Seizure Outcomes After Radiosurgery for Cerebral Arteriovenous Malformations: An Updated Systematic Review and Meta-Analysis

Natural History and Histopathology of Expanding Cysts and Hematomas After Stereotactic Radiosurgery for Arteriovenous Malformations of the Brain: A Case Series

BACKGROUND

We reviewed the clinical course and histopathologic findings for cases involving the formation of expanding cysts and/or hematomas after gamma knife surgery (GKS) for arteriovenous malformations (AVMs).

METHODS

We report a single-center retrospective review of 18 patients who presented with cyst and/or hematoma expansion after GKS for AVMs between 1993 and 2023. Expanding cysts and hematomas were defined as well-demarcated cavities filled with fluid or well-marginated heterogenous hematomas presenting with expansion proximal to or in the location of the original AVM, respectively. Patient demographics, AVM characteristics, history of interventions and surgeries, and imaging and histopathologic features of expanding cysts and hematomas were collected for analysis.

RESULTS

Among 1072 AVM patients treated using GKS, 18 presented with expanding cysts or hematomas during a total follow-up period of 16,757 patient-years (0.11 case/100 persons/patient-year). The time to cyst or hematoma identification was 4-13 years after initial GKS, with a mean duration of 8.6 years. Among the patients examined, 7 (38.9%) presented mainly with hematoma, 10 (55.6%) presented mainly with cysts, and 1 presented with approximately equal components of both. Among the 18 patients, 13 (72.2%) underwent craniotomy to treat cyst or hematoma expansion. All the specimens had similar histopathologic characteristics, including organizing hematoma with fresh and old hemorrhage, fibrinoid necrosis of the vessels, gliosis of normal brain tissue, infiltration of hemosiderin-laden histiocytes, and extravascular protein leakage.

CONCLUSIONS

Our findings suggest that the formation of these 2 complications can be attributed to a common mechanism involving radiation-induced vascular damage in brain tissue adjacent to the AVM and subsequent chronic inflammation and capillary dilatation.

New approaches for brain arteriovenous malformations-related epilepsy

BACKGROUND

The purpose of this review is to present the current literature and to highlight the most recent findings in brain arteriovenous malformations (bAVM)-related epilepsy research.

METHODS

We searched Medline, PubMed, Biblioinserm, Cochrane Central to study the latest research reports about the different factors that could be responsible for the genesis of bAVM-related epilepsy. We analyzed if epileptogenesis has any characteristics traits and its relation with the vascular malformation. The results of different treatments on epilepsy were considered. Typical errors that may lead towards incorrect or worse management of the seizures for these patients were also examined.

RESULTS

The development of bAVM results from multifactorial etiologies and bAVM-related epileptogenesis is likely specific for this pathology. Different types of evidence demonstrate a bidirectional relationship between bAVM and epilepsy. Currently, there is not enough published data to determine what may be the right management for these patients.

CONCLUSIONS

A better understanding of epileptogenesis in conjunction with knowledge of the complex alterations of structures and functions following bAVM-related seizures is necessary. Identification of biomarkers that can identify subgroups most likely to benefit from a specific intervention are needed to help guide clinical management. A new concept for the treatment of epilepsy related to an unruptured bAVM that cannot be treated invasively is proposed as well as new therapeutic perspectives. The next necessary step will be to propose additional algorithms to improve the development of future trials.

