Posterior circulation collaterals as predictors of outcome in basilar artery occlusion: a sub-analysis of the BASICS randomized trial

Introduction and purpose

Basilar artery occlusion (BAO) is still one of the most devastating neurological conditions associated with high morbidity and mortality. In the present study, we aimed to assess the role of posterior circulation collaterals as predictors of outcome in the BASICS trial and to compare two grading systems (BATMAN score and PC-CS) in terms of prognostic value.

Methods

We performed a sub-analysis of the BASICS trial. Baseline clinical and imaging variables were analyzed. For the imaging analysis, baseline CT and CTA were analyzed by a central core lab. Only those patients with good or moderate quality of baseline CTA and with confirmed BAO were included. Multivariable binary logistic regression analysis was used to test the independent association of clinical and imaging characteristics with a favorable outcome at 3 months (defined as a modified Rankin Score of ≤3). ROC curve analysis was used to assess and compare accuracy between the two collateral grading systems.

Results

The mean age was 67.0 (±12.5) years, 196 (65.3%) patients were males and the median NIHSS was 21.5 (IQR 11-35). Median NCCT pc-ASPECTS was 10 (IQR10-10) and median collateral scores for BATMAN and PC-CS were 8 (IQR 7-9) and 7 (IQR 6-8) respectively. Collateral scores were associated with favorable outcome at 3 months for both BATMAN and PC-CS but only with a modest accuracy on ROC curve analysis (AUC 0.62, 95% CI [0.55-0.69] and 0.67, 95% CI [0.60-0.74] respectively). Age (OR 0.97, 95% CI [0.95-1.00]), NIHSS (OR 0.91, 95% CI [0.89-0.94]) and collateral score (PC-CS - OR 1.2495% CI [1.02-1.51]) were independently associated with clinical outcome.

Conclusion

The two collateral grading systems presented modest prognostic accuracy. Only the PC-CS was independently associated with a favorable outcome at 3 months.

Endovascular Treatment for Acute Isolated Internal Carotid Artery Occlusion : A Propensity Score Matched Multicenter Study

PURPOSE

The benefit of endovascular treatment (EVT) in patients with acute symptomatic isolated occlusion of the internal carotid artery (ICA) without involvement of the middle and anterior cerebral arteries is unclear. We aimed to compare clinical and safety outcomes of best medical treatment (BMT) versus EVT + BMT in patients with stroke due to isolated ICA occlusion.

METHODS

We conducted a retrospective multicenter study involving patients with isolated ICA occlusion between January 2016 and December 2020. We stratified patients by BMT versus EVT and matched the groups using propensity score matching (PSM). We assessed the effect of treatment strategy on favorable outcome (modified Rankin scale ≤ 2) 90 days after treatment and compared reduction in NIHSS score at discharge, rates of symptomatic intracranial hemorrhage (sICH) and 3‑month mortality.

RESULTS

In total, we included 149 patients with isolated ICA occlusion. To address imbalances, we matched 45 patients from each group using PSM. The rate of favorable outcomes at 90 days was 56% for EVT and 38% for BMT (odds ratio, OR 1.89, 95% confidence interval, CI 0.84-4.24; p = 0.12). Patients treated with EVT showed a median reduction in NIHSS score at discharge of 6 points compared to 1 point for BMT patients (p = 0.02). Rates of symptomatic intracranial hemorrhage (7% vs. 4%; p = 0.66) and 3‑month mortality (11% vs. 13%; p = 0.74) did not differ between treatment groups. Periprocedural complications of EVT with early neurological deterioration occurred in 7% of cases.

CONCLUSION

Although the benefit on functional outcome did not reach statistical significance, the results for NIHSS score improvement, and safety support the use of EVT in patients with stroke due to isolated ICA occlusion.

Non-ischemic cerebral enhancing (NICE) lesions after flow diversion for intracranial aneurysms: a multicenter study

BACKGROUND

Non-ischemic cerebral enhancing (NICE) lesions have been reported as a rare complication of various neuroendovascular procedures, but information on their incidence after flow diversion is scant. It is unclear if specific devices or novel coating technologies may impact their occurrence.

METHODS

We conducted a multicenter study on the incidence of NICE lesions after flow diverter (FD) implantation for cerebral aneurysm treatment.

RESULTS

Eight centers identified 15 patients and provided detailed data. The clinical presentation ranged from asymptomatic to hemiplegia and cognitive impairment. The mean time to diagnosis after treatment was 65.1±101.5 days. Five centers disclosed information on all of their 1201 FD procedures during the inclusion period (2015-2022), during which 12 patients were diagnosed with NICE lesions in these institutions-that is, an incidence of 1%. FD coatings did not increase the incidence (6/591 patients (1%) treated with surface-modified FD vs 6/610 patients (1%) treated with bare FD; P=1.00). Significantly increased rates of 3.7% (6 cases in 161 procedures; P<0.01) and 3.3% (5 cases in 153 procedures; P<0.01) were found with stents of two specific product lines. The use of one product line was associated with a significantly lower incidence (0 cases in 499 procedures (0%); P<0.01).

