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Background Flow-diverting (FD) stents, with or without coiling, are a mainstay in endovascular treatment of intracranial aneurysms (IAs). One observed complication from flow diverter stent (FDS) insertion has been in-stent stenosis. Though previously studied in the short-term period, the long-term history of this complication has yet to be described. Methods We performed a retrospective cohort study of consecutive IAs treated with Pipeline Embolization Device (PED), with or without coiling, at our centre between September 2014 and December 2018 that had at least one digital subtraction angiogram (DSA) during follow-up. In-stent stenosis was measured from DSA images, and associated patient and procedural characteristics were analysed. Results 94 patients treated with PED for IA were identified. On initial DSA during follow-up, 52 patients (55.3%) had in-stent stenosis within the PED. Of these 52 patients, 17 had a second DSA during follow-up. In this 2nd DSA, improvement and/or stable in-stent stenosis was seen 16 patients (94.1%). One patient in this group had worsening in-stent stenosis had a vertebrobasilar junction FD stent. Of the patients without in-stent stenosis on initial DSA, 15 had a second DSA during follow-up. Only one of these patients (6.7%) had new appearance of in-stent stenosis (measuring 5%). Multivariate analysis found statin use to be predictive of in-stent stenosis (p = 0.020, Odds ratio = 0.279 and 95% confidence interval = 0.095–0.821). Conclusions In-stent stenosis after FDS placement was seen in 53.2% of cases, which had between 1–50% of stenosis. 82.4% had resolution/improvement of their stenosis. Statin use was protective of in-stent stenosis.

Background Angiographic reperfusion after endovascular thrombectomy in acute ischemic stroke is commonly graded using volume-based reperfusion scores such as the modified thrombolysis in cerebral infarct score. The location of non-reperfused regions is not included in modified thrombolysis in cerebral infarct score. We studied the predictive ability of an eloquence-based reperfusion score. Methods Consecutive cases of endovascular thrombectomy for anterior circulation strokes performed between January 2018 and April 2020 were included. Digital subtraction angiograms were reviewed by two blinded neurointerventionalist operators. Incomplete reperfusion was further classified by lobar regions lacking reperfusion to create various cohorts. Outcomes were graded four to seven days post-procedure with the National Institute of Health Stroke Scale (NIHSS) and 90 days post-procedure with the modified Rankin Scale. Results One hundred patients were identified. Via multivariate analysis, we found that frontal lobe non-reperfusion (mean difference (MD) = −1.60, p = 0.002) and occipital lobe non-reperfusion (MD = −1.68, p = 0.001) were associated with worse mental status improvement while left-sided stroke (MD = 2.02, p Conclusions Eloquence-based reperfusion assessment is an important predictor for functional outcomes after thrombectomy.

Introduction Endovascular therapy has shown to be safe and effective for the treatment of cerebral dural arteriovenous fistulas; however, recurrence after complete occlusion is not uncommon, and the timing of recurrence remains unknown. Methods A retrospective single-center cohort study was conducted from January 2005 to December 2020. Patients with high-grade (≥Borden II–Cognard IIB) dural arteriovenous fistulas treated with endovascular therapy were included in this study. Clinical and angiographic characteristics were collected for hospitalization and at follow-up. Results A total of 51 patients with a median age of 61 years were studied; 57% were female. High-flow symptoms related to the high-flow fistula were the most common presentation (67%), and 24% presented with intracranial hemorrhage. Transverse-sigmoid (26%) and cavernous (26%) sinuses were the most common dural arteriovenous fistula locations. A total of 40 patients (70%) had middle meningeal arterial feeders and 4 (7%) had deep cerebral venous drainage. The mean number of embolization procedures per patient was 1.4. Transarterial access was the most frequent approach (61%). Onyx alone was the most common embolic agent (26%). Complete occlusion rate was achieved in 46 patients (80.1%). Last mean radiographic follow-up time was 26.7 months for all 57 dural arteriovenous fistulas. Dural arteriovenous fistula recurrence after radiographic resolution at last treatment was seen in six cases (6/46, 13.1%). Mean time for recurrence was 15.8 months. Mean time of last clinical follow-up was 46.1 months for the 51 patients (100%). A total of 10 (20%) experienced any procedural complications, among which two (4%) became major thromboembolic events. Conclusion Endovascular therapy is safe and effective for the treatment of high-grade dural arteriovenous fistulas. Given the significant recurrence rate of embolized dural arteriovenous fistulas even after 2 years, long-term angiographic follow-up might be needed.

