Thrombectomy for Anterior Circulation Stroke in a Witnessed Late Time Window Versus Early Time Window.

Introduction: Thrombectomy is the standard treatment for anterior circulation stroke due to large vessel occlusions in a late time window (6 to 24 hours) for patients selected based on perfusion imaging. Most patients treated in late time window studies presented as unwitnessed or wake-up strokes. Whether patients presenting with unwitnessed stroke have an actual time window greater than 6 hours is unclear. The aim of this study was to assess the outcomes of thrombectomy in the treatment of patients presenting with anterior circulation large vessel stroke in an actual late time window of more than 6 hours. Methods: This single-center registry of thrombectomy in the treatment of stroke caused by anterior circulation large vessel occlusions (LVOs) included 430 patients treated between 2011 and 2019. Patients were divided into 2 groups: an early time window (≤ 6 hours) group and a late time window group (> 6 hours). Results: Outcomes of the early and the late time window groups, respectively, were recanalization of 86.8% vs 82.7% (P = .29), symptomatic intracranial hemorrhage of 8.2% vs 5.7% (P = .40), good clinical outcome of 45.4% vs 41.3% (P = .46), and mortality of 20.2% vs 25% (P = .30) at 3 months. Conclusions: Thrombectomy for anterior circulation large vessel occlusions after 6 hours of symptoms onset seems to be as safe and effective as the standard thrombectomy within 6 hours from symptoms onset, even without perfusion analysis. Randomized trials are needed to confirm these findings.

Two year follow-up of distal unruptured intracranial aneurysms treated with a surface modified flow diverter under prasugrel monotherapy.

BACKGROUND: A new generation of modified surface flow diverters (FDs) and monotherapy using new antiplatelets may reduce both ischemic and hemorrhagic complications during the treatment of intracranial aneurysms. Previous preliminary safety analysis of distal unruptured intracranial aneurysms treated with the FD p48 MW HPC (phenox-Wallaby, Bochum, Germany) under antiplatelet monotherapy with prasugrel showed promising results. However, the long term outcomes of distal intracranial aneurysms treated with FDs under antiplatelet monotherapy are not known. METHODS: This was a single center, prospective, pivotal, open single arm study. The primary (safety) endpoint was absence of any new neurological deficits after treatment until the 24 month follow-up. The primary (efficacy) endpoint was the incidence of complete aneurysm occlusion 24 months after treatment. The secondary (efficacy) endpoints were any incidence of aneurysm dome reduction 24 months after treatment. RESULTS: 21 patients harboring 27 distal aneurysms of the anterior circulation were included. No patient had neurologic deficits in the time from treatment to the 24 month follow-up. Complete aneurysm occlusion occurred in 20 (74%) of 27 aneurysms at the 24 month follow-up. Four aneurysms (14.8%) had dome reduction, and three aneurysms (11.1%) remained unchanged. CONCLUSIONS: In this pilot trial, treatment of distal unruptured intracranial aneurysms with an FD under monotherapy with prasugrel, followed by monotherapy with aspirin, appeared to be safe and effective. Randomized studies with long term follow-up are needed to confirm these results.

Endovascular treatment of anterior cranial base dural arteriovenous fistulas as a first-line approach: a multicenter study.

OBJECTIVE: Anterior cranial fossa dural arteriovenous fistulas (DAVFs) have been almost exclusively considered as surgical lesions. However, new advances in endovascular technology have made the endovascular treatment (EVT) of ethmoidal DAVFs feasible. The aim of this study was to report the clinical and angiographic outcomes of patients harboring DAVFs of the anterior cranial fossa who had undergone EVT as a first-line approach. METHODS: This was a retrospective study of a consecutive series of patients harboring anterior cranial base DAVFs who had undergone EVT as a first-line approach at four institutions. Angiographic follow-up was performed at 6 months. Immediate and late serious clinical events were assessed during follow-up, including death and stroke. Special emphasis was given to visual status before and after the treatment. RESULTS: Between 2008 and 2020, 37 patients with ethmoidal DAVFs were admitted to the participating centers. In 2 patients, EVT was not attempted; therefore, 35 patients underwent EVT as a first-line procedure. An isolated transarterial approach was performed in 19 (54.3%) patients. The transvenous approach was performed exclusively in 12 (34.3%) patients, and combined access was used in 4 (11.4%) patients. The most frequently used arterial access route was the ophthalmic artery in 82.6% of the patients. Immediately, complete angiographic occlusion was achieved in 31 (91.2%) of 34 patients whose treatment was accomplished. Six-month control angiography revealed that 30 (88.2%) DAVFs were totally occluded. Complications occurred in 3 (8.8%) patients, including 1 (2.9%) patient who had central retinal artery occlusion. No significant difference in complications or occlusion rates was noted between the transarterial and transvenous approaches. CONCLUSIONS: Most anterior cranial base DAVFs can be successfully treated via an endovascular approach. Neurological and visual complications are rare, even if the ophthalmic artery is used as the primary access route. Efforts should be focused on prospectively comparing the results of EVT and surgical management.