CONCLUSIONS

Novel stent coatings are not associated with an increased incidence of NICE lesions. The incidence rate of 1% suggests that these lesions may occur more often after flow diversion than after other endovascular treatments. We found a concerning accumulation of NICE lesion cases when FDs from two product families were used.

Endovascular thrombectomy for acute ischaemic stroke with established large infarct: multicentre, open-label, randomised trial

BACKGROUND

Recent evidence suggests a beneficial effect of endovascular thrombectomy in acute ischaemic stroke with large infarct; however, previous trials have relied on multimodal brain imaging, whereas non-contrast CT is mostly used in clinical practice.

METHODS

In a prospective multicentre, open-label, randomised trial, patients with acute ischaemic stroke due to large vessel occlusion in the anterior circulation and a large established infarct indicated by an Alberta Stroke Program Early Computed Tomographic Score (ASPECTS) of 3-5 were randomly assigned using a central, web-based system (using a 1:1 ratio) to receive either endovascular thrombectomy with medical treatment or medical treatment (ie, standard of care) alone up to 12 h from stroke onset. The study was conducted in 40 hospitals in Europe and one site in Canada. The primary outcome was functional outcome across the entire range of the modified Rankin Scale at 90 days, assessed by investigators masked to treatment assignment. The primary analysis was done in the intention-to-treat population. Safety endpoints included mortality and rates of symptomatic intracranial haemorrhage and were analysed in the safety population, which included all patients based on the treatment they received. This trial is registered with ClinicalTrials.gov, NCT03094715.

FINDINGS

From July 17, 2018, to Feb 21, 2023, 253 patients were randomly assigned, with 125 patients assigned to endovascular thrombectomy and 128 to medical treatment alone. The trial was stopped early for efficacy after the first pre-planned interim analysis. At 90 days, endovascular thrombectomy was associated with a shift in the distribution of scores on the modified Rankin Scale towards better outcome (adjusted common OR 2·58 [95% CI 1·60-4·15]; p=0·0001) and with lower mortality (hazard ratio 0·67 [95% CI 0·46-0·98]; p=0·038). Symptomatic intracranial haemorrhage occurred in seven (6%) patients with thrombectomy and in six (5%) with medical treatment alone.

INTERPRETATION

Endovascular thrombectomy was associated with improved functional outcome and lower mortality in patients with acute ischaemic stroke from large vessel occlusion with established large infarct in a setting using non-contrast CT as the predominant imaging modality for patient selection.

FUNDING

EU Horizon 2020.

Early Intubation in Endovascular Therapy for Basilar Artery Occlusion: A Post Hoc Analysis of the BASICS Trial

BACKGROUND

The optimal anesthetic management for endovascular therapy (EVT) in patients with posterior circulation stroke remains unclear. Our objective was to investigate the impact of early intubation in patients enrolled in the BASICS trial (Basilar Artery International Cooperation Study).

METHODS

BASICS was a multicenter, randomized, controlled trial that compared the efficacy of EVT compared with the best medical care alone in patients with basilar artery occlusion. In this post hoc analysis, early intubation within the first 24 hours of the estimated time of basilar artery occlusion was examined as an additional covariate using regression modeling. We estimated the adjusted relative risks (RRs) for favorable outcomes, defined as modified Rankin Scale scores of 0 to 3 at 90 days. An adjusted common odds ratio was estimated for a shift in the distribution of modified Rankin Scale scores at 90 days.

RESULTS

Of 300 patients in BASICS, 289 patients were eligible for analysis (151 in the EVT group and 138 in the best medical care group). compared with medical care alone, EVT was related to a higher risk of early intubation (RR, 1.29 [95% CI, 1.09-1.53]; P<0.01), and early intubation was negatively associated with favorable outcome (RR, 0.61 [95% CI, 0.45-0.84]; P=0.002). Whereas there was no overall treatment effect of EVT on favorable outcome (RR, 1.22 [95% CI, 0.95-1.55]; P=0.121), EVT was associated with favorable outcome (RR, 1.34 [95% CI, 1.05-1.71]; P=0.018) and a shift toward lower modified Rankin Scale scores (adjusted common odds ratio, 1.63 [95% CI, 1.04-2.57]; P=0.033) if adjusted for early intubation.

CONCLUSIONS

In this post hoc analysis of the neutral BASICS trial, early intubation was linked to unfavorable outcomes, which might mitigate a potential benefit from EVT by indirect effects due to an increased risk of early intubation. This relationship may be considered when assessing the efficacy of EVT in patients with basilar artery occlusion in future trials.

