Radiosurgery for angiographically occult vascular malformations

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.

Management of pediatric cerebral cavernous malformations with gamma knife radiosurgery: a report of 46 cases

INTRODUCTION

Pediatric cerebral cavernous malformations (CCMs) are commonly treated vascular anomalies with different clinical characteristics than their adult counterparts. Outcomes of Gamma Knife Radiosurgery (GKRS) for pediatric CCMs have not explicitly been reported. This paper reports our experience in managing pediatric CCMs with GKRS.

METHODS

We retrospectively reviewed the clinical features, GKRS parameters, and clinical and radiological outcomes of 46 children with 64 CCMs.

RESULTS

A total of 46 children, including 19 girls and 27 boys, with a median age of 16 years (3-17 years), were enrolled in the study. The median age at first CCM diagnosis was 13 years (range, 2-17 years). Twenty-two patients (47.8%) had more than one neurological symptom at the time of diagnosis, and the most common presenting symptom was seizure (28.3%). The most common location was supratentorial superficial (53.1%), and 17.4% of patients had multiple CCMs. A developmental venous anomaly was detected in 5 patients (10.9%). During a total of 52.4 retrospective patient-years in patients with > 1 hemorrhage episode, the calculated annual hemorrhage rate was 40.1%. The median post-GKRS follow-up was 79 months (range, 19-175 months), with an overall 306.2 prospective patient years. The annual hemorrhage rate (AHR) during the first 2 years after GKRS and after the initial 2 years was 1.11% and 0.46%, respectively. Regarding clinical factors and GKRS parameters, univariate analysis revealed a significant association with post-GKRS AHR and volume (p = 0.023) only. Patients with pre-GKRS seizures showed favorable seizure control (Engel class I and II) in 8 children (61.5%). There was no mortality in our series.

CONCLUSION

Low AHR following GKRS with no radiation-induced toxicity makes GKRS a therapeutic alternative for pediatric CCMs.

Brainstem Cavernous Malformations Management: Microsurgery vs. Radiosurgery, a Meta-Analysis

Given the rareness of available data, we performed a systematic review and meta-analysis on therapeutic strategy microsurgical resection and stereotactic radiosurgery (SRS) for brainstem cavernous malformations (BSCMs) and assessed mortality, permanent neurological deficits (PNDs), rebleeding rate, and patients who require reintervention to elucidate the benefits of each treatment modality. Preferred reporting items for systematic reviews and meta-analyses (PRISMA) were used for protocol development and manuscript preparation. After applying all inclusion and exclusion criteria, six remaining articles were included in the final manuscript pool. In total, this meta-analysis included 396 patients, among them 168 patients underwent microsurgical treatment and 228 underwent SRS. Findings of the present meta-analysis suggest that regarding the total group of patients, in terms of mortality, late rebleeding rate, and PNDs, there was no superiority of the one method over the other. Applying the leave-one-out method to our study suggests that with low robust of the results for the bleeding rate and patients who require reintervention outcome factor, there was no statistical difference among the surgical and SRS treatment. Microsurgical treatment of BSCMs immediately eliminates the risk of rehemorrhage; however, it requires complete excision of the lesion and it is associated with a similar rate of PNDs compared with SRS management. Apparently, SRS of BSCMs causes a marked reduction in the risk of rebleeding 2 years after treatment, but when compared with the surgical treatment, there was not any remarkable difference.

Outcome of intracerebral cavernoma treated by Gamma Knife radiosurgery based on a double-blind assessment of treatment indication

BACKGROUND

The benefit and the risk profile of Gamma Knife radiosurgery (GKRS) for intracerebral cavernoma remains incompletely defined in part due to the natural history of low incidence of bleeding and spontaneous regression of this vascular malformation. In this study, we retrieved cases from a prospectively collected database to assess the outcome of intracerebral cavernoma treated with GKRS using a double blinded review process for treatment.

METHODS

From 2003 to 2018, there were 94 cases of cavernoma treated by GKRS in the doubly blinded assessments by two experienced neurological and approved for GKRS treatment. All the patients received GKRS with margin dose of 11-12 (Gray) Gy and afterwards were assessed for neurological outcome, radiologic response, and quality of life.

RESULTS

The median age of the patients was 48 (15-85) years with median follow up of 77 (26-180) months post SRS. The mean target volume was 1.93 ± 3.45 cc. In those who has pre-SRS epilepsy, 7 of 16 (43.7%) achieved seizure freedom (Engel I/II) and 9 of 16 (56.3%) achieved decreased seizures (Engel III) after SRS. Rebleeding occurred in 2 cases (2.1%) at 13 and 52 months post SRS. The radiologic assessment demonstrated 20 (21.3%) cases of decreased cavernoma volume, 69 (73.4%) were stable, and 5 (7.3%) increased size. Eighty-seven of 94 (92.5%) cases at the last follow up achieve improvement in their quality of life, but 7 cases (7.4%) showed a deterioration. In statistical analysis, the effective seizure control class (Engel I/II) was highly correlated with patient harboring a single lesion (p < 0.05) and deep seated location of the cavernoma (p < 0.01). New neurological deficits were highly correlated with decreased mental (p < 0.001) and physical (p < 0.05) components of quality of life testing, KPS (p < 0.001), deep seated location (p < 0.01), and increased nidus volume (p < 0.05). Quality of life deterioration either in physical component (p < 0.01), mental component (p < 0.01), and KPS (p < 0.05) was highly correlated with increased cavernoma volume.