Analysis of 565 thrombectomies for anterior circulation stroke: A Brazilian registry.

INTRODUCTION: The benefits of mechanical thrombectomy in the treatment of patients with acute stroke due to large vessel occlusions (LVOs) have been extensively demonstrated by randomized trials and registries in developed countries. However, data on thrombectomy outside controlled trials are scarce in developing countries. The aim of this study was to assess the safety and efficacy, and to investigate the predictors for good and poor outcomes of thrombectomy for treatment of AIS due to anterior circulation LVOs in Brazil. MATERIALS AND METHODS: This was a single center registry of thrombectomy in the treatment of stroke caused by anterior circulation LVOs. Between 2011 and 2019, a total of 565 patients were included. RESULTS: the mean baseline NIHSS score on admission was 17.2. The average baseline ASPECTS was 8, and 91.0% of patients scored ≥6. Half of the patients received intravenous thrombolysis. The mean time from symptom onset to arterial puncture was 296.4 minutes. The mean procedure time was 61.4 minutes. The rates of the main outcomes were recanalization (TICI 2b-3) 85.6%, symptomatic intracranial hemorrhage (sICH) 8,1%, good clinical outcome (mRS=0-2) 43,5%, and mortality 22.1% at three months. CONCLUSIONS: This study demonstrates the efficacy and safety of mechanical thrombectomy for treatment of patients with AIS of the anterior circulation in real-life conditions under limited facilities and resources. The results of the present study were relatively similar to those of large trials and population registers of developed countries.

Blood pressure behavior during mechanical thrombectomy and drugs used for conscious sedation or general anesthesia.

BACKGROUND: The optimal blood pressure (BP) during mechanical thrombectomy for acute ischemic stroke is currently unclear. OBJECTIVE: To investigate BP behavior during mechanical thrombectomy in patients with acute ischemic stroke and its relationship with drugs used for sedation or general anesthesia. Additionally, we investigated the association between BP oscillation during mechanical thrombectomy and recanalization status, and with functional outcome at discharge. METHODS: Consecutive patients treated with mechanical thrombectomy for acute ischemic stroke were evaluated in a tertiary hospital from December/2009 to December/2015. Maximum, minimum, and mean systolic and diastolic BP, and mean arterial pressures were collected during the procedure. Sedative drugs were also reviewed. RESULTS: Fifty-three patients with a mean age of 71.9 years (60.4% men) were treated with mechanical thrombectomy. The mean reduction in systolic BP and mean arterial pressure from hospital admission to mechanical thrombectomy were respectively 42 and 36 mmHg. During the procedure, oscillations were 50.4 mmHg for systolic, and 33.2 mmHg for diastolic BP. Patients treated with neuromuscular blocking drugs had more oscillation in systolic BP from hospital admission to procedure (51.1 versus 26.2 mmHg, P=0.06). The use of cisatracurium (43.9 versus 29.6 mmHg, P=0.02) and succinylcholine (44.7 versus 29.3 mmHg, P=0.01) were associated with a significant drop in BP during the procedure. CONCLUSIONS: Significant BP oscillation occurs during mechanical thrombectomy. Drugs used for conscious sedation or general anesthesia, specifically neuromuscular blocking agents, might have an influence upon BP levels.

Endovascular treatment of residual or recurrent intracranial aneurysms after surgical clipping.