Endovascular Thrombectomy for Anterior Circulation Large Vessel Occlusion Stroke: An Evolution of Trials

The last decade's progress in demonstrating the clinical benefit of endovascular thrombectomy (EVT) in patients with large vessel occlusion stroke has transformed the paradigm of care for these patients. This review presents the milestones in implementing EVT as standard of care, demonstrates the current state of evidence, provides guidance for identifying the candidate patient for EVT, and highlights unsolved and controversial issues. Ongoing trials investigate broadening of EVT indications for patients who present with large core infarction, adjunctive intra-arterial thrombolysis, medium vessel occlusion, low NIHSS, and tandem occlusion.

Team Prenotification Reduces Procedure Times for Patients With Acute Ischemic Stroke Due to Large Vessel Occlusion Who Are Transferred for Endovascular Therapy

Background: The clinical benefit from endovascular therapy (EVT) for patients with acute ischemic stroke is time-dependent. We tested the hypothesis that team prenotification results in faster procedure times prior to initiation of EVT.

Methods: We analyzed data from our prospective database (01/2016–02/2018) including all patients with acute ischemic stroke who were evaluated for EVT at our comprehensive stroke center. We established a standardized algorithm (EVT-Call) in 06/2017 to prenotify team members (interventional neuroradiologist, neurologist, anesthesiologist, CT and angiography technicians) about patient transfer from remote hospitals for evaluation of EVT, and team members were present in the emergency department at the expected patient arrival time. We calculated door-to-image, image-to-groin and door-to-groin times for patients who were transferred to our center for evaluation of EVT, and analyzed changes before (–EVT-Call) and after (+EVT-Call) implementation of the EVT-Call.

Results: Among 494 patients in our database, 328 patients were transferred from remote hospitals for evaluation of EVT (208 -EVT-Call and 120 +EVT-Call, median [IQR] age 75 years [65–81], NIHSS score 17 [12–22], 49.1% female). Of these, 177 patients (54%) underwent EVT after repeated imaging at our center (111/208 [53%) -EVT-Call, 66/120 [55%] +EVT-Call). Median (IQR) door-to-image time (18 min [14–22] vs. 10 min [7–13]; p < 0.001), image-to-groin time (54 min [43.5–69.25] vs. 47 min [38.3–58.75]; p = 0.042) and door-to-groin time (74 min [58–86.5] vs. 60 min [49.3–71]; p < 0.001) were reduced after implementation of the EVT-Call.

Conclusions: Team prenotification results in faster patient assessment and initiation of EVT in patients with acute ischemic stroke. Its impact on functional outcome needs to be determined.

Association of Regular Thrombus Surface Phenotype With Complete Recanalization in First-Line Contact Aspiration Thrombectomy for Basilar Artery Occlusion

Objective: To assess whether angiographic thrombus surface phenotype has an impact on efficacy of contact aspiration (CA) thrombectomy in patients with basilar artery occlusion (BAO). Methods: From January 2016 to December 2019, consecutive stroke patients with a BAO and first-line CA were analyzed in this retrospective study. We assessed baseline and imaging characteristics and treatment and clinical outcomes. We rated thrombus surface phenotype on pre-treatment digital subtraction angiography in a three-reader-consensus setting. Primary outcome was complete recanalization (modified treatment in cerebral ischemia [mTICI] 3 and arterial occlusive lesion [AOL] 3) after first-line CA without additionally stent retriever passes. Data analysis was stratified according to thrombus surface phenotype and complete first-line recanalization. Results: Seventy-eight patients met the inclusion criteria. Median age was 74 years (IQR 64-80), 64% were male, and median baseline NIHSS score was 24 (IQR 7-32). Thirty patients had a regular and 16 patients had an irregular thrombus phenotype. Thrombus surface was not assessable in 32 patients. In patients with a regular phenotype, complete recanalization was more often achieved compared to irregular and non-ratable phenotypes (50 vs. 18.8% and 21.9%; p = 0.027). Patients with a regular phenotype [odds ratio [OR] 8.3; 95% confidence interval [CI]: 1.9-35.8; p = 0.005], cardioembolic stroke (OR 12.1, 95% CI: 2.0-72.8; p = 0.007), and proximal end of the thrombus in the middle basilar artery segment (OR 5.2, 95% CI: 1.0-26.6; p = 0.046) were more likely to achieve complete recanalization after first-line CA without rescue therapy. Conclusion: The efficacy of CA may differ according to the angiographic thrombus surface phenotype in patients with BAO. A regular phenotype is associated with higher rates of complete recanalization in first-line CA. However, assessment of thrombus phenotype is frequently not feasible in BAO.

Inadvertent hypothermia after endovascular therapy is not associated with improved outcome in stroke due to anterior circulation large vessel occlusion

BACKGROUND AND PURPOSE

Hypothermia may be neuroprotective in acute ischemic stroke. Patients with anterior circulation large vessel occlusion (acLVO) are frequently hypothermic after endovascular therapy (EVT). We sought to determine whether this inadvertent hypothermia is associated with improved outcome.

