Primary cCT Imaging Based Clinico-Neurological Assessment—Calling for Addition of Telestroke Video Consultation in Patients With Intracerebral Hemorrhage

Background and Purpose: Intracerebral hemorrhage (ICH) requires rapid decision making to decrease morbidity and mortality although time frame and optimal therapy are still ill defined. Ideally, specialized neurologists, neurosurgeons, and (neuro-) radiologists who know the patient's clinical status and their cerebral computed tomography imaging (cCT) make a joint decision on the clinical management. However, in telestroke networks, a shift toward cCT imaging criteria used for decisionmaking can be observed for practical reasons. Here we investigated the "reverse correlation" from cCT imaging to the actual clinical presentation as evaluated by the Glasgow Coma Scale (GCS) and the National Institutes of Health Stroke Scale (NIHSS). Methods: CCT images and basic information (age, sex, and time of onset) of 50 patients with hypertensive and lobar ICH were presented to 14 experienced neurologists and 15 neurosurgeons. Based on this information, the NIHSS and GCS scores were estimated for each patient. The differences between the actual GCS and NIHSS scores and the cCT-imaging-based estimated scores were plotted in a bland-Altman plot. Results: The average estimated GCS score mainly based on cCT imaging was 12. 4 +/- 2.8 (actual value: 13.0 +/- 2.5; p = 0.100), the estimated NIHSS score was 13.9 +/- 9.1 (actual value: 10.8 +/- 7.3; p < 0.001). Thus, in cCT-imaging-based evaluation, the neurological status of patients especially employing the NIHSS was estimated poorer, particularly in patients with lobar ICH. "Reverse clinical" evaluation based on cCT-imaging alone may increase the rate of intubation and secondary transferal and neurosurgical treatment. Telestroke networks should consider both, videoassessment of the actual clinical picture and cCT-imaging findings to make appropriate acute treatment decisions

Online measurement of microembolic signal burden by transcranial doppler during catheter ablation for atrial fibrillation - Results of a multicenter trial

Introduction: Left atrial pulmonary vein isolation (PVI) is an accepted treatment option for patients with symptomatic atrial fibrillation (AF). This procedure can be complicated by stroke or silent cerebral embolism. Online measurement of microembolic signals (MESs) by transcranial Doppler (TCD) may be useful for characterizing thromboembolic burden during PVI. In this prospective multicenter trial, we investigated the burden, characteristics, and composition of MES during left atrial catheter ablation using a variety of catheter technologies. Materials and methods: PVI was performed in a total of 42 patients using the circular-shaped multielectrode pulmonary vein ablation catheter (PVAC) technology in 23, an irrigated radiofrequency (IRF) in 14, and the cryoballoon (CB) technology in 5 patients. TCD was used to detect the total MES burden and sustained thromboembolic showers (TESs) of >30 s. During TES, the site of ablation within the left atrium was registered. MES composition was classified manually into solid, gaseous, or equivocal by off-line expert assessment. Results: The total MES burden was higher when using IRF compared to CB (2,336 +/- 1,654 vs. 593 +/- 231; p = 0.007) and showed a tendency toward a higher burden when using IRF compared to PVAC (2,336 +/- 1,654 vs. 1,685 +/- 2,255; p = 0.08). TES occurred more often when using PVAC compared to IRF (1.5 +/- 2 vs. 0.4 +/- 1.3; p = 0.04) and most frequently when ablation was performed close to the left superior pulmonary vein (LSPV). Of the MES, 17.004 (23%) were characterized as definitely solid, 13.204 (18%) as clearly gaseous, and 44.366 (59%) as equivocal. Discussion: We investigated the burden and characteristics of MES during left atrial catheter ablation for AF. All ablation techniques applied in this study generated a relevant number of MES. There was a significant difference in total MES burden using IRF compared to CB and a tendency toward a higher burden using IRF compared to PVAC. The highest TES burden was found in the PVAC group, particularly during ablation close to the LSPV. The composition of thromboembolic particles was balanced. The impact of MES, TES, and composition of thromboembolic particles on neurological outcome needs to be evaluated further

Interdisciplinary Decision Making in Hemorrhagic Stroke Based on CT Imaging—Differences Between Neurologists and Neurosurgeons Regarding Estimation of Patients' Symptoms, Glasgow Coma Scale, and National Institutes of Health Stroke Scale