CONCLUSION

Low margin dose GKRS for intracerebral cavernoma offers reasonable seizure control and improved quality of life while conferring a low risk of treatment complications including adverse radiation effect.

Trial Readiness in Cavernous Angiomas With Symptomatic Hemorrhage (CASH)

BACKGROUND

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

OBJECTIVE

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

METHODS

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

EXPECTED OUTCOMES

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

DISCUSSION

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

The natural history of cerebral cavernous malformations in children

OBJECT Cerebral cavernous malformations (CMs) are a source of neurological morbidity from seizures and focal neurological deficits due to mass effect and hemorrhage. Although several natural history reports exist for adults with CMs, similar data for pediatric patients are limited. METHODS The authors reviewed hospital databases to identify children with CMs who had not been treated surgically and who had clinical and radiological follow-up. Annual hemorrhage rates were calculated in lesion-years, and risk factors were assessed using the Cox proportional hazards model. RESULTS In a cohort of 167 patients with 222 CMs, the mean patient age at the time of diagnosis was 10.1 years old (SD 6.0). Ninety patients (54%) were male. One hundred four patients (62%) presented with hemorrhage from at least 1 CM, 58 (35%) with seizures with or without CM hemorrhage, and 43 (26%) with incidental lesions. Twenty-five patients (15%) had multiple CMs, 17 (10%) had a family history of CMs, and 33 (20%) had radiologically apparent developmental venous anomalies (DVAs). The overall annual hemorrhage rate was 3.3%. Permanent neurological morbidity was 29% per hemorrhage, increasing to 45% for brainstem, thalamic, or basal ganglia CM and decreasing to 15% for supratentorial lobar or cerebellar lesions. The annual hemorrhage rate for incidental CMs was 0.5%; for hemorrhagic CMs, it was 11.3%, increasing to 18.2% within the first 3 years. Hemorrhage clustering within 3 years was statistically significant (HR 6.1, 95% CI 1.72-21.7, p = 0.005). On multivariate analysis, hemorrhagic presentation (HR 4.63, 95% CI 1.53-14.1, p = 0.007), brainstem location (HR 4.42, 95% CI 1.57-12.4, p = 0.005), and an associated radiologically apparent DVA (HR 2.91, 95% CI 1.04-8.09, p = 0.04) emerged as significant risk factors for hemorrhage, whereas age, sex, CM multiplicity, and CM family history did not. CONCLUSIONS Prior hemorrhage, brainstem location, and associated DVAs are significant risk factors for symptomatic hemorrhage in children with CMs. Hemorrhage clustering within the first 3 years of a bleed can occur, a potentially important factor in patient management and counseling.

Angiographically occult vascular malformation of the intracranial accessory nerve: case report

Angiographically occult cerebral vascular malformations (AOVMs) are usually found in the supratentorial brain parenchyma. Uncommonly, AOVMs can be found within the cavernous sinus or basal cisterns and can be associated with cranial nerves. AOVMs involving the intracranial segment of the spinal accessory nerve have not been described. A 46-year-old female patient presented with a history of episodic frontal headaches and episodes of nausea and dizziness, as well as gait instability progressing over 6 months prior to evaluation. Imaging revealed a well-circumscribed 3-cm extraaxial T1-weighted isointense and T2-weighted hyperintense contrast-enhancing mass centered in the region of the right lateral cerebellomedullary cistern. The patient underwent resection of the lesion. Although the intraoperative appearance was suggestive of a cavernous malformation, some histological findings were atypical, leading to the final diagnosis of vascular malformation, not otherwise specified. The patient's postoperative course was uneventful with complete resolution of symptoms. To the authors' knowledge, this is the first report of an AOVM involving the intracranial portion of the accessory nerve. For any AOVM located within the cerebellomedullary cistern or one suspected of involving a cranial nerve, the authors recommend including immunohistochemistry with primary antibody to neurofilament in the histopathology workup.

