Cerebral Cavernous Malformations Patients Research Articles

Simplex cerebral cavernous malformations with MAP3K3 mutation have distinct clinical characteristics.

ObjectivesTo investigate the clinical characteristics of cerebral cavernous malformations (CCMs) with MAP3K3 somatic mutation.MethodsWe performed a retrospective review of our CCMs database between May 2017 and December 2019. The patients with simplex CCMs identified to harbor a MAP3K3 or CCM gene somatic mutation were included. Clinical characteristics were recorded. Univariate and multivariate logistic analyses were used to assess the risk factors associated with hemorrhage events of CCMs. To explore the underlying mechanism, we transfected MEKK3-I441M-overexpressing and CCM2-knockdown lentiviruses into human umbilical vein endothelial cells (HUVECs) and investigated thrombomodulin (TM) and tight junctions (TJs) protein expression by western blotting and immunofluorescence. Finally, immunohistochemistry was used to validate TM and TJs protein expression in surgical samples.ResultsFifty simplex CCMs patients were included, comprising 38 MAP3K3 mutations and 12 CCM gene mutations. Nine (23.7%) patients with MAP3K3 mutations and 11(91.7%) patients with CCM gene mutations exhibited overt hemorrhage, respectively. Multivariate logistic analyses revealed that MAP3K3 mutation was associated with a lower risk of hemorrhage events. In the vitro experiments, ZO-1 expression was not reduced in MEKK3-I441M-overexpressing HUVECs compared with wild type, whereas it was significantly decreased in CCM2-knockdown HUVECs compared with control. In the MEKK3-I441M-overexpressing HUVECs, TM expression was increased, and the NF-κB pathway was significantly activated. After treatment with an NF-κB signaling inhibitor, TM expression was further upregulated. Meanwhile, TM expression was increased, but the NF-κB pathway was not activated in CCM2-knockdown HUVECs. Accordingly, immunohistochemistry showed that ZO-1 expression in the MAP3K3-mutant samples was significantly higher than that in the CCM-mutant samples. TM expression in the MAP3K3-mutant lesions was significantly lower than that in the CCM-mutant samples.ConclusionSimplex CCMs with MAP3K3 mutation occasionally present with overt hemorrhage, which is associated with the biological function of MAP3K3 mutation.

MPR-Specific Actions Influence Maintenance of the Blood-Brain Barrier (BBB).

Cerebral cavernous malformations (CCMs) are characterized by abnormally dilated intracranial microvascular sinusoids that result in increased susceptibility to hemorrhagic stroke. It has been demonstrated that three CCM proteins (CCM1, CCM2, and CCM3) form the CCM signaling complex (CSC) to mediate angiogenic signaling. Disruption of the CSC will result in hemorrhagic CCMs, a consequence of compromised blood–brain barrier (BBB) integrity. Due to their characteristically incomplete penetrance, the majority of CCM mutation carriers (presumed CCM patients) are largely asymptomatic, but when symptoms occur, the disease has typically reached a clinical stage of focal hemorrhage with irreversible brain damage. We recently reported that the CSC couples both classic (nuclear; nPRs) and nonclassic (membrane; mPRs) progesterone (PRG)-receptors-mediated signaling within the CSC-mPRs-PRG (CmP) signaling network in nPR(−) breast cancer cells. In this report, we demonstrate that depletion of any of the three CCM genes or treatment with mPR-specific PRG actions (PRG/mifepristone) results in the disruption of the CmP signaling network, leading to increased permeability in the nPR(−) endothelial cells (ECs) monolayer in vitro. Finally, utilizing our in vivo hemizygous Ccm mutant mice models, we demonstrate that depletion of any of the three CCM genes, in combination with mPR-specific PRG actions, is also capable of leading to defective homeostasis of PRG in vivo and subsequent BBB disruption, allowing us to identify a specific panel of etiological blood biomarkers associated with BBB disruption. To our knowledge, this is the first report detailing the etiology to predict the occurrence of a disrupted BBB, an indication of early hemorrhagic events.