Background and Purpose: Acute intracerebral hemorrhage (ICH) requires rapid decision making toward neurosurgery or conservative neurological stroke unit treatment. In a previous study, we found overestimation of clinical symptoms when clinicians rely mainly on cerebral computed tomography (cCT) analysis. The current study investigates differences between neurologists and neurosurgeons estimating specific scores and clinical symptoms. Methods: Overall, 14 neurologists and 15 neurosurgeons provided clinical estimates and National Institutes of Health Stroke Scale (NIHSS) as well as Glasgow Coma Scale (GCS) based on cCT images and basic information of 50 patients with hypertensive and lobar ICH. Subgroup analyses were performed for the different professions (neurologists vs. neurosurgeons) and bleeding subtypes (typical location vs. atypical). The differences between the actual GCS and NIHSS scores and the cCT-imaging-based estimated scores were depicted as Bland-Altman plots and negative and positive predictive value (NPV and PPV) for prediction of clinical relevant items. Delta NIHSS points (Delta GCS points) were calculated as the difference between actual and rated NIHSS (GCS) including 95% confidence interval (CI). Results: Mean Delta GCS points for neurosurgeons was 1.16 (95% CI: -2.67-4.98); for neurologists, 0.99 (95% CI: -2.58-4.55), p = 0.308; mean Delta NIHSS points for neurosurgeons was -2.95 (95% CI: -12.71-6.82); for neurologists, -0.33 (95% CI: -9.60-8.94), p < 0.001. NPV and PPV for stroke symptoms were low, with large differences between different symptoms, bleeding subtypes, and professions. Both professions had more problems in proper rating of specific clinic-neurological symptoms than rating scores. Conclusion: Our results stress the need for joint decision making based on detailed neurological examination and neuroimaging findings also in telemedicine

Veränderungen der Blut-Hirn-Schranke nach experimenteller Hypoxie -3T-MRT-Studie über Ödementwicklung und Kontrastmittelübertritt im zeitlichen Verlauf

In dieser Arbeit wird das bi-phasische Muster der Blut-Hirn–Schranke (BHS) Permeabilität für Gd-DTPA-KM nach experimenteller reversibler zerebraler Ischämie bei Ratten durch serielle MRT untersucht und in Beziehung zum parallel gemessenen sich entwickelnden Hirnödem gesetzt. Mittels T1- gewichteten Sequenzen vor und nach Gabe von Kontrastmittel wurde die Permeabilitätsstörung der BHS dargestellt. Diese Sequenzen wurden an den letzten 3 Zeitpunkten durchgeführt. Die Ödementwicklung wurde mittels T2- gewichteten Sequenzen, wie auch T2- Relaxometrie dargestellt. Diese wurden 1 Stunde nach Ischämie, direkt und am 4, 24 und 48 Stunden nach Reperfusion aqueriert. Wir konnten eine starke Ödementwicklung mit Maximum bei 24 Stunden und darüber hinaus eine Größenabnahme des Ödems als Hinweis für die Resorption des Ödems im Verlauf zeigen, die insbesondere in den späteren Phasen nach Ischämie und Reperfusion nicht mit dem Maß der Blut-Hirn-Schrankenöffnung korrelierten. Die Entwicklung des Ödems mit peak nach 24h korrelierte nicht mit den Maxima der BHS-Öffnung nach 4h und 48h Reperfusion. Darüber hinaus zeigten sich Hinweise für Ödembildung auf der kontralateralen, nicht-ischämischen Hemisphäre, die auf systemische Effekte des Schlaganfalls hindeuten. Die Therapie nach einem ischämischen Schlaganfall als Ziel Reduktion der vasogenen Ödem oder Neuroprotektion kann sich an der Momentanen BHS Permeabilität Status richten. Die Ergebnisse sollen an Menschen überprüft werden

Neuromonitoring Using Neurosonography and Pupillometry in A Weaning and Early Neurorehabilitation Unit.