ImportanceApproximately 10% to 20% of large vessel occlusion (LVO) strokes involve tandem lesions (TLs), defined as concomitant intracranial LVO and stenosis or occlusion of the cervical internal carotid artery. Mechanical thrombectomy (MT) may benefit patients with TLs; however, optimal management and procedural strategy of the cervical lesion remain unclear.ObjectiveTo evaluate the association of carotid artery stenting (CAS) vs no stenting and medical management with functional and safety outcomes among patients with TL-LVOs.Design, Setting, and ParticipantsThis cross-sectional study included consecutive patients with acute anterior circulation TLs admitted across 17 stroke centers in the US and Spain between January 1, 2015, and December 31, 2020. Data analysis was performed from August 2021 to February 2022. Inclusion criteria were age of 18 years or older, endovascular therapy for intracranial occlusion, and presence of extracranial internal carotid artery stenosis (>50%) demonstrated on pre-MT computed tomography angiography, magnetic resonance angiography, or digital subtraction angiography.ExposuresPatients with TLs were divided into CAS vs nonstenting groups.Main Outcomes and MeasuresPrimary clinical and safety outcomes were 90-day functional independence measured by a modified Rankin Scale (mRS) score of 0 to 2 and symptomatic intracranial hemorrhage (sICH), respectively. Secondary outcomes were successful reperfusion (modified Thrombolysis in Cerebral Infarction score ≥2b), discharge mRS score, ordinal mRS score, and mortality at 90 days.ResultsOf 685 patients, 623 (mean [SD] age, 67 [12.2] years; 406 [65.2%] male) were included in the analysis, of whom 363 (58.4%) were in the CAS group and 260 (41.6%) were in the nonstenting group. The CAS group had a lower proportion of patients with atrial fibrillation (38 [10.6%] vs 49 [19.2%], P = .002), a higher proportion of preprocedural degree of cervical stenosis on digital subtraction angiography (90%-99%: 107 [32.2%] vs 42 [20.5%], P P = .003), a lower median (IQR) National Institutes of Health Stroke Scale score (15 [10-19] vs 17 [13-21], P P = .007), favorable shift in mRS scores (aOR, 1.46; 95% CI, 1.02-2.10; P = .04), and successful reperfusion (aOR, 1.70; 95% CI, 1.02-3.60; P = .002) were significantly higher for the CAS group compared with the nonstenting group. Both groups had similar odds of sICH (aOR, 0.90; 95% CI, 0.46-2.40; P = .87) and 90-day mortality (aOR, 0.78; 95% CI, 0.50-1.20; P = .27). No heterogeneity was noted for 90-day functional outcome and sICH in prespecified subgroups.Conclusions and RelevanceIn this multicenter, international cross-sectional study, CAS of the cervical lesion during MT was associated with improvement in functional outcomes and reperfusion rates without an increased risk of sICH and mortality in patients with TLs.

Introduction While mechanical thrombectomy (MT) is proven to be lifesaving and disability‐sparing, there remains disparities in access in low‐ to middle‐income countries (LTMICs), including the Caribbean. We hypothesized that team‐oriented MT workshops would improve MT skills and change practice patterns for MT services in this region. Methods We designed a 22‐hour MT workshop which was conducted as two identical events: in English (Jamaica, January 2022), and in Spanish (Dominican Republic, May 2022). The workshops included neurointerventional teams (practicing neurointerventionalists, neuroIR nurses and technicians), focused on patient selection, acutetreatment and post‐MT care of patients with stroke due to large vessel occlusion. MT skills, procedure duration and potential harmful techniques were recorded before and after by independent evaluators utilizing flow models under fluoroscopy. Overall course evaluation was performed. Press conferences were included to raise stroke awareness and emphasize the importance of early stroke presentation. Results Twenty‐two physicians and their teams from eight countries across the Caribbean completed the didactic and hands‐on training. Eighteen groups completed both pre‐ and post‐MT hands‐on testing and were included in the final analysis. Pre‐ and post‐course hands‐on assessment showed that the course effectively reduced the total time to complete a simulated MT procedure from 36.5 to 21.1 min (Figure 1; p< 1.0×10‐7). All groups showed an improvement in measures of good MT techniques, which resulted in a 39% improvement in complete reperfusion (8/18 groups achieved a TICI 3 score on pre‐course vs. 15/18 groups on post‐course). There was a significant reduction in total potentially dangerous maneuvers by 82% (p< 0.002), with 12/18 groups performing an average 2 dangerous maneuvers on pre‐course simulation vs. only 4/18 groups performing an average 1 dangerous maneuver after completing the course. Participants also demonstrated increased knowledge of stroke treatment and stroke system of care. Utilizing a basic stroke knowledge questionnaire, we found 28% respondents did not have a baseline passing grade vs 100% passed after the workshop. The average post‐workshop knowledge score was 80%. Universally the workshop was rated as very satisfactory and likely to change practice in 93% of the Dominican Republic participants and 75% among Jamaican participants. Conclusions A team‐based approach to MT training is novel, effective in reducing time to reperfusion and harmful techniques, and improves competencies. Team members independently demonstrated advanced stroke learning post‐training. To our knowledge, this is the first workshop of its kind; it is feasible, practice‐changing and creates a pathway for increasing access to MT in LTMICs.

Background and PurposeWe aimed to describe the safety and efficacy of mechanical thrombectomy (MT) with or without intravenous thrombolysis (IVT) for patients with tandem lesions (TLs) and whether using intraprocedural antiplatelet therapy (APT) influences MT’s safety with IVT treatment.MethodsThis is a sub-analysis of a pooled, international multicenter cohort of patients with acute anterior circulation TLs treated with MT. Primary outcomes included symptomatic intracranial hemorrhage (sICH) and parenchymal hematoma type 2 (PH2). Additional outcomes included hemorrhagic transformation (HT), successful reperfusion (modified Thrombolysis in Cerebral Infarction [mTICI] 2b-3), complete reperfusion (mTICI 3), favorable functional outcome (90-day modified Rankin score [mRS] 0-2), excellent functional outcome (90-day mRS 0-1), in-hospital mortality, and 90-days mortality.ResultsOf 691 patients, 599 were included (255 underwent IVT+MT and 344 MT alone). There was no difference in the risk of sICH (aOR=1.43; 95%CI:0.72–2.87;p=0.308), PH2 (aOR=1.14; 95%CI:0.57– 2.28;p=0.705), and HT (aOR=0.92; 95%CI:0.54–1.57;p=0.751) between the IVT+MT and MT alone groups after adjusting for confounders. There was an IVT-by-intraprocedural APT interaction for sICH (pinteraction=0.031). Administration of IVT was associated with an increased risk of sICH in patients who received IV-APT (aOR=3.58; 95%CI:1.17–10.89;p=0.025). The IVT+MT group had higher odds of 90-days mRS 0-2 (aOR=1.76; 95%CI:1.05–2.94;p=0.030). The odds of successful reperfusion, complete reperfusion, 90-days mRS 0-1, in-hospital mortality, or 90-days mortality did not differ between the IVT+MT vs. MT alone groups.ConclusionOur study showed that the combination of IVT with MT for TL did not increase the overall risk of sICH, PH2, or overall HT independently of the cervical revascularization technique used. However, intraprocedural IV-ATP during acute stent implantation might be associated with an increased risk of sICH in patients who received IVT prior to MT. Importantly, IVT+MT treatment was associated with a higher rate of favorable functional outcome at 90 days.