METHODS

We extracted data of consecutive patients (January 2016 to May 2019) who received EVT for acLVO from our prospective EVT register of all patients screened for EVT at our tertiary stroke center. We assessed functional outcome at 3 months and performed multivariate analysis to calculate adjusted risk ratios (aRRs) for favorable outcome (modified Rankin Scale scores = 0-2) and mortality across patients who were hypothermic (<36°C) and patients who were normothermic (≥36°C to <37.6°C) after EVT. Moreover, we compared the frequency of complications between these groups.

RESULTS

Among 837 patients screened, 416 patients received EVT for acLVO and fulfilled inclusion criteria (200 [48.1%] male, mean age = 76 ± 16 years, median National Institutes of Health Stroke Scale score = 16, interquartile range [IQR] = 12-20). Of these, 209 patients (50.2%) were hypothermic (median temperature = 35.2°C, IQR = 34.7-35.7) and 207 patients were normothermic (median temperature = 36.4°C, IQR = 36.1-36.7) after EVT. In multivariate analysis, hypothermia was not associated with favorable outcome (aRR = 0.99, 95% confidence interval [CI] = 0.75-1.31) and mortality (aRR = 1.18, 95% CI = 0.84-1.66). More hypothermic patients suffered from pneumonia (36.4% vs. 25.6%, p = 0.02) and bradyarrhythmia (52.6% vs. 16.4%, p < 0.001), whereas thromboembolic events were distributed evenly (5.7% vs. 6.8%, not significant).

CONCLUSIONS

Inadvertent hypothermia after EVT for acLVO is not associated with improved functional outcome or reduced mortality but is associated with an increased rate of pneumonia and bradyarrhythmia in patients with acute ischemic stroke.

Endovascular Therapy for Stroke Due to Basilar-Artery Occlusion

BACKGROUND

The effectiveness of endovascular therapy in patients with stroke caused by basilar-artery occlusion has not been well studied.

METHODS

We randomly assigned patients within 6 hours after the estimated time of onset of a stroke due to basilar-artery occlusion, in a 1:1 ratio, to receive endovascular therapy or standard medical care. The primary outcome was a favorable functional outcome, defined as a score of 0 to 3 on the modified Rankin scale (range, 0 to 6, with 0 indicating no disability, 3 indicating moderate disability, and 6 indicating death) at 90 days. The primary safety outcomes were symptomatic intracranial hemorrhage within 3 days after the initiation of treatment and mortality at 90 days.

RESULTS

A total of 300 patients were enrolled (154 in the endovascular therapy group and 146 in the medical care group). Intravenous thrombolysis was used in 78.6% of the patients in the endovascular group and in 79.5% of those in the medical group. Endovascular treatment was initiated at a median of 4.4 hours after stroke onset. A favorable functional outcome occurred in 68 of 154 patients (44.2%) in the endovascular group and 55 of 146 patients (37.7%) in the medical care group (risk ratio, 1.18; 95% confidence interval [CI], 0.92 to 1.50). Symptomatic intracranial hemorrhage occurred in 4.5% of the patients after endovascular therapy and in 0.7% of those after medical therapy (risk ratio, 6.9; 95% CI, 0.9 to 53.0); mortality at 90 days was 38.3% and 43.2%, respectively (risk ratio, 0.87; 95% CI, 0.68 to 1.12).

CONCLUSIONS

Among patients with stroke from basilar-artery occlusion, endovascular therapy and medical therapy did not differ significantly with respect to a favorable functional outcome, but, as reflected by the wide confidence interval for the primary outcome, the results of this trial may not exclude a substantial benefit of endovascular therapy. Larger trials are needed to determine the efficacy and safety of endovascular therapy for basilar-artery occlusion. (Funded by the Dutch Heart Foundation and others; BASICS ClinicalTrials.gov number, NCT01717755; Netherlands Trial Register number, NL2500.).

[Anesthesiological management in endovascular stroke treatment]

Early recanalization of the closed cerebral arteries after acute ischemic stroke (AIS) is the only treatment to minimize long-term disability and to reduce the associated morbidity and mortality. For a long time the only proven causal treatment of AIS was intravenous thrombolysis; however, after the publication of a series of randomized prospective studies concerning endovascular mechanical thrombectomy using stent retriever systems after AIS, new guidelines were published. It was found that endovascular treatment (EVT) dramatically improves the outcome of eligible patients. The stent retriever enables high recanalization rates by clot removal from the cerebral arterial system by means of aspiration of the thrombus via the catheter and/or by entrapping it with a stent system. The management of anesthesia during the procedure is indispensable to prevent hypoxia and hemodynamic instability; however, which form of anesthesia (i.e. general anesthesia vs. conscious sedation) is advantageous for the patient during EVT is controversially discussed. In the first studies using retrospective data conscious sedation resulted in a better outcome compared to general anesthesia following EVT; however, in prospective studies this finding could not be confirmed. To obtain optimal neurological results after AIS and EVT with general anesthesia, it is of tremendous importance not to delay the EVT due to the anesthesiology procedure. Furthermore, hypotension, hypovolemia and hypocapnia should also be strictly avoided. Finally, the optimal anesthesiological approach should be guided by the current clinical state and pre-existing comorbidities of the patient.

