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OBJECTIVEAspirin has emerged as a potential agent in the prevention of rupture of intracranial aneurysms (IAs). In this study, the authors’ goal was to test if aspirin is protective against aneurysm growth in patients harboring multiple IAs ≤ 5 mm.METHODSThe authors performed a retrospective review of a prospectively maintained database covering the period July 2009 through January 2019. Patients’ data were included if the following criteria were met: 1) the patient harbored multiple IAs; 2) designated primary aneurysms were treated by surgical/endovascular means; 3) the remaining aneurysms were observed for growth; and 4) a follow-up period of at least 5 years after the initial treatment was available. Demographics, earlier medical history, the rupture status of designated primary aneurysms, aneurysms’ angiographic features, and treatment modalities were gathered.RESULTSThe authors identified 146 patients harboring a total of 375 IAs. At the initial encounter, 146 aneurysms were treated and the remaining 229 aneurysms (2–5 mm) were observed. During the follow-up period, 24 (10.48%) of 229 aneurysms grew. All aneurysms observed to grow later underwent treatment. None of the observed aneurysms ruptured. Multivariate analysis showed that aspirin was significantly associated with a decreased rate of growth (odds ratio [OR] 0.19, 95% confidence interval [CI] 0.05–0.63). Variables associated with an increased rate of growth included hypertension (OR 14.38, 95% CI 3.83–53.94), drug abuse (OR 11.26, 95% CI 1.21–104.65), history of polycystic kidney disease (OR 9.48, 95% CI 1.51–59.35), and subarachnoid hemorrhage at presentation (OR 5.91, 95% CI 1.83–19.09).CONCLUSIONSIn patients with multiple IAs, aspirin significantly decreased the rate of aneurysm growth over time. Additional prospective interventional studies are needed to validate these findings.

Background Most trials have assessed intracranial atherosclerotic disease (ICAD) severity based on angiographic stenosis. However, anatomic stenosis might not accurately identify the actual state of functional post-stenotic flow limitation. Objective To investigate whether angiographic stenosis correlates with physiologic distal flow limitation, measured as trans-stenotic pressure gradients, in ICAD patients. Methods In patients referred for endovascular treatment of anterior circulation symptomatic ICAD who failed maximal medical therapy (MMT) per SAMMPRIS (Stenting versus Aggressive Medical Therapy for Intracranial Arterial Stenosis) criteria, angiographic luminal diameters and percentages of stenosis were correlated with trans-stenotic pressure gradients, calculated as distal/proximal pressure ratios (DPPR) and proximal minus distal pressure gradients (PDPG), by way of Spearman correlation coefficients. Results Nine patients (3 men, 6 women) were evaluated. Atherosclerotic lesions' locations included internal carotid artery in 5 subjects (2 cavernous, 3 supraclinoid) and proximal middle cerebral artery (M1) in 4 patients. Mean percentage of stenosis was 80 ± 8% (range 75%-94%). Minimal lumen diameter at the most stenotic ICAD site ranged from 0.2 to 0.9 mm (0.59 ± 0.41 mm). DPPR ranged from 0.38 to 0.63 (0.56 ± 0.14). PDPG ranged from 35 to 57 mm Hg (50 ± 8 mm Hg). Spearman coefficients showed no correlation between DPPR or PDPG and angiographic minimal luminal diameters or percentages of stenosis. There were no procedural complications related to trans-stenotic pressure measurements. Conclusion Angiographic stenosis does not reflect the physiologic severity of distal flow limitation in patients with ICAD. Hemodynamic assessment using trans-stenotic pressure ratios and gradients may serve as a more reliable predictive biomarker for MMT failure and response to revascularization.

Background: The use of Pipeline Embolization Device (PED) is approved by the US Food and Drug Administration (FDA) to treat aneurysms located between the petrous and superior hypophyseal segments of the internal carotid artery. The purpose of this study is to evaluate the feasibility and efficacy of treating aneurysms outside the FDA approved anatomical locations. Furthermore, we analyze the safety of our antiplatelet protocol. Methods: Data on all patients treated with PED at our center from March 2015 to December 2017 were reviewed. Only patients with aneurysms treated with PED as off label use were included. Procedural complications and long-term functional outcome measured by modified Rankin Scale (mRS) were recorded. Tirofiban maintenance infusion was administered intravenously after PED deployment. None of the patients had platelet function testing. Results: A total of 36 patients harboring 36 aneurysms were included in the study. Mean age was 58.2 years ±14.6. Nineteen were women (52.8%) and most aneurysms were unruptured (80.6%). There were no intraoperative complications. Five patients experienced postoperative complications – 4 ischemic strokes and one groin hematoma. None led to any significant disability at follow-up. Thirty-one patients (86.1%) achieved an mRS of 0–2 at follow-up. A Raymond-Roy classification of 1 was achieved in 78.9% of patients. Conclusion: The use of PED to treat aneurysms located outside the circle of Willis is feasible and effective. Our novel antiplatelet protocol did not require platelet function assay testing and did not lead to a higher rate of thrombo-embolic events compared to what has been previously reported.

Objective The management of chronic complete internal carotid artery (ICA) occlusion (COICA) has been challenging. Endovascular procedures have been performed with variable success and risks, depending on the type of occlusion and distal revascularization. We present a novel hybrid procedure to recanalize the ICA when previous endovascular interventions have failed or been deemed too risky. Methods Two patients presented with symptomatic COICA after maximal medical management. They were deemed at high risk of endovascular intervention and/or previous endovascular attempts had failed. Thus, they had indications for a hybrid procedure. Results A hybrid technique was used to create a stump by surgical endarterectomy, followed by recanalization using an endovascular approach via femoral access. We have described the technique in detail. Postoperative computed tomography perfusion scanning showed normalization of the mean transient time, cerebral blood volume, and cerebral blood flow compared with the preoperative findings. Cerebral angiography showed successful recanalization of the ICA. Neither patient experienced any complications. Conclusion A hybrid technique is feasible and should be considered for patients with COICA in whom maximal medical management has failed and who have a high-risk profile for endovascular intervention or in whom previous endovascular attempts have failed.

Objective: Imaging via MR-quantitative susceptibility mapping (QSM) can identify reliably microbleeds (MBs) associated with intracranial aneurysms (IAs) in subjects presenting with severe headache suggestive of sentinel headache (SH) preceding subarachnoid hemorrhage. However, its use is limited due to associated skull base bonny artifact. Vessel wall imaging (VWI) is not limited by bonny artifact and therefore could be an alternative to QSM in detecting MBs. The purpose of this study is to examine the correlation between QSM and the MR-VWI in detecting MBs associated with severe headache suggestive of SH. Methods: We performed a prospective single-center study of subjects with unruptured IAs with initial presentation of headaches. All subjects underwent evaluation using 3T-MRI protocol which included MRA, QSM, and pre- and post-contrast VWI of the IAs. Presence/absence of MBs detected by QSM was correlated with aneurysm wall enhancement (AWE) on MR-VWI. Results: In the interval of November 2017 to June 2019, a total of 40 subjects harboring 51 unruptured IAs were enrolled in the study. MBs and AWE were detected in 12 (23.5%) and 22 (43.1%) IAs, respectively. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of QSM detecting MBs associated with recent/remote SH was 100% for all, respectively. The sensitivity, specificity, PPV, and NPV of AWE on VWI for detecting MBs confirmed by QSM was 91.7%, 71.8%, 50%, and 96.6%, respectively. Conclusions: The combination of imaging findings of MR-VWI and QSM can be used reliably for detection of MBs in subjects with IAs whose presentation is suggestive of SH. If proven in larger cohort, this could eliminate the need for lumbar puncture to screen for SH in subjects with IAs presenting to the emergency department with headaches.

