Cerebral arteriovenous malformations and seizures: differential impact on the time to seizure-free state according to the treatment modalities

Incidence and risk factors associated with seizures in cerebral amyloid angiopathy

BACKGROUND AND PURPOSE

Cerebral amyloid angiopathy (CAA) is a common cause of intracranial hemorrhage (ICH), which is a risk factor for seizures. The incidence and risk factors of seizures associated with a heterogeneous cohort of CAA patients have not been studied.

METHODS

We conducted a retrospective study of patients with CAA treated at Mayo Clinic Florida between 1 January 2015 and 1 January 2021. CAA was defined using the modified Boston criteria version 2.0. We analyzed electrophysiological and clinical features, and comorbidities including lobar ICH, nontraumatic cortical/convexity subarachnoid hemorrhage (cSAH), superficial siderosis, and inflammation (CAA with inflammation [CAA-ri]). Cognition and mortality were secondary outcomes. Univariate and multivariate analyses were performed to determine risk of seizures relative to clinical presentation.

RESULTS

Two hundred eighty-four patients with CAA were identified, with median follow-up of 35.7 months (interquartile range = 13.5-61.3 months). Fifty-six patients (19.7%) had seizures; in 21 (37.5%) patients, seizures were the index feature leading to CAA diagnosis. Seizures were more frequent in females (p = 0.032) and patients with lobar ICH (p = 0.002), cSAH (p = 0.030), superficial siderosis (p < 0.001), and CAA-ri (p = 0.005), and less common in patients with microhemorrhage (p = 0.006). After controlling for age and sex, lobar ICH (odds ratio [OR] = 2.1, 95% confidence interval [CI] = 1.1-4.2), CAA-ri (OR = 3.8, 95% CI = 1.4-10.3), and superficial siderosis (OR = 3.7, 95% CI = 1.9-7.0) were independently associated with higher odds of incident seizures.

CONCLUSIONS

Seizures are common in patients with CAA and are independently associated with lobar ICH, CAA-ri, and superficial siderosis. Our results may be applied to optimize clinical monitoring and management for patients with CAA.

Risk factors of seizure presentation in brain arteriovenous malformation patients and seizure outcomes after single-modality treatments

BACKGROUND

Epileptic seizures are common symptoms in brain arteriovenous malformation patients and seizure control was an important issue in the treatments. This retrospective study attempted to define the risk factors of seizure presentation and to evaluate the effects of treatment modalities on seizure outcomes.

METHODS

Patients receiving single treatment modality during 2013-2016 years, followed up more than 2 years were recruited. Logistic regression analysis was used to detect independent predictors. The factors associated with seizure control were analyzed in patients with pre-treatment seizures, and the factors associated with de novo seizures were analyzed in patents without pre-treatment seizures.

RESULTS

Multivariate analysis identified that the independent predictors of seizure presentation were unruptured (ruptured vs. unruptured, OR = 0.314), and in the frontal (frontal vs. parietal, OR = 3.982) or temporal lobe (temporal vs parietal, OR = 3.313). In 47 patients with seizure presentation, good seizure outcomes were achieved in 26 cases. Partial obliteration of nidus (partial vs complete, OR = 32.301) and headache presentation were independent predictors of poor outcome. In 169 patients without seizure presentation, de novo seizures occurred in 22 cases. Treatments of microsurgery or radiosurgery led to a higher incidence of de novo seizures than intravascular embolization.

CONCLUSIONS

Patients with unruptured and frontal/temporal lobe located nidus were more likely to manifest seizure presentation. Incomplete nidus obliteration was an independent risk factor of poor outcomes in patients with pre-existing seizures. However, compared to microsurgery or radiosurgery, endovascular embolization was less likely to cause de novo seizures in patients without pre-existing seizures.

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.

Effect of Targeted Embolization on Seizure Outcomes in Patients with Brain Arteriovenous Malformations

BACKGROUND

Seizures are one of the most debilitating manifestations of brain arteriovenous malformations (AVMs). This study aimed to evaluate the effect of curative embolization on brain AVM patients presenting with seizures.

METHODS

The records of patients who underwent embolization for brain AVM from January 2012 to December 2020 were evaluated and patients presenting with seizures were interviewed. Patient responses were evaluated according to the International League Against Epilepsy (ILAE) and Engel classifications. Statistical analyses of factors associated with seizure outcomes and complications were performed using ANOVA and Fischer's exact tests.

RESULTS

The mean age of the participants was 35.2 ± 10.7 years. More than 80% of the patients received no or suboptimal dosages of antiepileptic drugs (AEDs) prior to embolization. Positive seizure dynamics were observed in 50% of the patients post-procedure. A correlation was found between length of seizures in anamnesis and outcomes of both Engel and ILAE score, where shorter length was associated with better outcomes. Post-embolization hemorrhage was associated with initial presentation with hemorrhage.

CONCLUSIONS

The embolization of brain AVMs had a positive effect on seizure presentation and a relatively low prevalence of complications. However, the results of the study are obscured by inadequate AED treatment received by the patients, which prompts prospective studies on the topic with careful patient selection.

Incidence and risk factors of epilepsy following brain arteriovenous malformation rupture in adult patients

BACKGROUND

Little is known about incidence, time of onset, clinical presentation, and risk factors of epileptic seizure following brain arteriovenous malformation (bAVM) rupture.