An 88-year-old woman with a medical history of diabetes, hypertension, and atrial fibrillation presented to the emergency room after being found unresponsive with a NIH Stroke Scale score of 23 and Glasgow Coma Scale score of 3. She was unresponsive to painful stimuli. Noncontrast CT demonstrated bilateral thalamic infarcts (figure 1A).

Background The value of clot imaging in patients with emergent large vessel occlusion (ELVO) treated with thrombectomy is unknown. Methods We performed retrospective analysis of clot imaging (clot density, perviousness, length, diameter, distance to the internal carotid artery (ICA) terminus and angle of interaction (AOI) between clot and the aspiration catheter) of consecutive cases of middle cerebral artery (MCA) occlusion and its association with first pass effect (FPE, TICI 2c-3 after a first attempt). Results Patients ( n = 90 total) with FPE had shorter clot length (9.9 ± 4.5 mm vs. 11.7 ± 4.6 mm, P = 0.07), shorter distance from ICA terminus (11.0 ± 7.1 mm vs. 14.7 ± 9.8 mm, P = 0.048), higher perviousness (39.39 ± 29.5 vs 25.43 ± 17.6, P = 0.006) and larger AOI (153.6 ± 17.6 vs 140.3 ± 23.5, P = 0.004) compared to no-FPE patients. In multivariate analysis, distance from ICA terminus to clot ≤13.5 mm (odds ratio (OR) 11.05, 95% confidence interval (CI) 2.65–46.15, P = 0.001), clot length ≤9.9 mm (OR 7.34; 95% CI 1.8–29.96, P = 0.005), perviousness ≥ 19.9 (OR 2.54, 95% CI 0.84–7.6, P = 0.09) and AOI ≥ 137°^ (OR 6.8, 95% CI 1.55–29.8, P = 0.011) were independent predictors of FPE. The optimal cut off derived using Youden’s index was 6.5. The area under the curve of a score predictive of FPE success was 0.816 (0.728–0.904, P Conclusions Clot imaging predicts the likelihood of achieving FPE in patients with MCA ELVO treated with the aspiration-first approach.

BackgroundDiffuse correlation spectroscopy (DCS) is a non-invasive optical technique that enables continuous blood flow measurements in various organs, including the brain. DCS quantitatively measures blood flow from temporal fluctuations in the intensity of diffusely reflected light caused by the dynamic scattering of light from moving red blood cells within the tissue.MethodsWe performed bilateral cerebral blood flow (CBF) measurements using a custom DCS device in patients undergoing neuroendovascular interventions for acute ischemic stroke. Experimental, clinical, and imaging data were collected in a prospective manner.ResultsThe device was successfully applied in nine subjects. There were no safety concerns or interference with the standard angiography suite or intensive care unit workflow. Six cases were selected for final analysis and interpretation. DCS measurements with photon count rates greater than 30 KHz had sufficient signal-to-noise to resolve blood flow pulsatility. We found an association between angiographic changes in cerebral reperfusion (partial or complete reperfusion established in stroke thrombectomy cases; temporary flow arrest during carotid artery stenting) and those observed intraprocedurally with CBF measurements via DCS. Limitations of the current technology included sensitivity to the interrogated tissue volume under the probe and the effect of local changes in tissue optical properties on the accuracy of CBF estimates.ConclusionOur initial experience with DCS in neurointerventional procedures showed the feasibility of this non-invasive approach in providing continuous measurement of regional CBF brain tissue properties.

BackgroundThe benefit of complete reperfusion (modified Thrombolysis in Cerebral Infarction (mTICI) 3) over near-complete reperfusion (≥90%, mTICI 2c) remains unclear. The goal of this study is to compare clinical outcomes between mechanical thrombectomy (MT)-treated stroke patients with mTICI 2c versus 3.MethodsThis is a retrospective study from the Stroke Thrombectomy and Aneurysm Registry (STAR) comprising 33 centers. Adults with anterior circulation arterial vessel occlusion who underwent MT yielding mTICI 2c or mTICI 3 reperfusion were included. Patients were categorized based on reperfusion grade achieved. Primary outcome was modified Rankin Scale (mRS) 0–2 at 90 days. Secondary outcomes were mRS scores at discharge and 90 days, National Institutes of Health Stroke Scale score at discharge, procedure-related complications, and symptomatic intracerebral hemorrhage.ResultsThe unmatched mTICI 2c and mTICI 3 cohorts comprised 519 and 1923 patients, respectively. There was no difference in primary (42.4% vs 45.1%; p=0.264) or secondary outcomes between the unmatched cohorts. Reperfusion status (mTICI 2c vs 3) was also not predictive of the primary outcome in non-imputed and imputed multivariable models. The matched cohorts each comprised 191 patients. Primary (39.8% vs 47.6%; p=0.122) and secondary outcomes were also similar between the matched cohorts, except the 90-day mRS which was lower in the matched mTICI 3 cohort (p=0.049). There were increased odds of the primary outcome with mTICI 3 in patients with baseline mRS ≥2 (36% vs 7.7%; p=0.011; pinteraction=0.014) and a history of stroke (42.3% vs 15.4%; p=0.027; pinteraction=0.041).ConclusionsComplete and near-complete reperfusion after MT appear to confer comparable outcomes in patients with acute stroke.