Complete seizure-free rates following interventional treatment of intracranial arteriovenous malformations: a systematic review and meta-analysis

Seizures are common presenting symptoms of intracranial arteriovenous malformations (AVMs). This systematic review and meta-analysis aims to assess the current evidence regarding complete seizure freedom rates following surgical resection, stereotactic radiosurgery (SRS), and/or endovascular embolization of intracranial AVMs. A systematic review of PubMed, Ovid MEDLINE, and Ovid EMBASE was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Included manuscripts were methodically scrutinized for quality, spontaneous AVM-associated or hemorrhage-associated seizures, complete seizure-free rates following each interventional treatment, follow-up duration; determination methods of seizure outcomes, and average time-to-onset of recurrent seizures after each treatment. Manuscripts that described patients with nondisabling seizures or reduced seizure frequency in their seizure-free calculations were excluded. Seizure freedom rates following surgical resection, SRS, and endovascular embolization were compared via random-effect analysis. Thirty-four studies with a total of 1765 intracranial AVM patients presenting with spontaneous AVM-associated seizures and 408 patients presenting with hemorrhage-associated seizures were qualitatively analyzed. For patients presenting with AVM-associated seizures, the complete seizure-free rates were 73.0% (321/440 patients; 95% CI 68.8-77.1%) following surgical resection, 60.5% (376/622 patients; 95% CI 56.6-64.3%) following SRS, and 44.6% (29/65 patients; 95% CI 32.5-56.7%) following endovascular embolization alone. For patients presenting with either AVM-associated or hemorrhage-associated seizures, the complete seizure-free rates were 73.0% (584/800 patients; 95% CI 69.9-76.1%) following surgical resection, 46.4% (572/1233 patients; 95% CI 43.6-49.2%) following SRS, and 44.6% (29/65 patients; 95% CI 32.5-56.7%) following embolization. For patients presenting with either AVM-associated or hemorrhage-associated seizures, the overall improvements in seizure outcomes regardless of complete seizure freedom were 82.6% (661/800 patients; 95% CI 80.0-85.3%), 70.6% (870/1233 patients; 95% CI 68.0-73.1%), and 70.8% (46/65 patients; 95% CI 59.7-81.1%) following surgical resection, SRS, and embolization, respectively. No study reported information about the time-to-onset for recurrent seizures in any patient following treatment, as seizure outcomes were only described at the last follow-up visit. The available data suggests that surgical resection results in the highest rate of complete seizure freedom. The rate of seizure improvement following surgery increased further to 82.3% when including patients who had improved seizure frequency without achieving true seizure freedom. Complete seizure-free rates following SRS or embolization were more ambiguous and lower when compared to surgical resection. There is a need for high quality studies evaluating AVM treatment modalities and clearly defined seizure outcomes, as the current literature consists mostly of heterogenous patient populations.

Benefits from Exclusion Treatment of Unruptured Brain Arteriovenous Malformations on Epilepsy in Adults

PURPOSE

In approximately 30% of the patients, brain arteriovenous malformations (bAVMs) are revealed by seizures, which may alter the patients' quality of life. Our objective was to evaluate the benefits of exclusion treatment (radiosurgery, embolization and/or surgery) on posttherapeutic epilepsy in bAVM patients without intracranial hemorrhage prior to treatment.

METHODS

Our retrospective observational single-center study included all consecutive adult patients with an unruptured bAVM and epilepsy, treated at our institution from 1995 to 2019 and who were followed for at least 1 year. Data on angioarchitectural characteristics of bAVMs, on epilepsy and posttreatment modified Rankin Scale (mRS) were collected. The primary endpoint was a seizure-free status (defined as Engel class IA) after exclusion treatment versus conservative management.

RESULTS

In this study one hundred and one consecutive adult patients with bAVMs, epilepsy and without bAVM rupture before any treatment were included; 21 (21%) in the conservative management group vs. 80 (79%) in the exclusion treatment group. After exclusion treatment, 55% of the patients from the group were Engel IA after treatment vs. 10% of the conservative management group (odds ratio [OR] 11.37, 95% confidence interval [CI] 2.48-107.24, p < 0.001).

CONCLUSION

Our results suggest that exclusion treatment in unruptured bAVMs with epilepsy is associated with a higher seizure-free rate in comparison with conservative management. Data from randomized controlled studies are necessary to confirm these findings.