METHODS

We performed a monocentric retrospective cohort study from January 2003 to March 2021. The main objective of this study was to determine the incidence of seizures after spontaneous bAVM rupture in nonepileptic adult patients and describe the corresponding clinical features. The secondary objective was to identify clinical, radiological, or biological predictors for the occurrence of de novo seizures after bAVM rupture.

RESULTS

Of the 296 cases of bAVM rupture registered during the study period, 247 nonepileptic patients (male 53%, median age 40) were included in the study. Fifty-nine patients (23.9%) had at least one seizure after bAVM rupture. The use of preventive antiepileptic drugs (10.3 [1.5-74.1]; P = 0.02) and decompressive craniectomy (15.4 [2.0-125]; P < 0.009) were independently associated with the occurrence of epilepsy after the bAVM rupture. The factors independently associated with the absence of any seizure after the rupture were isolated intraventricular hemorrhage (0.3 [0.1-0.99]; P = 0.04) and infratentorial location of the bAVM (0.2 [0.1-0.5]; P = 0.09). The first seizure occurred within the first year or within 5 years in, respectively, 83.1% and 98.3% of the patients.

CONCLUSIONS

Epilepsy affects nearly a quarter of patients after bAVM rupture. Decompressive craniectomy represents an independent risk factor significantly associated with the occurrence of epilepsy after bAVM rupture. The introduction of preventive AEDs after rupture could be considered in these most severe patients who have a decompressive craniectomy.

Seizure Outcomes After Interventional Treatment in Cerebral Arteriovenous Malformation-Associated Epilepsy: A Systematic Review and Meta-Analysis

BACKGROUND

Seizures are the second most common presenting symptom of cerebral arteriovenous malformations (AVMs). Evidence supporting different treatment modalities is continuously evolving and it remains unclear which modality offers better seizure outcomes.

OBJECTIVE

To compare various interventional treatment modalities (i.e., microsurgery, radiosurgery, endovascular embolization, or multimodality treatment), regarding outcomes in AVM-associated epilepsy.

METHODS

PubMed, Embase, and Web of Science were searched on December 31, 2020 for studies that evaluated outcomes in patients with AVM-associated epilepsy after undergoing different treatment modalities. Pooled analysis was performed using a random-effects model and stratified by different modalities.

RESULTS

Forty-nine studies including 2668 patients were included. Interventional management was associated with a 56.0% probability of seizure freedom and a 73.0% probability of seizure improvement. The probability of discontinuing antiepileptic drugs was estimated at 38.0%. The stratified analysis showed that microsurgery was associated with a higher probability of seizure freedom and seizure improvement than was radiosurgery, endovascular, or multimodality treatment. The probability of antiepileptic drug cessation was also higher after microsurgery compared with radiation therapy; however, only clinical but not statistical significance could be inferred because of the lack of comparative analyses.

CONCLUSIONS

Interventional management of AVM-related epilepsy was associated with seizure freedom and seizure improvement in 56% and 73% of cases. Microsurgery seemed to be associated with a higher incidence of seizure freedom and seizure improvement than did other modalities. Future well-designed comparative studies are needed to draw definitive conclusions regarding each modality.

Predictors of seizure control in patients with cerebral arteriovenous malformation

PURPOSE

We aimed to define the predictors of a 2-year seizure-free outcome among patients with cerebral arteriovenous malformation (AVM).

METHODS

A retrospective cohort study recruited patients diagnosed with AVM admitted in the hospital between 2002 and 2020. The demographic data, clinical presentations, seizure semiology, neuro-imaging findings, modality of treatment, and clinical outcomes were compared between the 2-year seizure-free and non-2-year seizure-free groups. A logistic regression model was applied to determine the significant predictors of a 2-year seizure-free outcome.

RESULTS

Of 372 radiologically confirmed patients with cerebral AVM, 105 (28.23%) experienced seizure and a 2-year seizure-free outcome was achieved in 76.19%. Most seizures presented as the initial symptom. Generalized onset seizure was the most common seizure semiology. A nidus diameter < 3 cm (adjusted odds ratio [aOR] 3.102; 95% CI 1.129-9.683; p = 0.046) was the independent predictor of a 2-year seizure-free period, whereas underlying epilepsy (aOR 0.141; 95% CI 0.010-0.688; p = 0.015) was an independent predictor against a 2-year seizure-free outcome.

CONCLUSION

A nidus diameter < 3 cm was the independent predictor of a 2-year seizure-free outcome, whereas underlying epilepsy was the factor against a 2-year seizure-free outcome.

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.

Arteriovenous Malformations-Associated Epilepsy in Pediatrics

PURPOSE

Seizures are the second most common presentation of cerebral arteriovenous malformations (AVMs); pediatric patients are more likely to develop AVM-associated epilepsy. We examined the role of multimodality AVM treatment in pediatric AVM-associated epilepsy to characterize long-term epilepsy outcomes.

METHODS

A retrospective chart review identified pediatric patients with AVM-associated epilepsy seen at our institution from 2005 to 2018. Variables measured included demographic and descriptive data. Primary outcomes included seizure freedom, seizure control, and functional outcomes.

RESULTS

Of 105 pediatric patients with AVMs, 18 had AVM-related epilepsy. Thirteen underwent surgical resection, of which 6 underwent preoperative embolization. Twelve (92.31%) had complete resection; one (7.69%) with residual underwent redo craniotomy with subsequent complete resection. All had radiographic cure at most recent follow-up, with no recurrence seen during length of follow-up (mean 2.17 years, SD 1.40, range 0.25-4.41). Eight (61.54%) experienced seizure freedom postoperatively; 12 (92.31%) were modified Engel Class I at last follow-up. Five patients underwent treatment without open surgical resection, with conservative management (3, 60%) or endovascular embolization (2, 40%). None in our cohort underwent radiosurgery. Of those embolized, one had complete AVM obliteration and two had partial obliteration. Four of the 5 patients (80%) treated without open surgery achieved seizure freedom.