Background Decompression illness often presents with a wide variety of vague neurologic symptoms. Animal models have suggested that intracranial hemorrhages may result from nitrogen bubble ischemic insults. However, there is a paucity of cases and no known case reported to date of non-aneurysmal subarachnoid hemorrhage after rapid ascension from diving. Case Description A 60-year-old man presented with headache, nausea, emesis, and confusion 2 days after ascending rapidly from scuba diving. Given the severity and his symptoms unremitting despite oxygen at home, a computed tomography scan of the head was obtained revealing a prepontine and right sylvian fissure subarachnoid hemorrhage with ventriculomegaly. No underlying vascular abnormality was discovered. The patient was discharged from the hospital posthemorrhage day 7, neurologically intact. Conclusions In patients presenting with persistent headache, nausea, emesis and/or other neurologic symptoms after diving, health care providers should consider intracranial hemorrhage in their work up.

Background and Purpose: The modified Thrombolysis in Cerebral Infarct (mTICI) score is used to grade angiographic outcome after endovascular thrombectomy. We sought to identify factors that decrease the accuracy of intraprocedural mTICI. Methods: We performed a 2-center retrospective cohort study comparing operator (n=6) mTICI scores to consensus scores from blinded adjudicators. Groups were also assessed by dichotomizing mTICI scores to 0–2a versus 2b–3. Results: One hundred thirty endovascular thrombectomy procedures were included. Operators and adjudicators had a pairwise agreement in 96 cases (73.8%). Krippendorff α was 0.712. Multivariate analysis showed endovascular thrombectomy overnight (odds ratio [OR]=3.84 [95% CI, 1.22–12.1]), lacking frontal (OR, 5.66 [95 CI, 1.36–23.6]), or occipital (OR, 7.18 [95 CI, 2.12–24.3]) region reperfusion, and higher operator mTICI scores (OR, 2.16 [95 CI, 1.16–4.01]) were predictive of incorrectly scoring mTICI intraprocedurally. With dichotomized mTICI scores, increasing number of passes was associated with increased risk of operator error (OR, 1.93 [95 CI, 1.22–3.05]). Conclusions: In our study, mTICI disagreement between operator and adjudicators was observed in 26.2% of cases. Interventions that took place between 22:30 and 4:00, featured frontal or occipital region nonperfusion, higher operator mTICI scores, and increased number of passes had higher odds of intraprocedural mTICI inaccuracy.

Background and Purpose: Mechanical thrombectomy (MT) is a time-dependent therapy that is only available at a limited number of hospitals. As such, patients that live at a considerable distance of those specialized centers often require rapid interhospital emergent evacuation with Helicopter Emergency Medical Services (HEMS) to be considered for MT. It is not known whether the use of HEMS is equitable across different groups of patients. Methods: Acute ischemic stroke patients emergently transferred to another facility were identified in a retrospective review of a large Medicare claims database. Mode of transportation (HEMS, advanced, or basic ground ambulances) was determined by CPT codes. Distance from patient's residence to the closest center with MT capabilities was calculated. Generalized linear mixed logit models were used to determine the odds of HEMS relative to ground services for Hispanic and non-Hispanic black (NHB) patients relative to non-Hispanic white (NHW) patients while controlling for confounders. Results: A total of 8027 patients that underwent emergent interhospital transportation were analyzed. HEMS utilization was 18.1% for NHB, 20.6% for Hispanics, and 21.6% for NHW (P = .054). In adjusted analyses for confounders, including distance to a MT-capable hospital, Hispanic patients were less likely than NHWs to be transported by HEMS. While that association had marginal significance for the whole United States (OR = .76; 95% CI, .57-1.01; P = .055), it was statistically significant for patients living in the southern region of the United States (OR = .6; 95% CI, .40-.92; P = .019). Discussion: Our findings suggest there is a disparity in the use of HEMS in Hispanic stroke patients compared to NHW. Such a disparity may delay arrival to a MT-capable hospital, delay treatment times, or lead to ineligibility for MT altogether. Given the known benefit of MT and known existing disparities in stroke treatment and outcomes, it is important to further investigate and address disparities in mode of interhospital transportation.

Purpose of the ReviewThis article reviews prehospital organization in the treatment of acute stroke. Rapid access to an endovascular therapy (EVT) capable center and prehospital assessment of large vessel occlusion (LVO) are 2 important challenges in acute stroke therapy. This article emphasizes the use of transfer protocols to assure the prompt access of patients with an LVO to a comprehensive stroke center where EVT can be offered. Available prehospital clinical tools and novel technologies to identify LVO are also discussed. Moreover, different routing paradigms like first attention at a local stroke center (“drip and ship”), direct transfer of the patient to an endovascular center (“mothership”), transfer of the neurointerventional team to a local primary center (“drip and drive”), mobile stroke units, and prehospital management communication tools all aimed to improve connection and coordination between care levels are reviewed.Recent FindingsLocal observational data and mathematical models suggest that implementing triage tools and bypass protocols may be an efficient solution. Ongoing randomized clinical trials comparing drip and ship vs mothership will elucidate which is the more effective routing protocol.SummaryPrehospital organization is critical in realizing maximum benefit from available therapies in acute stroke. The optimal transfer protocols directed to accelerate EVT are under study, and more accurate prehospital triage tools are needed. To improve care in the prehospital setting, efficient tools based on patient factors, local geography, and hospital capability are needed. These tools would optimally lead to individualized real-time decision-making.

