Direct clipping of large basilar trunk aneurysm.

A large basilar trunk aneurysm was incidentally found in a 77-year-old woman in examination for headache. Though it was asymptomatic, high signal intensity was noticed in the brainstem around the aneurysm on FLAIR image of MRI. As she was otherwise healthy, surgical clipping was performed through anterior temporal approach. The video can be found here: http://youtu.be/0soWM8meCW8 .

Feasibility of diffusion tensor tractography for preoperative prediction of the location of the facial and vestibulocochlear nerves in relation to vestibular schwannoma.

BACKGROUND: 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. METHODS: 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. RESULTS: 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%). CONCLUSIONS: 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.

In-Stent Restenosis of Carotid and Vertebral Arteries Treated by Angioplasty Using a Cutting Balloon: A Case Report.

Objective: We treated a patient with internal carotid artery and vertebral artery ostium in-stent restenosis (ISR) treated by cutting balloon (CB) angioplasty. Case Presentation: A 79-year-old man developed dizziness and right homonymous upper quadrantanopia. On arrival, magnetic resonance imaging (MRI) revealed acute-stage brain infarction. Angiography demonstrated left internal carotid artery and vertebral artery ostium stenosis (VAOS), which was thought to be related to the infarction. We performed stenting for both lesions, but 5 months later, restenosis occurred. The patient was successfully retreated by CB angioplasty for both lesions. Conclusion: When treating carotid or vertebral artery ISR, plain balloon (PB) and stent-in-stent (SIS) procedures may induce insufficient dilatation, and hamper re-retreatment because of neointimal hyperplasia. Using CB should be considered as an option in such cases.

Safety and Efficacy of the Pipeline Embolization Device Use in the Outside Circle of Willis Located Intracranial Aneurysms: A Single-Center Experience.

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.

Tirofiban Protocol Protects Against Delayed Cerebral Ischemia: A Case-Series Study.

BACKGROUND: There has not been any effective prophylaxis for delayed cerebral ischemia delayed cerebral ischemia (DCI) since the introduction of nimodipine. Platelet inhibition may reduce the risk by preventing the formation of microthrombi. Tirofiban has been used as a single monotherapy bridge given its safety profile and controlled platelet inhibition. OBJECTIVE: To assess the risk of DCI in aneurysmal subarachnoid hemorrhages (aSAH) patients treated with the tirofiban protocol. METHODS: aSAH patients between December 2010 and March 2019 who were treated with stent assisted coiling or flow-diverting device were started on a continuous tirofiban infusion protocol and were compared with patients who underwent coil embolization without antiplatelet therapy. Safety analysis was performed to assess DCI, hemorrhagic, and ischemic events. RESULTS: A total of 21 patients were included in the tirofiban series and 81 in the control group. There was no statistical difference in age, gender, Hunt-Hess grade, and Fisher scale between the 2 groups except for a higher Fisher grade II in the tirofiban group. Multivariate analysis revealed tirofiban to reduce the risk of vasospasm by 72 percent (OR .28, P = .03), without affecting the risk of hemorrhagic complications (OR = 0.50, P = .26). Tirofiban reduced the risk of symptomatic stroke endovascular procedure but it did not reach significance (P = .06). DCI, older age, and postprocedural symptomatic stroke were significant predictors of mortality. Tirofiban reduced the mortality risk, but this association was not statistically significant. CONCLUSION: The tirofiban protocol in aSAH patients reduces the risk of DCI without conferring additional risks. This supports previous findings were antiplatelet therapy reduced DCI in human and animal models.

Intracranial Atherosclerosis: A Disease of Functional, not Anatomic Stenosis? How Trans-Stenotic Pressure Gradients Can Help Guide Treatment.

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.

Quantitative Susceptibility Mapping and Vessel Wall Imaging as Screening Tools to Detect Microbleed in Sentinel Headache.

BACKGROUND: MR-quantitative susceptibility mapping (QSM) can identify microbleeds (MBs) in intracranial aneurysm (IA) wall associated with sentinel headache (SH) preceding subarachnoid hemorrhage. However, its use is limited, due to associated skull base bonny and air artifact. MR-vessel wall imaging (VWI) is not limited by such artifact and therefore could be an alternative to QSM. The purpose of this study was to investigate the correlation between QSM and VWI in detecting MBs and to help develop a diagnostic strategy for SH. METHODS: We performed a prospective study of subjects with one or more unruptured IAs in our hospital. All subjects underwent evaluation using 3T-MRI for MR angiography (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 VWI. RESULTS: A total of 40 subjects harboring 51 unruptured IAs were enrolled in the study. MBs evident on the QSM sequence was detected in 12 (23.5%) IAs of 11 subjects. All these subjects had a history of severe headache suggestive of SH. AWE was detected in 22 (43.1%) IAs. Using positive QSM as a surrogate for MBs, the sensitivity, specificity, positive predictive value, and negative predictive value of AWE on VWI for detecting MBs were 91.7%, 71.8%, 50%, and 96.6%, respectively. CONCLUSIONS: Positive QSM findings strongly suggested the presence of MBs with SH, whereas, the lack of AWE on VWI can rule it out with a probability of 96.6%. If proven in a larger cohort, combining QSM and VWI could be an adjunctive tool to help diagnose SH, especially in cases with negative or non-diagnostic CT and lumbar puncture.

