Cavernous malformations: natural history, diagnosis and treatment

Comprehensive analysis of Novel mutations in CCM1/KRIT1 and CCM2/MGC4607 and their clinical implications in Cerebral Cavernous malformations

BACKGROUND

Cerebral Cavernous Malformations (CCM) is a genetic disease characterized by vascular abnormalities in the brain and spinal cord, affecting 0.4-0.5 % of the population. We identified two novel pathogenic mutations, CCM1/KRIT1 c.811delT (p.Trp271GlyfsTer5) and CCM2/MGC4607 c.613_614insGG p.Glu205GlyfsTer31), which disrupt crucial protein domains and potentially alter disease progression.

OBJECTIVE

The study aims to comprehensively analyze a Brazilian cohort of CCM patients, integrating genetic, clinical, and structural aspects. Specifically, we sought to identify novel mutations within the CCM complex, and explore their potential impact on disease progression.

METHODS

We conducted a detailed examination of neuroradiological and clinical features in both symptomatic and asymptomatic CCM patients, performing genetic analyses through sequencing of the CCM1/KRIT1, CCM2/MGC4607, and CCM3/PDCD10 genes In silico structural predictions were carried out using PolyPhen-2, SIFT, and Human Genomics Community tools. Protein-protein interactions and docking analyses were explored using the STRING database.

RESULTS

Genetic analysis identifies 6 pathogenic mutations, 4 likely pathogenic, 1 variants of uncertain significance, and 7 unclassified mutations, including the novel mutations in CCM1 c.811delT and CCM2 c.613_614insGG. In silico structural analysis revealed significant alterations in protein structure, supporting their pathogenicity. Protein-protein interaction analysis indicated nuanced impacts on cellular processes. Clinically, we observed a broad spectrum of symptoms, including seizures and focal neurological deficits. However, no statistically significant differences were found in lesion burden, age of first symptom onset, or sex between the identified CCM1/KRIT1 and CCM2/MGC4607 mutations among all patients studied.

CONCLUSION

This study enhances the understanding of CCM by linking clinical variability, genetic mutations, and structural effects. The identification of these novel mutations opens new avenues for research and potential therapeutic strategies.

Long-Term Outcomes of Gamma Knife Radiosurgery for Cerebral Cavernous Malformations: 10 Years and Beyond

BACKGROUND

We aimed to evaluate long-term outcomes of gamma knife radiosurgery (GKS) for cerebral cavernous malformations (CCMs).

METHODS

Among the 233 CCM patients who underwent GKS, 79 adult patients (96 lesions) followed for over 10 years were included and analyzed retrospectively. Annual hemorrhage rate (AHR) was analyzed the entire cohort of 233 patients and the subset of 79 enrolled patients by dividing lesions into overall CCM lesions and brainstem lesions. AHR, neurologic outcome, adverse radiation effect (ARE), and changes of lesions in magnetic resonance imaging (MRI) were compared before and after GKS. Cox-regression analysis was performed to identify risk factors for hemorrhage following GKS.

RESULTS

Mean follow-up duration of 79 enrolled patients was 14 years (range, 10-23 years). The AHR of all CCMs for entire cohort at each time point was 17.8% (pre-GKS), 5.9% (≤ 2 years post-GKS), 1.8% (≤ 10 years post-GKS). The AHR of all CCM for 79 enrolled patients was 21.4% (pre-GKS), 3.8% (2 years post-GKS), 1.4% (10 years post-GKS), and 2.3% (> 10 years post-GKS). The AHR of brainstem cavernous malformation (CM) for entire cohort at each time point was 22.4% (pre-GKS), 10.1% (≤ 2 years post-GKS), 3.2% (≤ 10 years post-GKS). The AHR of brainstem CM for 79 enrolled patients was 27.2% (pre-GKS), 5.8% (2 years post-GKS), 3.4% (10 years post-GKS), and 3.5% (> 10 years post-GKS). Out of the 79 enrolled patients, 35 presented with focal neurologic deficits at the initial clinical visit. Among these patients, 74.3% showed recovery at the last follow-up. Symptomatic ARE occurred in five (6.4%) patients. No mortality occurred. Most lesions were decreased in size at the last follow-up MRI. Previous hemorrhage history (hazard ratio [HR], 8.38; 95% confidence interval [CI], 1.07-65.88; P = 0.043), and brainstem location (HR, 3.10; 95% CI, 1.26-7.64; P = 0.014) were significant risk factors for hemorrhage event.

CONCLUSION

GKS for CCM showed favorable long-term outcomes. GKS should be considered for CCM, especially when it has a previous hemorrhage history and brainstem location.

CT histogram analysis to distinguish between acute intracerebral hemorrhage and cavernous hemangioma

OBJECTIVE

Acute intracerebral hemorrhage (AICH) and cerebral cavernous hemangioma (CCM) are two common cerebral hemorrhage diseases with partially overlapping CT findings and clinical symptoms, making it hard to distinguish between them. The current study used histogram analysis based on CT images to differentiate between CCM and AICH and test its diagnosis performance.

METHODS

This retrospective study included 158 patients with CCM and 137 patients with AICH. The histograms of brain CT plain scan images of both groups were extracted using Python code and included 18 histogram parameters of the lesions. The most effective parameters were selected by univariate logistic regression analysis and Spearman correlation analysis and included in the final multivariate logistic regression model. The sample was randomly divided into the training set and the validation set by 7:3. The ROC curve was constructed to evaluate the discriminant efficiency of the final logistic regression model in distinguishing between AICH and CCM.

RESULTS

The univariate analysis identified seven significant histogram parameters with the following final logistic regression model: F = 3.731 + 2.6411 × 10-9 × Energy-1.192 × Kurtosis-0.003 × Minimum-1.449 × Skewness + 2.5002 × 10-10 × Total Energy-1.103 × Uniformity+0.009 × Variance. The model showed good diagnostic performance in distinguishing between AICH and CCM, with an AUC of 0.876, sensitivity of 70.8%, and specificity of 91.9% in the training set, and an AUC of 0.870, sensitivity of 82.9%, and specificity of 85.1% in the validation set.

CONCLUSIONS

The histogram analysis of brain CT images can be used as an auxiliary method to distinguish between AICH and CCM effectively.

Multiple Cavernous Malformation Syndrome in an Infant: A Case Report

Cerebral cavernomas belong to a group of vascular lesions characterized by varying structural properties and presentations. Clinical manifestations vary among patients and are particularly influenced by age, posing challenges in diagnosis and treatment. Here, we present a pediatric case of a cerebral cavernoma, which is very rare. We further aim to emphasize the importance of a good physical examination.

Cavernous Malformation From Cranial Nerves: A Systematic Review With a Novel Classification and Patient-Level Analysis

BACKGROUND AND OBJECTIVES

Cavernous malformations (CMs) occurring in the cranial nerve (CN) are extremely rare, and there is currently no comprehensive review on CN CMs, leading to a lack of sufficient understanding of CN CMs. We aimed to systematically review all published CN CM cases; summarize the epidemiology, clinical manifestations, treatment, and prognosis of CN CMs; and identify factors influencing the prognosis of CN CMs.

METHODS

This systematic review identified all cases potentially diagnosed with CN CM through a systematic search of PubMed, SCOPUS, Web of Science, and Cochrane databases. This represents the most comprehensive systematic review to date. We classified CN CMs based on their anatomic origins. Patient characteristics, disease manifestations, treatment approaches, and prognosis were summarized descriptively. Further analysis was conducted to identify factors influencing the prognosis of CN CMs.

RESULTS

The final analysis included 108 articles (127 individual patient cases). The optic nerve (49/128, 38.3%) is the most commonly affected nerve. Notably, CN CMs can be categorized into 3 types: Intraneural, Perineural, and Extraneural. Preoperative nerve function status and novel classification were associated with the prognosis of CN CMs (P = .001; P < .001). The postoperative neurological deterioration rate for the Intraneural type was 19/37 (51.4%); for the Extraneural type, it was 13/69 (18.8%); and for the Perineural type, it was 1/22 (4.5%) (P < .001).

CONCLUSION

We reviewed all the published CN CMs to date, offering a comprehensive description of CN CMs for the first time and identifying prognostic factors. The classification of CN CMs proposed in this study could serve as guidance for the selection of intraoperative treatment regimens. The findings of this systematic review are expected to provide a foundation for clinical decision-making in this crucial rare disease and lay the groundwork for developing relevant clinical guidelines.