Comparative Effectiveness of Management by Surgical Resection vs Observation for Cerebral Cavernous Malformations: A Matched Propensity Score Analysis

BACKGROUND: Despite increasing incidental identification of cerebral cavernous malformations (CCMs), uncertainty remains about how to best manage CCM patients. OBJECTIVE: To compare the outcomes of patients with surgically resected vs observed CCMs after adjusting for indication bias through propensity score matching. METHODS: Single-center retrospective chart review was performed on individuals treated for CCMs between 1995 and 2016 at Washington University and Barnes-Jewish Hospital. Participants underwent surgical resection (n = 54) or were observed without surgery (n = 203). Propensity score matching was used to match observed to surgical cases on characteristics at first observation or initial surgery. Time to first focal neurological deficit and mortality postinitial visit or postsurgery was estimated using a Cox proportional hazards model with robust sandwich estimators. Differences in the presence of specific follow-up symptoms were estimated using exact logistic regression. RESULTS: After propensity score matching, 34 matched pairs were created. The median (IQR) follow-up duration was 1.5 (0, 5) years for surgical cases and 3 (0, 5) years for observed cases. After matching, no significant differences were found for time to first focal neurological deficit (P = .37, hazard ratio [HR]: 0.76, 95% CI: 0.41, 1.39) or mortality (P = .91, HR: 0.85, 95% CI: 0.06, 12.24). No significant differences were found between the groups for seizure (P = .15, odds ratio: 0.33, 95% CI: 0.06, 1.34) or hemorrhage (P = 1.00, odds ratio 1.00, 95% CI: 0.07, 13.80). CONCLUSION: In this propensity scored–matched analysis, there were no significant differences between surgical or observed cases in time to focal neurological deficit, mortality, recurrent hemorrhage, or seizure.

Neurological event prediction for patients with symptomatic cerebral cavernous malformation: the BLED2 score.

Retrospective patient cohort studies have identified risk factors associated with recurrent focal neurological events in patients with symptomatic cerebral cavernous malformations (CCMs). Using a prospectively maintained database of patients with CCMs, this study identified key risk factors for recurrent neurological events in patients with symptomatic CCM. A simple scoring system and risk stratification calculator was then created to predict future neurological events in patients with symptomatic CCMs. This was a dual-center, prospectively acquired, retrospectively analyzed cohort study. Adult patients who presented with symptomatic CCMs causing focal neurological deficits or seizures were uniformly treated and clinically followed from the time of diagnosis onward. Baseline variables included age, sex, history of intracerebral hemorrhage, lesion multiplicity, location, eloquence, size, number of past neurological events, and duration since last event. Stepwise multivariable Cox regression was used to derive independent predictors of recurrent neurological events, and predictive accuracy was assessed. A scoring system based on the relative magnitude of each risk factor was devised, and Kaplan-Meier curve analysis was used to compare event-free survival among patients with different score values. Subsequently, 1-, 2-, and 5-year neurological event rates were calculated for every score value on the basis of the final model. In total, 126 (47%) of 270 patients met the inclusion criteria. During the mean (interquartile range) follow-up of 54.4 (12-66) months, 55 patients (44%) experienced recurrent neurological events. Multivariable analysis yielded 4 risk factors: bleeding at presentation (HR 1.92, p = 0.048), large size ≥ 12 mm (HR 2.06, p = 0.016), eloquent location (HR 3.01, p = 0.013), and duration ≤ 1 year since last event (HR 9.28, p = 0.002). The model achieved an optimism-corrected c-statistic of 0.7209. All factors were assigned 1 point, except duration from last event which was assigned 2 points. The acronym BLED2 summarizes the scoring system. The 1-, 2-, and 5-year risks of a recurrent neurological event ranged from 0.6%, 1.2%, and 2.3%, respectively, for patients with a BLED2 score of 0, to 48%, 74%, and 93%, respectively, for patients with a BLED2 score of 5. The BLED2 risk score predicts prospective neurological events in symptomatic CCM patients.

Contact-dependent signaling triggers tumor-like proliferation of CCM3 knockout endothelial cells in co-culture with wild-type cells

Cerebral cavernous malformations (CCM) are low-flow vascular lesions prone to cause severe hemorrhage-associated neurological complications. Pathogenic germline variants in CCM1, CCM2, or CCM3 can be identified in nearly 100% of CCM patients with a positive family history. In line with the concept that tumor-like mechanisms are involved in CCM formation and growth, we here demonstrate an abnormally increased proliferation rate of CCM3-deficient endothelial cells in co-culture with wild-type cells and in mosaic human iPSC-derived vascular organoids. The observation that NSC59984, an anticancer drug, blocked the abnormal proliferation of mutant endothelial cells further supports this intriguing concept. Fluorescence-activated cell sorting and RNA sequencing revealed that co-culture induces upregulation of proangiogenic chemokine genes in wild-type endothelial cells. Furthermore, genes known to be significantly downregulated in CCM3−/− endothelial cell mono-cultures were upregulated back to normal levels in co-culture with wild-type cells. These results support the hypothesis that wild-type ECs facilitate the formation of a niche that promotes abnormal proliferation of mutant ECs. Thus, targeting the cancer-like features of CCMs is a promising new direction for drug development.