Seizure Rates After Stereotactic Radiosurgery for Cerebral AVMs: A Single Center Study

OBJECTIVES

Seizure control after stereotactic radiosurgery (SRS) for arteriovenous malformations (AVMs) is an area of growing interest, with previous studies reporting up to 70% seizure freedom after treatment. The goals of this study were to identify specific patient and AVM characteristics associated with seizure presentation and seizure outcomes after SRS treatment.

METHODS

A retrospective review of consecutive patients undergoing SRS for brain AVMs between 2009 and 2019 at our institution was conducted. Chi-squared and logistic regression analyses were utilized to identify patient and AVM factors associated with preoperative seizure presentation and development of new onset seizures after SRS.

RESULTS

Two hundred ten consecutive patients presenting with AVMs treated with SRS were reviewed. Factors associated with seizure presentation included larger AVM size (P = 0.02), superficial venous drainage (P < 0.05), and parietal location (P = 0.04). Of 188 patients with follow-up (90%), 30 patients presented with seizures and 14 (47%) were seizure-free post-SRS. Of 158 patients presenting without seizure, 29 (18%) developed de novo seizures during follow-up. De novo post-SRS seizures were associated with prior craniotomy for resection of AVM (P = 0.04), post-treatment hemorrhage (P = 0.02), parietal location (P = 0.05), adverse effect requiring steroids (P < 0.01), and adverse effect requiring surgery (P < 0.01).

CONCLUSIONS

Seizures are a common presentation of brain AVMs and can be treated effectively with SRS. However, seizures can also be a complication of SRS and are associated with post-treatment hemorrhage, edema, and need for future open surgery.

Intracranial Gorgon: Surgical Case Report of a Large Calcified Brain Arteriovenous Malformation

Patient: Male, 55-year-old

Final Diagnosis: Right frontal arteriovenous malformation, partially calcified • multiple generalised epileptic seizures • chronic headache

Symptoms: Epilectic seizure • headache

Medication: —

Clinical Procedure: Neurosurgical resection of the right frontal AVM

Specialty: Neurosurgery

Arteriovenous malformation presenting with epilepsy: a multimodal approach to diagnosis and treatment

Arteriovenous malformation (AVM) presenting with epilepsy significantly impacts patient quality of life, and it should be considered very much a seizure disorder. Although hemorrhage prevention is the primary treatment aim of AVM surgery, seizure control should also be at the forefront of therapeutic management. Several hemodynamic and morphological characteristics of AVM have been identified to be associated with seizure presentation. This includes increased AVM flow, presence of long pial draining vein, venous outflow obstruction, and frontotemporal location, among other aspects. With the advent of high-throughput image processing and quantification methods, new radiographic attributes of AVM-related epilepsy have been identified. With respect to therapy, several treatment approaches are available, including conservative management or interventional modalities; this includes microsurgery, radiosurgery, and embolization or a combination thereof. Many studies, especially in the domain of microsurgery and radiosurgery, evaluate both techniques with respect to seizure outcomes. The advantage of microsurgery lies in superior AVM obliteration rates and swift seizure response. In addition, by incorporating electrophysiological monitoring during AVM resection, adjacent or even remote epileptogenic foci can be identified, leading to extended lesionectomy and improved seizure control. Radiosurgery, despite resulting in reduced AVM obliteration and prolonged time to seizure freedom, avoids the risks of surgery altogether and may provide seizure control through various antiepileptic mechanisms. Embolization continues to be used as an adjuvant for both microsurgery and radiosurgery. In this study, the authors review the latest imaging techniques in characterizing AVM-related epilepsy, in addition to reviewing each treatment modality.

MR characteristics of unruptured intracranial arteriovenous malformations associated with seizure as initial clinical presentation

Background

Patients with intracranial arteriovenous malformations (AVMs) are at increased risk of seizures.

Objective

To identify MRI characteristics of unruptured intracranial AVMs associated with seizures at presentation.