Modeling blood-brain barrier formation and cerebral cavernous malformations in human PSC-derived organoids

The human blood-brain barrier (hBBB) is a highly specialized structure that regulates passage across blood and central nervous system (CNS) compartments. Despite its critical physiological role, there are no reliable in vitro models that can mimic hBBB development and function. Here, we constructed hBBB assembloids from brain and blood vessel organoids derived from human pluripotent stem cells. We validated the acquisition of blood-brain barrier (BBB)-specific molecular, cellular, transcriptomic, and functional characteristics and uncovered an extensive neuro-vascular crosstalk with a spatial pattern within hBBB assembloids. When we used patient-derived hBBB assembloids to model cerebral cavernous malformations (CCMs), we found that these assembloids recapitulated the cavernoma anatomy and BBB breakdown observed in patients. Upon comparison of phenotypes and transcriptome between patient-derived hBBB assembloids and primary human cavernoma tissues, we uncovered CCM-related molecular and cellular alterations. Taken together, we report hBBB assembloids that mimic the core properties of the hBBB and identify a potentially underlying cause of CCMs.

Plasma water T2 detects age-stratified differences in cardiometabolic health among familial CCM patients with Hispanic CCM1 mutation

Cerebral cavernous malformations (CCMs) are abnormal clusters of capillaries in the nervous system. This pilot study analyzed the cardiometabolic health status of individuals with familial CCMs caused by a rare mutation in the CCM1 gene (fCCM1). The aim was to compare plasma water T2 values from individuals with fCCM1 with values from metabolically unhealthy and healthy individuals with no known CCM mutations. This observational, cross-sectional study included 75 participants: 11 fCCM1 patients, 24 metabolically unhealthy and 40 metabolically healthy individuals. Plasma water T2, an early, global and practical marker of cardiometabolic health, was measured in the time domain using benchtop magnetic resonance relaxometry. The results were stratified by age (equal to or less than 45 vs. older than 45 years). Group means were compared using Welch's one-way ANOVA and post hoc Tukey-Kramer tests. Multivariable linear regression, with T2 as the outcome variable, was used to explore associations with age, gender, Hispanic ethnicity and fCCM1 status. In the younger age stratum, the fCCM1 group had a mean plasma water T2 value comparable to the metabolically healthy group (p = 0.6388), but higher than the unhealthy group (p < 0.0001). By contrast, in the older stratum, the mean plasma water T2 value for the fCCM1 group was comparable to the metabolically unhealthy group (p = 0.7819) and lower than the healthy group (p = 0.0005). Multivariable linear regression revealed that age and the interaction between age and fCCM1 status were significant predictors of T2, even after adjusting for gender and Hispanic ethnicity. Plasma water T2 shows potential as a biomarker for assessing the health status of individuals with fCCM1. Further research is needed to validate these preliminary observations and elucidate the association between CCMs and cardiometabolic health.

Is endoscopic resection a useful technique for a cavernous sinus sellar cavernoma? A case report and literature review

BACKGROUND

Cavernous sinus cavernous malformations (CSCMs) is a vascular malformation of the cavernous sinus. Nowadays, there is an increasing preference to withhold using the terms cavernoma or cavernous hemangioma in order to stop considering these lesions as vascular neoplasms. These lesions are highly vascularized making surgical resection a challenge, mainly in endoscopic approaches. We present a case of this tumor treated in our institution with an endoscopic endonasal approach and incomplete resection. Because of the strenuous resection through this approach, we systematically reviewed the reported endoscopic cases of CSCMs to determine their intraoperative complications, results and tumor features.

METHODS

Using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, one database (PubMed) and crossed references were queried for CSCMs from 1948 to 2020. Data regarding demographic features, clinical presentation, MRI features, surgical results and overall pathology features extracted.

RESULTS

Eighteen patients were selected (including our case). The mean age was 50.4 ± 14 years. Pituitary dysfunction and cavernous sinus nerve compression were the most reported symptoms. Only five cases (27%) reported a gross total resection (GTR) through endoscopic endonasal approach. Intraoperative bleeding was the most frequent intraoperative complication.

CONCLUSION

We present a comprehensive analysis of every reported CSCM treated through endoscopic approach. Partial or subtotal resection are the most used techniques because of the intraoperative bleeding and the adherence to surrounding structures. Radiotherapy is a very good option for patients with incomplete resections.

Improved differentiation of cavernous malformation and acute intraparenchymal hemorrhage on CT using an AI algorithm

This study aimed to evaluate the utility of an artificial intelligence (AI) algorithm in differentiating between cerebral cavernous malformation (CCM) and acute intraparenchymal hemorrhage (AIH) on brain computed tomography (CT). A retrospective, multireader, randomized study was conducted to validate the performance of an AI algorithm in differentiating AIH from CCM on brain CT. CT images of CM and AIH (< 3 cm) were identified from the database. Six blinded reviewers, including two neuroradiologists, two radiology residents, and two emergency department physicians, evaluated CT images from 288 patients (CCM, n = 173; AIH, n = 115) with and without AI assistance, comparing diagnostic performance. Brain CT interpretation with AI assistance resulted in significantly higher diagnostic accuracy than without (86.92% vs. 79.86%, p < 0.001). Radiology residents and emergency department physicians showed significantly improved accuracy of CT interpretation with AI assistance than without (84.21% vs. 75.35%, 80.73% vs. 72.57%; respectively, p < 0.05). Neuroradiologists showed a trend of higher accuracy with AI assistance in the interpretation but lacked statistical significance (95.83% vs. 91.67%, p = 0.56). The use of an AI algorithm can enhance the differentiation of AIH from CCM in brain CT interpretation, particularly for nonexperts in neuroradiology.

Circulating Blood Prognostic Biomarker Signatures for Hemorrhagic Cerebral Cavernous Malformations (CCMs)

Cerebral cavernous malformations (CCMs) are a neurological disorder characterized by enlarged intracranial capillaries in the brain, increasing the susceptibility to hemorrhagic strokes, a major cause of death and disability worldwide. The limited treatment options for CCMs underscore the importance of prognostic biomarkers to predict the likelihood of hemorrhagic events, aiding in treatment decisions and identifying potential pharmacological targets. This study aimed to identify blood biomarkers capable of diagnosing and predicting the risk of hemorrhage in CCM1 patients, establishing an initial set of circulating biomarker signatures. By analyzing proteomic profiles from both human and mouse CCM models and conducting pathway enrichment analyses, we compared groups to identify potential blood biomarkers with statistical significance. Specific candidate biomarkers primarily associated with metabolism and blood clotting pathways were identified. These biomarkers show promise as prognostic indicators for CCM1 deficiency and the risk of hemorrhagic stroke, strongly correlating with the likelihood of hemorrhagic cerebral cavernous malformations (CCMs). This lays the groundwork for further investigation into blood biomarkers to assess the risk of hemorrhagic CCMs.

Comprehensive CCM3 Mutational Analysis in Two Patients with Syndromic Cerebral Cavernous Malformation

Cerebral cavernous malformation (CCM) is a vascular disease that affects the central nervous system, which familial form is due to autosomal dominant mutations in the genes KRIT1(CCM1), MGC4607(CCM2), and PDCD10(CCM3). Patients affected by the PDCD10 mutations usually have the onset of symptoms at an early age and a more aggressive phenotype. The aim of this study is to investigate the molecular mechanism involved with CCM3 disease pathogenesis. Herein, we report two typical cases of CCM3 phenotype and compare the clinical and neuroradiological findings with five patients with a familial form of KRIT1 or CCM2 mutations and six patients with a sporadic form. In addition, we evaluated the PDCD10 gene expression by qPCR and developed a bioinformatic pipeline to understand the structural changes of mutations. The two CCM3 patients had an early onset of symptoms and a high lesion burden. Furthermore, the sequencing showed that Patient 1 had a frameshift mutation in c.222delT; p.(Asn75Thrfs*14) that leads to lacking the last 124 C-terminal amino acids on its primary structure and Patient 2 had a variant on the splicing site region c.475-2A > G. The mRNA expression was fourfold lower in both patients with PDCD10 mutation. Using in silico analysis, we identify that the frameshift mutation transcript lacks the C-terminal FAT-homology domain compared to the wild-type PDCD10 and preserves the N-terminal dimerization domain. The two patients studied here allow estimating the potential impact of mutations in clinical interpretation as well as support to better understand the mechanism and pathogenesis of CCM3.

