) screened negative for underlying vascular lesion, met the inclusion criteria, and were enrolled in the trial (no vascular etiology group); and 1,205 cases (11.4%) were concurrently screened and excluded from the trial because of a demonstrated underlying vascular lesion (vascular etiology group). Cases with vascular lesion were less likely to be >45 years of age (OR 0.28, 95% CI 0.20-0.40), African-American (OR 0.23, 95% CI 0.18-0.31), or male gender (OR 0.48, 95% CI 0.38-0.60), and more likely to present with primary IVH (OR 1.85, 95% CI 1.37-2.51) compared to those with no vascular etiology (p < 0.001). Other demographic factors were associated with specific vascular lesion etiologies. A combination of demographic features increases the association with the absence of vascular lesion, but not with absolute reliability (OR 0.1, 95% CI 0.06-0.17, p < 0.001).

CONCLUSION

An underlying vascular lesion as etiology of IVH cannot be excluded solely by demographic parameters in any patient. Some form of vascular imaging is necessary in screening patients before contemplating interventions like intraventricular fibrinolysis, where safety may be impacted by the presence of vascular lesion.

Abstract 124: Plasma Biomarkers of inflammation Reflect Seizures and Hemorrhagic Activity of Cerebral Cavernous Malformations

Introduction: The clinical course cerebral of cavernous malformations (CCMs) is highly variable, with a limited number of recent studies querying factors associated with disease severity. We hereby explore a panel of peripheral plasma biomarkers implied with inflammation and angiogenesis in relation to CCM clinical activity.

Methods: Blood samples of 85 CCM patients (49 with solitary/sporadic lesions and 36 with multifocal/familial CCMs) were collected at the time of the clinical visit, concurrently with advanced MRI sequences. Twenty a priori chosen plasma biomarkers were quantified and analyzed in relation to established parameters of disease categorization and severity, including genotype, lesion burden, age at symptomatic presentation, CCM-related seizures and the number and timing of prior symptomatic hemorrhages. We first tested classic univariate correlations of each biomarker with disease features, including an FDR correction, and we then applied a multivariate hierarchical clustering approach. We further correlated the peripheral plasma biomarkers with measures of lesional permeability and iron deposition using previously validated MRI protocols.

Results: MMP2 and ICAM1 levels were significantly higher (p=0.02 and p=0.04 respectively) in patients with seizure activity while MMP9 was lower (p=0.04). VEGF and endoglin/CD105 (p=0.04 for both) plasma levels were both lower in patients who had suffered a symptomatic bleed in the prior 3 months. The hierarchical clustering analysis revealed a cluster of 4 plasma inflammatory cytokines (TNFα, IL1β, IL2 and IFNγ) separating patients into high and low inflammatory states. The high inflammatory state was associated with more CCM hemorrhagic events during a patient’s lifetime (p=0.04) but not recent bleeding. CCM lesion iron concentrations were inversely correlated with IL-10 (r=-0.61, p=0.02), CCL2/MCP1 (r=-0.60, p=0.02) and ROBO4 (r=-0.53, p=0.05) in CCM lesions that recently bled.

Conclusion: Peripheral plasma biomarkers reflect seizure and recent hemorrhagic activity from CCM. And clusters of pro-inflammatory biomarkers correlate with cumulative chronic disease aggressiveness. Other biomarkers may reflect the clearance of lesional iron after recent hemorrhage.

RhoA Kinase Inhibition With Fasudil Versus Simvastatin in Murine Models of Cerebral Cavernous Malformations

BACKGROUND AND PURPOSE

We sought to compare the effect of chronic treatment with commonly tolerated doses of Fasudil, a specific RhoA kinase (ROCK) inhibitor, and simvastatin (with pleiotropic effects including ROCK inhibition) on cerebral cavernous malformation (CCM) genesis and maturation in 2 models that recapitulate the human disease.

METHODS

Two heterozygous murine models, Ccm1^+/-Msh2^-/- and Ccm2^+/-Trp53^-/-, were treated from weaning to 4 to 5 months of age with Fasudil (100 mg/kg per day), simvastatin (40 mg/kg per day) or with placebo. Mouse brains were blindly assessed for CCM lesion burden, nonheme iron deposition (as a quantitative measure of chronic lesional hemorrhage), and ROCK activity.

RESULTS

Fasudil, but not simvastatin, significantly decreased mature CCM lesion burden in Ccm1^+/-Msh2^-/- mice, and in meta-analysis of both models combined, when compared with mice receiving placebo. Fasudil and simvastatin both significantly decreased the integrated iron density per mature lesion area in Ccm1^+/-Msh2^-/- mice, and in both models combined, compared with mice given placebo. ROCK activity in mature lesions of Ccm1^+/-Msh2^-/- mice was similar with both treatments. Fasudil, but not simvastatin, improved survival in Ccm1^+/-Msh2^-/- mice. Fasudil and simvastatin treatment did not affect survival or lesion development significantly in Ccm2^+/-Trp53^-/- mice alone, and Fasudil benefit seemed limited to males.

CONCLUSIONS

ROCK inhibitor Fasudil was more efficacious than simvastatin in improving survival and blunting the development of mature CCM lesions. Both drugs significantly decreased chronic hemorrhage in CCM lesions. These findings justify the development of ROCK inhibitors and the clinical testing of commonly used statin agents in CCM.