Paraneoplastic Syndrome and SARS-CoV-2-Incremental Effect of 2 Thrombogenic Conditions?

We present the case of a patient with a nonbacterial thrombotic aortic valve endocarditis experiencing severe thromboembolic complications and an acute right internal carotid artery occlusion in the context of a paraneoplastic syndrome and an asymptomatic severe acute respiratory syndrome coronavirus-2 infection, despite treatment with different and overlapping anticoagulant medications. Patients with increased thrombogenicity due to an underlying disease might be at increased risk for thrombotic events during a severe acute respiratory syndrome coronavirus-2 infection.

Impact of thrombus surface on first pass reperfusion in contact aspiration and stent retriever thrombectomy

BACKGROUND

To assess whether thrombus surface morphology has an impact on first pass reperfusion in contact aspiration (CA) and stent retriever (SR) thrombectomy.

METHODS

From January 2016 to December 2018, consecutive stroke patients with an occlusion of the middle cerebral artery and thrombectomy (CA or SR) were examined in this retrospective study. We assessed patients' characteristics, procedural data and clinical outcome. Thrombus surface on pretreatment digital subtraction angiography (DSA) was categorized into regular versus irregular phenotype by blinded three-reader-consensus. Primary outcome was successful reperfusion (modified treatment in cerebral ischemia (mTICI) 2b-3) after first pass. Data analysis was stratified according to thrombectomy technique and thrombus phenotype.

RESULTS

Among 203 patients (76 years (IQR 65.5-81.9), 47.3% male, National Institutes of Health Stroke Scale Score 16 (IQR 12-20)), 155 patients were treated primarily with CA and 48 with SR. 40% (n=62/155) CA and 41.7% (n=20/48) SR-treated patients had a regular thrombus phenotype. In the CA group, successful reperfusion after first pass was more frequently obtained in patients with regular compared with irregular phenotype (69.4% (n=43/62) vs 34.4% (n=32/93); P<0.0001). In contrast, in the SR group, reperfusion after first pass was achieved in 35% (n=7/20; P=0.01) of patients with regular phenotypes. In the CA group, median number of passes (1 (1-2) vs 2 (1-4); P<0.00001) and time from reaching the thrombus to reperfusion (19±27 vs 38±36 min; P=0.0001) were lower among patients with a regular phenotype.

CONCLUSION

Direct CA is associated with higher rates of successful first pass reperfusion in patients with a regular thrombus phenotype in pretreatment DSA.

Cerebral Venous Drainage in Patients With Space-Occupying Middle Cerebral Artery Infarction: Effects on Functional Outcome After Hemicraniectomy

Background: Cerebral venous drainage might influence brain edema characteristics and functional outcome of patients with severe ischemic stroke. The purpose of the study was to evaluate whether hypoplasia of transverse sinuses or the internal jugular veins is associated with poor functional outcome in patients with space-occupying middle cerebral artery (MCA) infarction who underwent decompressive surgery. Methods: We performed a retrospective analysis of patients with space-occupying MCA infarction treated with decompressive surgery at our university hospital. The transverse sinuses and the internal jugular veins were evaluated on baseline images and categorized as normal, hypoplastic or occluded. We defined composite variables for ipsilateral, contralateral or any abnormal cerebral venous drainage. We assessed the functional outcome at 12 months with the modified Rankin scale (mRS) score and defined poor functional outcome as mRS scores 5 and 6. Results: We analyzed 88 patients with available baseline imaging data [mean [SD] patient age 53 (±9) years; median[IQR] time to decompressive surgery 31(22-51) h]. At 12 months 44 patients (50%) had a poor outcome. In univariate analysis neither ipsilateral (OR 1.98;95%CI: 0.75-5.40), nor contralateral (OR 1.56;95%CI: 0.59-4.24) or any (OR 1.6; 95%CI: 0.68-3.79) hypoplasia or occlusion of venous drainage were significantly associated with poor functional outcome. In multivariate analyses, higher patient age (OR 1.07;95%CI 1.01-1.14) and baseline stroke severity (OR 3.42;95%CI 1.31-9.40) were independent predictors of poor functional outcome, but not ipsilateral hypoplasia or occlusion of venous drainage (OR 1.31;95%CI 0.47-3.67). Conclusions: The cerebral venous drainage pattern was not significantly associated with poor functional outcome in our cohort of patients with space-occupying MCA infarction who underwent decompressive surgery.

Collateral state and the effect of endovascular reperfusion therapy on clinical outcome in ischemic stroke patients

PURPOSE

Clinically successful endovascular therapy (EVT) in ischemic stroke requires reliable noninvasive pretherapeutic selection criteria. We investigated the association of imaging parameters including CT angiographic collaterals and degree of reperfusion with clinical outcome after EVT.