Materials and methods

A retrospective review was completed of patients diagnosed with unruptured intracranial AVMs on MRI between January 1, 2000 and December 31, 2016. Two blinded reviewers assessed demographics, lesion locality, and imaging and architectural characteristics of AVMs and surrounding parenchyma, including, but not limited to, AVM location, venous drainage pattern, venous varix, thrombosed venous varix, long draining vein, AVM-related gliosis, peri-AVM edema, and peri-AVM T2* signal. Findings were statistically analyzed for correlation with seizure using Student’s t-test for continuous variables and Χ2 test for categorical variables.

Results

Of 165 included patients, 57/165 (34.5%) patients were imaged as part of an investigation for seizures. Patients with seizures more commonly had peri-AVM edema (36.8%, compared with 11.1% of non-seizure patients, p<0.0001), peri-AVM T2* blooming (28.1% vs 7.4%; p=0.029), a venous pouch/varix (61.4% vs 31.5%, p=0.0003), long draining vein (91.2% vs 55.6%, p<0.0001), and larger size based on Spetzler-Martin grade categorization (p=0.006). By location, AVMs located in the frontal lobe, primary motor cortex, and primary sensory cortex were associated with seizures (p=0.004, p=0.001, and p=0.006, respectively); temporal lobe location was not associated with seizures (p=0.459).

Conclusions

Certain MRI characteristics of unruptured intracranial AVMs are associated with seizures. Such correlations may assist in identifying the pathophysiological mechanisms by which AVMs cause seizures.

Lausanne checklist for safe stereotactic radiosurgery

INTRODUCTION

Stereotactic radiosurgery (SRS) is increasingly used as a minimally invasive alternative in many neurosurgical conditions, including benign and malignant tumors, vascular malformations, and functional procedures. As for any surgical procedure, strict safety guidelines and checklists are necessary to avoid errors and the inherent unnecessary complications. With regard to the former, other groups have already reported human and/or technical errors. We describe our safety checklist for Gamma Knife radiosurgical procedures.

METHODS

We describe our checklist protocol after an experience gained over 1500 radiosurgical procedures, using Gamma Knife radiosurgery, performed over a period of 8 years, while employing the same list of items. Minor implementation has been performed over time to address some safety issues that could be improved.

RESULTS

Two types of checklist are displayed. One is related to the indications when a specific tissue volume is irradiated, including tumors or vascular disorders. The second corresponds to functional disorders, such as when the dose is prescribed to one specific point. Using these checklists, no human error had been reported during the past 8 years of practice in our institution.

CONCLUSION

The use of a safety checklist for SRS procedures promotes a zero-tolerance attitude for errors. This can lower the complications and is of major help in promoting multidisciplinary cooperation. We highly recommend the use of such tool, especially in the context of the increased use of SRS in the neurosurgical field.

Epileptic seizures as the first manifestation of the frontoparietal arteriovenous malformation of the brain

Abstract: Introduction: Arteriovenous malformations of the brain include a group of congenital disorders in the early development of arterial-venous blood vessels of the brain. Their clinical presentation is most common in the form of a brain hemorrhage, epileptic seizures, and headaches. Case report: We showed a man who at the age of 28 early in the morning after breakfast had the first generalized tonic-clonic seizure. After the second unprovoked epileptic seizure, antiepileptic therapy was introduced. The brain scanner showed the existence of arteriovenous malformations in the right frontoparietal region. As the size of the malformation was less than 30mm, it was decided that the patient should be treated with Gamma knife radiosurgery. After the successful radiosurgery together with the antiepileptic drugs treatment, the patient is in a stable 1.5 yearlong remission of epileptic seizures without neurological failures. Conclusion: Epileptic seizures can be the initial clinical manifestations of arteriovenous malformations of the brain. With an early diagnosis, adequate antiepileptic drugs therapy and neurosurgery, radiosurgery (Gamma Knife), which is often necessary, many symptomatic epilepsies enter a stable remission of epileptic seizures.