Pathology of cavernous malformations

GNA14 and GNAQ somatic mutations cause spinal and intracranial extra-axial cavernous hemangiomas

Extra-axial cavernous hemangiomas (ECHs) are complex vascular lesions mainly found in the spine and cavernous sinus. Their removal poses significant risk due to their vascularity and diffuse nature, and their genetic underpinnings remain incompletely understood. Our approach involved genetic analyses on 31 tissue samples of ECHs employing whole-exome sequencing and targeted deep sequencing. We explored downstream signaling pathways, gene expression changes, and resultant phenotypic shifts induced by these mutations, both in vitro and in vivo. In our cohort, 77.4% of samples had somatic missense variants in GNA14, GNAQ, or GJA4. Transcriptomic analysis highlighted significant pathway upregulation, with the GNAQ c.626A>G (p.Gln209Arg) mutation elevating PI3K-AKT-mTOR and angiogenesis-related pathways, while GNA14 c.614A>T (p.Gln205Leu) mutation led to MAPK and angiogenesis-related pathway upregulation. Using a mouse xenograft model, we observed enlarged vessels from these mutations. Additionally, we initiated rapamycin treatment in a 14-year-old individual harboring the GNAQ c.626A>G (p.Gln209Arg) variant, resulting in gradual regression of cutaneous cavernous hemangiomas and improved motor strength, with minimal side effects. Understanding these mutations and their pathways provides a foundation for developing therapies for ECHs resistant to current therapies. Indeed, the administration of rapamycin in an individual within this study highlights the promise of targeted treatments in treating these complex lesions.

Single-cell and bulk RNA-seq unveils the immune infiltration landscape associated with cuproptosis in cerebral cavernous malformations

BACKGROUND

Cerebral cavernous malformations (CCMs) are vascular abnormalities associated with deregulated angiogenesis. Their pathogenesis and optimal treatment remain unclear. This study aims to investigate the molecular signatures of cuproptosis, a newly identified type of cell death, associated with CCMs development.

METHODS

Bulk RNA sequencing (RNA-seq) from 15 CCM and 6 control samples were performed with consensus clustering and clustered to two subtypes based on expression levels of cuproptosis-related genes (CRGs). Differentially expressed genes and immune infiltration between subtypes were then identified. Machine learning algorithms including the least absolute shrinkage and selection operator and random forest were employed to screen for hub genes for CCMs associated with cuproptosis. Furthermore, Pathway enrichment and correlation analysis were used to explore the functions of hub genes and their association with immune phenotypes in CCMs. An external dataset was then employed for validation. Finally, employing the Cellchat algorithm on a single-cell RNA-seq dataset, we explored potential mechanisms underlying the participation of these hub genes in cell-cell communication in CCMs.

RESULTS

Our study revealed two distinct CCM subtypes with differential pattern of CRG expression and immune infiltration. Three hub genes (BTBD10, PFDN4, and CEMIP) were identified and validated, which may significantly associate with CCM pathogenesis. These genes were found to be significantly upregulated in CCM endothelial cells (ECs) and were validated through immunofluorescence and western blot analysis. Single-cell RNA-seq analysis revealed the cellular co-expression patterns of these hub genes, particularly highlighting the high expression of BTBD10 and PFDN4 in ECs. Additionally, a significant co-localization was also observed between BTBD10 and the pivotal cuproptosis gene FDX1 in Mki67+ tip cells, indicating the crucial role of cuproptosis for angiogenesis in CCMs. The study also explored the cell-cell communication between subcluster of ECs expressing these hub genes and immune cells, particularly M2 macrophages, suggesting a role for these interactions in CCM pathogenesis.

CONCLUSION

This study identifies molecular signatures linking cuproptosis to CCMs pathogenesis. Three hub genes-PFDN4, CEMIP, and BTBD10-may influence disease progression by modulating immunity. Further research is needed to understand their precise disease mechanisms and evaluate their potential as biomarkers or therapeutic targets for CCMs.