METHODS

In our database, we identified 93 patients with large vessel occlusion in the anterior circulation treated with EVT. Besides clinical data, we assessed the baseline Alberta Stroke Program Early CT score (ASPECTS) on noncontrast CT (NCCT) and CT angiography (CTA) source images, collaterals (CT-CS) and clot burden score (CBS) on CTA and the degree of reperfusion after EVT on angiography. Three readers, blinded to clinical information, evaluated the images in consensus. Data-driven multivariable ordinal regression analysis identified predictors of good outcome after 90 days as measured with the modified Rankin Scale.

RESULTS

Successful angiographic reperfusion (OR 26.50; 95%-CI 9.33-83.61) and good collaterals (OR 9.69; 95%-CI 2.28-59.27) were independent predictors of favorable outcome along with female sex (OR 0.35; 95%-CI 0.14-0.85), younger age (OR 0.88; 95%-CI 0.83-0.92) and higher NCCT ASPECTS (OR 2.54; 95%-CI 1.01-6.63). Outcome was best in patients with good collaterals and successful reperfusion, but there was no statistical interaction between collaterals and reperfusion.

CONCLUSIONS

CTA-collateral status was the strongest pretherapeutic predictor of favorable outcome in ischemic stroke patients treated with EVT. CTA-collaterals are thus well suited for patient selection in EVT. However, the independent effect of reperfusion on outcome tended to be stronger than that of CTA-collaterals.

Scoring flow restoration in cerebral angiograms after endovascular revascularization in acute ischemic stroke patients

Endovascular revascularization techniques are increasingly used to treat arterial occlusions in patients with acute ischemic stroke. To monitor and communicate treatment results, a valid, reproducible, and clinically relevant, yet easy to use grading scheme of arterial recanalization and tissue reperfusion for digital subtraction angiography is needed. An ideal scoring system would consider the target arterial lesion, the perfusion deficit, and the collateral status before treatment and measure recanalization, reperfusion, early venous shunting, vasospasm, as well as distal embolization after flow restoration. Currently, a variety of different flow restoration scales are in use, including the Thrombolysis in Myocardial Infarction scoring system, the Thrombolysis in Cerebral Infarction score, and the Arterial Occlusive Lesion score, which describe the local recanalization result. These scores are not used homogeneously throughout the literature, are often modified and not fully documented, which make them inept to compare treatment effects across studies. In addition, none of these scores cover all of the above-mentioned aspects, nor are they able to describe satisfactorily all relevant angiographic findings, and data on their reliability and predictive power regarding clinical outcome are sparse. We aimed to review and illustrate the different revascularization scales, discuss their advantages and limitations as well as the available data regarding standardization, reliability testing, and outcome prediction. In addition, we give examples for the use of the scales and show potential pitfalls.

Reliability of brain CT evaluation by stroke neurologists in telemedicine

OBJECTIVE

To determine the reliability and therapeutic impact of standardized cerebral CT evaluation and quantification of early ischemic changes (EIC) with the Alberta Stroke Program Early CT Score (ASPECTS) by stroke neurologists in the Stroke Eastern Saxony Network (SOS-NET), which provides telemedical consultations for patients with acute ischemic stroke.

METHODS

Two neuroradiologists re-evaluated all CT scans of consecutive SOS-NET patients in 2009 blinded to clinical information providing reference standard. We defined discrepant CT findings as all false-positive or false-negative EIC and brain pathology findings and ASPECTS deviations >1 point. We subsequently discussed the clinical impact of discrepant CT findings unblinded to clinical information. Weighted kappa (κ(w)) statistic was used to determine the interobserver agreement for ASPECTS.

RESULTS

Of 582 patients, complete imaging data were available for 536 patients (351 cerebral ischemic events, 105 primary intracranial hemorrhages, and 80 stroke mimics). The neuroradiologists detected discrepant CT findings in 43 patients (8.0%) that were rated as clinically relevant in 9 patients (1.7%). Stroke neurologists recommended IV thrombolysis in 8 patients despite extensive EIC (ASPECTS ≤5). One of these patients had symptomatic intracranial hemorrhage. In 1 nonthrombolyzed patient, the stroke neurologist missed subdural hematoma. The interobserver agreement on ASPECTS between stroke neurologists and expert readers was substantial (κ(w) = 0.62; 95% confidence interval 0.54-0.71).

CONCLUSIONS

Clinically relevant misinterpretation of the CT scans was rare in our acute telestroke service. ASPECTS is a reliable tool to assess the extent of EIC by stroke neurologists in telemedicine in real time.

