Thrombolysis in brain ischemia (TIBI) transcranial Doppler flow grades predict clinical severity, early recovery, and mortality in patients treated with intravenous tissue plasminogen activator

Validation of the transcranial Doppler rescue criteria for mechanical thrombectomy

BACKGROUND AND PURPOSE

Transcranial Doppler (TCD) identifies acute stroke patients with arterial occlusion where treatment may not effectively open the blocked vessel. This study aimed to examine the clinical utility and prognostic value of TCD flow findings in patients enrolled in a multicenter prospective study (CLOTBUST-PRO).

METHODS

Patients enrolled with intracranial occlusion on computed tomography angiography (CTA) who underwent urgent TCD evaluation before intravenous thrombolysis was included in this analysis. TCD findings were assessed using the mean flow velocity (MFV) ratio, comparing the reciprocal ratios of the middle cerebral artery (MCA) depths bilaterally (affected MCA-to-contralateral MCA MFV [aMCA/cMCA MFV ratio]).

RESULTS

A total of 222 patients with intracranial occlusion on CTA were included in the study (mean age: 64 ± 14 years, 62% men). Eighty-eight patients had M1 MCA occlusions; baseline mean National Institutes of Health Stroke Scale (NIHSS) score was 16, and a 24-hour mean NIHSS score was 10 points. An aMCA/cMCA MFV ratio of <.6 had a sensitivity of 99%, specificity of 16%, positive predictive value (PV) of 60%, and negative PV of 94% for identifying large vessel occlusion (LVO) including M1 MCA, terminal internal carotid artery, or tandem ICA/MCA. Thrombolysis in Brain Ischemia scale, with (grade ≥1) compared to without flow (grade 0), showed a sensitivity of 17.1%, specificity of 86.9%, positive PV of 62%, and negative PV of 46% for identifying LVO.

CONCLUSIONS

TCD is a valuable modality for evaluating arterial circulation in acute ischemic stroke patients, demonstrating significant potential as a screening tool for intravenous/intra-arterial lysis protocols.

Neurophysiologic Features Reflecting Brain Injury During Pediatric ECMO Support

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) provides lifesaving support to critically ill patients who experience refractory cardiopulmonary failure but carries a high risk for acute brain injury. We aimed to identify characteristics reflecting acute brain injury in children requiring ECMO support.

METHODS

This is a prospective observational study from 2019 to 2022 of pediatric ECMO patients undergoing neuromonitoring, including continuous electroencephalography, cerebral oximetry, and transcranial Doppler ultrasound (TCD). The primary outcome was acute brain injury. Clinical and neuromonitoring characteristics were collected. Multivariate logistic regression was implemented to model odds ratios (ORs) and identify the combined characteristics that best discriminate risk of acute brain injury using the area under the receiver operating characteristic curve.

RESULTS

Seventy-five pediatric patients requiring ECMO support were enrolled in this study, and 62 underwent neuroimaging or autopsy evaluations. Of these 62 patients, 19 experienced acute brain injury (30.6%), including seven (36.8%) with arterial ischemic stroke, four (21.1%) with hemorrhagic stroke, seven with hypoxic-ischemic brain injury (36.8%), and one (5.3%) with both arterial ischemic stroke and hypoxic-ischemic brain injury. A univariate analysis demonstrated acute brain injury to be associated with maximum hourly seizure burden (p = 0.021), electroencephalographic suppression percentage (p = 0.022), increased interhemispheric differences in electroencephalographic total power (p = 0.023) and amplitude (p = 0.017), and increased differences in TCD Thrombolysis in Brain Ischemia (TIBI) scores between bilateral middle cerebral arteries (p = 0.023). Best subset model selection identified increased seizure burden (OR = 2.07, partial R2 = 0.48, p = 0.013), increased quantitative electroencephalographic interhemispheric amplitude differences (OR = 2.41, partial R2 = 0.48, p = 0.013), and increased interhemispheric TCD TIBI score differences (OR = 4.66, partial R2 = 0.49, p = 0.006) to be independently associated with acute brain injury (area under the receiver operating characteristic curve = 0.92).