Background Penetrating vertebral artery injuries (VAIs) are rare but devastating trauma for which the approach to treatment varies greatly. The literature on treatment modalities is limited to case reports, case series, and 1 review, with the majority of cases being treated surgically. However, with the advent of digital subtraction angiography, treatment has shifted toward less invasive endovascular modalities that allows one to assess the flow and risks of sacrificing the vertebral artery (VA). Methods In accordance with Preferred Reporting Items for Systematic reviews and Meta-Analyses, a systematic review of VAI was performed. Two case reports were also detailed. Using a multidisciplinary team, a decision algorithm was proposed for approaching penetrating VAIs. Results We identified 169 patients. Of the penetrating VAI, the majority were occlusions, most commonly managed conservatively. Other injuries including pseudoaneurysm, dissection, transection, and arterial-venous fistula were treated predominantly endovascularly and occasionally with the surgical exploration/ligation. Most endovascular treatments included embolization without significant stroke or complication from VA sacrifice. However, there are incidences in which VA sacrifice should be avoided and these scenarios can be better delineated with digital subtraction angiography to assess flow and anatomy. Conclusions This systematic review not only details the updated treatment options but also provides a decision algorithm for the treatment of penetrating VAI. It highlights the shifting treatment options of penetrating VAI to endovascular therapy, as well as details VAI variants that may suggest stenting over embolization.

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.

Background Intracranial atherosclerotic disease (ICAD) is one of the most common causes of stroke worldwide and is associated with a high risk of stroke recurrence. We sought to perform a literature review of the epidemiology, pathophysiology, and treatment options. Methods A literature review on recent studies evaluating the epidemiology, risk factors, clinical presentation, and treatment was reviewed. ICAD is particularly common in Africa and Asia. Results Although the medical management of ICAD has improved over the past decade, a subgroup of patients with ICAD remains at significantly high risk of stroke recurrence, and newer studies that aim at improving our understanding of ICAD and evaluating new treatment methods are currently under way. Conclusion ICAD remains a common cause of stroke worldwide; further studies evaluating treatment options to prevent stroke recurrence are urgently needed.

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.

Background and Purpose: Complex wide-neck intracranial aneurysms are challenging to treat. We report a multicenter experience using the LVIS Jr stent for “Y-stent”-assisted coiling embolization of wide-neck bifurcation aneurysms. Methods: Seven centers provided retrospective data on patients who underwent Y-stenting. Technical complications, immediate posttreatment angiographic results, clinical outcomes, and imaging follow-up were assessed. Results: Thirty patients/aneurysms were treated: 15 basilar tip, 8 middle cerebral artery, 4 anterior communicating artery, 1 pericallosal, and 2 posterior inferior cerebellar artery aneurysms. The mean aneurysm size was 11 mm and the mean dome-to-neck ratio was 1.3 mm. Twenty-four aneurysms were unruptured and treated electively, and 6 were acutely ruptured. Fifty-eight LVIS Jr stents were successfully deployed without any technical issue. One pro­cedural and transient in-stent thrombosis resolved with the intravenous infusion of a glycoprotein IIb/IIIa inhibitor. Five periprocedural complications (within 30 days) occurred: 2 periprocedural neurological complications (1 small temporal stroke that presented with transient aphasia and 1 posterior cerebral artery infarct) and 3 nonneurological periprocedural complications (2 retroperitoneal hematomas, and 1 patient developed a disseminated intravascular coagulopathy). One permanent complication (3.3%) directly related to Y-stenting was reported in the patient who suffered the posterior cerebral artery infarct. Immediate complete obliteration (Raymond-Roy Occlusion Classification [RROC] I–II) was achieved in 26 cases (89.6%). Twenty-four patients had clinical and imaging follow-up (mean 5.2 months). Complete angiographic occlusion (RROC I–II) was observed in 23 patients (96%). A good functional outcome with a modified Rankin Scale score ≤2 was achieved in 26 cases. Conclusions: In this multicenter case series, Y-stent-assisted coiling of wide-neck aneurysms with the LVIS Jr device was feasible and relatively safe. Follow-up imaging demonstrated very low recanalization rates.

The treatment of palpebral and periorbital fistulas may be challenging due to the presence of multiple anastomosis with eloquent ophthalmic and intracranial vascular territories. Moreover, cosmetic and functional characteristics of this area pose unique challenges to open surgical approaches and endovascular therapy. We review the advantages and disadvantages of different liquid embolics in treating palpebral and periorbital fistulas as we describe three successfully treated cases. Moreover, we describe important anatomical landmarks that should be considered at the time of treatment of these lesions.

BackgroundIn response to the COVID-19 pandemic, many centers altered stroke triage protocols for the protection of their providers. However, the effect of workflow changes on stroke patients receiving mechanical thrombectomy (MT) has not been systematically studied.MethodsA prospective international study was launched at the initiation of the COVID-19 pandemic. All included centers participated in the Stroke Thrombectomy and Aneurysm Registry (STAR) and Endovascular Neurosurgery Research Group (ENRG). Data was collected during the peak months of the COVID-19 surge at each site. Collected data included patient and disease characteristics. A generalized linear model with logit link function was used to estimate the effect of general anesthesia (GA) on in-hospital mortality and discharge outcome controlling for confounders.Results458 patients and 28 centers were included from North America, South America, and Europe. Five centers were in high-COVID burden counties (HCC) in which 9/104 (8.7%) of patients were positive for COVID-19 compared with 4/354 (1.1%) in low-COVID burden counties (LCC) (PConclusionWe observed a low rate of COVID-19 infection among stroke patients undergoing MT in LCC. Overall, more than half of the patients underwent intubation prior to MT, leading to prolonged door to reperfusion time, higher in-hospital mortality, and lower likelihood of functional independence at discharge.