The functional neuroanatomy of odor evoked autobiographical memories cued by odors and words

Behavioral evidence indicates that odor evoked autobiographical memories (OEAMs) are older, more emotional, less thought of and induce stronger time traveling characteristics than autobiographical memories (AMs) evoked by other modalities. The main aim of this study was to explore the neural correlates of AMs evoked by odors as a function of retrieval cue. Participants were screened for specific OEAMs and later presented with the odor cue and its verbal referent in an fMRI paradigm. Because the same OEAM was retrieved across both cue formats (odor and word), potential cue dependent brain activations were investigated. The overall results showed that odor and word cued OEAMs activated regions typically associated with recollection of autobiographical information. Although no odors were presented, a verbal cuing of the OEAMs activated areas associated with olfactory perception (e.g., piriform cortex). However, relative to word cuing, an odor cuing of OEAMs resulted in more activity in MTL regions such as the parahippocampus, and areas involved in visual vividness (e.g., occipital gyrus and precuneus). Furthermore, odor cues activated areas related to emotional processing, such as limbic and tempopolar regions significantly more. In contrast, word cues relative to odor cues recruited a more widespread and bilateral prefrontal activity. Hippocampus activity did not vary as function of the remoteness of the memory, but recollection of OEAMs from the 1(st) vs the 2(nd) decade of life showed specific activation in the right OFC, whereas the 2(nd) reflected a higher activation in the left inferior frontal gyrus.

Correlation between olfactory bulb volume and olfactory function in children and adolescents

The olfactory bulb (OB) is considered to be the most important relay station in odor processing. The present study aimed to investigate the volumetric development of the human bulb and the olfactory function during childhood and youth. Furthermore, the present study aimed to investigate a possible correlation between OB volume and specific olfactory functions including odor threshold, odor discrimination and odor identification. A total of 87 subjects (46 boys, 41 girls), aged 1-17 years (mean age 8 years), participated in this study. None of them reported olfactory dysfunction or had signs of a dysfunctional sense of smell. Whenever possible, participants received a volumetric scan of the brain and lateralized olfactory tests. Volumetric measurements of the right and left OB were taken by manual segmentation of the coronal slices through the OB. Significant correlations between OB volumes and olfactory function were observed. Both, OB volumes and olfactory function increased with age, although the correlation between structure and function was not mediated by the subjects' age. In conclusion, for the first time, the present study showed a correlation between OB volume and olfactory functions in children.

Anatomy of the nasal cavity determines intranasal trigeminal sensitivity

BACKGROUND

Aim of this study was to investigate whether intranasal anatomy plays a role in intranasal trigeminal sensitivity.

MATERIAL AND METHODS

A total of 65 healthy subjects (30 female, 35 male) participated in this study (age range 18-35 years). Nasal cavities were assessed using magnetic resonance imaging (MRI). The area of the nasal cavity was measured in 5 coronal sections distributed across the length of the nasal cavity. Trigeminal function was assessed by determining thresholds for CO2, and responses to suprathreshold stimulation with CO2 and menthol (intensity ratings; event-related potentials). In addition, rhino-manometric measures were obtained.

RESULTS

A positive correlation was found between the size of the nasal cavity and trigeminal event-related potentials in response to suprathreshold CO2 and menthol stimuli. By contrast, no such correlations were found between nasal cavity size and CO2 thresholds. Results from rhino-manometry correlated only with the size of the nasal cavity in the nasal valve area.

CONCLUSIONS

These data suggest that, at least at a suprathreshold level, nasal anatomy plays a significant role in determining interindividual differences in the sensitivity to trigeminal stimuli.

Differential neural responses evoked by orthonasal versus retronasal odorant perception in humans

Odors perceived through the mouth (retronasally) as flavor are referred to the oral cavity, whereas odors perceived through the nose (orthonasally) are referred to the external world. We delivered vaporized odorants via the orthonasal and retronasal routes and measured brain response with fMRI. Comparison of retronasal versus orthonasal delivery produced preferential activity in the mouth area at the base of the central sulcus, possibly reflecting olfactory referral to the mouth, associated with retronasal olfaction. Routes of delivery produced differential activation in the insula/operculum, thalamus, hippocampus, amygdala, and caudolateral orbitofrontal cortex in orthonasal > retronasal and in the perigenual cingulate and medial orbitofrontal cortex in retronasal > orthonasal in response to chocolate, but not lavender, butanol, or farnesol, so that an interaction of route and odorant may be inferred. These findings demonstrate differential neural recruitment depending upon the route of odorant administration and suggest that its effect is influenced by whether an odorant represents a food.

Prevention and control of hypertension and diabetes in an underserved population through community outreach and disease management: a plan of action

Hypertension and diabetes are overrepresented in the African-American population and can be particularly devastating in this population. These diseases share genetic predisposition, medical risk factors, and environmental influences as etiologic factors, and they may be interrelated, at least in part, by obesity and accompanying hyperinsulinemia. Noncompliance with treatment plans is a significant barrier to health improvement in both diseases, but increased attention to patient involvement in care is a potential solution to this long-standing problem. The Baltimore Alliance for the Prevention and Control of Hypertension and Diabetes was established in January 1998 to promote care to the underserved community of West Baltimore, Maryland, and to improve outcomes of hypertension and diabetes. Based at the University of Maryland School of Medicine, the Baltimore Alliance comprises a community health worker program, a church-based education and screening effort, managed care and pharmaceutical company (Hoechst Marion Roussel) partners, a health policy and services research group, and inpatient/outpatient clinical care sites in the health system. Mobilization, cultural relevance, and partnership are employed to ensure that the Alliance's goals of increased patient enrollment and retention in treatment programs will be achieved. Thereby, improved outcomes--clinical, humanistic, and economic--will result. Novel as well as classic approaches to patient education, compliance, and goal achievement are being pursued. Complete expert systems for hypertension and diabetes disease management are being created and will be implemented in the near future. Baseline practices and current outcomes are being identified to act as historical controls. The organization and administration of the Alliance will serve as a prototype that others may follow.