Genetic genealogy uncovers a founder deletion mutation in the cerebral cavernous malformations 2 gene.

Cerebral cavernous malformations (CCM) are vascular malformations consisting of collections of enlarged capillaries occurring in the brain or spinal cord. These vascular malformations can occur sporadically or susceptibility to develop these can be inherited as an autosomal dominant trait due to mutation in one of three genes. Over a decade ago, we described a 77.6Kb germline deletion spanning exons 2-10 in the CCM2 gene found in multiple affected individuals from seemingly unrelated families. Segregation analysis using linked, microsatellite markers indicated that this deletion may have arisen at least twice independently. In the ensuing decades, many more CCM patients have been identified with this deletion. In this present study we examined 27 reportedly unrelated affected individuals with this deletion. To investigate the origin of the deletion at base pair level resolution, we sequenced approximately 10Kb upstream and downstream from the recombination junction on the deleted allele. All patients showed the identical SNP haplotype across this combined 20Kb interval. In parallel, genealogical records have traced 11 of these individuals to five separate pedigrees dating as far back as the 1600-1700s. These haplotype and genealogical data suggest that these families and the remaining "unrelated" samples converge on a common ancestor due to a founder mutation occurring centuries ago on the North American continent. We also note that another gene, NACAD, is included in this deletion. Although patient self-reporting does not indicate an apparent phenotypic consequence for heterozygous deletion of NACAD, further investigation is warranted for these patients.

406 The BLED2 Neurologic Event Prediction Score for Patients with Symptomatic Cerebral Cavernous Malformation

INTRODUCTION: Studies using retrospective patient cohorts have identified risk factors associated with recurrent focal neurologic events in patients with symptomatic cerebral cavernous malformations (CCMs). METHODS: Adult patients presenting with symptomatic CCMs causing focal neurologic deficits or seizures were included. Baseline variables included age, gender, history of intracerebral hemorrhage, lesion multiplicity, location, eloquence, size, number of past neurologic events, and duration since last event. Stepwise multivariable Cox regression was used to derive independent predictors of recurrent neurologic events, and predictive accuracy was assessed. A scoring system based on the relative magnitude of the risk factors was devised, and Kaplan-Meier curve analysis compared event-free survival between different score values. Subsequently, 1-, 2-, and 5-year neurologic event rates were calculated for every score value based on the final model. RESULTS: 126 (47%) of 270 patients met inclusion criteria. During a mean follow-up of 4.5 years (54.4 months, range 12-66 months), 55 patients (44%) experienced recurrent neurologic events. Multivariable analysis yielded four risk factors: Bleeding at presentation (HR=1.92, p=0.048), Large size =12mm (HR=2.06, p=0.016), Eloquent location (HR=3.01, p=0.013), and Duration of =1 year since last event (HR=9.28, p=0.002). The model achieved an optimism-corrected c-statistic of 0.7209. All factors were assigned 1 point except duration from last event, which was assigned 2 points. The acronym, BLED2 summarizes the scoring system. The 1-, 2-, and 5-year risk of a recurrent neurologic event ranged from 0.6%, 1.2%, and 2.3%, respectively for patients with a BLED2 score of 0, to 48%, 74%, and 93%, respectively for patients with a BLED2 score of 5. CONCLUSION: The BLED2 risk score predicts prospective neurologic events in symptomatic CCM patients.

Elevated proportion of TLR2- and TLR4-expressing Th17-like cells and activated memory B cells was associated with clinical activity of cerebral cavernous malformations