CONCLUSION

Long-term outcomes of AVM-related epilepsy are poorly characterized in children. We found that in addition to improved AVM outcomes regarding obliteration, treatment of residual, and recurrence, pediatric patients undergoing surgical AVM treatment had improved AVM-associated epilepsy outcomes, with 61.54% achieving seizure freedom and 92.31% classified as modified Engel Class I seizure control.

Chinese Cerebrovascular Neurosurgery Society and Chinese Interventional & Hybrid Operation Society, of Chinese Stroke Association Clinical Practice Guidelines for Management of Brain Arteriovenous Malformations in Eloquent Areas

Aim: The aim of this guideline is to present current and comprehensive recommendations for the management of brain arteriovenous malformations (bAVMs) located in eloquent areas. Methods: An extended literature search on MEDLINE was performed between Jan 1970 and May 2020. Eloquence-related literature was further screened and interpreted in different subcategories of this guideline. The writing group discussed narrative text and recommendations through group meetings and online video conferences. Recommendations followed the Applying Classification of Recommendations and Level of Evidence proposed by the American Heart Association/American Stroke Association. Prerelease review of the draft guideline was performed by four expert peer reviewers and by the members of Chinese Stroke Association. Results: In total, 809 out of 2,493 publications were identified to be related to eloquent structure or neurological functions of bAVMs. Three-hundred and forty-one publications were comprehensively interpreted and cited by this guideline. Evidence-based guidelines were presented for the clinical evaluation and treatment of bAVMs with eloquence involved. Topics focused on neuroanatomy of activated eloquent structure, functional neuroimaging, neurological assessment, indication, and recommendations of different therapeutic managements. Fifty-nine recommendations were summarized, including 20 in Class I, 30 in Class IIa, 9 in Class IIb, and 2 in Class III. Conclusions: The management of eloquent bAVMs remains challenging. With the evolutionary understanding of eloquent areas, the guideline highlights the assessment of eloquent bAVMs, and a strategy for decision-making in the management of eloquent bAVMs.

Surgical Treatment of Unruptured Brain AVMs: Short- and Long-Term Results

Unruptured brain AVMs (bAVMs) remain a controversial subject for practicing neurosurgeons, especially in the light of ARUBA and other observational studies. This retrospective study aims to analyze our experience with unruptured bAVMs to see whether it is beneficial in the long-term and how it corresponds to large literature trials. The study comprised 160 adult patients with unruptured bAVMs surgically treated in Burdenko NMC (Moscow) in 2009-2017. Mean age: 33.4 ± 10лет. Clinical presentations were: seizures in 99 (61.9%), chronical headaches-49 (30.6%), ischemic symptoms-4 (2.5%), asymptomatic in 8 (5%) patients. Spetzler-Martin scale: I-18 pt. (11.3%), II-71 pt. (44.4%), III-60 pt. (37.5%), IV-11 pt. (6.8%). Good outcomes (mRS = 0-2) at discharge were achieved in 149 (93.1%), satisfactory (mRS-3)-9 (5.6%). Follow-up was complete for 97 (60.6%) patients, mean-59.3 (13-108 month). Excellent outcomes (mRS = 0-1) reached in 94.8%. For epilepsy patients, Engel I outcome was found in 50 (84.8%); for chronic headaches, 43 (66.1%) patients reported improvement. Postoperative visual field defects were followed in 22 of 55 (40%), complete recovery was reported in 6 (27%) and partial recovery in 8 (36%) patients. Overall, our results support the conclusion that surgery for low-grade bAVMs (S-M I-II) is a beneficial, low-risk option.

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

Overview of the current concepts in the management of arteriovenous malformations of the brain

Background

There is a lack of consensus in the management of arteriovenous malformations (AVMs) of the brain since ARUBA (A Randomised trial of Unruptured Brain Arteriovenous malformations) trial showed that medical management is superior to interventional therapy in patients with unruptured brain AVMs. The treatment of brain AVM is associated with significant morbidity.

Objectives and methods

A review was done to determine the behaviour of brain AVMs and analyse the risks and benefits of the available treatment options. A search was done in the literature for studies on brain AVMs. Descriptive analysis was also done.

Results

The angiogenic factors such as vascular endothelial growth factor and inflammatory cytokines are involved in the growth of AVMs. Proteinases such as matrix metalloproteinase-9 contribute to the weakening and rupture of the nidus. The risk factors for haemorrhage are prior haemorrhage, deep and infratentorial AVM location, exclusive deep venous drainage and associated aneurysms. The advancements in operating microscope and surgical techniques have facilitated microsurgery. Stereotactic radiosurgery causes progressive vessel obliteration over 2–3 years. Endovascular embolisation can be done prior to microsurgery or radiosurgery and for palliation.

Conclusions

Spetzler-Martin grades I and II have low surgical risks. The AVMs located in the cerebellum, subarachnoid cisterns and pial surfaces of the brainstem can be treated surgically. Radiosurgery is preferable for deep-seated AVMs. A combination of microsurgery, embolisation and radiosurgery is recommended for deep-seated and Spetzler-Martin grade III AVMs. Observation is recommended for grades IV and V.