CONCLUSIONS

Increased seizure burden and increased interhemispheric differences in both quantitative electroencephalographic amplitude and TCD MCA TIBI scores are independently associated with acute brain injury in children undergoing ECMO support.

Clinical applications of ultrasound in neurosurgery and neurocritical care: A narrative review

Ultrasonography (USG) has become an invaluable tool in the assessment of neurocritical patients in the operating theaters and critical care units. Due to its easy availability, reliability, safety, and repeatability, neuro-intensivists and neuro-anesthesiologists utilize USG to make a diagnosis, assess prognosis, and decide upon treatment. In neurocritical care units, USG has myriad indications for use, both systemic and neurologic. The neurological indications include the assessment of stroke, vasospasm, traumatic brain injury, brain death, acute brain damage, optic nerve sheath diameter, and pupillary reflexes to name a few. The systemic indications range from assessment of cardio-pulmonary function and intravascular volume status to detection of deep venous thromboses, vocal cord assessment in intubated patients, placement of central venous catheters, and percutaneous tracheostomy. In this narrative review, we iterate the clinical applications of USG in neuroanesthesia and neurocritical care, which we penned after searching relevant databases in PubMed, Medline, Ovid, and Google Scholar by using terms such as ‘applications of transcranial Doppler’, ‘optic nerve sheath diameter’, ‘USG applications in the critical care unit’, and so on. Our search database includes several research papers, neurocritical care books, review articles, and scientific databases. This article reviews various applications of USG in neuroanesthesia, neurosurgery, and neurocritical care.

Role of Advanced Hemodynamic Ultrasound Evaluation in the Differential Diagnosis of Middle Cerebral Artery Stenosis: Introducing Morphological Criteria

OBJECTIVE

The aim of the work described here was to determine the possible impact of the new technique advanced hemodynamic ultrasound evaluation (AHUSE) in identification of severe intracranial stenosis. Transcranial Doppler (TCD) and transcranial color-coded Doppler (TCCD) provide reliable velocimetric data, the indirect analysis of which allows us to obtain information on the patency of vessels and assumed stenosis range. However, very tight stenoses (>95%) cannot be detected with velocimetric criteria because of spectrum drops and the absence of high velocities, so that the right curve of the Spencer equation cannot be solved. Likewise, high velocities are not detected when analyzing morphologically long stenosis. Furthermore, the current classifications based on velocimetric criteria do not provide any categorization on stenoses with multiple acceleration points (MAPs).

METHODS

With this Technical Note we aim to introduce, in addition to velocimetric criteria, more morphological criteria based on TCCD with the algorithm of AHUSE to optimize the characterization of intracranial stenosis (IS). TCCD-AHUSE relies on intensity-based next-generation techniques and can be used to identify IS with MAPs and simultaneously perform a morphological assessment of the stenosis length.

RESULTS

We introduce a new technical ultrasound (U) approach that we tested in a sample of four different types of stenoses combining velocimetric data and AHUSE using Esaote Microvascularization (MicroV) technique to the M1 tract of the middle cerebral artery (MCA).

CONCLUSION

The authors believe that a multiparametric evaluation is more sensitive and supports the clinician by introducing the morphological concept, not just the velocimetric concept, to differentiate the IS pattern of MCA. The potential for developing a diagnostic/prognostic algorithm is discussed.

Post-reperfusion hyperperfusion after endovascular stroke treatment: a prospective comparative study of TCD versus MRI

BACKGROUND

Increased middle cerebral artery (MCA) blood flow velocities on transcranial duplex sonography (TCD) were recently reported in individual patients after successful mechanical thrombectomy (MT) and were related to intracranial hemorrhage and poor outcome. However, the retrospective study design of prior studies precluded elucidation of the underlying pathomechanisms, and the relationship between TCD and brain parenchymal perfusion still remains to be determined.