BackgroundRecent evidences have suggested the involvement of toll-like receptor (TLR)-4 in the pathogenesis of cerebral cavernous malformations (CCM). Elevated frequency of TLR+T-cells has been associated with neurological inflammatory disorders. As T-cells and B-cells are found in CCM lesions, the objective of the present study was to evaluate the cytokine profile of T-cells expressing TLR2 and TLR4, as well as B-cell subsets, in asymptomatic (CCMAsympt) and symptomatic (CCMSympt) patients.MethodsFor our study, the cytokine profile from TLR2+ and TLR4+ T-cell and B-cell subsets in CCMAsympt and CCMSympt patients was investigated using flow cytometry and ELISA. T-cells were stimulated in vitro with anti-CD3/anti-CD28 beads or TLR2 (Pam3C) and TLR4 (LPS) ligands.ResultsCCMSymptc patients presented a higher frequency of TLR4+(CD4+ and CD8+) T-cells and greater density of TLR4 expression on these cells. With regard to the cytokine profile, the percentage of TLR2+ and TLR4+ Th17 cells was higher in CCMSympt patients. In addition, an elevated proportion of TLR4+ Tc-1 cells, as well as Tc-17 and Th17.1 cells expressing TLR2 and TLR4, was observed in the symptomatic patients. By contrast, the percentage of TLR4+ IL-10+CD4+ T cells was higher in the CCMAsympt group. Both Pam3C and LPS were more able to elevate the frequency of IL-6+CD4+T cells and Th17.1 cells in CCMSympt cell cultures. Furthermore, in comparison with asymptomatic patients, purified T-cells from the CCMSympt group released higher levels of Th17-related cytokines in response to Pam3C and, mainly, LPS, as well as after activation via TCR/CD28. Concerning the B-cell subsets, a higher frequency of memory and memory activated B-cells was observed in CCMSympt patients.ConclusionsOur findings reveal an increase in circulating Th17/Tc-17 cell subsets expressing functional TLR2 and, mainly, TLR4 molecules, associated with an increase in memory B-cell subsets in CCM patients with clinical activity of the disease.

Displacement of Gray Matter and Incidence of Seizures in Patients with Cerebral Cavernous Malformations.

Seizures are the most common presentation in patients with cerebral cavernous malformations (CCMs). Based on the hypothesis that the volume or proportion of gray matter (GM) displaced by CCMs is associated with the risk of seizure, we developed an algorithm by which to quantify the volume and proportion of displaced GM and the risk of seizure. Image analysis was conducted on 111 patients with solitary CCMs (divided into seizure and nonseizure groups) from our gamma knife radiosurgery (GKRS) database from February 2005 and March 2020. The CCM algorithm proved effective in quantifying the GM and CCM using T1WI MRI images. In the seizure group, 11 of the 12 patients exhibited seizures at the initial presentation, and all CCMs in the seizure group were supratentorial. The location of the limbic lobe within the CCM was significantly associated with the risk of seizure (OR = 19.6, p = 0.02). The risk of seizure increased when the proportion of GM displaced by the CCM exceeded 31%. It was also strongly correlated with the volume of displaced GM. The volume and proportion of displaced GM were both positively correlated with the risk of seizure presentation/development and thus could be used to guide seizure prophylaxis in CCM patients.

Readmissions in patients with cerebral cavernous malformations: a national readmission database study.

Cerebral cavernous malformations (CCMs) are microvascular CNS lesions prone to hemorrhage leading to neurological sequela such as stroke and seizure. A subset of CCM patients have aggressive disease leading to multiple bleeding events, likely resulting multiple hospitalizations. Hospital admission rates are an important metric that has direct financial impact on hospitals and an indicator of overall disease burden. Furthermore, analysis of hospital readmissions can lead to early identification of high-risk patients and provides insight into the pathogenesis of CCM lesions. The purpose of this study is to identify high risk CCM patients with increased all cause readmission and comorbidities associated with increased readmissions. All US hospital admissions due to CCMs were searched using the 2017 National Readmission Database (NRD). Patients with readmissions within 30 days of discharge from index hospitalization were identified and analyzed, relative to the remaining population. Among all patients hospitalized for CCM, 14.9% (13.7-16.2%) required all cause readmission within 30 days. Multivariate logistical regression analysis showed that substance abuse (P=0.003), diabetes (P=0.018), gastrointestinal bleed (P=0.002), renal failure (P=0.027), and coronary artery disease (P=0.010) were predictive of all cause readmissions, while age group 65-74 (P=0.042), private insurance (P<0.001), and treatment at a metropolitan teaching institution (P=0.039) were protective. Approximately half of all readmissions are caused by neurological (33.9%) and infectious (14.6%) etiologies. The 30-day lesion bleeding rate after index hospitalization is 0.8% (0.5-1.2%). All identified comorbidities associated with increased risks of readmission contribute to vascular stress, suggesting its role in lesion pathogenesis. This is the first and only study to analyze readmission metrics for CCMs in order to identify high risk patient factors to date.