Seizure control after radiosurgery for cerebral arteriovenous malformations: a 25-year experience

OBJECTIVE

Seizures are the second-most common presenting symptom in patients with lobar arteriovenous malformations (AVMs). However, few studies have assessed the long-term effect of stereotactic radiosurgery (SRS) on seizure control. The authors of this study assess the outcome of SRS for these patients to identify prognostic factors associated with seizure control.

METHODS

Patients with AVM who presented with a history of seizure and underwent SRS at the authors' institution between 1987 and 2012 were retrospectively assessed. The total cohort included 155 patients with a mean follow-up of 86 months (range 6-295 months). Primary outcomes assessed were seizure frequency, antiepileptic drug regimen, and seizure freedom for 6 months prior to last follow-up.

RESULTS

Seizure-free status was achieved in 108 patients (70%), with an additional 23 patients (15%) reporting improved seizure frequency as compared to their pre-SRS status. The median time to seizure-free status was estimated to be 12 months (95% CI 0-27 months) as evaluated via Kaplan-Meier survival analysis. The mean seizure frequency prior to SRS was 14.2 (95% CI 5.4-23.1) episodes per year. Although not all patients tried, the proportion of patients successfully weaned off all antiepileptic drugs was 18% (28/155 patients). On multivariate logistic regression, focal impaired awareness seizure type (also known as complex partial seizures) and superficial venous drainage were significantly associated with a decreased odds ratio for seizure-free status at last follow-up (OR 0.37 [95% CI 0.15-0.92] for focal impaired awareness seizures; OR 0.36 [95% CI 0.16-0.81] for superficial venous drainage). The effects of superficial venous drainage on seizure outcome were nonsignificant when excluding patients with < 2 years of follow-up. AVM obliteration did not correlate with long-term seizure freedom (p = 0.202, chi-square test).

CONCLUSIONS

This study suggests that SRS improves long-term seizure control and increases the likelihood of being medication free, independently of AVM obliteration. Patients with focal impaired awareness seizures were less likely to obtain long-term seizure relief.

[Arteriovenous malformations and epileptic seizures in children: risk factors of seizures and efficacy of their control depending on the surgical treatment modality]

Epileptic seizures are some of the most frequent manifestations of cerebral AVMs in children. Poor control of seizures can significantly affect patients' quality of life. In this case, factors that are associated with the development of seizures and affect the efficacy of their control upon treatment of cerebral AVMs are not well understood.

PURPOSE

The purpose of this study was to identify risk factors for the development of epileptic seizures as well as factors associated with a seizure-free outcome of AVM treatment in children.

MATERIAL AND METHODS

We analyzed the results of examination and treatment in 89 patients with cerebral AVMs aged 1 to 17 years.

RESULTS

Factors associated with the development of epileptic seizures in cerebral AVMs in children included male gender of the child, a large size of AVM and its superficial location, as well as localization of the pathology in the frontal and temporal lobes of the brain and draining varices. Regression of seizures after surgery was more often observed in the case of microsurgical and/or complex surgical treatment and complete exclusion of the AVM as well as in cases of rare attacks and a short course of the disease.

CONCLUSION

Complex and microsurgical treatment of AVMs in children provides effective control of epileptic seizures, which is obviously associated with complete exclusion of the AVM and removal of the epileptic focus located near the AVM.

[Immediate outcomes of microsurgical treatment of cerebral arteriovenous malformations in non-hemorrhagic patients]

Arteriovenous malformations (AVMs) are some of the most frequent congenital abnormalities of the cerebral vascular system and usually occur at a young age. Given the fact that AVMs can manifest, in addition to hemorrhages, as symptomatic epilepsy (17-40%) that occurs more often at a young age and may lead to significant disability, investigation of this pathology remains topical. Particular attention has recently been paid to the management of AVM patients without clinical signs of hemorrhage at the time of pathology diagnosis.

OBJECTIVE

The objective of this study was to optimize the management of patients with unruptured AVMs based on analysis of the immediate outcomes of microsurgical treatment.

MATERIAL AND METHODS

We retrospectively analyzed the immediate outcomes of microsurgical treatment of AVM patients hospitalized to the Burdenko Neurosurgical Institute in the period from 2009 to 2017. The patients included in the study met the following criteria: age over 18 years; microsurgical resection of AVM. The main exclusion criterion was a hemorrhage history confirmed by clinical data or verified by a neuroimaging study (MRI/CT). The study included 160 patients (58.1% males and 41.9% females) aged 18 to 67 years (mean, 33.5 years). According to the clinical course, patients with epileptic syndrome prevailed: 99 (61.9%) cases. Headaches occurred in 49 (30.6%) patients; 8 (5%) patients had asymptomatic AVMs; 4 (2.5%) patients had ischemic stroke. The surgical risk was assessed by using the Spetzler-Martin (S-M) scale: Grade I - 18 (11.3%) patients, Grade II - 71 (44.4%) patients, Grade III - 60 (37.5%) patients, and Grade IV - 11 (6.8%) patients. Direct surgery in patients with AVMs classified as S-M V was not planned.

RESULTS

Postoperative analysis revealed that 33 patients included in the study group in accordance with the above criteria had silent AVM hemorrhage that was confirmed only based on the intraoperative picture. The best surgical treatment outcomes were observed in patients with S-M I and II AVMs. The outcome scored 4 and 5 on the Glasgow Outcome Scale (GOS) was in 100% of cases in the S-M I group, 98.6% in the S-M II group, 86.7% in the S-M III group, and 81.8% in the S-M IV group. The relatively good outcomes of S-M IV AVM resection are explained by careful selection of patients for surgery. In general, good postoperative outcomes (GOS score of 4 and 5) were in 93.2% of patients. The main newly developed postoperative symptoms were visual impairments - visual field defects (64.7% of all complications). Postoperative mortality was 1.3%.