Mechanical Thrombectomy of Acutely Occluded Flow Diverters.

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.

Safety of tirofiban and dual antiplatelet therapy in treating intracranial aneurysms.

Background: Endovascular 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. Methods: We 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. Results: One-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. Conclusion: The 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.

Aspirin associated with decreased rate of intracranial aneurysm growth.

OBJECTIVE: Aspirin 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. METHODS: The 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. RESULTS: The 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). CONCLUSIONS: In patients with multiple IAs, aspirin significantly decreased the rate of aneurysm growth over time. Additional prospective interventional studies are needed to validate these findings.

External Ventricular Drain and Hemorrhage in Aneurysmal Subarachnoid Hemorrhage Patients on Dual Antiplatelet Therapy: A Retrospective Cohort Study.

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.

The Safety and Efficacy of Continuous Tirofiban as a Monoantiplatelet Therapy in the Management of Ruptured Aneurysms Treated Using Stent-Assisted Coiling or Flow Diversion and Requiring Ventricular Drainage.

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.

In vitro accuracy and inter-observer reliability of CT angiography in detecting intracranial aneurysm enlargement.

BACKGROUND AND PURPOSE: To evaluate the accuracy and inter-observer variability when CT angiography is used to identify unruptured intracranial aneurysm growth. METHODS: Two 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. RESULTS: The 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. CONCLUSION: The use of CT angiography was associated with a poor ability to identify aneurysm enlargementaccurately. Further human studies are required to confirm our findings.

Hybrid Surgery for Internal Carotid Artery Revascularization.

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.

Cognitive and cerebral hemodynamic effects of endovascular recanalization of chronically occluded cervical internal carotid artery: single-center study and review of the literature.

OBJECTIVE: Revascularization 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. METHODS: The 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. RESULTS: The 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). CONCLUSIONS: ETs 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.

Bradycardia and Asystole in Patients Undergoing Symptomatic Chronically Occluded Internal Carotid Artery Recanalization.

BACKGROUND: Reports have emerged describing the successful endovascular recanalization of the chronically occluded internal carotid artery (COICA). The impact this restoration of flow has on the sensitive carotid sinus baroreceptors has not been previously described. In this manuscript, we present the largest COICA surgical series to date, with a specific focus on perioperative heart rate abnormalities. METHODS: Patient demographics were obtained, and the COICAs were radiographically classified based on the anatomic distribution of the stenosis and collateral flow. Thirty-six patients had a total of 37 COICA revascularization procedures. RESULTS: A total of 23 patients had intraprocedural bradycardia during balloon angioplasty. Three patients went into transient asystole during the procedure, and 2 of these patients had symptomatic bradycardia with ischemic cerebral changes, 1 of which required permanent pacemaking. All other patients had immediate resolution of their bradycardia, asystole, and neurologic symptoms immediately following balloon deflation and pharmaceutical management. There was a statistically significant difference in the observed proportion of bradycardic patients among COICA classifications (P = 0.014). There was no statistically significant difference in mean age between patients with bradycardia and those without (aged 63.36 vs. 67.71 years, P = 0.2265). CONCLUSIONS: Bradycardia associated with angioplasty of the carotid bulb was observed in the majority of patients receiving COICA revascularization. A small percentage of these patients were symptomatic. Our results suggest that carotid sinus baroreceptors remain active while residing in a complete arterial occlusion, and close monitoring is necessary during balloon angioplasty of the proximal COICA.

Bone flap elevation for intracranial EEG monitoring: technical note.

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.

Utility and safety of depth electrodes within the supratemporal plane for intracranial EEG.

OBJECTIVE: The 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. METHODS: This 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. RESULTS: Fifty-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. CONCLUSIONS: Ictal 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.

Plasma Soluble Human Elastin Fragments as an Intra-Aneurysmal Localized Biomarker for Ruptured Intracranial Aneurysm.

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<0.001). Mean plasma level of soluble human elastin fragments did not have significant correlation with age, sex, size, or aneurysm location. 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.