Association of Variants in FCGR2A, PTPN2, and GM-CSF with Cerebral Cavernous Malformation: Potential Biomarkers for a Symptomatic Disease.

Cerebral Cavernous Malformations (CCM) predispose patients to a lifetime risk of seizures and symptomatic hemorrhage. Only a small percentage of people affected will develop clinical symptoms and the molecular mechanisms underlying lesional activity remain unclear. We analyzed a panel of Single Nucleotide Polymorphisms (SNPs) in CCM patients. We looked for plasmatic inflammatory cytokines, checking for a pattern of plasma expression heterogeneity and any correlation with genetic variations identified with different CCM clinical phenotypes. This was a case-control study from a long-term follow-up cohort including 23 CCM patients, of which 16 were symptomatic, and 7 were asymptomatic. A 200-SNP panel was considered through next-generation sequencing and 18 different plasma molecules were assessed through a suspension array system. Fcγ receptor IIa rs1801274 (FCGR2A) and protein tyrosine phosphatase non-receptor type 2 rs72872125 PTPN2 were statistically different between groups. Patients who had a combination of the presence of FCGR2A and the absence of PTPN2 also had symptoms earlier in life. The combination of genetic polymorphisms and serum level of GM-CSF showed the best diagnostic biomarker to distinguish symptomatic patients as formulated: [0.296*(FCGR2A)] + [-0.788*(PTPN2)] + [-0.107*(GM-CSF)]. We have shown that SNPs in inflammation genes might be related to a symptomatic phenotype in CCM. We also demonstrated that a formula based on two of these polymorphisms (FCGR2A+ and PTPN2+) is possibly capable of predicting a symptomatic phenotype during a patient's lifetime.

A novel insight into differential expression profiles of sporadic cerebral cavernous malformation patients with different symptoms

Cerebral cavernous malformation (CCM) is a vascular lesion of the central nervous system that may lead to distinct symptoms among patients including cerebral hemorrhages, epileptic seizures, focal neurologic deficits, and/or headaches. Disease-related mutations were identified previously in one of the three CCM genes: CCM1, CCM2, and CCM3. However, the rate of these mutations in sporadic cases is relatively low, and new studies report that mutations in CCM genes may not be sufficient to initiate the lesions. Despite the growing body of research on CCM, the underlying molecular mechanism has remained largely elusive. In order to provide a novel insight considering the specific manifested symptoms, CCM patients were classified into two groups (as Epilepsy and Hemorrhage). Since the studied patients experience various symptoms, we hypothesized that the underlying cause for the disease may also differ between those groups. To this end, the respective transcriptomes were compared to the transcriptomes of the control brain tissues and among each other. This resulted into the identification of the differentially expressed coding genes and the delineation of the corresponding differential expression profile for each comparison. Notably, some of those differentially expressed genes were previously implicated in epilepsy, cell structure formation, and cell metabolism. However, no CCM1-3 gene deregulation was detected. Interestingly, we observed that when compared to the normal controls, the expression of some identified genes was only significantly altered either in Epilepsy (EGLN1, ELAVL4, and NFE2l2) or Hemorrhage (USP22, EYA1, SIX1, OAS3, SRMS) groups. To the best of our knowledge, this is the first such effort focusing on CCM patients with epileptic and hemorrhagic symptoms with the purpose of uncovering the potential CCM-related genes. It is also the first report that presents a gene expression dataset on Turkish CCM patients. The results suggest that the new candidate genes should be explored to further elucidate the CCM pathology. Overall, this work constitutes a step towards the identification of novel potential genetic targets for the development of possible future therapies.

COVID-19 in a Hemorrhagic Neurovascular Disease, Cerebral Cavernous Malformation

COVID-19 in a Hemorrhagic Neurovascular Disease, Cerebral Cavernous Malformation

Pilot investigation of circulating angiogenic and inflammatory biomarkers associated with vascular malformations