CONCLUSION

Surgical treatment is indicated for patients with unruptured AVMs and S-M I or II surgical risk, regardless of clinical manifestations. In other cases, the treatment approach depends on a number of risk factors.

The Risk of Seizure Following Surgery for Brain Arteriovenous Malformation: A Prospective Cohort Study

BACKGROUND

The evidence for the risk of seizures following surgery for brain arteriovenous malformations (bAVM) is limited.

OBJECTIVE

To determine the risk of seizures after discharge from surgery for supratentorial bAVM.

METHODS

A prospectively collected cohort database of 559 supratentorial bAVM patients (excluding patients where surgery was not performed with the primary intention of treating the bAVM) was analyzed. Cox proportional hazards regression models (Cox regression) were generated assessing risk factors, a Receiver Operator Characteristic curve was generated to identify a cut-point for size and Kaplan–Meier life table curves created to identify the cumulative freedom from postoperative seizure.

RESULTS

Preoperative histories of more than 2 seizures and increasing maximum diameter (size, cm) of bAVM were found to be significantly (P &lt; .01) associated with the development of postoperative seizures and remained significant in the Cox regression (size as continuous variable: P = .01; hazard ratio: 1.2; 95% confidence interval: 1.0-1.3; more than 2 seizures: P = .02; hazard ratio: 2.1; 95% confidence interval: 1.1-3.8). The cumulative risk of first seizure after discharge from hospital following resection surgery for all patients with bAVM was 5.8% and 18% at 12 mo and 7 yr, respectively. The 7-yr risk of developing postoperative seizures ranged from 11% for patients with bAVM ≤4 cm and with 0 to 2 preoperative seizures, to 59% for patients with bAVM &gt;4 cm and with &gt;2 preoperative.

CONCLUSION

The risk of seizures after discharge from hospital following surgery for bAVM increases with the maximum diameter of the bAVM and a patient history of more than 2 preoperative seizures.

Seizures associated with cerebral arteriovenous malformations

Various types of seizures and epilepsy are associated with 20-45% of cerebral arteriovenous malformations (AVMs). The necessity to differentiate between occasional seizures, epilepsy with repetitive seizures, and the much rarer drug-resistant epilepsy (DRE) is underlined. It is clear that where there is frequent seizures or DRE, vascular surgeons should take epilepsy surgery aspects into account. The epidemiology of AVM-associated seizures, assumed pathophysiologic mechanisms, most frequent seizures types, and medical treatment are described. Depending on the severity of the epilepsy, the diagnostic workup, including electroencephalogram (EEG), video-EEG, and, rarely, invasive evaluation, is explained. An invasive presurgical workup is only necessary in rare cases of DRE. The indication to extend the resection to more than just removal of the AVM is defined and the various specific resection techniques for this rare form are outlined. In the vast majority of AVM cases removal of the AVM with some adjoining gliotic or hemosiderotic rim of cortex will be sufficient, however. In the majority of cases with preoperative epilepsy, patients will be seizure-free after surgery. Patients who never had a seizure before AVM removal may develop de novo epilepsy postoperatively (5-15%). Rates of seizure freedom after different treatments (microsurgery, radiosurgery, endovascular) vary.

Microsurgical Outcome of Unruptured Brain Arteriovenous Malformations: A Single-Center Experience

OBJECTIVE

We describe our single-center experience treating unruptured brain arteriovenous malformations (uBAVMs) with microsurgical treatment.

METHODS

During a 7-year period, 282 patients with uBAVMs were surgically treated at our institution. Patient clinical features, postsurgical complications, arteriovenous malformation obliteration rate, seizure control, and functional outcome were collected and analyzed. Seizure control was evaluated with the Engel classification system. Patient functional outcome was assessed with modified Rankin Scale score.

RESULTS

Complete obliteration was achieved in 98.2% of cases. Surgical mortality rate was zero, and overall mortality rate was 1.1%. Good functional outcome (modified Rankin Scale score 0-1) was achieved in 86.9% of all patients, including 92.5% of patients with Spetzler-Martin (S-M) grade I and II uBAVMs, 80.6% of patients with S-M grade III uBAVMs, and 62.5% of patients with S-M grade IV and V uBAVMs. Poor outcome was significantly associated with arteriovenous malformation size ≥6 cm, deep venous drainage, eloquent location, and poor seizure control (all P < 0.05). For 177 patients with presurgical seizures, good seizure outcome (Engel class I) was achieved in 124 (70.1%) patients after microsurgical treatment. A short history of seizure occurrence, fewer presurgical seizures, and generalized tonic-clonic seizure type may be predictors of good seizure outcome (all P < 0.05).

CONCLUSIONS

Good functional outcome can be achieved by microsurgical resection in S-M grade I and II and selected grade III uBAVMs. Surgical resection for high-grade (grade IV and V) uBAVMs is challenging. A high seizure-free rate can be achieved in patients with initial seizure presentation.

Seizure control following treatment of brain arteriovenous malformations in pediatric patients

PURPOSE

Seizure outcome after treatment for pediatric patients with arteriovenous malformations (AVMs) has been rarely described in the literature. The aim of this study was to determine the risk factors for seizure presentation in pediatric AVM patients and the predictors for seizure control following treatment.