An imaging review of the hippocampus and its common pathologies

The hippocampus is a complex structure located in the mesial temporal lobe that plays a critical role in cognitive and memory-related processes. The hippocampal formation consists of the dentate gyrus, hippocampus proper, and subiculum, and its importance in the neural circuitry makes it a key anatomic structure to evaluate in neuroimaging studies. Advancements in imaging techniques now allow detailed assessment of hippocampus internal architecture and signal features that has improved identification and characterization of hippocampal abnormalities. This review aims to summarize the neuroimaging features of the hippocampus and its common pathologies. It provides an overview of the hippocampal anatomy on magnetic resonance imaging and discusses how various imaging techniques can be used to assess the hippocampus. The review explores neuroimaging findings related to hippocampal variants (incomplete hippocampal inversion, sulcal remnant and choroidal fissure cysts), and pathologies of neoplastic (astrocytoma and glioma, ganglioglioma, dysembryoplastic neuroepithelial tumor, multinodular and vacuolating neuronal tumor, and metastasis), epileptic (mesial temporal sclerosis and focal cortical dysplasia), neurodegenerative (Alzheimer's disease, progressive primary aphasia, and frontotemporal dementia), infectious (Herpes simplex virus and limbic encephalitis), vascular (ischemic stroke, arteriovenous malformation, and cerebral cavernous malformations), and toxic-metabolic (transient global amnesia and opioid-associated amnestic syndrome) etiologies.

Infratentorial Cerebral Cavernous Malformation May be a Risk Factor for Symptomatic Bleeding and Precocity of Symptoms: A Multicenter, Propensity Score Matched, Case-Control Study

BACKGROUND

Cerebral Cavernous Malformation (CCM) is one of the most common types of vascular malformation of the central nervous system. Intracerebral hemorrhage, seizures, and lesional growth are the main clinical manifestations. Natural history studies have tried to identify many risk factors; however, the clinical course remains highly unpredictable.

OBJECTIVE

Here, we have analyzed a multicenter CCM cohort looking for the differential clinical data regarding the patients harboring supra and/or infratentorial cavernous malformations in order to better understand risk factors involved in the anatomical location of the unique neurosurgical disease.

METHODS

We have presented a multicenter, Propensity Score Matched (PSM), case-control study including 149 consecutive CCM cases clinically evaluated from May 2017 to December 2022 from three different neurosurgical centers. Epidemiological data were defined at each clinical assessment. Logistic regression was used to identify the independent contribution of each possible risk factor to the bleeding risk. To balance baseline covariates between patients with and without symptoms, and specifically between those with and without symptomatic bleeding, we used a PSM strategy. The Kaplan-Meier curve was drawn to evaluate if patients with infratentorial lesions had a greater chance of bleeding earlier in their life.

RESULTS

The presence of infratentorial lesions was a risk factor in the multivariate analysis comparing the bleeding risk with pure asymptomatic individuals (OR: 3.23, 95% CI 1.43 - 7.26, P = 0.005). Also, having an infratentorial CCM was a risk factor after PSM (OR: 4.56, 95% CI 1.47 - 14.10, P = 0.008). The presence of an infratentorial lesion was related to precocity of symptoms when the time to first bleed was compared to all other clinical presentations in the overall cohort (P = 0.0328) and in the PSM group (P = 0.03).

CONCLUSION

Here, we have provided some evidence that infratentorial cerebral cavernous malformation may have a more aggressive clinical course, being a risk factor for symptomatic haemorrhage and precocity of bleeding.

Seizure outcome in medically treated patients with adult-onset epilepsy and cerebral cavernous malformation

PURPOSE

We evaluated long-term seizure outcomes of antiseizure medications (ASMs) and risk factors for drug resistance in patients with adult-onset epilepsy associated with cerebral cavernous malformation (CCM).

MATERIALS AND METHODS

This retrospective observational study included patients newly diagnosed with adult-onset focal epilepsy associated with CCM. Patients received individualized treatments with ASMs. All patients were followed-up for at least 2 years. The main outcome measure was terminal 2 year seizure freedom (2-YSF).

RESULTS

Forty eight subjects (28 men and 20 women) were included. Thirty-one (64.6%) subjects achieved a terminal 2-YSF (range 2.0-17.0 years). After treatment with the first drug regimen, 31 (64.6%) subjects achieved 2-YSF, with 23 remaining seizure-free until final follow-up visit. Of the 23 subjects treated with the second drug regimen and the six treated with the third drug regimen, ten (43.5%) and one (16.7%), respectively, achieved a terminal 2-YSF. Stepwise logistic regression analyses showed that terminal 2-YSF was negatively associated with epileptiform discharge on EEG at the time of diagnosis (odds ratio = 0.214, p = 0.047) and tended to be associated with age ≥ 45 years at seizure onset (odds ratio = 4.260, p = 0.056).

CONCLUSION

The present study found that 64.6% of CCM patients with adult-onset epilepsy achieved terminal 2-YSF after ASM initiation. Interictal epileptiform discharge on EEG at the time of diagnosis was associated with poor prognosis. Failure to achieve sustained seizure freedom after two ASMs may indicate the need for surgical treatment.

Significance of perilesional T1 hyperintense areas in the differential diagnosis of primary adult-type diffuse glioma: A case report

Perilesional T1 hyperintensity on magnetic resonance imaging (MRI) of intra-axial brain masses is an unusual feature of the perilesional area, characteristic of cavernous malformations (CMs) and metastatic brain tumors (METs). Here, we report a case of primary diffuse glioma with a perilesional T1 hyperintense area (HIA) on MRI. A 61-year-old woman with transient aphasia visited our hospital. Radiological examination revealed an intra-axial mass with acute/subacute hemorrhaging and calcification in the left frontal lobe. It was presumed to be a CM because of the perilesional T1 HIA. Gross total resection of the tumor was performed, and the pathological diagnosis was anaplastic oligodendroglioma, not otherwise specified by World Health Organization 2016 classification. Histopathological findings in the perilesional T1 HIA indicated hemorrhage involvement in the surrounding white matter. No recurrence appeared after radio-chemotherapy. Perilesional T1 HIAs, characteristic of CMs and METs, are also seen in primary diffuse gliomas. Therefore, caution should be taken when using this sign for the differential diagnosis of intracranial masses.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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%).

CONCLUSIONS

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.

Role of Genetics and Surgical Interventions for the Management of Cerebral Cavernous Malformations (CMM)

Cerebral cavernous malformations (CCMs) are comprised of tissue matter within the brain possessing anomalous vascular architecture. In totality, the dilated appearance of the cavernomatakes on a mulberry-like shape contributed by the shape and relation to vascular and capillary elements. Analyzing its pathophysiology along with its molecular and genetic pathways plays a vital role in whether or not a patient receives GKRS, medical management, or Surgery, the most invasive of procedures. To avoid neurological trauma, microsurgical resection of cavernomas canbe guided by the novel clinical application of a 3D Slicer with Sina/MosoCam. When cavernomas present in deep lesions with poor accessibility, gamma knife stereotactic radiosurgery (GKSR) is recommended. For asymptomatic and non-multilobal lesions, medical and symptom management is deemed standard, such as antiepileptic therapy. The two-hit hypothesis serves to explain the mutations in three key genes that are most pertinent to the progression of cavernomas: CCM1/KRIT1, CCM2/Malcavernin, and CCM3/PDCD10. Various exon deletions and frameshift mutations can cause dysfunction in vascular structure through loss and gain of function mutations. MEKK3 and KLF2/4 are involved in a protein kinase signaling cycle that promotes abnormal angiogenesis and cavernoma formation. In terms of potential treatments, RhoKinase inhibitors have shown to decrease endothelial to mesenchymal transition and CCM lesion development in mice models. All in all, understanding the research behind the molecular genetics in CCMs can foster personalized medicine and potentially create new neurosurgical and medicative treatments.