OBJECTIVEIntracranial stenting and flow diversion require the use of dual antiplatelet therapy (DAPT) to prevent in-stent thrombosis. DAPT may significantly increase the risk of hemorrhagic complications in patients who require subsequent surgical interventions. In this study, the authors sought to investigate whether DAPT is a risk factor for hemorrhagic complications associated with ventriculoperitoneal (VP) shunt placement in patients with aneurysmal subarachnoid hemorrhage (aSAH). Moreover, the authors sought to compare VP shunt complication rates with respect to the shunt’s location from the initial external ventricular drain (EVD) site.METHODSPatients with aSAH who presented to the authors’ institution from July 2009 through November 2016 and required VP shunt placement for persistent hydrocephalus were included. The rates of hemorrhagic complications associated with VP shunt placement were compared between patients who were on a regimen of DAPT (aspirin and clopidogrel) for use of a stent or flow diverter, and patients who underwent microsurgical clipping or coiling only and were not on DAPT using a backward stepwise multivariate analysis. Rates of radiographic hemorrhage and infection-related VP shunt revision were compared between patients who underwent VP shunt placement along the same track and those who underwent VP shunt placement at a different site (contralateral or posterior) from the initial EVD.RESULTSA total of 443 patients were admitted for the management of aSAH. Eighty of these patients eventually required VP shunt placement. Thirty-two patients (40%) had been treated with stent-assisted coiling or flow diverters and required DAPT, whereas 48 patients (60%) had been treated with coiling without stents or surgical clipping and were not on DAPT at the time of VP shunt placement. A total of 8 cases (10%) of new hemorrhage were observed along the intracranial proximal catheter of the VP shunt. Seven of these hemorrhages were observed in patients on DAPT, and 1 occurred in a patient not on DAPT. After multivariate analysis, only DAPT was significantly associated with hemorrhage (OR 31.23, 95% CI 2.98–327.32; p = 0.0001). One patient (3%) on DAPT who experienced hemorrhage required shunt revision for hemorrhage-associated proximal catheter blockage. The remaining 7 hemorrhages were clinically insignificant. The difference in rates of hemorrhage between shunt placement along the same track and placement at a different site of 0.07 was not significant (6/47 vs 2/32, p = 0.46). The difference in infection-related VP shunt revision rate was not significantly different (1/47 vs 3/32, p = 0.2978).CONCLUSIONSThis clinical series confirms that, in patients with ruptured aneurysms who are candidates for stent-assisted coiling or flow diversion, the risk of clinically significant VP shunt–associated hemorrhage with DAPT is low. In an era of evolving endovascular therapeutics, stenting or flow diversion is a viable option in select aSAH patients.

Background Stenting and flow diversion for aneurysmal sub arachnoid hemorrhage (aSAH) require the use of dual antiplatelet therapy (DAPT). Objective To investigate whether DAPT is associated with hemorrhagic complication following placement of external ventricular drains (EVD) in patients with aSAH. Methods Rates of radiographically identified hemorrhage associated with EVD placement were compared between patients who received DAPT for stenting or flow diversion, and patients who underwent microsurgical clipping or coiling and did not receive DAPT by way of a backward stepwise multivariate analysis. Results Four hundred forty-three patients were admitted for aSAH management. Two hundred ninety-eight patients required placement of an EVD. One hundred twenty patients (40%) were treated with stent-assisted coiling or flow diversion and required DAPT, while 178 patients (60%) were treated with coiling without stents or microsurgical clipping and did not receive DAPT. Forty-two (14%) cases of new hemorrhage along the EVD catheter were identified radiographically. Thirty-two of these hemorrhages occurred in patients on DAPT, while 10 occurred in patients without DAPT. After multivariate analysis, DAPT was significantly associated with radiographic hemorrhage [odds ratio: 4.92, 95% confidence interval: 2.45-9.91, P = .0001]. We did not observe an increased proportion of symptomatic hemorrhage in patients receiving DAPT (10 of 32 [31%]) vs those without (5 of 10 [50%]; P = .4508). Conclusion Patients with aSAH who receive stent-assisted coiling or flow diversion are at higher risk for radiographic hemorrhage associated with EVD placement. The timing between EVD placement and DAPT initiation does not appear to be of clinical significance. Stenting and flow diversion remain viable options for aSAH patients.

Successful resection of hemangioblastoma depends on preoperative assessment of the precise locations of feeding arteries and draining veins. Simultaneous 3D visualization of feeding arteries, draining veins, and surrounding structures is needed. The present study evaluated the usefulness of high-resolution 3D multifusion medical imaging (hr-3DMMI) for preoperative planning of hemangioblastoma. The hr-3DMMI combined MRI, MR angiography, thin-slice CT, and 3D rotated angiography. Surface rendering was mainly used for the creation of hr-3DMMI using multiple thresholds to create 3D models, and processing took approximately 3–5 hours. This hr-3DMMI technique was used in 5 patients for preoperative planning and the imaging findings were compared with the operative findings. Hr-3DMMI could simulate the whole 3D tumor as a unique sphere and show the precise penetration points of both feeding arteries and draining veins with the same spatial relationships as the original tumor. All feeding arteries and draining veins were found intraoperatively at the same position as estimated preoperatively, and were occluded as planned preoperatively. This hr-3DMMI technique could demonstrate the precise locations of feeding arteries and draining veins preoperatively and estimate the appropriate route for resection of the tumor. Hr-3DMMI is expected to be a very useful support tool for surgery of hemangioblastoma.

Introduction: Due to advancements in the field of endovascular neurosurgery, use of intracranial stenting and flow diversion (ISFD) in the treatment of acute aneurysmal subarachnoid hemorrhage (aSAH) is on the rise. ISFD requires dual antiplatelet therapy (DAPT), which poses a challenge when patients undergo placement of an external ventricular drain (EVD) or ventriculo-peritoneal-shunt (VPS). We describe our experience with the use of intravenous tirofiban in similar settings. Methods: Patients with aSAH between July 2017 and June 2018 requiring intravenous tirofiban for ISFD after EVD placement and subsequent VPS were included in our retrospective study. Patients were started on intravenous tirofiban at maintenance dose prior to IFSD and continued until transitioned to DAPT after removal of EVD with or without VPS. Intravenous tirofiban was held 4 hours prior to EVD removal/VPS placement and resumed 2 hours later followed by loading dose of DAPT. Patients were monitored in ICU and CT head obtained 24-hours after the procedure. Results: 15 patients (mean age 55 years, 14 females and 1 male) with aSAH who required ISFD and were placed on intravenous tirofiban for 3-18 days. In total, 21 procedures were performed with placement of 16 EVDs (one patient had bilateral EVDs) and 5 VPS. Two patients had clinically asymptomatic small track hemorrhages and 1 patient had a retroperitoneal hemorrhage and thrombocytopenia. No thromboembolic complications were reported. We encountered an 18% risk of hemorrhages, which compares favorably to our previously published 22% risk of all hemorrhages with DAPT. Conclusions: The continuous infusion of tirofiban in patients with aSAH who require ISFD is feasible and has hemorrhagic complication rate similar to the use of DAPT.