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.

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 aims Extensive animal data indicate that mesenchymal stromal cells (MSCs) improve outcome in stroke models. Intra-arterial (IA) injection is a promising route of delivery for MSCs. Therapeutic effect of MSCs in stroke is likely based on the broad repertoire of secreted trophic and immunomodulatory cytokines produced by MSCs. We determined the differential effects of exposing MSCs to different types of clinically relevant vehicles, and/or different additives and passage through a catheter relevant to IA injections. Methods MSCs derived from human bone marrow were tested in the following vehicles: 5% albumin (ALB), 6% Hextend (HEX) and 40% dextran (DEX). Each solution was tested (i) alone, (ii) with low-dose heparin, (iii) with 10% Omnipaque, or (iv) a combination of heparin and Omnipaque. Cells in vehicles were collected directly or passed through an IA catheter, and MSC viability and cytokine release profiles were assessed. Results Cell viability remained above 90% under all tested conditions with albumin being the highest at 97%. Viability was slightly reduced after catheter passage or exposure to heparin or Omnipaque. Catheter passage had little effect on MSC cytokine secretion. ALB led to increased release of angiogenic factors such as vascular endothelial growth factor compared with other vehicles, while HEX and DEX led to suppression of pro-inflammatory cytokines such as interleukin-6. However, when these three vehicles were subjected to catheter passage and/or exposure to additives, the cytokine release profile varied depending on the combination of conditions to which MSCs were exposed. Discussion Exposure of MSCs to certain types of vehicles or additives changes the profile of cytokine secretion. The activation phenotype of MSCs may therefore be affected by the vehicles used for these cells or the exposure to the adjuvants used in their administration.

Time is the key factor in brain survivability in acute stroke treatment.1 The therapeutic effects of intravenous recombinant tissue Plasminogen Activator (IV rtPA) are highly dependent on time.1-3 Stroke patients presenting within the first 60 minutes, or the golden hour, are the most likely to benefit from recanalization therapy.1-3 Thus, making rapid clinical and imaging evaluation of stroke patients of upmost importance and very difficult to complete within the golden hour time window. Based on Get with the Guidelines-Stroke Program (April 2003 to October 2009), less than one-third of patients treated with IV rtPA have door-to-needle times of less than 60 minutes.4

Endovascular mechanical thrombectomy (MT) has become the standard of care for acute ischemic stroke patients with large vessel occlusions. The success of MT is mainly due to the development of new-generation devices that allow higher rates of successful revascularization with lower complications. In this chapter, we review the evolution of MT devices and technologies.

Objective: The purpose of this study is to compare long-term functional outcome for patients who receive intravenous alteplase (tPA) at a primary stroke center (spoke) through telestroke c...

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: Overall risk of ischemic stroke from a chronically occluded internal carotid artery (COICA) is around »7% per year. We propose 1) a radiographic classification of COICA to determine the technical success and safety of endovascular recanalization of symptomatic COICA and 2) assess changes in systemic blood pressure following successful revascularization. Methods: Radiographic imaging of 100 consecutive subjects with COICA was analyzed. A classification of COICA based on morphology and location of occlusion in addition to presence or absence of reconstitution of the distal ICA was utilized. Sixteen symptomatic COICA in 15 subjects refractory to medical therapy (4/15, 26.7% female) from 2016-17 were included. Carotid occlusion was defined as 100% occlusion of the vessel lumen based on CT or MR angiography and confirmed by digital subtraction angiogram. Results: Four types (A-D) of radiographic COICA were identified. Type A 29%, Type B 28%, Type C 33%, and Type D 10%. Types A/B were more amenable to safer revascularization than types C/D. Recanalization was successful in 68.75% (11/16 [Type A: 4/4; Type B: 3/3; Type C: 3/4; Type D: 1/5]) of the subjects. Perioperative complications was 4/16, 25%; [0/4 in Type A; 1/3 in type B; 2/4 in type C, and 1/5 in type D]. None of these complications led to permanent morbidity or mortality. Ten of fifteen (62.5%) subjects had improvement in symptoms during 2-6 month follow-up. Eight of ten subjects (80%) with revascularization had significant decrease in systolic blood pressure [SBP) following revascularization [baseline SBP= 141±9 vs. follow-up SBP= 123±8; 95% CI; -25.57 to -10.42; p=0.0001]. The remaining five subjects failing revascularization had no significant change in SBP [Baseline SBP=137±6 vs. follow-up SBP=135±11; 95% CI: -14.92 to 10.9; p=0.73]. Conclusion: This pilot study suggests that our proposed classification of COICA may be a useful guide to determine technical feasibility and safety of revascularization of symptomatic COICA using endovascular techniques. Successful revascularization may lead to significant decrease in SBP post procedure. A phase-2 trial to assess the safety and efficacy of this technique and to validate COICA classification in larger cohort is warranted.