OBJECTIVE: Total aneurysm occlusion is crucial for the prevention of rebleeding of a ruptured aneurysm or to avoid rupture of an unruptured lesion. Both surgical and endovascular embolization fail to achieve complete aneurysm occlusion in all the cases. The objective of the study was to establish the safety and efficacy of endovascular treatment for previously clipped residual or recurrent aneurysms. METHODS: This was an observational, retrospective study of patients harboring incompletely occluded intracranial aneurysms after clipping who underwent endovascular treatment. Patients were treated using 4 different techniques: (1) simple coiling, (2) balloon remodeling, (3) stent-assisted coiling, and (4) flow diversion. Analyses were performed to identify predictors of total aneurysm occlusion, recanalization and complications. RESULTS: Between May 2010 and September 2018, 70 patients harboring incompletely occluded intracranial aneurysms after clipping met the inclusion criteria in 5 centers. The mean residual aneurysm size was 7.5 mm. Fifty-nine aneurysms were unruptured. Total aneurysm occlusion was achieved in 75.3% of the aneurysms after 1 year. All aneurysms treated with flow diversion revealed complete occlusion according to control angiography. Recanalization was observed in 14.5%. Permanent morbidity and mortality occurred in 2.9% and 1.4% of the patients, respectively. CONCLUSIONS: Endovascular treatment of recurrent or residual aneurysms after surgical clipping was safe and efficacious. Flow diversion seems to be associated with better anatomical results. A more rigid study, a larger group of patients, and longterm follow-up are required to provide stronger conclusions about the best approach for residual clipped aneurysms.

Blood pressure behavior during mechanical thrombectomy and drugs used for conscious sedation or general anesthesia / Comportamento da pressão arterial durante trombectomia mecânica e drogas utilizadas para sedação consciente ou anestesia geral

ABSTRACT Background: The optimal blood pressure (BP) during mechanical thrombectomy for acute ischemic stroke is currently unclear. Objective: To investigate BP behavior during mechanical thrombectomy in patients with acute ischemic stroke and its relationship with drugs used for sedation or general anesthesia. Additionally, we investigated the association between BP oscillation during mechanical thrombectomy and recanalization status, and with functional outcome at discharge. Methods: Consecutive patients treated with mechanical thrombectomy for acute ischemic stroke were evaluated in a tertiary hospital from December/2009 to December/2015. Maximum, minimum, and mean systolic and diastolic BP, and mean arterial pressures were collected during the procedure. Sedative drugs were also reviewed. Results: Fifty-three patients with a mean age of 71.9 years (60.4% men) were treated with mechanical thrombectomy. The mean reduction in systolic BP and mean arterial pressure from hospital admission to mechanical thrombectomy were respectively 42 and 36 mmHg. During the procedure, oscillations were 50.4 mmHg for systolic, and 33.2 mmHg for diastolic BP. Patients treated with neuromuscular blocking drugs had more oscillation in systolic BP from hospital admission to procedure (51.1 versus 26.2 mmHg, P=0.06). The use of cisatracurium (43.9 versus 29.6 mmHg, P=0.02) and succinylcholine (44.7 versus 29.3 mmHg, P=0.01) were associated with a significant drop in BP during the procedure. Conclusions: Significant BP oscillation occurs during mechanical thrombectomy. Drugs used for conscious sedation or general anesthesia, specifically neuromuscular blocking agents, might have an influence upon BP levels.

RESUMO Antecedentes: Atualmente, a pressão arterial ideal durante a trombectomia mecânica em pacientes com acidente vascular cerebral isquêmico agudo não é clara. Objetivo: Investigar o comportamento da pressão arterial durante a trombectomia mecânica em pacientes com acidente vascular cerebral isquêmico agudo e sua relação com os medicamentos utilizados para sedação ou anestesia geral. Adicionalmente, investigar a associação entre a oscilação da pressão arterial durante a trombectomia mecânica e a capacidade de recanalização, além do status funcional no momento da alta hospitalar. Métodos: Avaliação de pacientes tratados com trombectomia mecânica por acidente vascular cerebral isquêmico agudo em um hospital terciário de dezembro/2009 a dezembro/2015. Valores máximos, mínimos e médios da pressão arterial sistólica, pressão diastólica e pressão arterial média foram coletados durante o procedimento. Drogas sedativas utilizadas também foram revisadas. Resultados: Um total de 53 pacientes com idade média de 71,9 anos (60,4% homens) foram tratados com trombectomia mecânica. A redução média da pressão arterial sistólica e da pressão arterial média desde a internação até a trombectomia mecânica foi respectivamente de 42 mmHg e 36 mmHg. Durante o procedimento, as oscilações da pressão arterial foram de 50,4 mmHg para pressão sistólica e 33,2 mmHg para pressão diastólica. Os pacientes tratados com bloqueadores neuromusculares apresentaram uma tendência a maior oscilação da pressão arterial sistólica desde a internação até o procedimento (51,1 mmHg versus 26,2 mmHg, P = 0,06). O uso de cisatracúrio (43,9 mmHg versus 29,6 mmHg, P = 0,02) e succinilcolina (44,7 mmHg versus 29,3 mmHg, P = 0,01) foram associados a uma queda significativa da pressão arterial durante o procedimento. Conclusões: Durante a trombectomia mecânica ocorre oscilação significativa da pressão arterial. Os medicamentos usados para sedação consciente ou anestesia geral, especificamente bloqueadores neuromusculares, podem ter influência nos níveis de pressão arterial.