METHODS

We prospectively investigated consecutive patients with stroke successfully recanalized by MT with TCD and MRI including contrast-enhanced perfusion sequences within 48 hours post-intervention. Increased MCA flow on TCD was defined as >30% mean blood flow velocity in the treated MCA compared with the contralateral MCA. MRI blood flow maps served to assess hyperperfusion rated by neuroradiologists blinded to TCD.

RESULTS

A total of 226 patients recanalized by MT underwent post-interventional TCD and 92 patients additionally had perfusion MRI. 85 patients (38%) had increased post-interventional MCA flow on TCD. Of these, 10 patients (12%) had an underlying focal stenosis. Increased TCD blood flow in the recanalized MCA was associated with larger infarct size, vasogenic edema, intracranial hemorrhage and poor 90-day outcome (all p≤0.005). In the subgroup for which both TCD and perfusion MRI were available, 29 patients (31%) had increased ipsilateral MCA flow velocities on TCD. Of these, 25 patients also showed parenchymal hyperperfusion on MRI (sensitivity 85%; specificity 62%). Hyperperfusion severity on MRI correlated with MCA flow velocities on TCD (rs=0.379, p<0.001).

CONCLUSIONS

TCD is a reliable bedside tool to identify post-reperfusion hyperperfusion, correlates well with perfusion MRI, and indicates risk of reperfusion injury after MT.

Assessment of cerebral blood flow velocities, brain midline shift and optic nerve sheath diameter by ultrasound in patients undergoing elective craniotomy: A prospective observational feasibility study

BACKGROUND

Brain ultrasound allows measuring the cerebral flow velocity, brain midline shift and optic nerve sheath diameter. Literature is scarce in determining the feasibility to perioperatively perform these measurements altogether and the cerebrovascular behavior in patients scheduled for elective craniotomy.

METHODS

We assessed bilateral cerebral flow velocities, composite index, brain midline shift and optic nerve sheath diameter by cerebral ultrasound in patients scheduled for elective craniotomy before anesthetic induction, at extubation, and at 6 and 24 h after. The aim was to assess the feasibility of brain ultrasound in patients for elective craniotomy and to describe the changes in cerebral flow velocities, brain midline shift and optic nerve sheath diameter from baseline values at different times in the postoperative period.

RESULTS

Sixteen patients were included, of these two were excluded from analysis due to an inadequate sonographic window. There were no changes throughout the study regarding cerebral flow velocity, brain midline shift nor optic nerve sheath diameter assessments. All parameters were maintained in the physiological range without significant variations during the procedure. No perioperative complications were detected.

CONCLUSIONS

The results of our study show the feasibility to perform a perioperative assessment of cerebral flow velocity, brain midline shift or optic nerve sheath diameter jointly and successfully to obtain additional information of baseline cerebral hemodynamics in patients scheduled for elective craniotomy and their postoperative changes during the first 24 h. Future studies with lager samples are needed to address the efficacy of cerebral ultrasound as a monitoring tool.

Neuromonitoring in Children with Cerebrovascular Disorders

BACKGROUND

Cerebrovascular disorders are an important cause of morbidity and mortality in children. The acute care of a child with an ischemic or hemorrhagic stroke or cerebral sinus venous thrombosis focuses on stabilizing the patient, determining the cause of the insult, and preventing secondary injury. Here, we review the use of both invasive and noninvasive neuromonitoring modalities in the care of pediatric patients with arterial ischemic stroke, nontraumatic intracranial hemorrhage, and cerebral sinus venous thrombosis.

METHODS

Narrative review of the literature on neuromonitoring in children with cerebrovascular disorders.

RESULTS

Neuroimaging, near-infrared spectroscopy, transcranial Doppler ultrasonography, continuous and quantitative electroencephalography, invasive intracranial pressure monitoring, and multimodal neuromonitoring may augment the acute care of children with cerebrovascular disorders. Neuromonitoring can play an essential role in the early identification of evolving injury in the aftermath of arterial ischemic stroke, intracranial hemorrhage, or sinus venous thrombosis, including recurrent infarction or infarct expansion, new or recurrent hemorrhage, vasospasm and delayed cerebral ischemia, status epilepticus, and intracranial hypertension, among others, and this, is turn, can facilitate real-time adjustments to treatment plans.