The Brainstem Cavernoma Case Series: A Formula for Surgery and Surgical Technique

Background and Objectives: Cavernous malformations (CM) are vascular malformations with low blood flow. The removal of brainstem CMs (BS) is associated with high surgical morbidity, and there is no general consensus on when to treat deep-seated BS CMs. The aim of this study is to compare the surgical outcomes of a series of deep-seated BS CMs with the surgical outcomes of a series of superficially located BS CMs operated on at the Department of Neurosurgery, College of Tuebingen, Germany. Materials and Methods: A retrospective evaluation was performed using patient charts, surgical video recordings, and outpatient examinations. Factors were identified in which surgical intervention was performed in cases of BS CMs. Preoperative radiological examinations included MRI and diffusion tensor imaging (DTI). For deep-seated BS CMs, a voxel-based 3D neuronavigation system and electrophysiological mapping of the brainstem surface were used. Results: A total of 34 consecutive patients with primary superficial (n = 20/58.8%) and deep-seated (n = 14/41.2%) brainstem cavernomas (BS CM) were enrolled in this comparative study. Complete removal was achieved in 31 patients (91.2%). Deep-seated BS CMs: The mean diameter was 14.7 mm (range: 8.3 to 27.7 mm). All but one of these lesions were completely removed. The median follow-up time was 5.8 years. Two patients (5.9%) developed new neurologic deficits after surgery. Superficial BS CMs: The median diameter was 14.9 mm (range: 7.2 to 27.3 mm). All but two of the superficial BS CMs could be completely removed. New permanent neurologic deficits were observed in two patients (5.9%) after surgery. The median follow-up time in this group was 3.6 years. Conclusions: The treatment of BS CMs remains complex. However, the results of this study demonstrate that with less invasive posterior fossa approaches, brainstem mapping, and neuronavigation combined with the use of a blunt "spinal cord" dissection technique, deep-seated BS CMs can be completely removed in selected cases, with good functional outcomes comparable to those of superficial BS CM.

Somatic variants of MAP3K3 are sufficient to cause cerebral and spinal cord cavernous malformations

Cerebral cavernous malformations (CCMs) and spinal cord cavernous malformations (SCCMs) are common vascular abnormalities of the CNS that can lead to seizure, haemorrhage and other neurological deficits. Approximately 85% of patients present with sporadic (versus congenital) CCMs. Somatic mutations in MAP3K3 and PIK3CA were recently reported in patients with sporadic CCM, yet it remains unknown whether MAP3K3 mutation is sufficient to induce CCMs. Here we analysed whole-exome sequencing data for patients with CCM and found that ∼40% of them have a single, specific MAP3K3 mutation [c.1323C>G (p.Ile441Met)] but not any other known mutations in CCM-related genes. We developed a mouse model of CCM with MAP3K3I441M uniquely expressed in the endothelium of the CNS. We detected pathological phenotypes similar to those found in patients with MAP3K3I441M. The combination of in vivo imaging and genetic labelling revealed that CCMs were initiated with endothelial expansion followed by disruption of the blood-brain barrier. Experiments with our MAP3K3I441M mouse model demonstrated that CCM can be alleviated by treatment with rapamycin, the mTOR inhibitor. CCM pathogenesis has usually been attributed to acquisition of two or three distinct genetic mutations involving the genes CCM1/2/3 and/or PIK3CA. However, our results demonstrate that a single genetic hit is sufficient to cause CCMs.

Plasma water T2 detects age-stratified differences in cardiometabolic health among familial CCM patients with Hispanic CCM1 mutation

Introduction

Cerebral cavernous malformations (CCMs) are abnormal clusters of capillaries in the nervous system. This pilot study analyzed the cardiometabolic health status of individuals with familial CCMs caused by a rare mutation in the CCM1 gene (fCCM1). The aim was to compare plasma water T2 values from individuals with fCCM1 with values from metabolically unhealthy and healthy individuals with no known CCM mutations.

Design

This observational, cross-sectional study included 75 participants: 11 fCCM1 patients, 24 metabolically unhealthy and 40 metabolically healthy individuals. Plasma water T2, an early, global and practical marker of cardiometabolic health, was measured in the time domain using benchtop magnetic resonance relaxometry. The results were stratified by age (equal to or less than 45 vs. older than 45 years). Group means were compared using Welch's one-way ANOVA and post hoc Tukey-Kramer tests. Multivariable linear regression, with T2 as the outcome variable, was used to explore associations with age, gender, Hispanic ethnicity and fCCM1 status.

Results

In the younger age stratum, the fCCM1 group had a mean plasma water T2 value comparable to the metabolically healthy group (p=0.6388), but higher than the unhealthy group (p<0.0001). By contrast, in the older stratum, the mean plasma water T2 value for the fCCM1 group was comparable to the metabolically unhealthy group (p=0.7819) and lower than the healthy group (p=0.0005). Multivariable linear regression revealed that age and the interaction between age and fCCM1 status were significant predictors of T2, even after adjusting for gender and Hispanic ethnicity.

Conclusion

Plasma water T2 shows potential as a biomarker for assessing the health status of individuals with fCCM1. Further research is needed to validate these preliminary observations and elucidate the association between CCMs and cardiometabolic health.

Plasma water T2 detects age-stratified differences in cardiometabolic health among familial CCM patients with Hispanic CCM1 mutation

Introduction

Cerebral cavernous malformations (CCMs) are abnormal clusters of capillaries in the nervous system. This pilot study analyzed the cardiometabolic health status of individuals with familial CCMs caused by a rare mutation in the CCM1 gene (fCCM1). The aim was to compare plasma water T2 values from individuals with fCCM1 with values from metabolically unhealthy and healthy individuals with no known CCM mutations.

Design

This observational, cross-sectional study included 75 participants: 11 fCCM1 patients, 24 metabolically unhealthy and 40 metabolically healthy individuals. Plasma water T2, an early, global and practical marker of cardiometabolic health, was measured in the time domain using benchtop magnetic resonance relaxometry. The results were stratified by age (≤ 45 vs. >45 years). Group means were compared using Welch's one-way ANOVA and post hoc Tukey-Kramer tests. Multivariable linear regression, with T2 as the outcome variable, was used to explore associations with age, gender, Hispanic ethnicity and fCCM1 status.

Results

In the younger age stratum, the fCCM1 group had a mean plasma water T2 value comparable to the metabolically healthy group (p=0.6388), but higher than the unhealthy group (p<0.0001). By contrast, in the older stratum, the mean plasma water T2 value for the fCCM1 group was comparable to the metabolically unhealthy group (p=0.7819) and lower than the healthy group (p=0.0005). Multivariable linear regression revealed that age and the interaction between age and fCCM1 status were significant predictors of T2, even after adjusting for gender and Hispanic ethnicity.

Conclusion

Plasma water T2 shows potential as a biomarker for assessing the health status of individuals with fCCM1. Further research is needed to validate these preliminary observations and elucidate the association between CCMs and cardiometabolic health.

Cavernous hemangioma of the cisternal segment of the auditory nerve: case report

BACKGROUND

Extraaxial cerebellopontine angle cavernous hemangiomas are rare and their diagnosis and treatment are challenging.

CASE PRESENTATION

A 43-year-old female was admitted to the hospital who had repeated hearing loss in her left ear accompanied by tinnitus. Magnetic resonance imaging revealed a hemangioma-like lesion in the left cerebellopontine angle extra-axial cisternal segment. During the surgery, it was found that the lesion was located in the cisternal segment of the root of the auditory nerve. Postoperative pathological examination confirmed that the lesion was a cavernous hemangioma.

CONCLUSION

We report a case of cavernous hemangioma in the brain spatula cisternal segment of the left auditory nerve. For cranial nerve CMs early diagnosis and surgical removal may maximize the chance of a positive outcome.

CmPn/CmP Signaling Networks in the Maintenance of the Blood Vessel Barrier

Cerebral cavernous malformations (CCMs) arise when capillaries within the brain enlarge abnormally, causing the blood-brain barrier (BBB) to break down. The BBB serves as a sophisticated interface that controls molecular interactions between the bloodstream and the central nervous system. The neurovascular unit (NVU) is a complex structure made up of neurons, astrocytes, endothelial cells (ECs), pericytes, microglia, and basement membranes, which work together to maintain blood-brain barrier (BBB) permeability. Within the NVU, tight junctions (TJs) and adherens junctions (AJs) between endothelial cells play a critical role in regulating the permeability of the BBB. Disruptions to these junctions can compromise the BBB, potentially leading to a hemorrhagic stroke. Understanding the molecular signaling cascades that regulate BBB permeability through EC junctions is, therefore, essential. New research has demonstrated that steroids, including estrogens (ESTs), glucocorticoids (GCs), and metabolites/derivatives of progesterone (PRGs), have multifaceted effects on blood-brain barrier (BBB) permeability by regulating the expression of tight junctions (TJs) and adherens junctions (AJs). They also have anti-inflammatory effects on blood vessels. PRGs, in particular, have been found to play a significant role in maintaining BBB integrity. PRGs act through a combination of its classic and non-classic PRG receptors (nPR/mPR), which are part of a signaling network known as the CCM signaling complex (CSC). This network couples both nPR and mPR in the CmPn/CmP pathway in endothelial cells (ECs).