Background & Purpose: In the mechanical thrombectomy (MT) era, it is imperative to ensure that patients with stroke have a fair access to advanced ground ambulances (AGA) or the more rapid Helicopter Emergency Medical Services (HEMS) to avoid disparities in functional outcomes. In this study we investigated racial/ethnic disparities in the use of AGA or HEMS for inter-hospital transfer of stroke patients in the US. Methods: We used Medicare claims for years 2010-2013 for Medicare beneficiaries with a new diagnosis of atrial fibrillation. Cases were patients with a primary diagnosis of ischemic or hemorrhagic stroke that underwent an inter-hospital transfer between acute facilities within the day of the stroke. Transportation was categorized as basic ground, AGA or HEMS. A multinomial logit model was used to adjust for confounders such as patient’s characteristics, distance and geographical location. Results: A total of 11,172 acute hospital to hospital transfers were analyzed. In unadjusted analysis, 17.7% of black, 20.9% of Hispanic and 21.7% of white patients were transferred by HEMS, and 73.7% of black, 67.3% of Hispanic and 69.9% of white patients were transferred by AGA (p=0.003). These differences, however, disappeared after controlling for confounders. The exception were Hispanic patients, who remain less likely to be transported by HEMS (OR=0.64; 0.45-0.90; p=0.01) or AGA than white patients (OR=0.74; 0.55-1.00; p=0.048) Conclusion: Hispanic patients with stroke undergoing an acute inter-facility transfer are less likely to be transported by HEMS or advance ground ambulances after adjusting for all possible confounders, including distance and insurance. This unacceptable disparity is a barrier to timely access to a thrombectomy-capable hospital and best care en-route for these patients, which may result in worse outcomes after MT.

Objective Treatment of ruptured posterior circulation dissecting aneurysms is technically challenging with potentially high morbidity and mortality. We sought to assess the safety and feasibility of using a flow-diversion device (FDD) and a specific acute antiplatelet aggregation protocol in the management of ruptured dissecting aneurysms. Methods Subjects with ruptured dissecting aneurysms treated during a 3-year period were retrospectively identified from a prospective registry. Intraoperative complications, morbidity, and mortality were recorded. Tirofiban maintenance infusion without bolus was administered intravenously immediately after deployment of the FDD, and almost all patients were loaded with dual antiplatelet (aspirin and clopidogrel) post procedure. Clinical follow-up evaluation and modified Rankin Scale were assessed. Results Nine subjects with ruptured posterior circulation dissecting aneurysms were treated with an FDD: 5 vertebral artery, 2 basilar artery, and 2 posterior inferior cerebellar artery aneurysms. Average World Federation of Neurosurgical Societies score was 2 (range 1–5). Seven patients had external ventricular drain placed acutely for hydrocephalus. Eight patients received tirofiban infusion without bolus after FDD. No intraoperative complications occurred. Two subjects developed asymptomatic intraparenchymal hemorrhage found on surveillance noncontrast computed tomography. One subject suffered a major intraparenchymal hemorrhage and died a few days post intervention after additional anticoagulation was started for a left ventricular assist device. Follow-up modified Rankin Scale within 12 months was 0 in 3 subjects, 1 in 3 subjects, 2 in 1 subject, and 4 in 1. Conclusions Treatment of dissecting posterior circulation aneurysms with FDDs is feasible and a potential alternative to deconstructive techniques.

We examined platelet transfusion (PTx) in the Ethnic/Racial Variations of Intracerebral Hemorrhage (ERICH) study, hypothesizing that rates of PTx would vary among hospitals and depend on whether patients were on an antiplatelet therapy or underwent intracerebral hemorrhage (ICH) surgical treatment.The ERICH study is a prospective observational study evaluating risk factors for ICH among whites, blacks, and Hispanics. We identified factors associated with PTx, examined practice patterns of PTx across the United States, and explored the association of PTx with mortality and poor outcome (modified Rankin Scale score 4-6).Nineteen centers enrolled 2572 ICH cases; 11.7% received PTx. Factors significantly associated with PTx were antiplatelet use before onset (odds ratio [OR], 5.02; 95% confidence interval [CI], 3.81-6.61, P .0001), thrombocytopenia (OR, 13.53; 95% CI, 8.43-21.72, P .0001), and ventriculostomy placement (OR, 1.85; 95% CI, 1.36-2.52, P .0001). Blacks were less likely (OR, .57; 95% CI, .41-0.80) to receive PTx. Among patients who received PTx, 42.4% were not on an antiplatelet therapy before onset. Twenty-three percent of patients on antiplatelet therapy received PTx, but percentages varied from 0% to 71% across centers. There was no difference in mortality or poor outcome at 3 months between patients receiving PTx and those who did not.The frequency of PTx for ICH varies across academic centers. Thrombocytopenia, antiplatelet use, vascular risk factors, and ventriculostomy placement were associated with PTx. PTx was not associated with improved outcomes. We anticipate reduced PTx use over time given recent clinical trial data suggesting its use could be harmful; however, the issue of whether surgical management warrants PTx remains.

The incidence of acute ischaemic stroke with mild neurological deficits (called mild ischaemic stroke [MIS]) is increasing, and studies show that a large percentage of untreated patients have poor long-term outcomes. Many physicians do not, however, routinely treat patients with MIS with intravenous recombinant tissue plasminogen activator (rtPA)--the only thrombolytic therapy currently approved by the FDA. Here, we discuss the reasons why physicians do not treat patients with MIS and we review the studies published to date regarding the potential risks and benefits of administering rtPA in this patient population. We then provide our perspective on why patients with MIS should be treated with intravenous rtPA and we highlight the need for a randomized clinical trial to address treatment of MIS.