Background: Fragmentation of the tunica media is a hallmark of intracranial aneurysm formation, often leading to aneurysmal progression and subsequent rupture. The objective of this study is to determine the plasma level of elastin fragments in the lumen of ruptured versus unruptured human intracranial aneurysms. Methods: One hundred consecutive patients with/without ruptured saccular intracranial aneurysms undergoing endovascular coiling or stent-assisted coiling were recruited. Blood samples were collected from the lumen of intracranial aneurysm using a micro-catheter. The tip of the microcatheter was placed inside the aneurysm’s sac in close proximity to the inner wall of the dome. Plasma levels of elastin fragments were measured using an ELISA-based method. Results: The mean plasma level of soluble human elastin fragments was significantly greater in ruptured aneurysms when compared to non-ruptured aneurysms (102.0 ± 15.5 vs. 39.3 ± 9.6 ng/ml, P Conclusions: The present study revealed that a significantly higher concentration of soluble human elastin fragments in the lumen of ruptured intracranial aneurysms when compared to non-ruptured ones.

Objective: To evaluate pre and postop cerebral hemodynamics and the effects it has on neurocognitive outcomes in patients with chronically occluded internal carotid artery (COICA) who have undergone successful recanalization. Methods: Patients with symptomatic COICA who underwent revascularization technique using either angioplasty and stenting (AS) or a hybrid of carotid endarterectomy and AS are included in this analysis. Results: From January 2016 to June of 2018, 31 subjects underwent revascularization. Only 5 subjects (6 COICA) had CTP and MoCA scores pre and post revascularization. All 5 subjects had very large penumbra involving the ipsilateral hemisphere, which has resolved postop. No permanent complications were associated with the procedure. All patients have objective improvement in their neurocognitive outcomes (pre MoCA: 19.8±2.4, post MoCA: 27±1.6; p-0.0038). Conclusions: CTP can guide in patient selections for recanalization. Successful recanalization lead to improvement in CTP parameters and neurocognitive functions.

Background and Purpose: Sentinel symptoms of aneurysm’s micro - hemorrhage such as sentinel headache or cranial nerve (CN) neuropathies are associated with an increased risk of subarachnoid hemorrhage (SAH). We tested a new MRI protocol that may aid the identification of microbleeds associated with sentinel symptoms in patients with negative head CTs and lumbar punctures. Methods: Twenty-eight consecutive subjects with a total of 35 aneurysms were enrolled in this pilot study between March/2018 to July/2018. All subjects presented with sentinel symptoms, no evidence of SAH on head CT or spinal puncture. The MRI protocol included: MRA with gadolinium, high-resolution MR vessel wall imaging (MRI-VWI) and MR imaging quantitative susceptibility mapping (MRI-QSM). Two blinded neuroimaging experts reviewed every image to determine evidence of vessel-wall enhancement or positive MRI-QSM signal. A third adjudicator intervened in case of disagreement. Statistical differences were determined by Student t-test, as well as Mann-Whitney U test for non-parametric variables. Results: 35 CAs (100%) were analyzed with MR-VWI, whereas only 24 CAs (77.1%) on MRI-QSM due artifact form the skull base bone ( P =0.005). Fifty percent (50%) of anterior communicating artery aneurysm were not visualized on MRI-QSM. Four subjects presented with typical sentinel headache and twenty four with some cranial neuropathy. Interobserver agreement was 100% for MRI-QSM, while 83.9% in MRI-VWI (P=0.06). Disagreements derived from the differentiation between mild and no contrast enhancement in MR-VWI. MRI-QSM had a sensitivity of 100% and a specificity of 100% in micro-hemorrhage identification. Whereas, MRI-VWI had sensitivity of 100% and specificity of 51.9%. Conclusions: MRI-QSM is a valuable tool in identifying micro-hemorrhage in patients who present with sentinel symptoms. However, its main limitation is bone artifact in aneurysms close to bone structures.

Objective: The overall risk of ischemic stroke from a chronically occluded internal carotid artery (COICA) is around 5%-7% per year despite receiving the best medical therapy. We propose a radiographic classification of COICA that can be used as a guide to determine the technical success and safety of endovascular recanalization for symptomatic COICA. Methods: The radiographic images of 100 consecutive subjects with COICA were analyzed. A new classification of COICA was proposed based on the morphology, location of occlusion, and presence or absence of reconstitution of the distal ICA. The classification was used to predict successful revascularization in 32 symptomatic COICAs in 31 patients. Patients were included in the study if they had a COICA with ischemic symptoms refractory to medical therapy. Results: Four types (A-D) of radiographic COICA were identified. Types A and B were more amenable to safe revascularization than types C and D. Recanalization was successful at a rate of 68.75% (22/32 COICAs; type A: 8/8; type B: 8/8; type C: 4/8; type D: 2/8). The perioperative complication rate was 18.75% (6/32; type A: 0/8 [0%]; type B: 1/8 [12.50%]; type C: 3/8 [37.50%], type D: 2/8 [25.00%]). None of these complications led to permanent morbidity or death. Twenty (64.52%) of 31 subjects had improvement in their symptoms at the 2-6 months' follow-up. A statistically significant decrease in systolic blood pressure (SBP) was noted in 17/21 (80.95%) patients who had successful revascularization, which persisted on follow-up (p = 0.0001). The remaining 10 subjects in whom revascularization failed had no significant changes in SBP (p = 0.73). Conclusions: The pilot study suggested that our proposed classification of COICA may be useful as an adjunctive guide to determine the technical feasibility and safety of revascularization for symptomatic COICA using endovascular techniques. Additionally, successful revascularization may lead to a significant decrease in SBP postprocedure. A Phase 2b trial in larger cohorts to assess the efficacy of endovascular revascularization using our COICA classification is warranted.

Background and purposeTo evaluate the accuracy and inter-observer variability when CT angiography is used to identify unruptured intracranial aneurysm growth.MethodsTwo silicone phantom models were used in this study. Each phantom had eight aneurysms of variable size. The size and location of aneurysms in phantom 1 were representative of real patient aneurysms who presented to our institution. Phantom 2 contained aneurysms in the same locations, but with enlargement in various directions. Three blinded board-certified neuroradiologists were asked to identify the size of each aneurysm in three dimensions using CT angiography. The individual enlargement detection rates and inter-observer agreement rates of aneurysm enlargement among the three experts were calculated.ResultsThe detection rate of aneurysm enlargement in one dimension was 58.3% among the three observers. Accurate detection of enlargement in all dimensions was 12.5% among the three observers. Detection accuracy was not related to the size of enlargement. Significant inter-observer measurement variability was present.ConclusionThe use of CT angiography was associated with a poor ability to identify aneurysm enlargementaccurately. Further human studies are required to confirm our findings.