METHODS

We searched our characteristics of seizures associated with brain arteriovenous malformations prospectively maintained AVM database at Beijing Tiantan Hospital and identified 198 pediatric patients with brain AVMs between the year 2009 and 2014. Seizure presentation, patient characteristics, AVM features, treatment modalities, and postoperative outcomes, especially post-treatment seizure control were collected. Univariate and multivariate logistic regression analyses were applied to determine the risk factors for seizure presentation as well as the predictors for seizure control.

RESULTS

Before initiation of any treatments, 63 (31.8 %) of the overall 198 patients presented with seizure. According to multivariate analyses, larger AVM size, frontal AVM location, and history of prior hemorrhage were significantly associated with seizure presentation (all p < 0.05). For patients with pre-treatment seizure presentation, good seizure outcome was achieved in 73.8 %. AVM obliteration, short-period history of seizure, and short duration for seizure onset were independent predictors of good seizure outcome in the multivariate analysis. For the 135 patients without seizures at presentation, the overall rate of de novo seizures was 4.4 %.

CONCLUSION

In pediatric patients with brain AVMs, prior hemorrhage, larger AVM size, and frontal lobe location may predict subsequent seizures. Highest seizure control can be achieved by complete obliteration of the AVMs with microsurgical resection.

Medical vs. invasive therapy in AVM-related epilepsy: Systematic review and meta-analysis

OBJECTIVE

To compare invasive arteriovenous malformation (AVM) therapy to conservative management using only antiepileptic drugs (AEDs) for achieving seizure freedom in patients with AVM-related epilepsy.

METHODS

We searched Medline, Embase, and Cochrane Central up to June 2015 using epilepsy and AVM Medical Subject Headings and keywords. We included original research involving controlled observational cohort studies or randomized controlled trials (RCTs) comparing seizure outcomes between invasive AVM treatments vs. AED management alone, and uncontrolled case series of invasive AVM therapy for seizures that contained ≥20 patients. The estimates of seizure freedom were pooled using meta-analysis for the controlled trials, while the estimates for the case series were evaluated using descriptive statistics.

RESULTS

Of 2,166 identified abstracts, 98 were reviewed in full text, of which 31 were included in the final dataset. We identified 2 controlled observational studies (n = 106 patients) and 29 uncontrolled case series. We identified 1 RCT but it did not report seizure outcomes. The pooled risk ratio for seizure freedom in controlled studies (0.99; 95% confidence interval [CI] 0.69, 1.43) did not indicate superiority to either approach. Seizure freedom in case series varied from 19% (95% CI 11, 30%) to 95% (95% CI 76, 99%) at last follow-up.

CONCLUSIONS

There is insufficient evidence available to determine if invasive AVM management is superior to AED only for controlling seizures. An RCT of interventional vs. medical management using standardized epilepsy-specific presurgical protocols is warranted.

Radiosurgery for temporal lobe arteriovenous malformations: effect of temporal location on seizure outcomes

OBJECT

The temporal lobe is particularly susceptible to epileptogenesis. However, the routine use of anticonvulsant therapy is not implemented in temporal lobe AVM patients without seizures at presentation. The goals of this case-control study were to determine the radiosurgical outcomes for temporal lobe AVMs and to define the effect of temporal lobe location on postradiosurgery AVM seizure outcomes.

METHODS

From a database of approximately 1400 patients, the authors generated a case cohort from patients with temporal lobe AVMs with at least 2 years follow-up or obliteration. A control cohort with similar baseline AVM characteristics was generated, blinded to outcome, from patients with non-temporal, cortical AVMs. They evaluated the rates and predictors of seizure freedom or decreased seizure frequency in patients with seizures or de novo seizures in those without seizures.

RESULTS

A total of 175 temporal lobe AVMs were identified based on the inclusion criteria. Seizure was the presenting symptom in 38% of patients. The median AVM volume was 3.3 cm3, and the Spetzler-Martin grade was III or higher in 39% of cases. The median radiosurgical prescription dose was 22 Gy. At a median clinical follow-up of 73 months, the rates of seizure control and de novo seizures were 62% and 2%, respectively. Prior embolization (p = 0.023) and lower radiosurgical dose (p = 0.027) were significant predictors of seizure control. Neither temporal lobe location (p = 0.187) nor obliteration (p = 0.522) affected seizure outcomes. The cumulative obliteration rate was 63%, which was significantly higher in patients without seizures at presentation (p = 0.046). The rates of symptomatic and permanent radiation-induced changes were 3% and 1%, respectively. The annual risk of postradiosurgery hemorrhage was 1.3%.

CONCLUSIONS

Radiosurgery is an effective treatment for temporal lobe AVMs. Furthermore, radiosurgery is protective against seizure progression in patients with temporal lobe AVM–associated seizures. Temporal lobe location does not affect radiosurgery-induced seizure control. The low risk of new-onset seizures in patients with temporal or extratemporal AVMs does not seem to warrant prophylactic use of anticonvulsants.

Factors associated with seizure occurrence and long-term seizure control in pediatric brain arteriovenous malformation: a retrospective analysis of 89 patients

Background

Few studies have examined seizures in pediatric brain arteriovenous malformation. In our study, risk factors associated with seizure occurrence and long-term seizure control outcomes after different treatments in pediatric arteriovenous malformation patients were investigated.