Endovascular Treatment of Tentorial Dural Arteriovenous Fistulas Using the Transarterial Approach as a First-Line Strategy.

BACKGROUND: In recent decades, endovascular approaches have become the standard treatment for most tentorial dural arteriovenous fistulas (TDAVFs). Although endovascular treatment (EVT) is associated with better clinical outcomes, the angiographic occlusion rates are lower than those of surgical or combined approaches. OBJECTIVE: To evaluate the efficacy and safety of EVT for TDAVFs using the transarterial approach (TAA) as a first-line strategy. METHODS: Clinical and radiological data from 45 consecutive patients with TDAVFs who underwent EVT at 2 centers were retrospectively reviewed. Patient demographics and clinical and angiographic data were registered. Postprocedural and 6-mo follow-up angiographic and clinical results were evaluated. Univariable and multivariable logistic regression were performed to identify angiographic occlusion predictors after the first session and predictors of clinical complications. RESULTS: An isolated TAA was used for 40 TDAVFs (88.9%). A total of 37 (82.2%) TDAVFs were completely occluded after a single EVT session, and 44 TDAVFs (97.8%) were completely occluded after the last procedure. The presence of fewer than 5 arterial feeders was a predictor for total occlusion after the first treatment session (odds ratio [OR], 18.9; 95% CI 2.06-173.57; P = .01). Six-month angiographic control was performed in 42 patients, and all TDAVFs were occluded. Good long-term neurological outcomes were observed in 41 patients (91.1%). Clinical complications occurred in 7 (15.6%) patients. They were related to the number of accessed arteries to perform TAA (odds ratio, 2.53; 95% CI 1.10-5.86; P = .03). The procedure-related mortality rate was 2.2%. CONCLUSION: TAA is a safe and effective treatment for TDAVFs.

Treatment of distal unruptured intracranial aneurysms using a surface-modified flow diverter under prasugrel monotherapy: a pilot safety trial.

BACKGROUND: Flow diverters (FDs) are effective in the treatment of carotid aneurysms. Compared with carotid aneurysms, the treatment of distal intracranial aneurysms with FDs has been associated with a relatively high incidence of complications. Low thrombogenic modified-surface FDs may reduce ischemic complications and allow for the use of a single antiplatelet medication. The aim of this study was to assess the safety and efficacy of the p48 MW HPC Flow Modulation Device (Phenox GmbH, Bochum, Germany) to treat distal intracranial aneurysms used in combination with prasugrel monotherapy. METHODS: This was a single-center, prospective, pivotal, open, single-arm study. Patients were included in this study from December 2019 to September 2020. The primary endpoints were the incidence of any neurologic deficit after treatment until 1 month of follow-up, defined as National Institutes of Health Stroke Scale (NIHSS) ≥1, and the incidence of acute ischemic lesions in magnetic resonance imagin (MRI) images 48 hours after treatment. The secondary endpoint was the rate of complete occlusion of the aneurysms at the 1-month follow-up. RESULTS: Twenty-one patients harboring 27 distal aneurysms of the anterior circulation were included. Mean age was 57.8 (SD 9.7) years, and 16 patients were female (80%). No patient had neurologic symptoms at the 1-month follow-up. Four patients (20%) had asymptomatic acute brain ischemic lesions on MRI. Complete aneurysm occlusion occurred in 9/27 (33.3%) aneurysms at the 1-month follow-up. CONCLUSION: In this pilot safety trial, treatment of distal intracranial aneurysms with p48 MW HPC under monotherapy with prasugrel appeared to be safe.