Background: The wall-to-lumen ratio (WLR) is an important parameter in vascular medicine because it indicates the character of vascular wall as well as the degree of stenosis. Despite the advances in medical imaging technologies, it is still difficult to measure the thin-walled normal intracranial arteries, and the reports on the WLR of normal intracranial artery are limited. It might be possible to calculate the WLR using the indocyanine green (ICG) angiography, which is used to observe intracranial vessels during microsurgery. Purpose: To evaluate the WLR of normal intracranial arteries using ICG angiography. Materials and Methods: From the three cases in which ICG angiography was recorded with a ruler during microsurgery, 20 measurement points were chosen for the analysis. The ICG was injected intravenously with a dose of 0.2 mg/kg, and the vessels were inspected at high magnification using an operating microscope equipped with near-infrared illumination system. The vessel outer diameter and the luminal diameter were measured using the images before and after the ICG arrival based on the pixel ratio method using a ruler as reference, respectively. The WLR was calculated as 0.5 × (vessel outer diameter − vessel luminal diameter). Results: The WLR (mean ± standard deviation) of normal intracranial arteries was 0.086 ± 0.022. The WLR tended to be high in small arteries. Conclusion: The WLR of normal intracranial arteries calculated using ICG angiography was consistent with the WLR reported in the previous reports based on human autopsy.

OBJECTIVERevascularization of a symptomatic, medically refractory, cervical chronically occluded internal carotid artery (COICA) using endovascular techniques (ETs) has surfaced as a viable alternative to extracranial-intracranial bypass. The authors aimed to assess the safety, success, and neurocognitive outcomes of recanalization of COICA using ETs or hybrid treatment (ET plus carotid endarterectomy) and to identify candidate radiological markers that could predict success.METHODSThe authors performed a retrospective analysis of their prospectively collected institutional database and used their previously published COICA classification to assess the potential benefits of ETs or hybrid surgery to revascularize symptomatic patients with COICA. Subjects who had undergone CT perfusion (CTP) imaging and Montreal Cognitive Assessment (MoCA) testing, both pre- and postprocedure, were included. The authors then performed a review of the literature on patients with COICA to further evaluate the success and safety of these treatment alternatives.RESULTSThe single-center study revealed 28 subjects who had undergone revascularization of symptomatic COICA. Five subjects had CTP imaging and MoCA testing pre- and postrevascularization and thus were included in the study. All 5 patients had very large penumbra involving the entire hemisphere supplied by the ipsilateral COICA, which resolved postoperatively. Significant improvement in neurocognitive outcome was demonstrated by MoCA testing after treatment (preprocedure: 19.8 ± 2.4, postprocedure: 27 ± 1.6; p = 0.0038). Moreover, successful revascularization of COICA led to full restoration of cerebral hemodynamics in all cases. Review of the literature identified a total of 333 patients with COICA. Of these, 232 (70%) showed successful recanalization after ETs or hybrid surgery, with low major and minor complication rates (3.9% and 2.7%, respectively).CONCLUSIONSETs and hybrid surgery are safe and effective alternatives to revascularize patients with symptomatic COICA. CTP imaging could be used as a radiological marker to assess cerebral hemodynamics and predict the success of revascularization. Improvement in CTP parameters is associated with significant improvement in neurocognitive functions.

BackgroundEndovascular treatment of intracranial aneurysms usually involves stent-assisted coiling (SAC) and flow diverters. Glycoprotein IIb/IIIa inhibitors such as tirofiban and dual antiplatelet therapy (DAPT) are required to prevent thromboembolic complications afterwards. We sought to determine the safety of tirofiban and DAPT in these cases.MethodsWe conducted a retrospective analysis of our database for patients with intracranial aneurysms who underwent SAC or flow diversion. The tirofiban-DAPT protocol used is described. Data regarding duration of infusion, placement of external ventricular devices (EVDs), complications, haemoglobin levels and platelet count before and 24 hours after antiplatelet therapy were collected and analysed.ResultsOne-hundred and forty-one patients with 148 aneurysms/procedures were included. 110 aneurysms were treated acutely and 38 electively. Minor and major haemorrhagic events were recognised in 20% (30/148) aneurysms. Only 5 (3.4%) intracerebral haemorrhages were symptomatic: 3 cortical/SAH and 2 EVD-related. The average blood volume in symptomatic haemorrhages was 24.8 cc versus 5.42 cc in asymptomatic haemorrhages (p=0.002). The rate of EVD-related haemorrhages was 15.7% (19/121) and only 2 (1.7%) were symptomatic. Most haemorrhagic events occurred in ruptured aneurysms (90.1%, p=0.01). No significant change in platelet count or haemoglobin levels before and 24 hours after administration of tirofiban and DAPT was documented. Concomitant administration of heparin did not increase haemorrhagic events.ConclusionThe use of the GP IIb/IIIa inhibitors tirofiban and DAPT in this series was safe. Tirofiban and DAPT did not affect platelet count or haemoglobin levels and did not increase rate of symptomatic haemorrhages or thromboembolic complications.

Background Hemorrhagic complications are a major concern for aneurysmal subarachnoid hemorrhage patients treated with stenting or stent-assisted coiling and undergoing additional procedures such as shunting, ventriculostomy placement, and craniotomies/craniectomies. Objective To assess the safety and efficacy of using a continuous infusion of tirofiban as a monoantiplatelet therapy in the management of ruptured aneurysms in the setting of either stent-assisted coiling (SAC) or flow diversion devices (FDD) in patients requiring either an external ventricular drain (EVD) or ventriculoperitoneal shunt (VPS). Methods Aneurysmal subarachnoid hemorrhage (aSAH) patients between July 2017 and September 2018 who were treated with SAC or FDD were started on a continuous tirofiban infusion protocol (0.10 μg/kg/min) with no preceding loading dose as a monoantiplatelet therapy. Safety analysis was performed retrospectively to assess the complication rate, hemorrhagic rate, and rate of ischemic events. There were no hemorrhages related to the VPS surgery. Results Nineteen subjects were included in the series. The patients received a total of 25 procedures that included 19 EVDs and 6 VPSs. Two patients (8.3%) developed small asymptomatic track hemorrhages after EVD placement. One patient developed a large retroperitoneal hemorrhage due to renal artery branch injury during procedure, and another patient developed an idiosyncratic transient thrombocytopenia which resolved after stopping the medication. One patient (4%) developed a transient ischemic attack, which resolved after a bolus of tirofiban. Conclusion Our study suggests that long-term use of intravenous tirofiban monotherapy in aSAH subjects for endovascular SAC or FDD is safe in the perioperative setting.

Background Fragmentation of the tunica media is a hallmark of intracranial aneurysm formation, often leading to aneurysmal progression and subsequent rupture. The objective of this study is to determine the plasma level of elastin fragments in the lumen of ruptured versus unruptured human intracranial aneurysms. Methods and Results One hundred consecutive patients with/without ruptured saccular intracranial aneurysms undergoing endovascular coiling or stent‐assisted coiling were recruited. Blood samples were collected from the lumen of intracranial aneurysm using a microcatheter. The tip of the microcatheter was placed inside the aneurysm's sac in close proximity to the inner wall of the dome. Plasma levels of elastin fragments were measured using an ELISA ‐based method. Mean plasma level of soluble human elastin fragments was significantly greater in ruptured aneurysms when compared with nonruptured aneurysms (102.0±15.5 versus 39.3±9.6 ng/mL; P Conclusions The present study revealed that a significantly higher concentration of soluble human elastin fragments in the lumen of ruptured intracranial aneurysms when compared with nonruptured ones.