BackgroundFavorable imaging profile according to the Alberta Stroke Program Early CT Score (ASPECTS) on non-contrast head CT is a key criterion for the selection of patients with ischemic stroke from large vessel occlusion (LVO) for IA revascularization therapies.ObjectiveTo analyze factors associated with changes in ASPECTS during inter-hospital transfer and to determine how deterioration of ASPECTS affects eligibility for endovascular procedures.MethodsWe analyzed factors associated with changes in ASPECTS during inter-hospital transfer and their potential impact on eligibility for IA stroke therapies in patients with anterior circulation ischemic strokes. Clinical and demographic characteristics between patients with favorable (ASPECTS ≥6) and unfavorable (ASPECTS ResultsStroke evolution towards unfavorable ASPECTS occurred in 13/42 (31%) patients who initially had a favorable imaging profile at outside hospitals. A higher National Institutes of Health Stroke Scale (NIHSS) score was the only significant predictor of ASPECTS decay, whereas other clinical characteristics, such as the use of IV thrombolysis and site of LVO, were similar between the two groups.ConclusionsIn our cohort, one out of three patients became ineligible for IA thrombectomy because of unfavorable ASPECTS ‘decay’ following inter-hospital transfer. Except for NIHSS severity, baseline clinical factors could not identify which patients were at risk for ASPECTS deterioration.

Cardiac embolism, primarily from atrial fibrillation (AF), is implicated in a quarter of all ischemic strokes. In the setting of AF, contraindications to traditional therapies can create a clinical dilemma when choosing an agent for secondary stroke prophylaxis. Newer horizons in the medical and surgical management of AF have helped us choose from a wide variety of available therapies, the best possible management. In this article, we review the current trends in AF management including newer oral anticoagulants as well as surgical devices from a neurologist's view.

Background There are several forms of agraphia, including: aphasic agraphia, where patients have impairments in writing the correct words or correctly spelling words; apraxic agraphia, where patients are impaired in making the movements needed to write letters; and spatial agraphia, where patients might fail to write letters on one side of a word or write on one side of a page. In several of these agraphic disorders, patients can make perseverative errors, and perseverative errors can even be seen in patients who do not have aphasia or apraxic agraphia. Patients who make continuous perseverative errors repeatedly writes the same letter (fruuuit) or word, and patients with recurrent perseverations change their letters, but then incorrectly use letter or word that was previously used (fruiut). We report a patient who demonstrated a different form of graphic perseveration. Methods and results A 61-year-old man with a right parietal lobe lesion and left-sided neglect developed an inability to write. When attempting to write, he repeatedly wrote the same letter that he first wrote, and wrote these in the same spatial position as the first letter. When spelling, reading aloud, and using a keyboard to write he did not perseverate letters or words. When performing the cancellation test and drawings, he also perseverated. Conclusions This patient demonstrated a novel form of perseverative behavior. Although the mechanism of this spatially adherent graphemic perseveration remains to be elucidated fully we provide evidence that this patient's right parietal lesion caused a visuomotor disengagement disorder.

The association between the street drug spice (K-2 or herbal incense), a synthetic marijuana, and intracranial hemorrhage (ICH) has not yet been described, but it has with acute ischemic stroke (AIS),1 seizure, and myocardial infarction.2 Two young patients (31 and 25 years old) independently presented to our hospital with subarachnoid hemorrhage (SAH) after spice inhalation. The first also had 2 large intraparenchymal hemorrhages (IPH); the other also had AIS. Both were previously healthy without hypertension, coagulopathy, bleeding diathesis, thrombocytopenia, intracranial aneurysm, arteriovenous malformation, connective tissue disease, or anticoagulant/antiplatelet medication use.

Osmotic demyelination syndrome (ODS) is a recognized complication of rapid correction of hyponatremia. However, other medical conditions have been associated recently with the development of ODS in the absence of changes in serum sodium. We present a 23-year-old man who developed left hemiparesis and encephalopathy after treatment of hyperglycemia. MRI demonstrated changes in the splenium of the corpus callosum and the posterior limb of the right internal capsule. This report, together with others, suggests that the full spectrum of lesions of ODS, pontine and extrapontine, can occur in the setting of any rapid change in osmolar state.

Neuroimaging techniques have been beneficial in identifying patients with salvageable penumbra. We sought to validate the mean transit time (MTT) map on computed tomography perfusion (CTP) imaging utilizing an Aquilion ONE computed tomography (CT) scanner running a singular value decomposition plus algorithm in patients with acute large vessel ischemic stroke who underwent endovascular therapy.We conducted a retrospective analysis of consecutive patients presenting to the emergency room who met the following criteria: 1) had a large vessel acute ischemic stroke; 2) had a high-quality whole-brain CTP; 3) treated with endovascular therapy; and 4) received a follow-up MRI with diffusion-weighted imaging (DWI) within 48 h. A blinded neurologist, neuroradiologist, and neurosurgeon utilized the Vitrea software to process the images independently using an infarct perimeter method.Twelve patients met the inclusion criteria. A comparison was made between the volumes of infarct core (IC) utilizing MTT and DWI after accounting for other co-founding factors (i.e., recanalization rate, time between CT and MRI, time to achieve recanalization, and IV t-PA administration). MTT was redefined as capillary MTT (cMTT) which represented evolving capillary flow influenced by hypoxia induced vasodilation/vasoconstriction. We divided the patients into two groups based on the degree of reperfusion: A) patients with a TICI score of IIb or III and B) patients with a TICI score of I or IIa. We compared the two groups and found that the rate of reperfusion significantly affected the volume of the infarct on MTT when compared with a follow-up MRI (p value0.04). Furthermore, we found a strong positive correlation R(2) = 0.6 between the average MTT infarct volume and the final DWI MR volumes. In addition, the averaged MTT IC volumes were 84% of the final averaged DWI IC volumes.Although further studies are required to validate this retrospective study, preliminary data suggest that cMTT maps can be a valuable and accurate tool in the assessment of patients with acute stroke who may benefit from aggressive endovascular therapy.