Leukoaraiosis Distribution and Cerebral Collaterals: A Systematic Review and Meta-Analysis.

Background and Objective: Microvascular failure might result in the collapse of cerebral collaterals. However, controversy remains regarding the role of leukoaraiosis (LA) in collateral recruitment. We, therefore, performed a systematic review and meta-analysis of the association between LA and cerebral collaterals. Methods: Ovid Medline, PubMed, Embase, Web of Science, and three Chinese databases were searched from inception to August 2021. Two types of cerebral collaterals, including Circle of Willis (CoW) and leptomeningeal collaterals (LC), were investigated separately. Random effect models were used to calculate the pooled odds ratio (OR). Meta-regression and subgroup analyses were performed to explore the potential sources of heterogeneity. Results: From 14 studies (n = 2,451) that fulfilled our inclusion criteria, data from 13 could be pooled for analysis. Overall, there was a significant association between severe LA and incomplete CoW (pooled OR 1.66, 95% CI 1.18-2.32, p = 0.003), with low heterogeneity (I 2 = 5.9%). This association remained significant in deep LA (pooled OR 1.48, 95% CI 1.04-2.11, p = 0.029, I 2 = 0), but not periventricular LA. Similarly, there was a significant association between LA and LC (pooled OR 1.73, 95% CI 1.03-2.90, p = 0.037), but with high heterogeneity (I 2 = 67.2%). Meta-regression indicated a negative association of sample size with the effect sizes (p = 0.029). In addition, most of the studies (7/9) included into the analysis of the relationship of severe LA with poor LC enrolled subjects with large vessel occlusion stroke, and this relationship remained significant when pooling the seven studies, but with high heterogeneity. Conclusion: Severe LA is associated with a higher prevalence of poor collaterals. This association is robust for CoW but weak for LC. Further studies are required to explore the underlying mechanisms.

Impact of Leukoaraiosis Severity on the Association of Time to Successful Reperfusion with 90-Day Functional Outcome After Large Vessel Occlusion Stroke.

The chance for a favorable outcome after mechanical thrombectomy (MT) for large vessel occlusion stroke decreases with the symptom onset-to-reperfusion time (OTR). Patients with severe leukoaraiosis are at increased risk for a poor outcome after MT. However, whether leukoaraiosis modulates to the association between OTR and 90-day functional outcome is uncertain. We retrospectively analyzed 144 consecutive patients with successful (TICI ≥ 2b/3) MT for anterior circulation large vessel occlusion within 24 h form OTR between January 2012 to November 2016. Leukoaraiosis was dichotomized to absent-to-mild (van Swieten scale score 0-2) versus moderate-to-severe (3-4) as assessed on admission head CT. Multiple linear, logistic, and ordinal regression analyses were used to determine the association between leukoaraiosis, OTR, and 90-day modified Rankin Scale (mRS) score, after adjustment for pertinent covariates. Leukoaraiosis was independently associated with the OTR on multivariable linear regression (p = 0.003). The association between OTR and 90-day outcome depended on the degree of pre-existing leukoaraiosis burden as shown by a significant leukoaraiosis-by-OTR interaction on multivariable logistic regression (OR 0.76, 95% CI 0.58-0.98, p = 0.037) and multivariable ordinal regression (OR 0.87, 95% CI 0.78-0.97, p = 0.011). Pre-existing leukoaraiosis is associated with the 90-day functional outcome after successful reperfusion and impacts the association between the OTR and 90-day mRS among patients undergoing MT. Patients with high leukoaraiosis burden need to present earlier than patients with low leukoaraiosis burden for a similar favorable outcome. Pending confirmation, these results may have important implications for optimizing patient selection for acute stroke therapies.

Multicenter Validation of the Survival After Acute Civilian Penetrating Brain Injuries (SPIN) Score.