Background Embolization of intracranial aneurysms with the pipeline embolization device (PED; Medtronic, Dublin, Ireland) is a widely used technique. Despite adequate dual antiplatelet therapy and intraprocedural anticoagulation, in-stent thrombosis has been described. There is limited evidence for best management of this complication. Objective To describe in detail the technique used to perform thrombectomy of a recently placed PED with in-stent thrombosis. The aim of the procedure is to leave the PED in place and only perform thrombectomy of the luminal clot. Methods We describe two cases of successful thrombectomy with a stentriever of acutely occluded PEDs. A total of 2 patients underwent PED embolization of 2 previously clipped aneurysms. Despite optimal deployment of the PEDs and excellent angiographic results, both patients developed symptoms of right hemispheric stroke within 1 h of the procedure. A thrombectomy was performed in each patient with the stentriever within the newly deployed PED. Thrombectomy was successful and there was no evidence of PED displacement of vascular injury. Results Stentriever thrombectomy of intraluminal clot can be performed effectively when the entire stentriever device is deployed within the PED. We did not experience any PED displacement, vessel damage, spasm, or device malfunction using this technique. Conclusion We report the use of a stentriever to perform thrombectomy for in-stent thrombosis after PED placement as an additional treatment option of acute occlusion. This technique has not been previously described.

OBJECTSentinel headaches (SHs) associated with cerebral aneurysms (CAs) could be due to microbleeds, which are considered a sign that an aneurysm is unstable. Despite the prognostic importance of these microbleeds, they remain difficult to detect using routine imaging studies. The objective of this pilot study is to detect microbleeds associated with SH using a magnetic resonance imaging (MRI) quantitative susceptibility mapping (QSM) sequence and then evaluate the morphological characteristics of unstable aneurysms with microbleeds.METHODSTwenty CAs in 16 consecutive patients with an initial presentation of headache (HA) leading to a diagnosis of CA were analyzed. Headaches in 4 of the patients (two of whom had 2 aneurysms each) met the typical definition of SH, and the other 12 patients (two of whom also had 2 aneurysms each) all had migraine HA. All patients underwent imaging with the MRI-QSM sequence. Two independent MRI experts who were blinded to the patients’ clinical history performed 3D graphical analysis to evaluate for potential microbleeds associated with these CAs. Computational flow and morphometric analyses were also performed to estimate wall shear and morphological variables.RESULTSIn the 4 patients with SH, MRI-QSM results were positive for 4 aneurysms, and hence these aneurysms were considered positive for non-heme ferric iron (microbleeds). The other 16 aneurysms were negative. Among aneurysm shape indices, the undulation index was significantly higher in the QSM-positive group than in the QSM-negative group. In addition, the spatial averaged wall shear magnitude was lower in the aneurysm wall in direct contact with microbleeds.CONCLUSIONSMRI-QSM allows for objective detection of microbleeds associated with SH and therefore identification of unstable CAs. CAs with slightly greater undulation indices are associated with positive MRI-QSM results and hence with microbleeds. Studies with larger populations are needed to confirm these preliminary findings.

The objective of this study is to determine the impact of intraventricular hemorrhage (IVH) on the cognitive prognosis of subarachnoid hemorrhage (SAH) due to ruptured cerebral aneurysm, independent of the presence of intraparenchymal hemorrhage, hydrocephalus or vasospasm.A Retrospective review of a prospectively collected database of patients with aneurysmal SAH from July 2009 to November 2016 was performed. Patients were included if they had a saccular aneurysm with a Hunt-Hess grade (HHG) 1-3. Those who underwent craniectomy/clipping and those with vasospasm were excluded. Patients with IVH were grouped into 5 groups depending on the blood distribution in the ventricles. Functional outcomes studied were modified Rankin score (mRS) 0-2, cognitive impairment and memory impairment, and the presence of amnesia to the event. A univariate followed by a multivariate analysis ware performed.A total of 443 patients were identified and 124 patients met the criterion. There were no significant differences in the proportion of patients with mRS of 0-2 between patients with IVH and those without IVH but with EVD (external ventricular drain). There was a higher proportion of cognitive deficits in patients with IVH (71.95%), compared to those without (31.58%; p = 0.01). Patients with IVH had a higher rate of anterograde amnesia (100% vs. 4.3% p 0.0001), lower rate of mRS 0-2 (78% vs 100% p 0.001), and higher rate of cognitive impairment (71.9% vs. 13% p 0.0001) compared with those who did not require an EVD. Grade 3 and grade 4 were shown to have lower rate of patients with mRS 0-2 and a higher rate of cognitive impairment. In multivariate analysis, independent predictors of cognitive and memory impairment were increasing HHG (OR = 155.33; P 0.01), ACOM/A1/ACA/anterior choroidal aneurysms, (OR = 5.24; P = 0.04), increasing Fischer scale (OR = 6.93; P = 0.01), and increasing IVH grade (OR = 6.9; P = 0.01). Only worse HHG (OR = 2704.22; P = 0.01) and IVH grade 2-4 were associated (perfect predictor, OR cannot be extracted) with anterograde amnesia.IVH is an independent prognosticator of SAH cognitive outcomes. The effect of IVH drainage and other intraventricular therapies on SAH course is an attractive topic for further investigation.

Introduction: Clinical vasospasm and delayed cerebral ischemia (DCI) are devastating complications of aneurysmal subarachnoid hemorrhage (aSAH). Several theories have been postulated as potential etiologies of clinical vasospasm and DCI, involving platelet activation. However, the effects of dual anti-platelet therapy (DAPT: aspirin and clopidogrel) on clinical vasospasm and DCI have not been previously investigated. The objective of this study was to evaluate the effects of DAPT on clinical vasospasm and DCI in aSAH patients. Methods: Analysis of patients treated for aSAH during the period from July 2009 to April 2014 was performed in a single-institution retrospective study. Patients were divided into two groups: patients who underwent stent-assisted coiling or placement of flow diverters requiring DAPT (DAPT group) and patients who underwent coiling only without DAPT (control group). The frequency of symptomatic clinical vasospasm and DCI and of hemorrhagic complications was compared between the two groups, utilizing univariate and multivariate logistic regression. Results: Of 312 aSAH patients considered for this study, 161 patients met the inclusion and exclusion criteria and were included in the analysis (85 patients in the DAPT group and 76 patients in the control group). The risk of clinical vasospasm (OR: 0.244; CI 95% [0.097 - 0.615]; p = 0.003) and DCI (OR: 0.056; CI 95% [0.01 - 0.318]; p = 0.001) were significantly lower in patients receiving DAPT. Hemorrhagic complications associated with placement of external ventricular drains and ventriculoperitoneal shunts were similar in both groups (4% versus 2%; p = 0.9). Conclusions: The use of DAPT was associated with a lower risk of clinical vasospasm and DCI in patients treated for aSAH without an increased risk of hemorrhagic complications.