Aspirin monotherapy in the treatment of distal intracranial aneurysms with a surface modified flow diverter: a pilot study.

BACKGROUND: Flow diverters (FDs) result in high occlusion rates of aneurysms located distally to the carotid artery. However, the complications reported are not negligible. New modified surface FDs have low thrombogenic properties that may reduce ischemic complications related to the treatment. In addition, a modified surface FD may allow for the use of a single antiplatelet medication to reduce hemorrhagic risk during the procedure. The aim of this study was to assess the safety and efficacy of the p48 MW HPC (phenox, Bochum, Germany) to treat distal intracranial aneurysms under the use of aspirin monotherapy. METHODS: The primary endpoint was the incidence of any neurologic deficit after treatment after 6 months of follow-up. The secondary endpoint was the rate of the complete occlusion of the aneurysms at the 6-month follow-up. Enrollment of 20 patients was planned, but after inclusion of seven patients the study was stopped due to safety issues. RESULTS: Seven patients with eight aneurysms were included. Among the seven patients, three (42.8%) had ischemic complications on the second day after FD deployment. Two patients experienced complete recovery at discharge (National Institutes of Health Stroke Scale (NIHSS) score=0), while one patient maintained mild dysarthria at discharge (NIHSS score=1) which improved after 6 months (NIHSS score=0). All three patients had no new symptoms during the 6-month follow-up. Complete aneurysm occlusion occurred in six (75%) of the eight aneurysms at the 6-month follow-up. CONCLUSIONS: Antiplatelet monotherapy with aspirin for the treatment of distal intracranial aneurysms with this modified surface FD resulted in a significant incidence of ischemic complications after treatment.

Performance evolution over 645 acute stroke thrombectomies in a public Brazilian healthcare institution.

BACKGROUND: Assessment of the impact of the thrombectomy learning curve on clinical outcomes is essential for developing healthcare system protocols. AIMS: The aim of this study was to assess the effect of thrombectomy case volume on procedural and clinical outcomes in a Brazilian registry. METHODS: A total of 645 patients with acute ischemic stroke treated by thrombectomy were included in the analysis. Patients were divided into two groups regarding the period of treatment: the early period group and the late period group. RESULTS: In the adjusted analysis, treatment in the late period was an independent predictor of recanalization (odds ratio 1.91, 95% CI 1.28-2.86) and excellent neurologic outcomes at three months (odds ratio 1.77, 95% CI 1.04-3.01). Treatment in the late period had no significant association with mortality (odds ratio 0.88, 95% CI 0.55-1.41). CONCLUSIONS: An increase in thrombectomy case volume for the treatment of AIS over time was an independent predictor of recanalization and excellent neurologic outcome.

Thrombectomy for Posterior Circulation Stroke: Predictors of Outcomes in a Brazilian Registry.

BACKGROUND: Acute basilar artery occlusion is a devastating life-threatening condition. Early recanalization is the therapeutic goal in patients with acute ischemic stroke. Despite the high rates of recanalization achieved with modern devices for basilar occlusions, many patients have had poor clinical outcomes. This study aimed to assess the predictors of good and poor outcomes among patients with basilar artery occlusion treated with thrombectomy. METHODS: A consecutive registry of 80 patients was included in this retrospective study. The primary end point was to access variables associated with neurologic outcomes defined by a modified Rankin Scale (mRS) score of 0-2, symptomatic intracranial hemorrhage (sICH), and mortality at 3 months follow-up. RESULTS: Recanalization was achieved in 86.2%, and the sICH rate was 8.7%. A good neurologic outcome (mRS score 0-2) was observed in 26.2% and a moderate outcome (mRS score 0-3) in 32.5% of patients. The mortality was 38.7% at 3 months follow-up. CONCLUSIONS: After thrombectomy for posterior circulation strokes, young patients, V4-proximal basilar occlusion, (high) baseline posterior circulation Alberta Stroke Program Early CT Score, and complete recanalization were independent predictors of good neurologic outcomes. Failure to recanalize was strongly related to sICH and mortality. In addition, diabetes, atrial fibrillation, and baseline National Institutes of Health Stroke Scale scores ≥10 had an independent association with mortality. This study contributes to the knowledge required to optimize recanalization treatments for posterior circulation strokes and may help to improve future clinical studies.

Safety and Effectiveness of the Pipeline Flex Embolization Device With Shield Technology for the Treatment of Intracranial Aneurysms: Midterm Results From a Multicenter Study.