BACKGROUND AND PURPOSE Long-term surveillance of intracranial pressure (ICP) in neurological/neurosurgical patients during ventilator weaning and early neurorehabilitation currently relies on clinical observation because neuroimaging is rarely readily available. In this prospective study, multimodal neurosonography and pupillometry are evaluated for follow-up monitoring. METHODS Sonographic neuromonitoring was used to noninvasively examine patients' ICP during weaning and early neurorehabilitation. It allowed assessments of third ventricle width, possible midline shift, middle cerebral artery flow velocities, and bilateral optic nerve sheath diameters. Quantitative pupillometry was used to determine pupil size and reactivity. Other neuroimaging findings, spinal tap ICP measurements, and clinical follow-up data served as controls. RESULTS Seventeen patients-11 suffering from intracranial hemorrhage, four from encephalopathies, and two from ischemic stroke-were examined for ICP changes by using neurosonography and pupillometry during a mean observation period of 21 days. In total, 354 of 980 analyses (36.1%) yielded pathological results. In 15 of 17 patients (88.2%), pathological values were found during follow-up without a clear clinical correlate. In two patients (11.8%), clinically relevant changes in ICP occurred and were identified using neurosonography. Abnormal pupillometry findings displayed a high predictive value for absent clinical improvement. CONCLUSION Multimodal neurosonography may be a noninvasive means for long-term ICP assessment, whereas pupillometry may only detect rapid ICP changes during acute neurointensive care. The study also illustrates common pitfalls in neuromonitoring in general, with large numbers of pathological albeit nonsignificant findings. Additional controlled studies should validate the influence of detected subtle changes in ICP on neurological outcome

Longitudinal Diffusion Tensor Imaging-Based Assessment of Tract Alterations: An Application to Amyotrophic Lateral Sclerosis

Objective: The potential of magnetic resonance imaging (MRI) as a technical biomarker for cerebral microstructural alterations in neurodegenerative diseases is under investigation. In this study, a framework for the longitudinal analysis of diffusion tensor imaging (DTI)-based mapping was applied to the assessment of predefined white matter tracts in amyotrophic lateral sclerosis (ALS), as an example for a rapid progressive neurodegenerative disease.Methods: DTI was performed every 3 months in six patients with ALS (mean (M) = 7.7; range 3 to 15 scans) and in six controls (M = 3; range 2–5 scans) with the identical scanning protocol, resulting in a total of 65 longitudinal DTI datasets. Fractional anisotropy (FA), mean diffusivity (MD), axonal diffusivity (AD), radial diffusivity (RD), and the ratio AD/RD were studied to analyze alterations within the corticospinal tract (CST) which is a prominently affected tract structure in ALS and the tract correlating with Braak’s neuropathological stage 1. A correlation analysis was performed between progression rates based on DTI metrics and the revised ALS functional rating scale (ALS-FRS-R).Results: Patients with ALS showed an FA and AD/RD decline along the CST, while DTI metrics of controls did not change in longitudinal DTI scans. The FA and AD/RD decrease progression correlated significantly with ALS-FRS-R decrease progression.Conclusion: On the basis of the longitudinal assessment, DTI-based metrics can be considered as a possible noninvasive follow-up marker for disease progression in neurodegeneration. This finding was demonstrated here for ALS as a fast progressing neurodegenerative disease

A mobile battery-powered brain perfusion ultrasound (BPU) device designed for prehospital stroke diagnosis: correlation to perfusion MRI in healthy volunteers.

BACKGROUND: Early prehospital stroke identification is crucial for goal directed hospital admission especially in rural areas. However, clinical prehospital stroke scales are designed to identify any stroke but cannot sufficiently differentiate hemorrhagic from ischemic stroke, including large vessel occlusion (LVO) amenable to mechanical thrombectomy. We report on a novel small, portable and battery driven point-of-care ultrasound system (SONAS®) specifically developed for mobile non-invasive brain perfusion ultrasound (BPU) measurement after bolus injection of an echo-enhancing agent suitable for the use in prehospital stroke diagnosis filling a current, unmet and critical need for LVO identification. METHODS: In a phase I study of healthy volunteers we performed comparative perfusion-weighted magnetic resonance imaging (PWI) and BPU measurements, including safety analysis. RESULTS: Twelve volunteers (n = 7 females, n = 5 males, age ranging between 19 and 55&nbsp;years) tolerated the measurement extremely well including analysis of blood-brain barrier integrity, and the correlation coefficient between the generated time kinetic curves after contrast agent bolus between PWI and BPU transducers ranged between 0.89 and 0.76. CONCLUSIONS: Mobile BPU using the SONAS® device is feasible and safe with results comparable to PWI. When applied in conjunction with prehospital stroke scales this may lead to a more accurate stroke diagnosis and patients bypassing regular stroke units to comprehensive stroke centers. Further studies are needed in acute stroke patients and in the prehospital phase including assessment of immediate and long-term morbidity and mortality in stroke. TRIAL REGISTRATION: Clinical trials.gov, registered 28.Sep.2017, Identifier: NCT03296852