Proteomics on human cerebral cavernous malformations reveals novel biomarkers in neurovascular dysfunction for the disease pathology

BACKGROUND

Cerebral cavernous malformation (CCM) is a disease associated with an elevated risk of focal neurological deficits, seizures, and hemorrhagic stroke. The disease has an inflammatory profile and improved knowledge of CCM pathology mechanisms and exploration of candidate biomarkers will enable new non-invasive treatments.

METHODS

We analyzed protein signatures in human CCM tissue samples by using a highly specific and sensitive multiplexing technique, proximity extension assay.

FINDINGS

Data analysis revealed CCM specific proteins involved in endothelial dysfunction/inflammation/activation, leukocyte infiltration/chemotaxis, hemostasis, extracellular matrix dysfunction, astrocyte and microglial cell activation. Biomarker expression profiles matched bleeding status, especially with higher levels of inflammatory markers and activated astrocytes in ruptured than non-ruptured samples, some of these biomarkers are secreted into blood or urine. Furthermore, analysis was also done in a spatially resolving manner by separating the lesion area from the surrounding brain tissue. Our spatial studies revealed that although appearing histologically normal, the CCM border areas were pathological when compared to control brain tissues. Moreover, the functional relevance of CD93, ICAM-1 and MMP9, markers related to endothelial cell activation and extracellular matrix was validated by a murine pre-clinical CCM model.

INTERPRETATION

Here we present a novel strategy for proteomics analysis on human CCMs, offering a possibility for high-throughput protein screening acquiring data on the local environment in the brain. Our data presented here describe CCM relevant brain proteins and specifically those which are secreted can serve the need of circulating CCM biomarkers to predict cavernoma's risk of bleeding.

Cavernous venous malformations in and around the central nervous system. Part 2: Intradural

Cavernous venous malformations (CavVMs) account for a spectrum of lesions with a shared pathogenesis. Their anatomical location dictates their clinical features and surgical treatment. Extradural and dura-based CavVMs were discussed in Part 1 of this review. In this part, intradural CavVMs are discussed, encompassing malformations growing within the intradural space without direct dural involvement. In addition to classic intra-axial CavVMs, cranial nerve CavVMs, intraventricular CavVMs, and intradural extramedullary spinal CavVMs are discussed in this group, given the similar natural history and specific management challenges. Herein the authors focus on critical clinical aspects of and surgical management of these malformations based on their location and discuss optimal surgical approaches at each of these anatomical locations with illustrative cases. The commonalities of the natural history and surgical management that are dictated by anatomical considerations lend to a new location-based taxonomy for classification of CavVMs.

Optochiasmatic Cavernomas: Updated systematic review and proposal of a novel classification with surgical approaches

Cavernomas are histologically benign vascular malformations found at different sites in the brain. A rare site for such cavernomas, however, is the anterior optic pathway, comprising the optic nerve, chiasma, and optic tract-called optochiasmatic cavernomas (OCC). These lesions usually present with sudden onset or progressive vision loss, headache, and features mimicking pituitary apoplexy. In this paper, we describe a case of OCC operated at our center. We carry out an updated review of literature depicting cases of OCC, their clinical presentation, management, and postoperative complications. We also propose a novel classification system based on lesion location and further analyze these cavernoma types with respect to the surgical approach used and visual outcome. A 30-year-old lady had presented with a 3-week history of progressive bilateral vision loss and headache. Based on imaging, she was suspected to have a cavernous angioma of the chiasma and left optic tract. Due to progressive vision deterioration, the lesion was surgically excised using pterional craniotomy. Postoperatively, her visual symptoms improved, but she developed diabetes insipidus. Clinical and radiological follow-up has been done for 18 months after surgery. A total of 81 cases have been described in the literature, including the present case. Chiasmal apoplexy is the most common presentation. Surgical excision is the standard of care. Our analysis based on lesion location shows the most appropriate surgical approach to be used for each cavernoma type. Visual outcome correlates with the preoperative visual status. Visual outcome is good in patients presenting with acute chiasmal apoplexy, and when complete surgical excision is performed. The endonasal endoscopic approach was found to provide the best visual outcome. In addition to preoperative visual status, complete surgical excision predicts favorable visual outcomes in OCC. Our proposed classification system guides the appropriate surgical approach required for a particular location of the cavernoma.