BACKGROUND: The safety and efficacy of the first generation of the Pipeline Embolization Device (PED; Medtronic Inc) have been proven in large case series. Ischemic events are one of the most common complications following treatment of aneurysms with flow diverters. The new PED Flex with Shield technology (PED Shield; Medtronic Inc) was introduced to minimize the rate of complications. OBJECTIVE: To evaluate the outcomes of patients harboring aneurysms treated with the PED Shield. METHODS: This was an observational, prospective, single-arm multicenter study of patients treated with the PED Shield. The primary safety endpoint was the absence of major neurological complications and death. The secondary effectiveness endpoint was angiographic occlusion at 6 and 12 mo. Technical complications were also reported. RESULTS: Between November 2017 and December 2018, 151 patients from 7 centers with 182 aneurysms were enrolled. The mean aneurysm size was 7.0 mm; 27 (14.8%) aneurysms were large, and 7 (3.8%) were giant. In 141 of 151 patients (93.4%), the primary endpoint was reached. The overall rate of periprocedural complications was 7.3%. Of the aneurysms, 79.7% met the study's secondary endpoint of complete occlusion at 6 mo and 85.3% at 12 mo. CONCLUSION: The PED Shield is a safe and effective treatment for intracranial aneurysms. The results regarding total occlusion and ischemic complications did not differ from those obtained in case series using previous versions of the PED. Long-term follow-up and comparative studies are required to provide stronger conclusions regarding the reduced thrombogenicity of this device.

Derivo Embolization Device for the Treatment of Intracranial Aneurysms.

Background and Purpose- Flow diverter technology improvements are necessary to provide safe and good results and enable the treatment of a larger variety of aneurysms. We report a nationwide experience with the Derivo Embolization Device in the treatment of intracranial aneurysms. Methods- BRAIDED (Brazilian Registry of Aneurysms Assigned to Intervention With the Derivo Embolization Device) is a multicenter, prospective, interventional, single-arm trial of the Derivo Embolization Device for the treatment of intracranial aneurysms. The primary effectiveness end point was total aneurysm occlusion at 6- and 12-month angiographies. The secondary safety end point was the absence of serious adverse events during follow-up. Univariable and multivariable logistic regression was performed to identify predictors of aneurysm persistence, periprocedural complications, and adverse events during follow-up. Results- Between December 2016 and October 2018, 146 patients harboring 183 intracranial aneurysms were treated in 151 interventions at 7 centers. Derivo Embolization Device placement was technically successful in all patients. Most aneurysms (86.9%) were located at the internal carotid artery, and the mean diameter was 6.7 mm. At 6 months, 113 of 140 (80.7%) aneurysms met the study's primary end point, and 74 of 83 (89.2%) met the study's primary end point at 12 months. Saccular morphology of the aneurysm (odds ratio, 5.66; 95% CI, 1.01-31.77) and the presence of a branch arising from the sac (odds ratio, 6.36; 95% CI, 2.11-22.36) predicted persistence. A long duration of follow-up (odds ratio, 0.86; 95% CI, 0.78-0.95) predicted total occlusion. Of the 146 enrolled patients, 138 (94.5%) were treated without serious adverse events during follow-up. In the multivariable analysis, aneurysms located at a sidewall were less likely to experience these events than those located at bifurcations (odds ratio, 0.07; 95% CI, 0.01-0.51). Conclusions- The Derivo Embolization Device is a safe and effective treatment for intracranial aneurysms. Clinical Trial Registration- URL: http://plataformabrasil.saude.gov.br/login.jsf. Unique identifier: CAAE 77089717.7.1001.5125.

Multimodal quantitative magnetic resonance imaging analysis with individualized postprocessing in patients with drug-resistant focal epilepsy and conventional visual inspection negative for epileptogenic lesions.