Object: Stenting and flow diversion of ruptured intracranial aneurysms requires the use of dual antiplatelet therapy (DAPT). These patients may be at increased risk for post surgical hemorrhagic complication. In this study, we sought to investigate whether DAPT is a risk factor for hemorrhagic complication associated with placement of external ventricular drains (EVD) in patients with aneurysmal sub-arachnoid hemorrhage (aSAH). Methods: Patients at our institution with aSAH requiring placement of an EVD for obstructive hydrocephalus between July of 2009 and November of 2016 were included. Rates of radiographically identified hemorrhage associated with EVD placement were compared between patients who were on DAPT for use of a stent or flow diverter, and patients who underwent microsurgical clipping or coiling and were not on DAPT by way of a backward stepwise multivariate analysis. Hemorrhages were judged to be clinically significant if they were temporally associated with neurologic declines, required surgical intervention, or caused seizures. Results: 443 patients were admitted for management of aSAH. 298 Required placement of an EVD. 120 (40%) were treated with stent assisted coiling or flow diverters and required DAPT, while 178 (60%) were treated with coiling without stents or microsurgical clipping and were not on DAPT. 42 (14%) cases of new hemorrhage along the EVD catheter were identified radiographically. 32 of these hemorrhages occurred in patients on DAPT, while while 10 occurred in patients not on DAPT. After multivariate analysis, DAPT was significantly associated with radiographic hemorrhage [OR: 4.92, 95% CI: 2.45-9.91, p=.0001]. 5 hemorrhages (5 of 10 [50%]) were classified as symptomatic in those patients not receiving DAPT, while 10 hemorrhages (10 of 32 [31%]) were classified as symptomatic in those patients on DAPT (p=.4508). Conclusions: Our series confirms that patients with aSAH who receive stent assisted coiling or flow diversion are at higher risk for radiographic hemorrhage associated with EVD placement. This increased hemorrhage risk does not appear to be clinically significant. These data suggest that stent assisted coiling and flow diversion for aSAH are viable options in an era of evolving endovascular therapeutics.

Objective: Aneurysm growth is considered predictive of future rupture of intracranial aneurysms. However, it is still unknown how accurately neuroradiologists can reliably detect incremental aneurysm growth using clinical magnetic resonance imaging (MRI) imaging. The purpose of this study is to assess the agreement rate of detecting aneurysm enlargement using generally used MRI imaging modalities. Methods: Three silicone flow phantom models each with eight aneurysms of various sizes in different sites were used in this study. The aneurysm models were identical except for an incremental increase in size of the 8 aneurysms ranging from 0.4mm to 2mm. The phantoms were imaged on 1.5 tesla (T) and 3T MRI units with both time-of-flight (TOF) and contrast enhanced magnetic resonance angiography (MRA). Three independent expert neuroradiologists measured the aneurysms in a blinded fashion utilizing different measurement approaches. The individual and agreement rate among the three experts in detecting aneurysm enlargement were calculated. Results: The average detection rate of any increase in any aneurysmal dimensions was 95.7%. The detection rate for the three readers (A, B and C) was 98.0%, 96.6% and 92.7%, respectively ( P =0.22). The detection rate in each MRI modality was 91.3% using 1.5 T TOF, 97.2% using 1.5T gadolinium (Gad), 95.8% using 3.0T TOF and 97.2% using 3.0T Gad ( P =0.31). As the incremental enlargement value increased, the detection rate for aneurysm enlargement increased. Use of Gad in 1.5T improved the detection rate in small incremental enlargement (e.g. 0.4 - 1mm) of the aneurysm ( P =0.04). The locations of the aneurysms also affected detection rate for aneurysm enlargement ( P Conclusions: The detection rate and interobserver agreement was very high for aneurysm enlargement of 0.4mm to 2 mm. Detection rate of any increase in any aneurysmal dimensions did not depend on the choice of MRI imaging modalities and measurement protocols.

Background: Aspirin is a promising medical therapy for the prevention of intracranial aneurysm (IA) rupture. Recently, we found that men have a better response to aspirin than women. The purpose of this study was to determine whether a sex differential exists in the level of 15-hydroxyprostaglandin dehydrogenase (15-PGDH) in the lumen of human IAs. Methods and Results: Consecutive patients undergoing coiling or stent-assisted coiling for a saccular IA at our institution were enrolled. Two samples (A and B) were collected from IA lumens and the plasma level of 15-PGDH was measured using an ELISA-based method. The study included 38 patients, with 20 women and 18 men. Women and men were comparable with respect to baseline characteristics. In samples A, the mean plasma concentration of 15-PGDH in IA lumens was significantly higher in men (75.8±13.8 ng/ml) than women (51.2±6.4 ng/ml, p Conclusions: Higher enzyme levels of 15-PGDH consistently exist in the lumen of IAs of men compared with women. This observation could explain why aspirin confers better protection against IA rupture in men than in women. The susceptibility of an individual to aspirin may differ according to the level of 15-PGDH.

Object: Intracranial stenting and flow diversion requires the use of dual antiplatelet therapy (DAPT) to prevent in-stent thrombosis. DAPT may significantly increase the risk of hemorrhagic complications in patients who require subsequent surgical interventions. In this study, we sought to investigate whether DAPT is a risk factor for hemorrhagic complication associated with ventriculoperitoneal (VP) shunt placement in aneurysmal subarachnoid hemorrhage (aSAH) patients. Methods: Patients with aSAH who presented to our institution from July 2009 through November 2016 requiring VP shunt placement for persistent hydrocephalus were included. The rates of hemorrhagic complication associated with VP shunt placement were compared between patients who were on DAPT (Aspirin and Clopidogrel) for use of a stent or flow diverter, and patients who underwent microsurgical clipping or coiling only and were not on DAPT by way of a backward stepwise multivariate analysis. Results: 443 patients were admitted for management of aSAH. Eighty of these patients eventually required VP shunt placement. 32 patients (40%) had been treated with stent-assisted coiling or flow diverters and required DAPT, whereas 48 patients (60%) had been treated with coiling without stents or surgical clipping and were not on DAPT at the time of VP shunt placement. A total of 8 cases (10%) of new hemorrhage along the intracranial proximal catheter of the VP shunt were observed. Seven of these hemorrhages were observed in patients on DAPT, while one occurred in a patient not on DAPT. After multivariate analysis, only DAPT was significantly associated with hemorrhage [OR: 31.23, 95% CI: 2.98-327.32, p=.0001]. One hemorrhage (1 of 32 [3%]) in a patient on DAPT required shunt revision for hemorrhage-associated proximal catheter blockage. The remaining seven hemorrhages were clinically insignificant. Conclusions: Our clinical series confirms that in patients with ruptured aneurysms that are candidates for stent assisted coiling or flow diversion, the risk of clinically significant VP shunt associated hemorrhage with DAPT is low. In an era of evolving endovascular therapeutics, stenting or flow diversion is a viable option in select aSAH patients.