BackgroundVascular malformations in the central nervous system are difficult to monitor and treat due to their inaccessible location. Angiogenic and inflammatory proteins are secreted into the bloodstream and may serve as useful biomarkers for identifying patients at risk for complications or with certain disease phenotypes.MethodsA validated multiplex protein array consisting of 26 angiogenic and inflammatory biomarkers (Angiome) was assessed in plasma isolated from healthy controls and patients with either sporadic brain arteriovenous malformation (BAVM), familial cerebral cavernous malformation (CCM), or hereditary hemorrhagic telangiectasia (HHT). These samples were obtained from archives of ongoing research studies at the University of California San Francisco and through prospective collection at the Toronto HHT Centre at St. Michael’s Hospital.ResultsWe compared circulating biomarker levels from each patient group to healthy controls and analyzed each pairwise combination of patient groups for differences in biomarker levels. Additionally, we analyzed the HHT samples to determine the association between biomarker levels and the following HHT-specific phenotypes, BAVM, pulmonary arteriovenous malformation (PAVM), liver vascular malformation (LVM), and gastrointestinal (GI) bleeding. Compared to controls, levels of SDF1 were significantly elevated in HHT patients (Proportional Increase [PI] = 1.87, p < 0.001, q = 0.011). Levels of sENG were significantly reduced in HHT patients compared to controls (PI = 0.56, p < 0.001, q < 0.001), reflecting the prevalence of HHT1 patients in this cohort. Levels of IL6 (PI = 3.22, p < 0.001, q < 0.001) and sTGFβR3 (PI = 0.70, p = 0.001, q < 0.029) differed significantly in CCM patients compared to controls. Compared to controls, ten of the biomarkers were significantly different in sporadic BAVM patients (q-values < 0.05). Among the pairwise combinations of patient groups, a significant elevation was observed in TGFβ1 in CCM patients compared to sporadic BAVM patients (PI = 2.30, p < 0.001, q = 0.034). When examining the association of circulating biomarker levels with HHT-specific phenotypes, four markers were significantly lower in HHT patients with BAVM (q-values < 0.05), and four markers were significantly higher in patients with LVM (q-values < 0.05).ConclusionsThis pilot study suggests that the profile of circulating angiogenic and inflammatory biomarkers may be unique to each type of vascular malformation. Furthermore, this study indicates that circulating biomarkers may be useful for assessing phenotypic traits of vascular malformations.

Clinical, neuroradiological and genetic findings in a cohort of patients with multiple Cerebral Cavernous Malformations.

Cerebral cavernous malformations (CCM) consist of clusters of irregular dilated capillaries and represent the second most common type of vascular malformation affecting the central nervous system. CCM might be asymptomatic or cause cerebral hemorrhage, seizures, recurrent headaches and focal neurologic deficits. Causative mutations underlining CCM have been reported in three genes: KRIT1/CCM1, MGC4607/CCM2 and PDCD10/CCM3. Therapeutic avenues are limited to surgery. Here we present clinical, neuroradiological and molecular findings in a cohort of familial and sporadic CCM patients. Thirty subjects underwent full clinical and radiological assessment. Molecular analysis was performed by direct sequencing and MLPA analysis. Twenty-eight of 30 subjects (93%) experienced one or more typical CCM disturbances with cerebral/spinal hemorrhage being the most common (43%) presenting symptom. A molecular diagnosis was achieved in 87% of cases, with three novel mutations identified. KRIT1/CCM1 patients displayed higher risk of de novo CCMs appearance and bleedings. Magnetic Resonance Imaging (MRI) showed that infratentorial region was more frequently affected in mutated subjects while brainstem was often spared in patients with negative genetic testing.

Endoscopic Surgery for Supratentorial Deep Cavernous Malformation Adjacent to Cortical Spinal Tract: Preliminary Experience and Technical Note.

In this study, we aimed to introduce a technical note and to explore the efficacy of endoscopic surgery combined with diffusion tensor imaging (DTI) navigation for supratentorial deep cerebral cavernous malformations (CCM). A prospectively maintained database of CCM patients was reviewed to identify all CCM patients treated by endoscopic surgery. The sagittal T1-weighted anatomical magnetic resonance imaging (MRI) and DTI were acquired before surgery. Endoscopic surgery was planned and performed based on preoperative DTI images and intraoperative DTI navigation. All patients were followed up more than 6 months. Motor function deficit and modified Rankin scale (mRS) scores were documented on follow-up. A final mRS score of 0–2 was considered a good outcome, and a final mRS score >2 was considered a poor outcome. Second DTI and 3DT1 were performed at 3 months after surgery. We tracked the ipsilateral corticospinal tract (CST) on pre- and postoperative DTI images. The overall mean FA values and the number of fibers of tracked CST were compared on pre- and postoperative DTI images. Risk factors associated with motor deficits and poor outcomes were analyzed. Seven patients with deep CCM and treated by endoscopic surgery were enrolled in this study. The mean value of preoperative mRS was 1.5 ± 0.98, but that score recovered to 0.86 ± 1.22 3 months later. The mRS scores were improved significantly according to statistical analysis (p = 0.012). According to the Spearman non-parametric test, only the fiber number of ipsilateral CST on postoperative DTI was significantly associated with muscle strength 6 months after surgery (p = 0.032). Compared with preoperative CST characteristics on DTI, the change of FA value (p = 0.289) and fiber number (p = 0.289) of ipsilateral CST on postoperative DTI was not significant It meant that the CST was protected during endoscopic surgery. Endoscopic surgery based on DTI navigation might be an effective method to protect fiber tracts in supratentorial deep CCM patients and improve long-term outcomes. However, more studies and cases are needed to confirm our findings.