CONCLUSIONS

Our understanding of pediatric cerebrovascular disorders has increased dramatically over the past several years, in part due to advances in the neuromonitoring modalities that allow us to better understand these conditions. We are now poised, as a field, to take advantage of advances in neuromonitoring capabilities to determine how best to manage and treat acute cerebrovascular disorders in children.

Diagnostic Ultrasonography in Neurology

OBJECTIVE

Ultrasonography allows neurologists to complement clinical information with additional useful, easily acquired, real-time data. This article highlights its clinical applications in neurology.

LATEST DEVELOPMENTS

Diagnostic ultrasonography is expanding its applications with smaller and better devices. Most indications in neurology relate to cerebrovascular evaluations. Ultrasonography contributes to the etiologic evaluation and is helpful for hemodynamic diagnosis of brain or eye ischemia. It can accurately characterize cervical vascular atherosclerosis, dissection, vasculitis, or other rarer disorders. Ultrasonography can aid in the diagnosis of intracranial large vessel stenosis or occlusion and evaluation of collateral pathways and indirect hemodynamic signs of more proximal and distal pathology. Transcranial Doppler (TCD) is the most sensitive method for detecting paradoxical emboli from a systemic right-left shunt such as a patent foramen ovale. TCD is mandatory for sickle cell disease surveillance, guiding the timing for preventive transfusion. In subarachnoid hemorrhage, TCD is useful in monitoring vasospasm and adapting treatment. Some arteriovenous shunts can be detected by ultrasonography. Cerebral vasoregulation studies are another developing field of interest. TCD enables monitoring of hemodynamic changes related to intracranial hypertension and can diagnose cerebral circulatory arrest. Optic nerve sheath measurement and brain midline deviation are ultrasonography-detectable signs of intracranial hypertension. Most importantly, ultrasonography allows for easily repeated monitoring of evolving clinical conditions or during and after interventions.

ESSENTIAL POINTS

Diagnostic ultrasonography is an invaluable tool in neurology, used as an extension of the clinical examination. It helps diagnose and monitor many conditions, allowing for more data-driven and rapid treatment interventions.

Local cerebral blood flow assessment using transcranial Doppler ultrasonography in a dog with brain infarction in the right middle cerebral artery territory

A 12-year-old neutered male Chihuahua was diagnosed with acute brain infarction in the right middle cerebral artery (MCA) territory. Transcranial Doppler ultrasonography (TCD) was performed to assess the local cerebral blood flow at the time of diagnosis and after 4 and 31 hr. Initially, the right MCA retained blood flow but with a lower cerebral blood flow velocity (CBFV; 14.9 cm/sec) than the left MCA (27.9 cm/sec). The TCD vascular resistance variables were higher in the right than in the left MCA. An increase in the CBFV and a decrease in TCD vascular resistance variables were observed, consistent with improvements in neurological symptoms. TCD can be a non-invasive, and easy-to-use modality for bedside monitoring of cerebral edema and infarction.

Mechanisms of Transcranial Doppler Ultrasound phenotypes in paediatric cerebral malaria remain elusive

Background

Cerebral malaria (CM) results in significant paediatric death and neurodisability in sub-Saharan Africa. Several different alterations to typical Transcranial Doppler Ultrasound (TCD) flow velocities and waveforms in CM have been described, but mechanistic contributors to these abnormalities are unknown. If identified, targeted, TCD-guided adjunctive therapy in CM may improve outcomes.

Methods

This was a prospective, observational study of children 6 months to 12 years with CM in Blantyre, Malawi recruited between January 2018 and June 2021. Medical history, physical examination, laboratory analysis, electroencephalogram, and magnetic resonance imaging were undertaken on presentation. Admission TCD results determined phenotypic grouping following a priori definitions. Evaluation of the relationship between haemodynamic, metabolic, or intracranial perturbations that lead to these observed phenotypes in other diseases was undertaken. Neurological outcomes at hospital discharge were evaluated using the Paediatric Cerebral Performance Categorization (PCPC) score.