OBJECTIVES: Approximately one-third of candidates for epilepsy surgery have no visible abnormalities on conventional magnetic resonance imaging. This is extremely discouraging, as these patients have a less favorable prognosis. We aimed to evaluate the utility of quantitative magnetic resonance imaging in patients with drug-resistant neocortical focal epilepsy and negative imaging. METHODS: A prospective study including 46 patients evaluated through individualized postprocessing of five quantitative measures: cortical thickness, white and gray matter junction signal, relaxation rate, magnetization transfer ratio, and mean diffusivity. Scalp video-electroencephalography was used to suggest the epileptogenic zone. A volumetric fluid-attenuated inversion recovery sequence was performed to aid visual inspection. A critical assessment of follow-up was also conducted throughout the study. RESULTS: In the subgroup classified as having an epileptogenic zone, individualized postprocessing detected abnormalities within the region of electroclinical origin in 9.7% to 31.0% of patients. Abnormalities outside the epileptogenic zone were more frequent, up to 51.7%. In five patients initially included with negative imaging, an epileptogenic structural abnormality was identified when a new visual magnetic resonance imaging inspection was guided by information gleaned from postprocessing. In three patients, epileptogenic lesions were detected after visual evaluation with volumetric fluid-attenuated sequence guided by video electroencephalography. CONCLUSION: Although quantitative magnetic resonance imaging analyses may suggest hidden structural lesions, caution is warranted because of the apparent low specificity of these findings for the epileptogenic zone. Conversely, these methods can be used to prevent visible lesions from being ignored, even in referral centers. In parallel, we need to highlight the positive contribution of the volumetric fluid-attenuated sequence.

Multimodal quantitative magnetic resonance imaging analysis with individualized postprocessing in patients with drug-resistant focal epilepsy and conventional visual inspection negative for epileptogenic lesions

OBJECTIVES: Approximately one-third of candidates for epilepsy surgery have no visible abnormalities on conventional magnetic resonance imaging. This is extremely discouraging, as these patients have a less favorable prognosis. We aimed to evaluate the utility of quantitative magnetic resonance imaging in patients with drug-resistant neocortical focal epilepsy and negative imaging. METHODS: A prospective study including 46 patients evaluated through individualized postprocessing of five quantitative measures: cortical thickness, white and gray matter junction signal, relaxation rate, magnetization transfer ratio, and mean diffusivity. Scalp video-electroencephalography was used to suggest the epileptogenic zone. A volumetric fluid-attenuated inversion recovery sequence was performed to aid visual inspection. A critical assessment of follow-up was also conducted throughout the study. RESULTS: In the subgroup classified as having an epileptogenic zone, individualized postprocessing detected abnormalities within the region of electroclinical origin in 9.7% to 31.0% of patients. Abnormalities outside the epileptogenic zone were more frequent, up to 51.7%. In five patients initially included with negative imaging, an epileptogenic structural abnormality was identified when a new visual magnetic resonance imaging inspection was guided by information gleaned from postprocessing. In three patients, epileptogenic lesions were detected after visual evaluation with volumetric fluid-attenuated sequence guided by video electroencephalography. CONCLUSION: Although quantitative magnetic resonance imaging analyses may suggest hidden structural lesions, caution is warranted because of the apparent low specificity of these findings for the epileptogenic zone. Conversely, these methods can be used to prevent visible lesions from being ignored, even in referral centers. In parallel, we need to highlight the positive contribution of the volumetric fluid-attenuated sequence.

Safety of Onyx Transarterial Embolization of Skull Base Dural Arteriovenous Fistulas from Meningeal Branches of the External Carotids also Fed by Meningeal Branches of Internal Carotid or Vertebral Arteries.

PURPOSE: To analyze the angiographic and clinical results of transarterial embolization with Onyx (Medtronic-Covidien, Irvine, CA) in dural arteriovenous fistulas (DAVFs) partially fed by arteries arising from the carotid siphon or the vertebral arteries. METHODS: We isolated 40 DAVFs supplied by either the tentorial artery of the internal carotid artery (ICA) or the posterior meningeal artery of the vertebral artery. These DAVFs were embolized with Onyx through the middle meningeal artery or the occipital artery. We reviewed the occurrence of reflux into the arteries of carotid or vertebral origin. RESULTS: In all the cases, reflux occurred into the first millimeters of the DAVF arterial feeders arising from carotid or vertebral arteries but slowly enough to be controlled by interruption of Onyx injection. Reflux was always minimal and Onyx never reached the ostium of the arteries. No cerebral ischemic complications occurred in our series. CONCLUSION: The behavior of Onyx is clearly different from that of cyanoacrylate glue, resulting in superior control during injection. Reflux into arteries arising from the ICA or vertebral artery during DAVF treatment always carries a risk of unintentional non-target embolization of normal cerebral vasculature but Onyx appears to be safe in this situation.