Rho kinase as a target for cerebral vascular disorders

The development of novel pharmaceutical treatments for disorders of the cerebral vasculature is a serious unmet medical need. These vascular disorders are typified by a disruption in the delicate Rho signaling equilibrium within the blood vessel wall. In particular, Rho kinase overactivation in the smooth muscle and endothelial layers of the vessel wall results in cytoskeletal modifications that lead to reduced vascular integrity and abnormal vascular growth. Rho kinase is thus a promising target for the treatment of cerebral vascular disorders. Indeed, preclinical studies indicate that Rho kinase inhibition may reduce the formation/growth/rupture of both intracranial aneurysms and cerebral cavernous malformations.

Stereotactic radiosurgery of brainstem cavernous malformations: a systematic review and meta-analysis

OBJECT

Over the last two decades, stereotactic radiosurgery (SRS) has arisen as a promising approach in the management of brainstem cavernous malformations (CMs). In the present study, the authors report a systematic review and meta-analysis of the available published data regarding the radiosurgical management of brainstem CMs.

METHODS

To identify eligible studies, systematic searches for brainstem CMs treated with SRS were conducted in major scientific publication databases. The search yielded 5 studies, which were included in the meta-analysis. Data from 178 patients with brainstem CMs were extracted. Hemorrhage rates before and after SRS were calculated, a meta-analysis was performed, and the risk ratio (RR) was determined.

RESULTS

Four studies showed a statically significant reduction in the annual hemorrhage rate after SRS. The overall RR was 0.161 (95% CI 0.052-0.493; p = 0.001), and 21 patients (11.8%) had transient or permanent neurological deficits.

CONCLUSIONS

The present meta-analysis for the radiosurgical management of brainstem CMs shows that SRS can decrease the rate of repeat hemorrhage and has a low rate of adverse effects compared with surgery. The authors suggest that SRS may be considered as an alternative treatment for brainstem CMs that are inoperable or have a high operative risk.

Cerebral cavernous malformations: from molecular pathogenesis to genetic counselling and clinical management

Cerebral cavernous (or capillary-venous) malformations (CCM) have a prevalence of about 0.1-0.5% in the general population. Genes mutated in CCM encode proteins that modulate junction formation between vascular endothelial cells. Mutations lead to the development of abnormal vascular structures.In this article, we review the clinical features, molecular and genetic basis of the disease, and management.

A Proposed Grading System of Brain and Spinal Cavernomas

BACKGROUND:

Most cavernomas in the central nervous system are characterized by a benign natural course. Progressive symptoms warrant surgical removal. In the literature, the factors affecting long-term postoperative outcome are not statistically well confirmed.

OBJECTIVE:

To perform a multifactorial analysis of risk factors on a large patient series and to use the results to propose a simple grading scale to predict outcome.

METHODS:

We studied 303 consecutive patients with cavernomas treated surgically at our department from 1980 to 2009. Follow-up assessment was performed on average 5.7 years postoperatively (range, 0.2-36 years). The main outcome measure was the patients' condition at the last follow-up on Glasgow Outcome Scale. For statistical analysis, the outcome measure was dichotomized to favorable (Glasgow Outcome Scale 5) and unfavorable (Glasgow Outcome Scale 1–4). Binary logistic regression analysis was used to estimate the effect of age, sex, seizures, preexisting neurological deficits, hemorrhage, and size and location of cavernoma on long-term outcome.

RESULTS:

Infratentorial, basal ganglia, or spinal location and preexisting neurological deficit were the only independent risk factors for unfavorable outcome, with relative risks of 2.7 (P = .008) and 3.2 (P = .002), respectively. We formulated a grading system based on a score of 1 to 3. When applied to our series, the proposed grading system strongly correlated with outcome (P &lt; .001, Pearson χ2 test). The risk for long-term unfavorable outcome was 13%, 22%, and 55% for grades 1 through 3, respectively.

CONCLUSION:

The proposed grading system showed a convincing correlation with postoperative outcome in surgically treated cavernoma patients.

Modern management of brainstem cavernous malformations

Over the last 2 decades, there have been dramatic advancements in our understanding of and the ability to treat brainstem cavernous malformations (BCMs). Once thought untreatable, BCMs are now being more aggressively and safely treated microsurgically as a result of advances in monitoring and imaging technologies, as well as refinement of surgical techniques. BCMs deemed inoperable are being treated with radiosurgery, and experience with dosing and targeting has improved the safety of this treatment modality as well. Much work remains to be done, and prospective randomized trials would undoubtedly further existing knowledge.

Cerebral cavernous malformations as a disease of vascular permeability: from bench to bedside with caution

Tremendous insight into the molecular and genetic pathogenesis of cerebral cavernous malformations (CCMs) has been gained over the past 2 decades. This includes the identification of 3 distinct genes involved in familial CCMs. Still, a number of unanswered questions regarding the process from gene mutation to vascular malformation remain. It is becoming more evident that the disruption of interendothelial junctions and ensuing vascular hyperpermeability play a principal role. The purpose of this review is to summarize the current understanding of CCM genes, associated proteins, and functional pathways. Promising molecular and genetic therapies targeted at identified molecular aberrations are discussed as well.