According to recent findings, diffusion tensor tractography (DTT) only allows prediction of facial nerve location in relation to vestibular schwannoma (VS) with high probability. However, previous studies have not mentioned why only the facial nerve was selectively visualized. Our previous report investigated the optimal conditions of DTT for normal facial and vestibulocochlear nerves. In the present study, we applied the optimal conditions of DTT to VS patients to assess the feasibility of DTT for the facial and vestibulocochlear nerves. We investigated 11 patients with VS who underwent tumor resection. Visualized tracts were compared with locations of the facial and cochlear nerves as identified by intraoperative electrophysiological monitoring. With the proposed method, visualized tracts corresponded to pathway area of the facial or cochlear nerves in nine of 11 patients (81.8 %); specifically, to the pathway area of the facial nerve in three of 11 patients (27.3 %), and to the pathway area of the cochlear nerve in six of 11 patients (54.5 %). We visualized facial or vestibulocochlear nerves in nine of 11 patients (81.8 %). For the first time, DTT proved able to visualize not only the facial nerve but also the vestibulocochlear nerve in VS patients. Despite our findings, good methods for distinguishing whether a visualized nerve tract represents facial nerve, vestibulocochlear nerve, or only noise remain unavailable. Close attention should therefore be paid to the interpretation of visualized fibers.

Three-dimensional (3D) computer graphics (CG) are useful for preoperative planning of neurosurgical operations. However, application of 3D CG to intraoperative navigation is not widespread because existing commercial operative navigation systems do not show 3D CG in sufficient detail. We have developed a microscopic optically tracking navigation system that uses high-resolution 3D CG. This article presents the technical details of our microscopic optically tracking navigation system. Our navigation system consists of three components: the operative microscope, registration, and the image display system. An optical tracker was attached to the microscope to monitor the position and attitude of the microscope in real time; point-pair registration was used to register the operation room coordinate system, and the image coordinate system; and the image display system showed the 3D CG image in the field-of-view of the microscope. Ten neurosurgeons (seven males, two females; mean age 32.9 years) participated in an experiment to assess the accuracy of this system using a phantom model. Accuracy of our system was compared with the commercial system. The 3D CG provided by the navigation system coincided well with the operative scene under the microscope. Target registration error for our system was 2.9 ± 1.9 mm. Our navigation system provides a clear image of the operation position and the surrounding structures. Systems like this may reduce intraoperative complications.

OBJECTIVEClinical vasospasm and delayed cerebral ischemia (DCI) are devastating complications of aneurysmal subarachnoid hemorrhage (aSAH). Several theories involving platelet activation have been postulated as potential explanations of the development of clinical vasospasm and DCI. However, the effects of dual antiplatelet therapy (DAPT; aspirin and clopidogrel) on clinical vasospasm and DCI have not been previously investigated. The objective of this study was to evaluate the effects of DAPT on clinical vasospasm and DCI in aSAH patients.METHODSAnalysis of patients treated for aSAH during the period from July 2009 to April 2014 was performed in a single-institution retrospective study. Patients were divided into 2 groups: patients who underwent stent-assisted coiling or placement of flow diverters requiring DAPT (DAPT group) and patients who underwent coiling only without DAPT (control group). The frequency of symptomatic clinical vasospasm and DCI and of hemorrhagic complications was compared between the 2 groups, utilizing univariate and multivariate logistic regression.RESULTSOf 312 aSAH patients considered for this study, 161 met the criteria for inclusion and were included in the analysis (85 patients in the DAPT group and 76 patients in the control group). The risks of clinical vasospasm (OR 0.244, CI 95% 0.097–0.615, p = 0.003) and DCI (OR 0.056, CI 95% 0.01–0.318, p = 0.001) were significantly lower in patients receiving DAPT. The rates of hemorrhagic complications associated with placement of external ventricular drains and ventriculoperitoneal shunts were similar in both groups (4% vs 2%, p = 0.9).CONCLUSIONSThe use of DAPT was associated with a lower risk of clinical vasospasm and DCI in patients treated for aSAH, without an increased risk of hemorrhagic complications.

Background Aspirin is a promising medical therapy for the prevention of intracranial aneurysm ( IA ) rupture. Recently, we found that men have a better response to aspirin than women. The purpose of this study was to determine whether a sex differential exists in the level of 15‐hydroxyprostaglandin dehydrogenase (15‐ PGDH ) in the lumen of human IA s. Methods and Results Consecutive patients undergoing coiling or stent‐assisted coiling for a saccular IA at our institution were enrolled. Two samples (A and B) were collected from IA lumens, and the plasma level of 15‐ PGDH was measured using an ELISA ‐based method. The study included 38 patients, with 20 women and 18 men. Women and men were comparable on baseline characteristics. The mean plasma concentration of 15‐ PGDH did not differ statistically between sample A (62.8±16.2 ng/mL) and sample B (61.8±17.9 ng/mL; 95% confidence interval −6.6 to 9.4). The mean plasma concentration of 15‐ PGDH in IA lumens of samples A and B was significantly higher in men (73.8±13.5 ng/mL) than women (49.6±7.8 ng/mL; P Conclusions Higher enzyme levels of 15‐ PGDH exist in the lumen of IA s of men compared with women. This observation could explain why aspirin confers better protection against IA rupture in men than in women. The susceptibility of an individual to aspirin may differ according to the level of 15‐ PGDH .

Intracranial electroencephalography (iEEG) provides invaluable information in determining seizure focus and spread due to its high spatial and temporal resolution, which are not afforded by noninvasive studies. Electrodes of various types (e.g., grid, strip, and depth electrodes) and configurations are often used for optimum coverage of suspected areas of seizure onset and propagation. Given the fixed intracranial volume and added mass effect from placement of cortical electrodes, brain edema and postoperative deficits can occur.The authors describe a simple, inexpensive, and highly effective technique of bone flap replacement using standard titanium plates to expand the intracranial volume and minimize risks of brain compression and intracranial hypertension. Rectangular titanium plates are bent and placed in a way that secures the bone flap in a slightly elevated position relative to the adjacent calvaria during iEEG monitoring. The authors evaluated the degree of bone flap elevation and amount of volume created using this technique in 3 iEEG cases. They then compared these results with the bone flap elevation and volume created using linear titanium plates, a method they had used previously. The use of rectangular plates produced on average 6.6 mm of bone flap elevation, compared with only 1.8 mm of bone flap elevation with the use of linear plates, resulting in a statistically significant 261% increase in bone flap elevation (p ≤ 0.001). The authors suggest that rectangular plates may provide stronger resistance to scalp tension after myocutaneous skin closure compared with the linear plates and that subsidence of the bone flap likely occurred with the use of linear plates. In summary, the described technique utilizing rectangular plates creates significantly increased bone flap elevation compared with a similar method using linear plates, and it may reduce the risk of neurological deficits related to intracranial electrode placement.