Circulating biomarkers in familial cerebral cavernous malformation

BACKGROUND

Cerebral Cavernous Malformation (CCM) is a rare cerebrovascular disease, characterized by the presence of multiple vascular malformations that may result in intracerebral hemorrhages (ICHs), seizure(s), or focal neurological deficits (FND). Familial CCM (fCCM) is due to loss of function mutations in one of the three independent genes KRIT1 (CCM1), Malcavernin (CCM2), or Programmed Cell death 10 (PDCD10/CCM3). The aim of this study was to identify plasma protein biomarkers of fCCM to assess the severity of the disease and predict its progression.

METHODS

Here, we have investigated plasma samples derived from n = 71 symptomatic fCCM patients (40 female/31 male) and n = 17 healthy donors (HD) (9 female/8 male) of the Phase 1/2 Treat_CCM trial, using multiplexed protein profiling approaches.

FINDINGS

Biomarkers as sCD14 (p = 0.00409), LBP (p = 0.02911), CXCL4 (p = 0.038), ICAM-1 (p = 0.02013), ANG2 (p = 0.026), CCL5 (p = 0.00403), THBS1 (p = 0.0043), CRP (p = 0.0092), and HDL (p = 0.027), were significantly different in fCCM compared to HDs. Of note, sENG (p = 0.011), THBS1 (p = 0.011) and CXCL4 (p = 0.011), were correlated to CCM genotype. sROBO4 (p = 0.014), TM (p = 0.026) and CRP (p = 0.040) were able to predict incident adverse clinical events, such as ICH, FND or seizure. GDF-15, FLT3L, CXCL9, FGF-21 and CDCP1, were identified as predictors of the formation of new MRI-detectable lesions over 2-year follow-up. Furthermore, the functional relevance of ang2, thbs1, robo4 and cdcp1 markers was validated by zebrafish pre-clinical model of fCCM.

INTERPRETATION

Overall, our study identifies a set of biochemical parameters to predict CCM progression, suggesting biological interpretations and potential therapeutic approaches to CCM disease.

FUNDING

Italian Medicines Agency, Associazione Italiana per la Ricerca sul Cancro (AIRC), ERC, Leducq Transatlantic Network of Excellence, Swedish Research Council.

Diagnosis and treatment status of suprasellar optic pathway cavernous malformations

Cerebral cavernous malformations constitute a subtype of cerebral vascular malformation typically located in the cerebral cortex. However, their occurrence in the suprasellar optic pathway is relatively rare. There is some uncertainty surrounding the clinical diagnostic methods and optimal treatment strategies specific to suprasellar optic pathway cavernous malformations. In this narrative review, we retrospectively analyzed relevant literature related to suprasellar visual pathway cavernous malformations. We conducted a study involving 90 patients who were postoperatively diagnosed with cavernous malformations, including the 16-year-old male patient mentioned in this article. We have summarized crucial clinical data, including the patient age distribution, sex ratio, lesion locations, primary symptoms, and surgical approaches. The comprehensive analysis of this clinical information underscores the critical importance of timely intervention in relieving symptoms and improving neurological deficits in affected patients. These findings provide valuable guidance and insight for clinical practitioners and researchers dealing with this specific medical condition.

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.

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.