Methods

A retrospective analysis was conducted with clinical data from a cohort of 89 pediatric brain arteriovenous malformation patients acquired between 2008 and 2013. Univariate and multivariate analyses were used to assess risk factors associated with seizure incidence. Patients who presented with seizure before treatment were evaluated using the Engel classification during the follow-up period.

Results

A higher risk of seizure occurrence was observed in large size and unruptured brain arteriovenous malformations using multivariate logistic regression analysis (p < 0.05). A total of 22 children, who presented with seizure before the interventions, were included in subsequent analysis. During a mean follow-up period of 2.3 years after the intervention, 12 (55 %) of these children were classified as Engel class I after treatment.

Conclusions

Seizures were the most common symptom in unruptured bAVMs. Size of the brain arteriovenous malformation is highly significant to seizure occurrence. Patients with cerebral hemorrhage are prone to having an acute seizure occurrence. The different therapies examined all improved seizure control to varying degrees.

Electronic supplementary material

The online version of this article (doi:10.1186/s12883-015-0402-5) contains supplementary material, which is available to authorized users.

Seizure Outcomes in Patients With Surgically Treated Cerebral Arteriovenous Malformations

BACKGROUND:

Epilepsy is the second most common symptom in cerebral arteriovenous malformation (AVM) patients. The consecutive reduction of life quality is a clinically underrated problem because treatment usually focuses on the prevention of intracerebral hemorrhage.

OBJECTIVE:

To evaluate postoperative seizure outcome with the aim of more accurate counseling for postoperative seizure outcome.

METHODS:

From 1985 to 2012, 293 patients with an AVM were surgically treated by J.S. One hundred twenty-six patients with preoperative seizures or epilepsy could be identified; 103 of 126 had a follow-up of at least 12 months and were included in the analysis. The different epilepsy subtypes were categorized (sporadic seizures, chronic epilepsy, drug-resistant epilepsy [DRE]). Preoperative workup and surgical technique were evaluated. Seizure outcome was analyzed by using International League Against Epilepsy classification.

RESULTS:

Sporadic seizures were identified in 41% of patients (chronic epilepsy and DRE were identified in 36% and 23%, respectively). Detailed preoperative epileptological workup was done in 13%. Seizure freedom was achieved in 77% (79% at 5 years, 84% at 10 years). Outcome was significantly poorer in DRE cases. More extensive resection was performed in 11 cases with longstanding symptoms (&gt;24 months) and resulted in better seizure outcome as well as the short duration of preoperative seizure history.

CONCLUSION:

Patients presenting with AVM-associated epilepsy have a favorable seizure outcome after surgical treatment. Long-standing epilepsy and the progress into DRE markedly deteriorate the chances to obtain seizure freedom and should be considered an early factor in establishing the indication for AVM removal.

Seizure and anticonvulsant outcomes following stereotactic radiosurgery for intracranial arteriovenous malformations

OBJECT

Epilepsy associated with arteriovenous malformations (AVMs) has an unclear course after stereotactic radiosurgery (SRS). Neither the risks of persistent seizures nor the requirement for postoperative antiepileptic drugs (AEDs) are well defined.

METHODS

The authors performed a retrospective review of all patients with AVMs who underwent SRS at the University of Virginia Health System from 1989 to 2012. Seizure status was categorized according to a modified Engel classification. The effects of demographic, AVM-related, and SRS treatment factors on seizure outcomes were evaluated with logistic regression analysis. Changes in AED status were evaluated using McNemar's test.

RESULTS

Of the AVM patients with pre- or post-SRS seizures, 73 with pre-SRS epilepsy had evaluable data for subsequent analysis. The median patient age was 37 years (range 5-69 years), and the median follow-up period was 65.6 months (range 12-221 months). Sixty-five patients (89%) achieved seizure remission (Engel Class IA or IB outcome). Patients presenting with simple partial or secondarily generalized seizures were more likely to achieve Engel Class I outcome (p = 0.045). Twenty-one (33%) of 63 patients tapered off of pre-SRS AEDs. The incidence of freedom from AED therapy increased significantly after SRS (p < 0.001, McNemar's test). Of the Engel Class IA patients who continued AED therapy, 54% had patent AVM nidi, whereas only 19% continued AED therapy with complete AVM obliteration (p = 0.05).

CONCLUSIONS

Stereotactic radiosurgery is an effective treatment for long-term AVM-related epilepsy. Seizure-free patients on continued AED therapy were more likely to have residual AVM nidi. Simple partial or secondarily generalized seizure type were associated with better seizure outcomes following SRS.

Stereotactic radiosurgery for sylvian fissure arteriovenous malformations with emphasis on hemorrhage risks and seizure outcomes

Object

Sylvian fissure arteriovenous malformations (AVMs) present substantial management challenges because of the critical adjacent blood vessels and functional brain. The authors investigated the outcomes, especially hemorrhage and seizure activity, after stereotactic radiosurgery (SRS) of AVMs within or adjacent to the sylvian fissure.

Methods

This retrospective single-institution analysis examined the authors' experiences with Gamma Knife surgery for AVMs of the sylvian fissure in cases treated from 1987 through 2009. During this time, 87 patients underwent SRS for AVMs in the region of the sylvian fissure. Before undergoing SRS, 40 (46%) of these patients had experienced hemorrhage and 36 (41%) had had seizures. The median target volume of the AVM was 3.85 cm3 (range 0.1–17.7 cm3), and the median marginal dose of radiation was 20 Gy (range 13–25 Gy).