Cerebral ischemia-reperfusion injury in rats : A 3T MRI study on biphasic blood-brain barrier opening and the dynamics of edema formation

Serial magnetic resonance imaging (MRI) was performed to investigate the temporal and spatial relationship between the biphasic nature of blood-brain barrier (BBB) opening and in parallel, edema formation following ischemia-reperfusion (I/R) injury in rats. T(2)-weighted imaging combined with T(2)-relaxometry mainly for edema assessment was performed at 1 hour post-ischemia, following reperfusion, and at 4, 24, and 48 hours post-reperfusion. T(1)-weighted imaging was performed pre/post-gadolinium contrast at the last three time points to assess BBB integrity. The biphasic course of BBB opening with significant reduction in BBB permeability at 24 hours post-reperfusion associated with progressive expansion of leaky BBB volume was accompanied by a peak ipsilateral edema formation. In addition, at 4 hours post-reperfusion, edema formation could also be detected at the contralateral striatum as determined by the elevated T(2) values that persisted to varying degrees indicative of widespread effects of I/R injury. The observations of this study may indicate a dynamic temporal shift in mechanisms responsible for bi-phasic BBB permeability changes with complex relations to edema formation. Stroke therapy aimed at vasogenic edema and drug delivery for neuroprotection may also be guided according to the functional status of the BBB and these findings should be confirmed in human stroke

Value of fluid‐attenuated inversion recovery MRI data analyzed by the lesion segmentation toolbox in amyotrophic lateral sclerosis

Background MRI fluid-attenuated inversion recovery (FLAIR) studies reported hyperintensity in the corticospinal tract and corpus callosum of patients with amyotrophic lateral sclerosis (ALS). Purpose To evaluate the lesion segmentation toolbox (LST) for the objective quantification of FLAIR lesions in ALS patients. Study Type Retrospective. Population Twenty-eight ALS patients (eight females, mean age: 50 range: 24-73, mean ALSFRS-R sum score: 36) were compared with 31 age-matched healthy controls (12 females, mean age: 45, range: 25-67). ALS patients were treated with riluzole and additional G-CSF (granulocyte-colony stimulating factor) on a named patient basis. Field Strength/Sequence 1.5 T, FLAIR, T-1-weighted MRI. Assessment The lesion prediction algorithm (LPA) of the LST enabled the extraction of individual binary lesion maps, total lesion volume (TLV), and number (TLN). Location and overlap of FLAIR lesions across patients were investigated by registration to FLAIR average space and an atlas. ALS-specific functional rating scale revised (ALSFRS-R), disease progression, and survival since diagnosis served as clinical correlates. Statistical Tests Univariate analysis of variance (ANOVA), repeated-measures ANOVA, t-test, Bravais-Pearson correlation, Chi-square test of independence, Kaplan-Meier analysis, Cox-regression analysis. Results Both ALS patients and healthy controls exhibited FLAIR alterations. TLN significantly depended on age (F(1,54) = 24.659, P < 0.001) and sex (F(1,54) = 5.720, P = 0.020). ALS patients showed higher TLN than healthy controls depending on sex (F(1, 54) = 5.076, P = 0.028). FLAIR lesions were small and most pronounced in male ALS patients. FLAIR alterations were predominantly detected in the superior and posterior corona radiata, anterior capsula interna, and posterior thalamic radiation. Patients with pyramidal tract (PT) lesions exhibited significantly inferior survival than patients without PT lesions (P = 0.013). Covariate age exhibited strong prognostic value for survival (P = 0.015). Data Conclusion LST enables the objective quantification of FLAIR alterations and is a potential prognostic biomarker for ALS. Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;50:552-559