Endothelial hyperactivation of mutant MAP3K3 induces cerebral cavernous malformation enhanced by PIK3CA GOF mutation

Cerebral cavernous malformations (CCMs) refer to a common vascular abnormality that affects up to 0.5% of the population. A somatic gain-of-function mutation in MAP3K3 (p.I441M) was recently reported in sporadic CCMs, frequently accompanied by somatic activating PIK3CA mutations in diseased endothelium. However, the molecular mechanisms of these driver genes remain elusive. In this study, we performed whole-exome sequencing and droplet digital polymerase chain reaction to analyze CCM lesions and the matched blood from sporadic patients. 44 of 94 cases harbored mutations in KRIT1/CCM2 or MAP3K3, of which 75% were accompanied by PIK3CA mutations (P = 0.006). AAV-BR1-mediated brain endothelial-specific MAP3K3I441M overexpression induced CCM-like lesions throughout the brain and spinal cord in adolescent mice. Interestingly, over half of lesions disappeared at adulthood. Single-cell RNA sequencing found significant enrichment of the apoptosis pathway in a subset of brain endothelial cells in MAP3K3I441M mice compared to controls. We then demonstrated that MAP3K3I441M overexpression activated p38 signaling that is associated with the apoptosis of endothelial cells in vitro and in vivo. In contrast, the mice simultaneously overexpressing PIK3CA and MAP3K3 mutations had an increased number of CCM-like lesions and maintained these lesions for a longer time compared to those with only MAP3K3I441M. Further in vitro and in vivo experiments showed that activating PI3K signaling increased proliferation and alleviated apoptosis of endothelial cells. By using AAV-BR1, we found that MAP3K3I441M mutation can provoke CCM-like lesions in mice and the activation of PI3K signaling significantly enhances and maintains these lesions, providing a preclinical model for the further mechanistic and therapeutic study of CCMs.

Immunothrombosis and vascular heterogeneity in cerebral cavernous malformation

Cerebral cavernous malformation (CCM) is a neurovascular disease that results in various neurological symptoms. Thrombi have been reported in surgically resected CCM patient biopsies, but the molecular signatures of these thrombi remain elusive. Here, we investigated the kinetics of thrombi formation in CCM and how thrombi affect the vasculature and contribute to cerebral hypoxia. We used RNA sequencing to investigate the transcriptome of mouse brain endothelial cells with an inducible endothelial-specific Ccm3 knock-out (Ccm3-iECKO). We found that Ccm3-deficient brain endothelial cells had a higher expression of genes related to the coagulation cascade and hypoxia when compared with wild-type brain endothelial cells. Immunofluorescent assays identified key molecular signatures of thrombi such as fibrin, von Willebrand factor, and activated platelets in Ccm3-iECKO mice and human CCM biopsies. Notably, we identified polyhedrocytes in Ccm3-iECKO mice and human CCM biopsies and report it for the first time. We also found that the parenchyma surrounding CCM lesions is hypoxic and that more thrombi correlate with higher levels of hypoxia. We created an in vitro model to study CCM pathology and found that human brain endothelial cells deficient for CCM3 expressed elevated levels of plasminogen activator inhibitor-1 and had a redistribution of von Willebrand factor. With transcriptomics, comprehensive imaging, and an in vitro CCM preclinical model, this study provides experimental evidence that genes and proteins related to the coagulation cascade affect the brain vasculature and promote neurological side effects such as hypoxia in CCMs. This study supports the concept that antithrombotic therapy may be beneficial for patients with CCM.

Dysregulated Hemostasis and Immunothrombosis in Cerebral Cavernous Malformations

Cerebral cavernous malformation (CCM) is a neurovascular disease that affects 0.5% of the general population. For a long time, CCM research focused on genetic mutations, endothelial junctions and proliferation, but recently, transcriptome and proteome studies have revealed that the hemostatic system and neuroinflammation play a crucial role in the development and severity of cavernomas, with some of these publications coming from our group. The aim of this review is to give an overview of the latest molecular insights into the interaction between CCM-deficient endothelial cells with blood components and the neurovascular unit. Specifically, we underscore how endothelial dysfunction can result in dysregulated hemostasis, bleeding, hypoxia and neurological symptoms. We conducted a thorough review of the literature and found a field that is increasingly poised to regard CCM as a hemostatic disease, which may have implications for therapy.