BACKGROUND: Civilian penetrating traumatic brain injury (pTBI) is a serious public health problem in the United States, but predictors of outcome remain largely understudied. We previously developed the Survival After Acute Civilian Penetrating Brain Injuries (SPIN) score, a logistic, regression-based risk stratification scale for estimating in-hospital and 6-mo survival after civilian pTBI with excellent discrimination (area under the receiver operating curve [AUC-ROC = 0.96]) and calibration, but it has not been validated. OBJECTIVE: To validate the SPIN score in a multicenter cohort. METHODS: We identified pTBI patients from 3 United States level-1 trauma centers. The SPIN score variables (motor Glasgow Coma Scale [mGCS], sex, admission pupillary reactivity, self-inflicted pTBI, transfer status, injury severity score, and admission international normalized ratio [INR]) were retrospectively collected from local trauma registries and chart review. Using the original SPIN score multivariable logistic regression model, AUC-ROC analysis and Hosmer-Lemeshow goodness of fit testing were performed to determine discrimination and calibration. RESULTS: Of 362 pTBI patients available for analysis, 105 patients were lacking INR, leaving 257 patients for the full SPIN model validation. Discrimination (AUC-ROC = 0.88) and calibration (Hosmer-Lemeshow goodness of fit, P value = .58) were excellent. In a post hoc sensitivity analysis, we removed INR from the SPIN model to include all 362 patients (SPINNo-INR), still resulting in very good discrimination (AUC-ROC = 0.82), but reduced calibration (Hosmer-Lemeshow goodness of fit, P value = .04). CONCLUSION: This multicenter pTBI study confirmed that the full SPIN score predicts survival after civilian pTBI with excellent discrimination and calibration. Admission INR significantly adds to the prediction model discrimination and should be routinely measured in pTBI patients.

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.

Vascular permeability and iron deposition biomarkers in longitudinal follow-up of cerebral cavernous malformations.

OBJECTIVE Vascular permeability and iron leakage are central features of cerebral cavernous malformation (CCM) pathogenesis. The authors aimed to correlate prospective clinical behavior of CCM lesions with longitudinal changes in biomarkers of dynamic contrast-enhanced quantitative permeability (DCEQP) and quantitative susceptibility mapping (QSM) assessed by MRI. METHODS Forty-six patients with CCMs underwent 2 or more permeability and/or susceptibility studies in conjunction with baseline and follow-up imaging and clinical surveillance during a mean 12.05 months of follow-up (range 2.4-31.27 months). Based on clinical and imaging features, cases/lesions were classified as stable, unstable, or recovering. Associated and predictive changes in quantitative permeability and susceptibility were investigated. RESULTS Lesional mean permeability and QSM values were not significantly different in stable versus unstable lesions at baseline. Mean lesional permeability in unstable CCMs with lesional bleeding or growth increased significantly (+85.9% change; p = 0.005), while mean permeability in stable and recovering lesions did not significantly change. Mean lesional QSM values significantly increased in unstable lesions (+44.1% change; p = 0.01), decreased slightly with statistical significance in stable lesions (-3.2% change; p = 0.003), and did not significantly change in recovering lesions. Familial cases developing new lesions during the follow-up period showed a higher background brain permeability at baseline (p = 0.001), as well as higher regional permeability (p = 0.003) in the area that would later develop a new lesion as compared with the homologous contralateral brain region. CONCLUSIONS In vivo assessment of vascular permeability and iron deposition on MRI can serve as objective and quantifiable biomarkers of disease activity in CCMs. This may be applied in natural history studies and may help calibrate clinical trials. The 2 techniques are likely applicable in other disorders of vascular integrity and iron leakage such as aging, hemorrhagic microangiopathy, and traumatic brain injury.

Exceptional aggressiveness of cerebral cavernous malformation disease associated with PDCD10 mutations.