OBJECTIVEAneurysm growth is considered predictive of future rupture of intracranial aneurysms. However, how accurately neuroradiologists can reliably detect incremental aneurysm growth using clinical MRI is still unknown. The purpose of this study was to assess the agreement rate of detecting aneurysm enlargement employing generally used MRI modalities.METHODSThree silicone flow phantom models, each with 8 aneurysms of various sizes at different sites, were used in this study. The aneurysm models were identical except for an incremental increase in the sizes of the 8 aneurysms, which ranged from 0.4 mm to 2 mm. The phantoms were imaged on 1.5-T and 3-T MRI units with both time-of-flight (TOF) and contrast-enhanced MR angiography. Three independent expert neuroradiologists measured the aneurysms in a blinded manner using different measurement approaches. The individual and agreement detection rates of aneurysm enlargement among the 3 experts were calculated.RESULTSThe mean detection rate of any increase in any aneurysmal dimension was 95.7%. The detection rates of the 3 observers (observers A, B, and C) were 98.0%, 96.6%, and 92.7%, respectively (p = 0.22). The detection rates of each MRI modality were 91.3% using 1.5-T TOF, 97.2% using 1.5-T with Gd, 95.8% using 3.0-T TOF, and 97.2% using 3.0-T with Gd (p = 0.31). On the other hand, the mean detection rate for aneurysm enlargement was 54.8%. Specifically, the detection rates of observers A, B, and C were 49.0%, 46.1%, and 66.7%, respectively (p = 0.009). As the incremental enlargement value increased, the detection rate for aneurysm enlargement increased. The use of 1.5-T Gd improved the detection rate for small incremental enlargement (e.g., 0.4–1 mm) of the aneurysm (p = 0.04). The location of the aneurysm also affected the detection rate for aneurysm enlargement (p < 0.0001).CONCLUSIONSThe detection rate and interobserver agreement were very high for aneurysm enlargement of 0.4–2 mm. The detection rate for at least 1 increase in any aneurysm dimension did not depend on the choice of MRI modality or measurement protocol. Use of Gd improved the accuracy of measurement. Aneurysm location may influence the accuracy of detecting enlargement.

OBJECTIVEIntracranial electroencephalography (iEEG) provides valuable information that guides clinical decision-making in patients undergoing epilepsy surgery, but it carries technical challenges and risks. The technical approaches used and reported rates of complications vary across institutions and evolve over time with increasing experience. In this report, the authors describe the strategy at the University of Iowa using both surface and depth electrodes and analyze outcomes and complications.METHODSThe authors performed a retrospective review and analysis of all patients who underwent craniotomy and electrode implantation from January 2006 through December 2015 at the University of Iowa Hospitals and Clinics. The basic demographic and clinical information was collected, including electrode coverage, monitoring results, outcomes, and complications. The correlations between clinically significant complications with various clinical variables were analyzed using multivariate analysis. The Fisher exact test was used to evaluate a change in the rate of complications over the study period.RESULTSNinety-one patients (mean age 29 ± 14 years, range 3–62 years), including 22 pediatric patients, underwent iEEG. Subdural surface (grid and/or strip) electrodes were utilized in all patients, and depth electrodes were also placed in 89 (97.8%) patients. The total number of electrode contacts placed per patient averaged 151 ± 58. The duration of invasive monitoring averaged 12.0 ± 5.1 days. In 84 (92.3%) patients, a seizure focus was localized by ictal onset (82 cases) or inferred based on interictal discharges (2 patients). Localization was achieved based on data obtained from surface electrodes alone (29 patients), depth electrodes alone (13 patients), or a combination of both surface and depth electrodes (42 patients). Seventy-two (79.1%) patients ultimately underwent resective surgery. Forty-seven (65.3%) and 18 (25.0%) patients achieved modified Engel class I and II outcomes, respectively. The mean follow-up duration was 3.9 ± 2.9 (range 0.1–10.5) years. Clinically significant complications occurred in 8 patients, including hematoma in 3 (3.3%) patients, infection/osteomyelitis in 3 (3.3%) patients, and edema/compression in 2 (2.2%) patients. One patient developed a permanent neurological deficit (1.1%), and there were no deaths. The hemorrhagic and edema/compression complications correlated significantly with the total number of electrode contacts (p = 0.01), but not with age, a history of prior cranial surgery, laterality, monitoring duration, and the number of each electrode type. The small number of infectious complications precluded multivariate analysis. The number of complications decreased from 5 of 36 cases (13.9%) to 3 of 55 cases (5.5%) during the first and last 5 years, respectively, but this change was not statistically significant (p = 0.26).CONCLUSIONSAn iEEG implantation strategy that makes use of both surface and depth electrodes is safe and effective at identifying seizure foci in patients with medically refractory epilepsy. With experience and iterative refinement of technical surgical details, the risk of complications has decreased over time.

OBJECTIVEThe epileptogenic zones in some patients with temporal lobe epilepsy (TLE) involve regions outside the typical extent of anterior temporal lobectomy (i.e., “temporal plus epilepsy”), including portions of the supratemporal plane (STP). Failure to identify this subset of patients and adjust the surgical plan accordingly results in suboptimum surgical outcomes. There are unique technical challenges associated with obtaining recordings from the STP. The authors sought to examine the clinical utility and safety of placing depth electrodes within the STP in patients with TLE.METHODSThis study is a retrospective review and analysis of all cases in which patients underwent intracranial electroencephalography (iEEG) with use of at least one STP depth electrode over the 10 years from January 2006 through December 2015 at University of Iowa Hospitals and Clinics. Basic clinical information was collected, including the presence of ictal auditory symptoms, electrode coverage, monitoring results, resection extent, outcomes, and complications. Additionally, cases in which the temporal lobe was primarily or secondarily involved in seizure onset and propagation were categorized based upon how rapidly epileptic activity was observed within the STP following seizure onsets: within 1 second, between 1 and 15 seconds, after 15 seconds, and not involved.RESULTSFifty-two patients underwent iEEG with STP coverage, with 1 STP electrode used in 45 (86.5%) cases and 2 STP electrodes in the other cases. There were no complications related to STP electrode placement. Of 42 cases in which the temporal lobe was primarily or secondarily involved, seizure activity was recorded from the STP in 36 cases (85.7%): in 5 cases (11.9%) within 1 second, in 5 (11.9%) between 1 and 15 seconds, and in 26 (61.9%) more than 15 seconds following seizure onset. Seizure outcomes inversely correlated with rapid ictal involvement of the STP (Engel class I achieved in 25%, 67%, and 82% of patients in the above categories, respectively). All patients without ictal STP involvement achieved seizure freedom. Only 4 (11.1%) patients with STP ictal involvement reported auditory symptoms.CONCLUSIONSIctal involvement of the STP is common even in the absence of auditory symptoms and can be effectively detected by the STP electrodes. These electrodes are safe to implant and provide useful prognostic information.

Diffusion tensor tractography (DTT) is not adequately reliable for prediction of facial and vestibulocochlear (VII–VIII) nerve locations, especially relative to a vestibular schwannoma (VS). Furthermore, it is often not possible to visualize normal VII–VIII nerves by DTT (visualization rates were 12.5–63.6 %). Therefore, DTT post-processing was optimized for normal VII–VIII nerve visualization with and without manual noise elimination. DTT examinations of ten patients were evaluated to assess the improvement in performance by modifying seed region of interest (ROI) and fractional anisotropy (FA) threshold. Seed ROI was placed at the porus of the internal auditory meatus, and FA threshold values were either fixed or variable for each patient. DTT visualization of cranial nerves VII–VIII was evaluated and the noise effect was measured. Cranial nerves VII–VIII were visualized in 90 % of patients without using manual noise elimination by modifying the seed ROI and FA threshold. The visualization rate with FA threshold of the upper limit in each patient (100 %) was significantly higher than that with FA threshold of 0.1 (75 %) ( $$p=0.02$$ ). The incidence rate of noise with FA threshold of the upper limit (10 %) was not significantly different than the FA threshold of 0.1 (20 %) ( $$p=0.66$$ ). Seed ROI modification and FA thresholding can improve the visualization of cranial nerve VII–VIII locations in DTT. This technique is promising for its potential to determine the relationship of cranial nerves VII–VIII to VS.