Abstract P737: Human Homologs Of Differentially Expressed Plasma MicroRNAs In Preclinical Murine Models Target Fundamental Mechanisms Of Cerebral Cavernous Malformation

Introduction: There is a current need for sensitive and specific biomarkers of Cerebral Cavernous Malformation (CCM) that can be readily translated from preclinical to human models to accurately diagnose and monitor disease states and response to novel therapeutics. MiRNAs are small non-coding RNAs that influence gene expression and whose levels can be affected by disease states. We hypothesize that there are human homologs of differentially expressed (DE) miRNA in the plasma of CCM murine models that can be identified in CCM patients. We further hypothesize that these miRNAs have gene targets within previously published CCM transcriptomes, mechanistically linking them to CCM disease. Methods: Plasma miRNAs from homozygous and heterozygous Ccm1 and Ccm3 mice, as well as their respective wild type controls were sequenced and analyzed. Putative gene targets of DE miRNAs [p&lt;0.05, false discovery rate (FDR) corrected] were queried in previously published mouse CCM transcriptomes. The human homologs of the DE miRNAs in the plasma of Ccm1 and Ccm3 mouse models were identified and assessed in the plasma of healthy controls (n=13), CCM1 (n=11), and CCM3 (n=11) patients using RT-qPCR. Results: 5 miRNAs in homozygous and 10 in heterozygous for Ccm1 , while 45 in homozygous and 2 in heterozygous for Ccm3 were DE in the plasma of mouse models (p&lt;0.05, FDR corrected), had gene targets within CCM mouse transcriptomes, and have a human homolog. Preliminary results show mmu-miR-375-3p as DE in both Ccm1 +/- and Ccm3 -/- mice. RT-qPCR assays show that plasma relative quantification values of the human homolog hsa-miR-375-3p were higher in CCM3 than in CCM1 patients ( p &lt;0.001) and in healthy controls ( p &lt;0.05). Conclusion: DE plasma miRNAs identified in mouse models with human homologs and putative gene targets mechanistically implicated in CCM disease may be used as candidate biomarkers for specific clinical contexts.

Modifiable Cardiovascular Risk Factors in Patients With Sporadic Cerebral Cavernous Malformations

This study aims to assess the influence of modifiable cardiovascular risk factors on hemorrhage risk of sporadic cerebral cavernous malformations (CCMs). From 1219 consecutive CCM patients (2003-2018), adult subjects with sporadic CCM and complete magnetic resonance imaging were included. We evaluated presence of intracerebral hemorrhage (ICH) as mode of presentation, occurrence of ICH during follow-up and risk factors arterial hypertension, diabetes, hyperlipidemia, nicotine abuse, and obesity (body mass index >30 kg/m2). Impact of risk factors on ICH at presentation was calculated using univariate and multivariate logistic regression with age and sex adjustment. We performed Kaplan-Meier and Cox regression to analyze cumulative 5-year risk for (re)bleeding. We included 682 patients with CCM. The univariate logistic regression showed a significant relationship (odds ratio=1.938 [95% CI, 1.120-3.353], P=0.018) between obesity and ICH as mode of presentation. Multivariate adjusted logistic regression confirmed significant correlation with odds ratio=1.902 (95% CI, 1.024-3.532, P=0.042). Cox regression did not identify predictors for occurrence of (re)hemorrhage (P>0.05; hazard ratios: arterial hypertension 1.112 [95% CI, 0.622-1.990], diabetes 0.850 [95% CI, 0.208-3.482], hyperlipidemia 0.719 [95% CI, 0.261-1.981], nicotine abuse 1.123 [95% CI, 0.591-2.134], and obesity 0.928 [95% CI, 0.416-2.070]). This study provides evidence that obesity may be a risk factor for CCM hemorrhage. It was significantly associated with ICH as mode of presentation. Other risk factors (arterial hypertension, diabetes, hyperlipidemia, and current nicotine abuse) showed no such effect. None of the factors showed to be independent predictors for cumulative 5-year risk of (re)bleeding.