Cavernoma-Related Epilepsy: Postoperative Epilepsy Outcome and Analysis of the Predictive Factors, Case Series

BACKGROUND

Epilepsy is common in patients harboring cavernous malformation, and surgery is reported to be an effective treatment. However, few patients still experience seizures after surgery. We analyzed the outcome and predictive factors after cavernoma-related epilepsy (CRE) surgery.

METHODS

A database was created for all patients with CRE treated surgically from 2003 to 2020 at a university hospital. A chart review, perioperative epilepsy workup, surgical strategies, and postoperative and follow-up notes were analyzed. Postoperative seizure outcome was evaluated according to the Engel classification.

RESULTS

Thirty-seven patients (40.5% women; mean age 39.1 ± 14.5 years) were studied. The mean follow-up time was 5.6 ± 3.9 years. Among 37 patients, 32 (86.5%) achieved Engel class I at the last follow-up. Engel class II was found in 1 (2.7%), Engel class III in 1 (2.7%), and Engel class IV in 3 (8.1%) cases. Engel class Ia was observed in 23 patients (62.2%). None of the patients had a worse seizure outcome after the operation (Engel class IVc). Univariate and multivariate analysis showed that short-standing, sporadic, or low-frequent (≤3) seizures were the only variables significantly associated with seizure freedom, whereas longstanding, drug-resistant, or high-frequent seizure history were associated with worse seizure outcomes.

CONCLUSIONS

Surgical treatment results in favorable seizure control in most patients after CRE surgery. Long duration of epilepsy before surgery, high seizure frequency, and drug-resistant epilepsy could have a negative effect on seizure outcome (Engel class II-IV). Therefore, early surgical resection of the cavernoma after careful presurgical planning is recommended to achieve an optimal result.

KRIT1: A Traffic Warden at the Busy Crossroads Between Redox Signaling and the Pathogenesis of Cerebral Cavernous Malformation Disease

Significance: KRIT1 (Krev interaction trapped 1) is a scaffolding protein that plays a critical role in vascular morphogenesis and homeostasis. Its loss-of-function has been unequivocally associated with the pathogenesis of Cerebral Cavernous Malformation (CCM), a major cerebrovascular disease of genetic origin characterized by defective endothelial cell-cell adhesion and ensuing structural alterations and hyperpermeability in brain capillaries. KRIT1 contributes to the maintenance of endothelial barrier function by stabilizing the integrity of adherens junctions and inhibiting the formation of actin stress fibers. Recent Advances: Among the multiple regulatory mechanisms proposed so far, significant evidence accumulated over the past decade has clearly shown that the role of KRIT1 in the stability of endothelial barriers, including the blood-brain barrier, is largely based on its involvement in the complex machinery governing cellular redox homeostasis and responses to oxidative stress and inflammation. KRIT1 loss-of-function has, indeed, been demonstrated to cause an impairment of major redox-sensitive mechanisms involved in spatiotemporal regulation of cell adhesion and signaling, which ultimately leads to decreased cell-cell junction stability and enhanced sensitivity to oxidative stress and inflammation. Critical Issues: This review explores the redox mechanisms that influence endothelial cell adhesion and barrier function, focusing on the role of KRIT1 in such mechanisms. We propose that this supports a novel model wherein redox signaling forms the common link between the various pathogenetic mechanisms and therapeutic approaches hitherto associated with CCM disease. Future Directions: A comprehensive characterization of the role of KRIT1 in redox control of endothelial barrier physiology and defense against oxy-inflammatory insults will provide valuable insights into the development of precision medicine strategies. Antioxid. Redox Signal. 38, 496-528.

Endothelial Differentiation of CCM1 Knockout iPSCs Triggers the Establishment of a Specific Gene Expression Signature

Cerebral cavernous malformation (CCM) is a neurovascular disease that can lead to seizures and stroke-like symptoms. The familial form is caused by a heterozygous germline mutation in either the CCM1, CCM2, or CCM3 gene. While the importance of a second-hit mechanism in CCM development is well established, it is still unclear whether it immediately triggers CCM development or whether additional external factors are required. We here used RNA sequencing to study differential gene expression in CCM1 knockout induced pluripotent stem cells (CCM1^-/- iPSCs), early mesoderm progenitor cells (eMPCs), and endothelial-like cells (ECs). Notably, CRISPR/Cas9-mediated inactivation of CCM1 led to hardly any gene expression differences in iPSCs and eMPCs. However, after differentiation into ECs, we found the significant deregulation of signaling pathways well known to be involved in CCM pathogenesis. These data suggest that a microenvironment of proangiogenic cytokines and growth factors can trigger the establishment of a characteristic gene expression signature upon CCM1 inactivation. Consequently, CCM1^-/- precursor cells may exist that remain silent until entering the endothelial lineage. Collectively, not only downstream consequences of CCM1 ablation but also supporting factors must be addressed in CCM therapy development.

Functional outcome after initial and multiple intracerebral hemorrhages in children with cerebral cavernous malformations

BACKGROUND AND PURPOSE

We aimed to assess the course and predictors of functional outcome after single and multiple intracerebral hemorrhage (ICH) in pediatric patients with cerebral cavernous malformations (CCMs) and to conduct a risk assessment of a third bleed during the first follow-up year after second ICH.

METHODS

We included patients aged ≤18 years with complete baseline characteristics, a magnetic resonance imaging dataset, ≥1 CCM-related ICH and ≥1 follow-up examination, who were treated between 2003 and 2021. Neurological functional status was obtained using modified Rankin Scale scores at diagnosis, before and after each ICH, and at last follow-up. Kaplan-Meier analysis was performed to determine the cumulative 1-year risk of third ICH.

RESULTS

A total of 55 pediatric patients (median [interquartile range] age 12 [11] years) were analyzed. Univariate analysis identified brainstem cavernous malformation (BSCM; p = 0.019) as a statistically significant predictor for unfavorable outcome after second ICH. Outcome after second ICH was significantly worse in 12 patients (42.9%; p = 0.030) than after first ICH and in five patients (55.6%; p = 0.038) after a third ICH compared to a second ICH. Cumulative 12-month risk of rebleeding during the first year after a second ICH was 10.7% (95% confidence interval 2.8%-29.37%).

CONCLUSIONS

Pediatric patients with a BSCM have a higher risk of worse outcome after second ICH. Functional outcome improves over time after an ICH but worsens following each ICH compared to baseline or previous ICH. Second bleed was associated with neurological deterioration compared to initial ICH, and this deteriorated further after a third ICH.

Functional outcome after pediatric cerebral cavernous malformation surgery

The purpose of this study was to investigate the functional outcome following surgical resection of cerebral cavernous malformations (CCM) in pediatric patients. We screened our institutional database of CCM patients treated between 2003 and 2021. Inclusion regarded individuals younger or equal than 18 years of age with complete clinical baseline characteristics, magnetic resonance imaging dataset, and postoperative follow-up time of at least three months. Functional outcome was quantified using the modified Rankin Scale (mRS) score and assessed at admission, discharge, and last follow-up examination. The primary endpoint was the postoperative functional outcome. As a secondary endpoint, predictors of postoperative functional deterioration were assessed. A total of 49 pediatric patients with a mean age of 11.3 ± 5.7 years were included for subsequent analyses. Twenty individuals (40.8%) were female. Complete resection of the lesion was achieved in 44 patients (89.8%), and two patients with incomplete resection were referred for successive remnant removal. The mean follow-up time after surgery was 44 months (IQR: 13 - 131). The mean mRS score was 1.6 on admission, 1.7 at discharge, and 0.9 at the latest follow-up. Logistic regression analysis adjusted to age and sex identified brainstem localization (aOR = 53.45 [95%CI = 2.26 - 1261.81], p = .014) as a predictor of postoperative deterioration. This study indicates that CCM removal in children can be regarded as safe and favorable for the majority of patients, depending on lesion localization. Brainstem localization implies a high risk of postoperative morbidity and indication for surgery should be balanced carefully. Minor evidence indicates that second-look surgery for CCM remnants might be safe and favorable.