Results

One hundred seventy-four patients were enrolled. Seven (4%) had a normal TCD examination, 57 (33%) met criteria for hyperaemia, 50 (29%) for low flow, 14 (8%) for microvascular obstruction, 11 (6%) for vasospasm, and 35 (20%) for isolated posterior circulation high flow. A lower cardiac index (CI) and higher systemic vascular resistive index (SVRI) were present in those with low flow than other groups (p < 0.003), though these values are normal for age (CI 4.4 [3.7,5] l/min/m2, SVRI 1552 [1197,1961] dscm-5m2). Other parameters were largely not significantly different between phenotypes. Overall, 118 children (68%) had a good neurological outcome. Twenty-three (13%) died, and 33 (19%) had neurological deficits. Outcomes were best for participants with hyperaemia and isolated posterior high flow (PCPC 1–2 in 77 and 89% respectively). Participants with low flow had the least likelihood of a good outcome (PCPC 1–2 in 42%) (p < 0.001). Cerebral autoregulation was significantly better in children with good outcome (transient hyperemic response ratio (THRR) 1.12 [1.04,1.2]) compared to a poor outcome (THRR 1.05 [0.98,1.02], p = 0.05).

Conclusions

Common pathophysiological mechanisms leading to TCD phenotypes in non-malarial illness are not causative in children with CM. Alternative mechanistic contributors, including mechanical factors of the cerebrovasculature and biologically active regulators of vascular tone should be explored.

Transcranial color Doppler sonography as an alternative tool for evaluation of terminal internal carotid artery steno-occlusion in moyamoya disease

OBJECTIVE

To investigate color Doppler ultrasonography criteria and its value in assessing the steno-occlusion of the terminal internal carotid artery in moyamoya disease.

METHODS

According to the digital subtraction angiography findings, patients were divided into three groups: occlusion of the terminal internal carotid artery, >50% stenosis, and ≤50% stenosis. We measured the terminal and proximal internal carotid artery parameters of each group using transcranial and cervical color Doppler sonography.

RESULTS

Blood flow signals in 12 terminal internal carotid arteries were absent, which were verified as occlusion by digital subtraction angiography. Parameters were obtained in the remaining 159 terminal/proximal internal carotid arteries to predict cutoffs for >50% stenosis and occlusion. For >50% stenosis, mean flow velocity >88.50 cm/s in the terminal internal carotid artery could achieved the highest receiver operating characteristic curve area of 0.776 with 62.50% sensitivity, 88.15% specificity, 48.39% positive predictive values, 92.97% negative predictive value, and 84.27% overall accuracy. For the occlusion, mean flow velocity <49.50 cm/s in the terminal internal carotid artery achieve the highest receiver operating characteristic curve area of 0.734 with 55.56% sensitivity, 83.81% specificity, 63.83% positive predictive values, 78.57% negative predictive value, and 74.21% overall accuracy. The area under receiver operating characteristic curve cutoffs for other parameters were less than 0.7.

CONCLUSION

Mean flow velocity of terminal internal carotid artery provides useful diagnostic information for detecting steno-occlusion in moyamoya disease. It may be used as an alternative tool to evaluate steno-occlusion of the terminal internal carotid artery in moyamoya disease.

Multimodal Monitoring in Large Hemispheric Infarction: Quantitative Electroencephalography Combined With Transcranial Doppler for Prognosis Prediction

Background: We aimed to explore whether transcranial Doppler (TCD) combined with quantitative electroencephalography (QEEG) can improve prognosis evaluation in patients with a large hemispheric infarction (LHI) and to establish an accurate prognosis prediction model.

Methods: We prospectively assessed 90-day mortality in patients with LHI. Brain function was monitored using TCD-QEEG at the bedside of the patient.