Morbidity After Symptomatic Hemorrhage of Cerebral Cavernous Malformation: A Nomogram Approach to Risk Assessment.

Symptomatic hemorrhage contributes to an increased risk of repeated bleeding and morbidity in cerebral cavernous malformation (CCM). A better understanding of morbidity after CCM hemorrhage would be helpful to identify patients of higher risk for unfavorable outcome and tailor individualized management. We identified 282 consecutive patients who referred to our institute from 2014 to 2018 for CCM with symptomatic hemorrhage and had an untreated follow-up period over 6 months after the first hemorrhage. The morbidity after hemorrhage was described in CCM of different features. Nomogram to predict morbidity was formulated based on the multivariable model of risk factors. The predictive accuracy and discriminative ability of nomogram were determined with concordance index (C-index) and calibration curve, and further validated in an independent CCM cohort of a prospective multicenter study from 2019 to 2020. The overall morbidity of CCM was 26.2% after a mean follow-up of 1.9 years (range 0.5-3.5 years) since the first hemorrhage. The morbidity during untreated follow-up was associated with hemorrhage ictus (adjusted odds ratio per ictus increase, 4.17 [95% CI, 1.86-9.33]), modified Rankin Scale score at initial hemorrhage (adjusted odds ratio per point increase, 2.57 [95% CI, 1.82-3.63]), brainstem location (adjusted odds ratio, 2.93 [95% CI, 1.28-6.68]), and associated developmental venous anomaly (adjusted odds ratio, 2.21 [95% CI, 1.01-4.83]). Subgroup analysis revealed similar findings in brainstem and non-brainstem CCM. Nomogram was contracted based on these features. The calibration curve showed good agreement between nomogram prediction and actual observation. The C-index of nomogram predicting morbidity was 0.83 (95% CI, 0.77-0.88). In validation cohort, the nomogram maintained the discriminative ability (C-index, 0.87 [95% CI, 0.78-0.96]). Multiple symptomatic hemorrhages, initial neurological function after hemorrhage, brainstem location, and associated developmental venous anomaly were associated with morbidity of CCM hemorrhage. The nomogram represented a practical approach to provide individualized risk assessment for CCM patients. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT04076449.

Antibodies in cerebral cavernous malformations react with cytoskeleton autoantigens in the lesional milieu

Previous studies have reported robust inflammatory cell infiltration, synthesis of IgG, B-cell clonal expansion, deposition of immune complexes and complement within cerebral cavernous malformation (CCM) lesions. B-cell depletion has also been shown to reduce the maturation of CCM in murine models. We hypothesize that antigen(s) within the lesional milieu perpetuate the pathogenetic immune responses in CCMs. This study aims to identify those putative antigen(s) using monoclonal antibodies (mAbs) derived from plasma cells found in surgically removed human CCM lesions. We produced human mAbs from laser capture micro-dissected plasma cells from four CCM patients, and also germline-reverted versions. CCM mAbs were assayed using immunofluorescence on central nervous system (CNS) tissues and immunocytochemistry on human primary cell lines. Antigen characterization was performed using a combination of confocal microscopy, immunoprecipitation and mass spectrometry. Affinity was determined by enzyme-linked immunosorbent assay, and specificity by multi-color confocal microscopy and quantitative co-localization. CCM mAbs bound CNS tissue, especially endothelial cells and astrocytes. Non-muscle myosin heavy chain IIA (NMMHCIIA), vimentin and tubulin are three cytoskeleton proteins that were commonly targeted. Selection of cytoskeleton proteins by plasma cells was supported by a high frequency of immunoglobulin variable region somatic hypermutations, high affinity and selectivity of mAbs in their affinity matured forms, and profoundly reduced affinity and selectivity in the germline reverted forms.Antibodies produced by plasma cells in CCM lesions commonly target cytoplasmic and cytoskeletal autoantigens including NMMHCIIA, vimentin and tubulin that are abundant in endothelial cells and astrocytes. Binding to, and selection on autoantigen(s) in the lesional milieu likely perpetuates the pathogenetic immune response in CCMs. Blocking this in situ autoimmune response may yield a novel treatment for CCM.