Multidrug-Loaded Lipid Nanoemulsions for the Combinatorial Treatment of Cerebral Cavernous Malformation Disease

Cerebral cavernous malformation (CCM) or cavernoma is a major vascular disease of genetic origin, whose main phenotypes occur in the central nervous system, and is currently devoid of pharmacological therapeutic strategies. Cavernomas can remain asymptomatic during a lifetime or manifest with a wide range of symptoms, including recurrent headaches, seizures, strokes, and intracerebral hemorrhages. Loss-of-function mutations in KRIT1/CCM1 are responsible for more than 50% of all familial cases, and have been clearly shown to affect cellular junctions, redox homeostasis, inflammatory responses, and angiogenesis. In this study, we investigated the therapeutic effects of multidrug-loaded lipid nanoemulsions in rescuing the pathological phenotype of CCM disease. The pro-autophagic rapamycin, antioxidant avenanthramide, and antiangiogenic bevacizumab were loaded into nanoemulsions, with the aim of reducing the major molecular dysfunctions associated with cavernomas. Through Western blot analysis of biomarkers in an in vitro CCM model, we demonstrated that drug-loaded lipid nanoemulsions rescue antioxidant responses, reactivate autophagy, and reduce the effect of pro-angiogenic factors better than the free drugs. Our results show the importance of developing a combinatorial preventive and therapeutic approach to reduce the risk of lesion formation and inhibit or completely revert the multiple hallmarks that characterize the pathogenesis and progression of cavernomas.

The use of stereotactic MRI-guided laser interstitial thermal therapy for the treatment of pediatric cavernous malformations: the SUNY Upstate Golisano Children's Hospital experience

PURPOSE

Cavernous malformations (CM) are central nervous system lesions characterized by interlaced vascular sinusoids coated with endothelial cells without intervening parenchyma. Magnetic resonance imaging-guided laser interstitial thermal therapy (MRIgLITT) is a minimally invasive treatment modality that can precisely treat pathologic cerebral tissue, making it an effective alternative for the management of cavernomas. We describe the outcomes of a series of pediatric patients with cavernous brain malformations treated with MRIgLITT between 2014 and 2018 at our institution.

METHODS

We retrospectively analyzed 11 cavernomas in 6 pediatric patients treated with MRIgLITT. Both the Visualase System^® and/or Neuroblate^® systems were used. A variation of the surgical technique on the application of the laser was developed. Post-ablation MRIs were obtained to assess ablated areas.

RESULTS

A total of 11 cavernomas in 6 patients were treated with MRIgLITT. Median age was 15 years (12 to 17 years); 75% were males. Presenting symptoms were headache (75%) and seizures (25%). Two patients presented with multiple CMs. All lesions in this study were supratentorial (cerebral hemispheres 81.8%, corpus callosum 9.1%, basal ganglia 9.1%). Our surgical technique was well-tolerated, with no significant adverse events observed. Hospital stay for all patients was less than 48 hours.

CONCLUSION

MRIgLITT is an effective minimally invasive technique for the treatment of pediatric CMs. It represents a useful and safe tool, when other therapeutic alternatives may represent a greater risk of surgical morbidity.

Clinical characteristics and risk factors of cerebral cavernous malformation-related epilepsy

PURPOSE

This study aimed to summarize the clinical characteristics and explore the risk factors for cerebral cavernous malformation (CCM)-related epilepsy (CRE).

METHODS

We retrospectively analyzed the clinical data of patients with CCM in our cerebral vascular malformations database. Descriptive statistics were used to present the clinical characteristics of CRE patients. Patients were divided into a CRE and a non-CRE group according to clinical presentation. Binary logistic regression analysis was used to analyze the risk factors of CRE.

RESULTS

A total of 199 patients with CCM confirmed by postoperative pathological examination were enrolled, 93 of whom were diagnosed with CRE, and 34 patients had drug-resistant epilepsy. The most common seizure type of CRE patients was focal to bilateral tonic-clonic seizure (FBTCS), followed by focal impaired awareness motor seizure. All CCM lesions were supratentorial, 97.8% of which involved the cerebral cortex, 86.0% of lesions had hemosiderin rim, and 50.5% of lesions were located in the temporal lobe. Binary logistic regression analysis indicated that CCM diagnosis age ≤ 44 years (odds ratio [OR] 2.79, p = 0.010), temporal lobe lesion location (OR = 9.07, p = 0.042), medial temporal lobe lesion (OR = 14.09, p = 0.002), cortical involvement of the lesion (OR = 32.77, p = 0.010), and hemosiderin rim around the lesion (OR = 16.48, p = 0.001) significantly increased the risk of CRE.

CONCLUSIONS

The most common seizure type of CRE was FBTCS. Those whose CCM diagnosis age was ≤ 44 years, having a temporal lobe lesion location, especially the medial temporal lobe lesion, cortical involvement, and hemosiderin rim around the lesion had a higher risk of developing CRE.

Behavioral Seizure in a Patient With a Cavernous Malformation Finding in CT: A Case Report

Behavioral epileptic seizures (BES) are a unique type of seizure that can be presented with or without the classic limb movements of epilepsy. This type of seizure is commonly associated with the frontal and temporal lobes of the brain. Symptoms consist of anxiety, smiling, crying, fear, aggression, irritability, and change in awareness or activity. We report a case of unusual seizure presentation of jerky movements followed by intense fear and crying caused by a right parietal cavernous malformation with chronic bleeding.

Distant Recurrence of a Cerebral Cavernous Malformation in the Vicinity of a Developmental Venous Anomaly: Case Report of Local Oxy-Inflammatory Events

BACKGROUND

Cerebral cavernous malformations (CCMs) are a major type of cerebrovascular lesions of proven genetic origin that occur in either sporadic (sCCM) or familial (fCCM) forms, the latter being inherited as an autosomal dominant condition linked to loss-of-function mutations in three known CCM genes. In contrast to fCCMs, sCCMs are rarely linked to mutations in CCM genes and are instead commonly and peculiarly associated with developmental venous anomalies (DVAs), suggesting distinct origins and common pathogenic mechanisms.

CASE REPORT

A hemorrhagic sCCM in the right frontal lobe of the brain was surgically excised from a symptomatic 3 year old patient, preserving intact and pervious the associated DVA. MRI follow-up examination performed periodically up to 15 years after neurosurgery intervention demonstrated complete removal of the CCM lesion and no residual or relapse signs. However, 18 years after surgery, the patient experienced acute episodes of paresthesia due to a distant recurrence of a new hemorrhagic CCM lesion located within the same area as the previous one. A new surgical intervention was, therefore, necessary, which was again limited to the CCM without affecting the pre-existing DVA. Subsequent follow-up examination by contrast-enhanced MRI evidenced a persistent pattern of signal-intensity abnormalities in the bed of the DVA, including hyperintense gliotic areas, suggesting chronic inflammatory conditions.

CONCLUSIONS

This case report highlights the possibility of long-term distant recurrence of hemorrhagic sCCMs associated with a DVA, suggesting that such recurrence is secondary to focal sterile inflammatory conditions generated by the DVA.

Medication intake and hemorrhage risk in patients with familial cerebral cavernous malformations

OBJECTIVE

The objective of this study was to analyze the impact of medication intake on hemorrhage risk in patients with familial cerebral cavernous malformation (FCCM).

METHODS

The authors' institutional database was screened for patients with FCCM who had been admitted to their department between 2003 and 2020. Patients with a complete magnetic resonance imaging (MRI) data set, evidence of multiple CCMs, clinical baseline characteristics, and follow-up (FU) examination were included in the study. The authors assessed the influence of medication intake on first or recurrent intracerebral hemorrhage (ICH) using univariate and multivariate logistic regression adjusted for age and sex. The longitudinal cumulative 5-year risk of hemorrhage was calculated by applying Kaplan-Meier and Cox regression analyses adjusted for age and sex.