Vertigo due to cerebellar cavernous malformation: A case report

Central vertigo is a result of vestibular structure dysfunction in the central nervous system. Currently, misdiagnoses between peripheral and central lesions are frequent, and diagnostic testing costs are high. Identifying the characteristics of these 2 conditions is challenging. We can provide better treatment if we can establish a diagnosis earlier. Cerebral cavernous malformation (CCM) at the cerebellum is a cerebellar lesion that causes symptoms of central vertigo. We report a patient, 20th years old, female, with vertigo for 1 month before being admitted. Vertigo was getting worse, and when the patient arrived at our hospital, vertigo was accompanied by headache, right and left abducens nerve palsy, horizontal nystagmus bidirectional, vertical nystagmus, and weakness on the right side of the body. A brain magnetic resonance imaging (MRI) was performed before surgery and shows a lesion suggestive of CCM at the cerebellum with a hemorrhagic component inside and non-communicating hydrocephalus. There is no vascular malformation based on digital subtraction angiography result. MRI is the most sensitive and specific modality for detecting CCM, whereas cerebral angiography rarely detects this malformation. The patient got surgical treatment, with suboccipital decompression procedures and CCM excision. The histopathological results after surgical treatment revealed a cerebral cavernous malformation. Vertigo, headache, double vision, and weakness on the right side of the body were resolved after surgery.

[Cerebral and spinal cavernomas]

CLINICAL/METHODICAL ISSUE

Cavernous malformations or cavernomas belong to the angiodysplasias. They may be sporadic or familial and cause symptoms (epilepsy) despite the absence of a left-to-right shunt. In addition to intracranial locations, spinal cavernomas are also found.

STANDARD RADIOLOGICAL METHODS

Magnetic resonance imaging (MRI) and computed tomography (CT) are used for diagnosis PERFORMANCE: MRI, except for acutely or subacutely hemorrhaged cavernomas, is superior to CT for lesion detection.

ACHIEVEMENTS

CT is reserved for acute diagnosis. MRI, especially susceptibility-sensitive gradient echo sequences, can also detect cavernomas without (sub-)acute hemorrhage or calcifications.

PRACTICAL RECOMMENDATIONS

MRI is also useful for differentiating the familial form vs. sporadic form. Digital subtraction angiography (DSA) is used for differential diagnosis in rare cases, as cavernomas show no correlate here.

Cavernous malformations

Cavernous malformations are relatively common intracerebral malformations of which we only became properly aware after the introduction of MRI. They may be sporadic or familial. Familial CMs may be multiple and new lesions appear over time requiring intermittent MR control. Many sporadic CMs have no symptoms. The commonest location is in the supratentorial cerebral parenchyma presenting with epilepsy. The best treatment is microsurgery. A small proportion are in the brainstem and may rebleed and even be lethal. Treatment includes microsurgery and radiosurgery. Microsurgery cures the patient but has substantial problems with complications, deterioration and partial removal. Radiosurgery has taken time to demonstrate that it can over 2 years substantially reduce the risk of rebleeds without the risks of microsurgery. Both methods have a part to play in the treatment.

Giant Frontotemporal Cavernous Malformation in a 2-Month-Old Infant: A Case Report and Review of the Literature

INTRODUCTION

Cavernous malformations in the pediatric population are exceedingly rare, especially in infants. Giant cavernous malformations (GCM) are even more rare and have a diameter >4 cm. The onset of symptoms predominantly occurs in adulthood, but the rate of hemorrhage is significantly higher in the pediatric population. Similar to non-GCM, GCM can be misidentified as tumors on imaging due to their tumefactive pattern with edema. Here, we present a rare case of a right frontotemporal GCM in a 2-month-old girl, the youngest recorded case in the existing literature.

CASE PRESENTATION

A previously healthy 2-month-old girl presented to the emergency department following an increasing frequency of seizure-like activity that began 3 days prior to presentation. Magnetic resonance imaging of the brain with and without contrast characterized a large (5.8 × 4.3 × 4.2 cm) heterogeneous lesion of the right temporal lobe with diffuse scattered blood products of various ages seen throughout the lesion. She underwent a right-sided craniotomy where a gross total excision was achieved. Pathology confirmed the diagnoses of a GCM. The patient's seizures subsequently resolved, and she continues to do well postoperatively.