Neuroleptic malignant syndrome. Patient with unique clinical and physiologic features

Lethargy, marked muscle weakness and rigidity, a maximal temperature of 40 degrees C, and a maximal creatine kinase value of 17,240 IU/liter developed in a 36-year-old woman following treatment with several neuroleptics. Initial treatment with dantrolene was unsuccessful. The patient's condition improved gradually over a 10-day period with no specific therapy. Muscle biopsy revealed a contracture pattern diagnostic of malignant hyperthermia susceptibility, as well as abnormal sensitivity to fluphenazine. This report may be the first description of a patient with neuroleptic malignant syndrome in whom muscle biopsy response similar to that seen in malignant hyperthermia occurred and documents that dantrolene is not uniformly successful therapy for this syndrome.

The effect of antidepressant drugs on regional cerebral glucose utilization in the rat

The 2-deoxyglucose (2-DG) technique is a potentially powerful method for assessing the effect of centrally acting drugs on local neuronal function in the brain. Since little is established on the effect of antidepressant drugs on local functional activity throughout the brain, we have employed this technique to study the effects of desmethylimipramine (DMI), a tricyclic antidepressant, and assessing the effect of centrally acting drugs on local neuronal function in the brain. Since little is established on the effect of antidepressant drugs on local functional activity throughout the brain, we have employed this technique to study the effects of desmethylimipramine (DMI), a tricyclic antidepressant, and assessing the effect of centrally acting drugs on local neuronal function in the brain. Since little is established on the effect of antidepressant drugs on local functional activity throughout the brain, we have employed this technique to study the effects of desmethylimipramine (DMI), a tricyclic antidepressant, and phenelzine, a monoamine oxidase inhibitor used clinically as an antidepressant, on local glucose utilization. The drugs were administered either as an acute dose, or repeatedly for 7 days, or chronically for 28 days. The local metabolic rate of glucose was determined in 30 regions of rat brain. Acute DMI increased glucose utilization in 11 regions whereas, in contrast, chronic DMI decreased glucose utilization in 7 regions of rat brain. Many of the areas affected are those of the telencephalon and diencephalon that receive prominent noradrenergic innervation. This is consistent with the notion that acute DMI treatment leads to enhanced and chronic DMI treatment leads to reduced noradrenergic functioning in the CNS. In contrast to these effects with DMI, phenelzine had little effects on glucose utilization either after acute or chronic dosing.

Levels of gamma-aminobutyric acid in cerebrospinal fluid in various neurologic disorders

Levels of gamma-aminobutyric acid (GABA) in CSF were measured by the ion exchange-fluorometric method in 136 patients who underwent evaluation for neurologic disorders. In 19 patients with no organic neurologic or mental disorders who acted as normal controls, the mean (+/-SD) GABA level in CSF was 239 +/- 76 picomoles/mL. Patients with acute hypoxic encephalopathy showed a mean GABA level in CSF higher than that of the controls, a difference that was statistically significant. In all the other disorders studied, the mean GABA level in CSF was either equal to or lower than that found in the controls. Statistically significant reductions of the GABA level in CSF were seen in patients with Huntington's disease, dementias, cerebellar cortical atrophy, multiple sclerosis, epilepsy, and Parkinson's disease.

Gamma-aminobutyric acid in peripheral tissue, with emphasis on the endocrine pancreas: presence in two species and reduction by streptozotocin

A screen of selected periphral organs of the rat found that gamma-aminobutyric acid (GABA) is generally present outside the central nervous system, and, of those organs examined, GABA was present at the highest concentration in the pancreas (approximately 40 pmol/mg wet wt). Furthermore, this putative inhibitory neurotransmitter was found to be present at even higher levels in islets of Langerhans tissue isolated from rat pancreas (190 pmol/mg). Administration of streptozotocin, a selective beta-cell toxin, decreased pancreatic GABA levels significantly, but had no or only small effects on the GABA content of other organs. Normal teleost (catfish) Brockmann body contains about the same level of GABA as normal rat islet tissue.

[Mandibular osteosynthesis according to the Michelet technic. II. Presentation of new material. Results]

The purpose of this communication is: - To report the conclusions of a critical study realized in collaboration with a group of engineers and concerning some presently obtainable osteosynthesis materials. - To ascertain mechanical characteristics required by screws and plates used for this type of surgery. - To relate a 4 years experience concerning 130 osteosynthesis (32 performed with a new material worked out according to biomechanical data).