RESULTS

Two hundred five patients with FCCMs were included in the study. Multivariate Cox regression analysis revealed ICH as a predictor for recurrent hemorrhage during the 5-year FU. The authors also noted a tendency toward a decreased association with ICH during FU in patients on statin medication (HR 0.22, 95% CI 0.03-1.68, p = 0.143), although the relationship was not statistically significant. No bleeding events were observed in patients on antithrombotic therapy. Kaplan-Meier analysis and log-rank test showed a tendency toward a low risk of ICH during FU in patients on antithrombotic therapy (p = 0.085), as well as those on statin therapy (p = 0.193). The cumulative 5-year risk of bleeding was 22.82% (95% CI 17.33%-29.38%) for the entire cohort, 31.41% (95% CI 23.26%-40.83%) for patients with a history of ICH, 26.54% (95% CI 11.13%-49.7%) for individuals on beta-blocker medication, 6.25% (95% CI 0.33%-32.29%) for patients on statin medication, and 0% (95% CI 0%-30.13%) for patients on antithrombotic medication.

CONCLUSIONS

ICH at diagnosis was identified as a risk factor for recurrent hemorrhage. Although the relationships were not statistically significant, statin and antithrombotic medication tended to be associated with decreased bleeding events.

Heterozygous Loss of KRIT1 in Mice Affects Metabolic Functions of the Liver, Promoting Hepatic Oxidative and Glycative Stress

KRIT1 loss-of-function mutations underlie the pathogenesis of Cerebral Cavernous Malformation (CCM), a major vascular disease affecting the central nervous system (CNS). However, KRIT1 is also expressed outside the CNS and modulates key regulators of metabolic and oxy-inflammatory pathways, including the master transcription factor FoxO1, suggesting a widespread functional significance. Herein, we show that the KRIT1/FoxO1 axis is implicated in liver metabolic functions and antioxidative/antiglycative defenses. Indeed, by performing comparative studies in KRIT1 heterozygous (KRIT1^+/−) and wild-type mice, we found that KRIT1 haploinsufficiency resulted in FoxO1 expression/activity downregulation in the liver, and affected hepatic FoxO1-dependent signaling pathways, which are markers of major metabolic processes, including gluconeogenesis, glycolysis, mitochondrial respiration, and glycogen synthesis. Moreover, it caused sustained activation of the master antioxidant transcription factor Nrf2, hepatic accumulation of advanced glycation end-products (AGEs), and abnormal expression/activity of AGE receptors and detoxifying systems. Furthermore, it was associated with an impairment of food intake, systemic glucose disposal, and plasma levels of insulin. Specific molecular alterations detected in the liver of KRIT1^+/− mice were also confirmed in KRIT1 knockout cells. Overall, our findings demonstrated, for the first time, that KRIT1 haploinsufficiency affects glucose homeostasis and liver metabolic and antioxidative/antiglycative functions, thus inspiring future basic and translational studies.

Using CRISPR/Cas9 genome editing in human iPSCs for deciphering the pathogenicity of a novel CCM1 transcription start site deletion

Cerebral cavernous malformations are clusters of aberrant vessels that can lead to severe neurological complications. Pathogenic loss-of-function variants in the CCM1, CCM2, or CCM3 gene are associated with the autosomal dominant form of the disease. While interpretation of variants in protein-coding regions of the genes is relatively straightforward, functional analyses are often required to evaluate the impact of non-coding variants. Because of multiple alternatively spliced transcripts and different transcription start points, interpretation of variants in the 5' untranslated and upstream regions of CCM1 is particularly challenging. Here, we identified a novel deletion of the non-coding exon 1 of CCM1 in a proband with multiple CCMs which was initially classified as a variant of unknown clinical significance. Using CRISPR/Cas9 genome editing in human iPSCs, we show that the deletion leads to loss of CCM1 protein and deregulation of KLF2, THBS1, NOS3, and HEY2 expression in iPSC-derived endothelial cells. Based on these results, the variant could be reclassified as likely pathogenic. Taken together, variants in regulatory regions need to be considered in genetic CCM analyses. Our study also demonstrates that modeling variants of unknown clinical significance in an iPSC-based system can help to come to a final diagnosis.

Next-Generation Sequencing Advances the Genetic Diagnosis of Cerebral Cavernous Malformation (CCM)

Cerebral Cavernous Malformation (CCM) is a cerebrovascular disease of genetic origin that predisposes to seizures, focal neurological deficits and fatal intracerebral hemorrhage. It may occur sporadically or in familial forms, segregating as an autosomal dominant condition with incomplete penetrance and highly variable expressivity. Its pathogenesis has been associated with loss-of-function mutations in three genes, namely KRIT1 (CCM1), CCM2 and PDCD10 (CCM3), which are implicated in defense mechanisms against oxidative stress and inflammation. Herein, we screened 21 Italian CCM cases using clinical exome sequencing and found six cases (~29%) with pathogenic variants in CCM genes, including a large 145−256 kb genomic deletion spanning the KRIT1 gene and flanking regions, and the KRIT1 c.1664C>T variant, which we demonstrated to activate a donor splice site in exon 16. The segregation of this cryptic splicing mutation was studied in a large Italian family (five affected and seven unaffected cases), and showed a largely heterogeneous clinical presentation, suggesting the implication of genetic modifiers. Moreover, by analyzing ad hoc gene panels, including a virtual panel of 23 cerebrovascular disease-related genes (Cerebro panel), we found two variants in NOTCH3 and PTEN genes, which could contribute to the abnormal oxidative stress and inflammatory responses to date implicated in CCM disease pathogenesis.

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.

Tailored Treatment Options for Cerebral Cavernous Malformations

The diagnosis and treatment of cerebral cavernous malformations (CCMs), or cavernomas, continues to evolve as more data and treatment modalities become available. Intervention is necessary when a lesion causes symptomatic neurologic deficits, seizures, or has high risk of continued hemorrhage. Future medical treatment directions may specifically target the pathogenesis of these lesions. This review highlights the importance of individualized treatment plans based on specific CCM characteristics.

Cerebral Cavernous Malformation Pathogenesis: Investigating Lesion Formation and Progression with Animal Models

Cerebral cavernous malformation (CCM) is a cerebromicrovascular disease that affects up to 0.5% of the population. Vessel dilation, decreased endothelial cell-cell contact, and loss of junctional complexes lead to loss of brain endothelial barrier integrity and hemorrhagic lesion formation. Leakage of hemorrhagic lesions results in patient symptoms and complications, including seizures, epilepsy, focal headaches, and hemorrhagic stroke. CCMs are classified as sporadic (sCCM) or familial (fCCM), associated with loss-of-function mutations in KRIT1/CCM1, CCM2, and PDCD10/CCM3. Identifying the CCM proteins has thrust the field forward by (1) revealing cellular processes and signaling pathways underlying fCCM pathogenesis, and (2) facilitating the development of animal models to study CCM protein function. CCM animal models range from various murine models to zebrafish models, with each model providing unique insights into CCM lesion development and progression. Additionally, these animal models serve as preclinical models to study therapeutic options for CCM treatment. This review briefly summarizes CCM disease pathology and the molecular functions of the CCM proteins, followed by an in-depth discussion of animal models used to study CCM pathogenesis and developing therapeutics.

Magnetic Resonance Imaging of Multiple Cerebral and Spinal Cavernous Malformations of a Patient with Dementia and Tetraparesis

Cavernomas are rare cerebrovascular malformations that usually occur in sporadic forms with solitary lesions located most often in the hemispheric white matter, but also in the infratentorial or spinal region. Multiple lesions at different CNS levels are considered a hallmark for the familial form of the disease. The diagnostic modality of choice for cerebral cavernous malformations (CCMs) is magnetic resonance imaging (MRI). We present an intriguing case of a 65-year-old male admitted to our hospital with tetraparesis and cognitive impairment where highly sensitive MRI sequences identified many cerebral cavernous lesions at the supra-, infratentorial and cervical–thoracic spine levels, some of them with recent signs of bleeding in a patient with oral anticoagulant therapy due to atrial fibrillation. The mechanism of cognitive impairment in this patient is most probably the interruption of strategic white matter tracts, as it is known to happen in other subcortical vascular pathologies. MRI can be helpful not only in mapping the anatomical distribution of lesions, but also in weighing the risks and making decisions regarding whether or not to continue oral anticoagulant therapy.

Role of i-CT, i-US, and Neuromonitoring in Surgical Management of Brain Cavernous Malformations and Arteriovenous Malformations: A Case Series

OBJECTIVE

We retrospectively reviewed the institutional experience in patients who underwent microsurgical resection of cavernous malformations (CMs) or arteriovenous malformations (AVMs) using a multimodal intraoperative protocol including neuronavigation, intraoperative ultrasound (i-US), computed tomography (i-CT), and neuromonitoring.