DISCUSSION/CONCLUSION

GCM can be mistaken for tumors due to their large size, cystic nature, and surrounding edema, but a vascular lesion should always remain in the differential diagnosis before operating, even in infants. Surgery is generally recommended in patients that present with a symptomatic hemorrhage, recurrent hemorrhages, persistent seizures despite medical management, or progressively worsening neurological deficits if the GCM is in a safe location. It has been shown that 70-99% of patients undergoing surgery with successful removal of the GCM can achieve seizure freedom 2 years postoperatively. Complete surgical excision of this infant's GCM was successful in treating her neurologic symptoms; therefore, pathological confirmation of this lesion is critical and should prompt a complete surgical excision.

Abortive intussusceptive angiogenesis causes multi-cavernous vascular malformations

Mosaic inactivation of CCM2 in humans causes cerebral cavernous malformations (CCMs) containing adjacent dilated blood-filled multi-cavernous lesions. We used CRISPR-Cas9 mutagenesis to induce mosaic inactivation of zebrafish ccm2 resulting in a novel lethal multi-cavernous lesion in the embryonic caudal venous plexus (CVP) caused by obstruction of blood flow by intraluminal pillars. These pillars mimic those that mediate intussusceptive angiogenesis; however, in contrast to the normal process, the pillars failed to fuse to split the pre-existing vessel in two. Abortive intussusceptive angiogenesis stemmed from mosaic inactivation of ccm2 leading to patchy klf2a overexpression and resultant aberrant flow signaling. Surviving adult fish manifested histologically typical hemorrhagic CCM. Formation of mammalian CCM requires the flow-regulated transcription factor KLF2; fish CCM and the embryonic CVP lesion failed to form in klf2a null fish indicating a common pathogenesis with the mammalian lesion. These studies describe a zebrafish CCM model and establish a mechanism that can explain the formation of characteristic multi-cavernous lesions.

Pediatric Cerebral Cavernous Malformations

Cerebral cavernous malformations are the second most common vascular malformations in the central nervous system, and over one-third are found in children. Lesions may be solitary or multiple, be discovered incidentally, be sporadic, or be secondary to familial cavernomatosis or radiation therapy. Children may present with focal seizures, intracranial hemorrhage, or focal neurological deficits without radiological evidence of recent hemorrhage. We present several children with cerebral cavernous malformations and explore the challenges of their diagnosis in children, their key imaging features, the role of follow-up imaging, and their subsequent management including stereotactic radiosurgery and microsurgical resection. Individual patient risk stratification is advocated for all affected children and their families.

European Reference Network for Rare Vascular Diseases (VASCERN) position statement on cerebral screening in adults and children with hereditary haemorrhagic telangiectasia (HHT)

Hereditary haemorrhagic telangiectasia (HHT) is a multisystemic vascular dysplasia inherited as an autosomal dominant trait. Approximately 10 % of patients have cerebral vascular malformations, a proportion being cerebral arteriovenous malformations (AVMs) and fistulae that may lead to potentially devastating consequences in case of rupture. On the other hand, detection and treatment related-risks are not negligible, and immediate. While successful treatment can be undertaken in individual cases, current data do not support the treatment of unruptured AVMs, which also present a low risk of bleeding in HHT patients. Screening for these AVMs is therefore controversial.

Structured discussions, distinctions of different cerebrovascular abnormalities commonly grouped into an “AVM” bracket, and clear guidance by neurosurgical and neurointerventional radiology colleagues enabled the European Reference Network for Rare Vascular Disorders (VASCERN-HHT) to develop the following agreed Position Statement on cerebral screening:

1) First, we emphasise that neurological symptoms suggestive of cerebral AVMs in HHT patients should be investigated as in general neurological and emergency care practice. Similarly, if an AVM is found accidentally, management approaches should rely on expert discussions on a case-by-case basis and individual risk-benefit evaluation of all therapeutic possibilities for a specific lesion.