PURPOSE: The phenotypic manifestations of cerebral cavernous malformation disease caused by rare PDCD10 mutations have not been systematically examined, and a mechanistic link to Rho kinase-mediated hyperpermeability, a potential therapeutic target, has not been established. METHODS: We analyzed PDCD10 small interfering RNA-treated endothelial cells for stress fibers, Rho kinase activity, and permeability. Rho kinase activity was assessed in cerebral cavernous malformation lesions. Brain permeability and cerebral cavernous malformation lesion burden were quantified, and clinical manifestations were assessed in prospectively enrolled subjects with PDCD10 mutations. RESULTS: We determined that PDCD10 protein suppresses endothelial stress fibers, Rho kinase activity, and permeability in vitro. Pdcd10 heterozygous mice have greater lesion burden than other Ccm genotypes. We demonstrated robust Rho kinase activity in murine and human cerebral cavernous malformation vasculature and increased brain vascular permeability in humans with PDCD10 mutation. Clinical phenotype is exceptionally aggressive compared with the more common KRIT1 and CCM2 familial and sporadic cerebral cavernous malformation, with greater lesion burden and more frequent hemorrhages earlier in life. We first report other phenotypic features, including scoliosis, cognitive disability, and skin lesions, unrelated to lesion burden or bleeding. CONCLUSION: These findings define a unique cerebral cavernous malformation disease with exceptional aggressiveness, and they inform preclinical therapeutic testing, clinical counseling, and the design of trials.Genet Med 17 3, 188-196.

Evaluation of iron content in human cerebral cavernous malformation using quantitative susceptibility mapping.

OBJECTIVES: The aims of this study were to investigate and validate quantitative susceptibility mapping (QSM) for lesional iron quantification in cerebral cavernous malformations (CCMs). MATERIALS AND METHODS: Magnetic resonance imaging studies were performed in phantoms and 16 patients on a 3-T scanner. Susceptibility weighted imaging, QSM, and R2* maps were reconstructed from in vivo data acquired with a 3-dimensional, multi-echo, and T2*-weighted gradient echo sequence. Magnetic susceptibility measurements were correlated to susceptibility weighted imaging and R2* results. In addition, iron concentrations from surgically excised CCM lesion specimens were determined using inductively coupled plasma mass spectrometry and correlated with QSM measurements. RESULTS: The QSM images demonstrated excellent image quality for depicting CCM lesions in both sporadic and familial cases. Susceptibility measurements revealed a positive linear correlation with R2* values (R(2) = 0.99 for total, R(2) = 0.69 for mean; P < 0.01). Quantitative susceptibility mapping values of known iron-rich brain regions matched closely with those of previous studies and in interobserver consistency. A strong correlation was found between QSM and the concentration of iron phantoms (0.925; P < 0.01), as well as between QSM and mass spectroscopy estimation of iron deposition (0.999 for total iron, 0.86 for iron concentration; P < 0.01) in 18 fragments of 4 excised human CCM lesion specimens. CONCLUSIONS: The ability of QSM to evaluate iron deposition in CCM lesions was illustrated via phantom, in vivo, and ex vivo validation studies. Quantitative susceptibility mapping may be a potential biomarker for monitoring CCM disease activity and response to treatments.

Dynamic permeability and quantitative susceptibility: related imaging biomarkers in cerebral cavernous malformations.

BACKGROUND AND PURPOSE: Hyperpermeability and iron deposition are 2 central pathophysiological phenomena in human cerebral cavernous malformation (CCM) disease. Here, we used 2 novel MRI techniques to establish a relationship between these phenomena. METHODS: Subjects with CCM disease (4 sporadic and 17 familial) underwent MRI imaging using the dynamic contrast-enhanced quantitative perfusion and quantitative susceptibility mapping techniques that measure hemodynamic factors of vessel leak and iron deposition, respectively, previously demonstrated in CCM disease. Regions of interest encompassing the CCM lesions were analyzed using these techniques. RESULTS: Susceptibility measured by quantitative susceptibility mapping was positively correlated with permeability of lesions measured using dynamic contrast-enhanced quantitative perfusion (r=0.49; P≤0.0001). The correlation was not affected by factors, including lesion volume, contrast agent, and the use of statin medication. Susceptibility was correlated with lesional blood volume (r=0.4; P=0.0001) but not with lesional blood flow. CONCLUSIONS: The correlation between quantitative susceptibility mapping and dynamic contrast-enhanced quantitative perfusion suggests that the phenomena of permeability and iron deposition are related in CCM; hence, more leaky lesions also manifest a more cumulative iron burden. These techniques might be used as biomarkers to monitor the course of this disease and the effect of therapy.