Results

Over a median follow-up period of 64 months (range 3–275 months), AVM obliteration was confirmed by MRI or angiography for 43 patients. The actuarial rates of confirmation of total obliteration were 35% at 3 years, 60% at 4 and 5 years, and 76% at 10 years. Of the 36 patients who had experienced seizures before SRS, 19 (53%) achieved outcomes of Engel class I after treatment. The rate of seizure improvement was 29% at 3 years, 36% at 5 years, 50% at 10 years, and 60% at 15 years. No seizures developed after SRS in patients who had been seizure free before treatment. The actuarial rate of AVM hemorrhage after SRS was 5% at 1, 5, and 10 years. This rate equated to an annual hemorrhage rate during the latency interval of 1%; no hemorrhages occurred after confirmed obliteration. No permanent neurological deficits developed as an adverse effect of radiation; however, delayed cyst formation occurred in 3 patients.

Conclusions

Stereotactic radiosurgery was an effective treatment for AVMs within the region of the sylvian fissure, particularly for smaller-volume AVMs. After SRS, a low rate of hemorrhage and improved seizure control were also evident.

Seizure outcomes following radiosurgery for cerebral arteriovenous malformations

Object

Seizures are a common presentation of cerebral arteriovenous malformations (AVMs). The authors evaluated the efficacy of stereotactic radiosurgery (SRS) for the management of seizures associated with AVMs and identified factors influencing seizure outcomes following SRS for AVMs.

Methods

A systematic literature review was performed using PubMed. Studies selected for review were published in English, included at least 5 patients with both cerebral AVMs and presenting seizures treated with SRS, and provided post-SRS outcome data regarding obliteration of AVMs and/or seizures. Demographic, radiosurgical, radiological, and seizure outcome data were extracted and analyzed. All seizure outcomes were categorized as follows: 1) seizure free, 2) seizure improvement, 3) seizure unchanged, and 4) seizure worsened. Systematic statistical analysis was conducted to assess the effect of post-SRS AVM obliteration on seizure outcome.

Results

Nineteen case series with a total of 3971 AVM patients were included for analysis. Of these, 28% of patients presented with seizures, and data for 997 patients with available seizure outcome data who met the inclusion criteria were evaluated. Of these, 437 (43.8%) patients achieved seizure-free status after SRS, and 530 (68.7%) of 771 patients with available data achieved seizure control (seizure freedom or seizure improvement) following SRS. Factors associated with improved seizure outcomes following SRS for AVMs were analyzed in 9 studies. Seizure-free status was achieved in 82% and 41.0% of patients with complete and incomplete AVM obliteration, respectively. Complete AVM obliteration offered superior seizure-free rates compared with incomplete AVM obliteration (OR 6.13; 95% CI 2.16–17.44; p = 0.0007).

Conclusions

Stereotactic radiosurgery offers favorable seizure outcomes for AVM patients presenting with seizures. Improved seizure control is significantly more likely with complete AVM obliteration.

Epilepsy and headache after resection of cerebral arteriovenous malformations

The therapeutic benefits of microsurgery for cerebral arteriovenous malformations (AVM) with regard to headache and epilepsy are not well known. The objective of the present review is to discuss the available evidence and our own experience, which showed that two-thirds of the patients with preoperative epilepsy experienced long-term improvement, one-sixth no significant change, and an equal number worsening. New seizures occurred postoperatively in 18 % of the patients presenting with hemorrhage. Regarding headache, 40 % of patients with preoperative chronic headache reported improvement and 50 % described no change, whereas 10 % suffered from deterioration. With regard to epilepsy, the available literature suggests, that an epileptological approach with preoperative identification of the seizure focus and corresponding resection might improve the results. With regard to headache outcome, almost no information is available in the literature, suggesting that these complaints of the patients have so far not received the necessary attention. In conclusion, the long-term treatment results regarding chronic epilepsy and chronic headache need further study and optimization.

Impact on Seizure Control of Surgical Resection or Radiosurgery for Cerebral Arteriovenous Malformations

BACKGROUND:

Seizures are a common presenting symptom of arteriovenous malformations (AVMs). However, the impact of treatment modality on seizure control remains unclear.

OBJECTIVE:

To compare seizure control after surgical resection or radiosurgery for AVMs.

METHODS:

We analyzed retrospectively collected information for 378 patients with cerebral AVMs treated at our institution from 1990 to 2010. The application of strict inclusion criteria resulted in a study population of 164 patients.

RESULTS:

In our cohort, 31 patients (20.7%) had Spetzler-Martin grade I AVMs, 51 (34.0%) grade II, 47 (31.3%) grade III, 20 (13.3%) grade IV, and 1 (0.7%) grade V. Of the 49 patients (30%) presenting with seizures, 60.4% experienced seizure persistence after treatment. For these patients, radiosurgery was associated with seizure recurrence (odds ratio: 4.32, 95% confidence interval: 1.24-15.02, P = .021). AVM obliteration was predictive of seizure freedom at last follow-up (P = .002). In contrast, for patients presenting without seizures, 18.4% experienced de novo seizures after treatment, for which surgical resection was identified as an independent risk factor (hazard ratio: 8.65, 95% confidence interval: 3.05-24.5, P &lt; .001).

CONCLUSION:

Although our data suggest that achieving seizure freedom should not be the primary goal of AVM treatment, surgical resection may result in improved seizure control compared with radiosurgery for patients who present with seizures. Conversely, in patients without presenting seizures, surgical resection increases the risk of new-onset seizures compared with radiosurgery, but primarily within the early posttreatment period. Surgical resection and radiosurgery result in divergent seizure control rates depending on seizure presentation.