2) The current evidence base does not favour the treatment of unruptured cerebral AVMs, and therefore cannot be used to support widespread screening of asymptomatic HHT patients.

3) Individual situations encompass a wide range of personal, cultural and clinical states. In order to enable informed patient choice, and avoid conflicting advice, particularly arising from non-neurovascular interpretations of the evidence base, we suggest that all HHT patients should have the opportunity to discuss knowingly brain screening issues with their healthcare provider.

4) Any screening discussions in asymptomatic individuals should be preceded by informed pre-test review of the latest evidence regarding preventative and therapeutic efficacies of any interventions. The possibility of harm due to detection of, or intervention on, a vascular malformation that would not have necessarily caused any consequence in later life should be stated explicitly.

We consider this nuanced Position Statement provides a helpful, evidence-based framework for informed discussions between healthcare providers and patients in an emotionally charged area.

Cavernous Hemangioma of the Chiasm and Left Optic Nerve

Cavernous malformations (CMs) of the optic nerves, chiasm, and optic tract are very rare. This report describes a 26-year-old man who presented with recurring headaches, loss of vision in his left eye, and elevated blood pressure. After being diagnosed with glioma of the chiasm, he was referred to our department. Magnetic resonance imaging revealed signs of a mass lesion of the left chiasmal area, a finding confirmed after transcranial biopsy. In February 2015, he underwent gross total resection of the cavernous angioma of the chiasm and the left optic nerve. Three months later, the patient's vision returned to normal. The absence of a typical clinical picture and the lack of radiological visualization can hinder pathologic diagnosis. Total microsurgical resection is the optimal treatment strategy for patients with CMs of the chiasm and optic nerve because it usually results in improved vision and long-term benefits. The results in this patient demonstrate the importance of rapid diagnosis and gross total surgical resection of CMs of the chiasm and left optic nerve.

Sudden bilateral vision loss due to third ventricular cavernous angioma with intratumoral hemorrhage - case report

Background

We report a rare case of sudden bilateral vision loss due to third ventricular cavernous angioma with intratumoral hemorrhage.

Case presentation

A 45-year-old woman presented decreased visual acuity in both eyes. Her best corrected visual acuity was 0.1 in the right eye and 0.15 in the left eye. Goldmann perimetry showed bilateral central scotomas and bitemporal visual field defects. MRI demonstrated a lesion with mixed hypo- and hyperintensity at the optic chiasm, which was thought to be an intratumoral hemorrhage. The patient underwent bifrontal craniotomy. The tumor was exposed via an anterior interhemispheric approach, and histological evaluation of the mass led to a diagnosis of cavernous angioma. Six months after the surgery, her best corrected visual acuity was 0.9 in the right eye and 0.9 in the left, with slight bitemporal visual field defects.

Conclusion

Third ventricular cavernous angioma is considered in the differential diagnosis of chiasmal syndrome. Contrast-enhanced MRI and FDG-PET might be useful for differential diagnosis of cavernous angioma from other chiasmal tumors including glioblastoma.

Temporal Lobe Cavernous Malformation Caused Epileptic Amnesic Episodes and Mild Cognitive Impairment

Neuropathological features in Alzheimer's disease (AD) are amyloid β (Aβ) deposits and neurofibrillary changes. AD is characterized by memory impairment and cognitive dysfunction, with some reports associating these impairments with hyperexcitability caused by Aβ in the medial temporal lobe. Epileptic seizures are known to be common in AD. We encountered a 65-year-old patient with cavernous malformation (CM) in the right temporal lobe who exhibited epileptic amnesia (EA) and AD-like symptoms. Scalp electroencephalography (EEG), including long-term video-EEG, showed no interictal discharges, but intraoperative subdural electrode (SE) recording from the right parahippocampal area showed frequent epileptiform discharges. Neuropathologically, senile plaques were found in the surrounding normal cortex of the CM. Postoperatively, the patient has remained free of EA and AD-like symptoms since total removal of the CM. This is the first surgical case report to confirm temporal lobe hyperexcitability associated with EA and AD-like symptoms.