METHODS

Twenty-four patients (14 male), with a mean age of 47.5 years (range 27-73), have been included: 20 of them suffered from CMs and 4 suffered from AVMs. Neuromonitoring was used in 18 cases, when lesions were located in eloquent areas; 2 patients underwent awake craniotomy. First, an i-CT scan with and without contrast was acquired after patient positioning. Navigated B-mode ultrasound acquisition was carried out after dural opening to identify the lesion (CMs or AVMs nidus). Following identification and resection of vascular lesions, postcontrast i-CT (or CT-angio) was performed to detect and localize any small or calcified remnant (in cases of CMs) or residual vessels feeding the nidus (in cases of AVMs).

RESULTS

In 5 cases of CMs and in 1 case of AVM, i-CT identified small residual lesions. In these cases, new i-CT images were uploaded into the navigation system and used for further resection. i-US was useful before starting transsulcal or transcortical approach to identify the lesions and guide the trajectory of the approach. However, several artifacts were observed during subsequent steps of dissection, making image interpretation difficult.

CONCLUSIONS

The combination of different intraoperative real-time imaging modalities (i-CT and i-US), coupled with neuromonitoring, in the surgical management of vascular lesions, particularly if located in eloquent areas, has a positive impact on clinical outcome.

Neuropathology of the temporal lobe

Neuropathological examination of the temporal lobe provides a better understanding and management of a wide spectrum of diseases. We focused on inflammatory diseases, epilepsy, and neurodegenerative diseases, and highlighted how the temporal lobe is particularly involved in those conditions. Although all these diseases are not specific or restricted to the temporal lobe, the temporal lobe is a key structure to understand their pathophysiology. The main histological lesions, immunohistochemical markers, and molecular alterations relevant for the neuropathological diagnostic reasoning are presented in relation to epidemiology, clinical presentation, and radiological findings. The inflammatory diseases section addressed infectious encephalitides and auto-immune encephalitides. The epilepsy section addressed (i) susceptibility of the temporal lobe to epileptogenesis, (ii) epilepsy-associated hippocampal sclerosis, (iii) malformations of cortical development, (iv) changes secondary to epilepsy, (v) long-term epilepsy-associated tumors, (vi) vascular malformations, and (vii) the absence of histological lesion in some epilepsy surgery samples. The neurodegenerative diseases section addressed (i) Alzheimer's disease, (ii) the spectrum of frontotemporal lobar degeneration, (iii) limbic-predominant age-related TDP-43 encephalopathy, and (iv) α-synucleinopathies. Finally, inflammatory diseases, epilepsy, and neurodegenerative diseases are considered as interdependent as some pathophysiological processes cross the boundaries of this classification.

Semiology, EEG, and neuroimaging findings in temporal lobe epilepsies

Temporal lobe epilepsy (TLE) is the most common type of focal epilepsy. First descriptions of TLE date back in time and detailed portraits of epileptic seizures of temporal origin can be found in early medical reports as well as in the works of various artists and dramatists. Depending on the seizure onset zone, several subtypes of TLE have been identified, each one associated with peculiar ictal semiology. TLE can result from multiple etiological causes, ranging from genetic to lesional ones. While the diagnosis of TLE relies on detailed analysis of clinical as well as electroencephalographic (EEG) features, the lesions responsible for seizure generation can be highlighted by multiple brain imaging modalities or, in selected cases, by genetic investigations. TLE is the most common cause of refractory epilepsy and despite the great advances in diagnostic tools, no lesion is found in around one-third of patients. Surgical treatment is a safe and effective option, requiring presurgical investigations to accurately identify the seizure onset zone (SOZ). In selected cases, presurgical investigations need intracerebral investigations (such as stereoelectroencephalography) or dedicated metabolic imaging techniques (interictal PET and ictal SPECT) to correctly identify the brain structures to be removed.

Treatment strategies and prognostic factors for spinal cavernous malformation: a single-center retrospective cohort study

OBJECTIVE

The authors aimed to identify factors that influence neurological function after treatment in order to facilitate clinician decision-making during treatment of spinal cavernous malformation (SCM) and about when and whether to perform surgical intervention.

METHODS

The authors performed a retrospective observational cohort study of patients with SCM who were treated at their institution between January 2004 and December 2019. Multiple logistic and Cox regression analyses were performed to determine the prognostic predictors of clinical outcome. Neurological status was assessed according to Frankel grade.

RESULTS

A total of 112 patients met the inclusion criteria, and a minimum 24 months of follow-up was achieved by 73 surgically treated and 39 conservatively treated patients. The mean ± SD lesion size was 8.7 ± 5.2 mm. In the surgically treated group, preoperative lesion size ≤ 5 mm (OR 13.62, 95% CI 1.05-175.98, p = 0.045), complete intramedullary lesion (OR 7.48, 95% CI 1.39-40.15, p = 0.019), and subarachnoid hemorrhage (OR 6.26, 95% CI 1.13-34.85, p = 0.036) were independent predictors of worse outcome. In the conservative treatment group, lesion size ≥ 10 mm (HR 9.77, 95% CI 1.18-80.86, p = 0.034), ≥ 3 segments with hemosiderin deposition (HR 13.73, 95% CI 1.94-97.16, p = 0.009), and subarachnoid hemorrhage (HR 13.44, 95% CI 2.38-75.87, p = 0.003) were significant predictors of worse outcome. The annual hemorrhage rate of the conservatively treated patients was 4.3%.

CONCLUSIONS

Subarachnoid hemorrhage, lesion size, morphology, extent of hemosiderin involvement, and motor dysfunction were independent risk factors of prognosis. In clinical practice, these parameters may help to identify patients at high risk for worse outcome. The treatment strategy for patients with SCM should be based on these risk factors and balanced with clinical symptoms.

Cavernous malformations of the hypothalamus: a single-institution series of 12 cases and review of the literature

OBJECTIVE

There remains a paucity of literature on hypothalamic cavernous malformations (HCMs). Here, the authors present the largest series of HCMs to date and review the literature to gain additional insight into this rare disease subset.

METHODS

A prospectively managed database was retrospectively reviewed for patients diagnosed with symptomatic HCM and treated surgically between 1987 and 2019. Data gathered included demographics, presenting signs, radiological measurements, surgical approach, and postoperative events. Functional outcome was measured using the modified Rankin Scale (mRS) and Glasgow Outcome Scale-Extended (GOSE) pre- and postoperatively. A PRISMA guideline systematic review of HCM in the literature was performed.

RESULTS

Our cohort study consisted of 12 patients with symptomatic, and radiographically confirmed, HCM treated with microsurgery by the senior author (G.K.S.). An additional 16 surgically or conservatively managed patients were also identified from the literature, and the authors analyzed the data of all 28 patients (with 54% of patients being male; mean age 39 ± 16 years, range 10-68 years). Patients harboring HCMs most commonly presented with headache (16/28, 57%), short-term memory impairment (11/28, 39%), and gait disturbance (8/28, 32%). Radiographically, lesions most commonly involved the mammillary region (18/23, 78%), the tuberal/infundibulum region (13/23, 57%), and the preoptic/lamina terminalis region (12/23, 52%), with a mean diameter of 2.5 ± 1.4 cm (range 0.8-7 cm) at presentation. Acute hemorrhage was identified in 96% (23/24) of patients on presentation, with 96% (23/24) intraparenchymal and 29% (7/24) intraventricular. Of 24 patients who were managed surgically, gross-total resection (GTR) was achieved in 88% (21/24) of cases. There were no reports of perioperative infarction or mortality. With a mean follow-up period of 41 months (range 0.5-309 months), 77% (20/26) of patients experienced functional improvement, while 12% (3/26) had no change, and 12% (3/26) experienced increased disability. In our cohort of 12 patients, 83% (10/12) continued to report symptoms at the last follow-up (mean 4.8 years, range 0.1-25.7 years). However, there was a significant improvement in mRS score noted after surgery (mean 1.4 vs 3.1, p = 0.0026) and a trend toward improvement in GOSE score (mean 6.3 vs 5.1, p = 0.09).

CONCLUSIONS

Hemorrhage from HCMs can cause a symptomatic mass effect on adjacent eloquent structures. While patients are unlikely to be deficit free following surgery, GTR allows for functional improvement and reduces recurrent hemorrhage rates. Microsurgery remains a viable option for symptomatic HCMs in experienced hands.