Results: Of the 59 (55.3 ± 10.6 years; 17 men) enrolled patients, 37 (67.3%) patients died within 90 days. The Cox regression analyses revealed that the Glasgow Coma Scale (GCS) score ≤ 8 [hazard ratio (HR), 3.228; 95% CI, 1.335–7.801; p = 0.009], TCD-terminal internal carotid artery as the offending vessel (HR, 3.830; 95% CI, 1.301–11.271; p = 0.015), and QEEG-a (delta + theta)/(alpha + beta) ratio ≥ 3 (HR, 3.647; 95% CI, 1.170–11.373; p = 0.026) independently predicted survival duration. Combining these three factors yielded an area under the receiver operating characteristic curve of 0.905 and had better predictive accuracy than those of individual variables (p < 0.05).

Conclusion: TCD and QEEG complement the GCS score to create a reliable multimodal method for monitoring prognosis in patients with LHI.

A Prospective Study to Investigate Controlling Blood Pressure Under Transcranial Doppler After Endovascular Treatment in Patients With Occlusion of Anterior Circulation

Objective: The objective of this study was to evaluate the effect of blood pressure (BP) management with transcranial Doppler (TCD) guidance in patients with large-vessel occlusion in the anterior circulation after endovascular thrombectomy (EVT) on the long-term prognosis.

Methods: This was a prospective study; 232 patients were nonrandomized assigned to TCD-guided BP management (TBM) group or non-TCD-guided BP management (NBM) group. In the TBM group, BP was controlled according to TCD showing cerebral blood flow fluctuation. In the NBM group, BP was controlled according to the guidelines. The primary endpoint was a modified Rankin scale (mRS) score of 2 or lower at 90 days. The safety outcomes were the rates of symptomatic or any intracerebral hemorrhage (ICH) and mortality at 90 days.

Results: One hundred sixty-three patients were assigned to the TBM group, and 69 were assigned to the NBM group. In the propensity score-matched cohort (65 matches in both groups), there was significant difference in the proportion of participants with mRS 0–2 at 90 days according to BP management (adjusted odds ratio 3.34, 95% CI 1.36 to 8.22). There was no difference in the rates of symptomatic or any ICH and mortality between two groups. In inverse probability-weighted regression adjustment analysis, mortality decreased significantly in the TBM group than in the NBM group (adjusted odds ratio 0.86, 95% CI 0.76–0.99, p = 0.03).

Conclusion: In patients with acute ischemic stroke from large-vessel occlusion in the anterior circulation, BP management under TCD was superior to NBM in improving the clinical outcomes at 90 days.

Clinical Trial Registration: (URL: https://www.chictr.org.cn/showproj.aspx?proj=55484; Identifier: ChiCTR2000034443.

Therapeutic Use of Microbubbles and Ultrasound in Acute Peripheral Arterial Thrombosis: A Systematic Review

Catheter-directed thrombolysis (CDT) for acute peripheral arterial occlusion is time consuming and carries a risk of major hemorrhage. Contrast-enhanced sonothrombolysis (CEST) might enhance outcomes compared with standard CDT. In the study described here, we systematically reviewed all in vivo studies on contrast-enhanced sonothrombolysis in a setting of arterial thrombosis. A systematic search of the PubMed, Embase, Cochrane Library and Web of Science databases was conducted. Two reviewers independently performed the study selection, quality assessment and data extraction. Primary outcomes were recanalization rate and thrombus weight. Secondary outcome was any possible adverse event. The 35 studies included in this review were conducted in four different (pre)clinical settings: ischemic stroke, myocardial infarction, (peripheral) arterial thrombosis and arteriovenous graft occlusion. Because of the high heterogeneity among the studies, it was not possible to conduct a meta-analysis. In almost all studies, recanalization rates were higher in the group that underwent a form of CEST. One study was terminated early because of a higher incidence of intracranial hemorrhage. Studies on CEST suggest that adding microbubbles and ultrasound to standard intra-arterial CDT is safe and might improve outcomes in acute peripheral arterial thrombosis. Further research is needed before CEST can be implemented in daily practice.

Sonothrombolysis in Patients With Acute Ischemic Stroke With Large Vessel Occlusion: An Individual Patient Data Meta-Analysis

BACKGROUND AND PURPOSE

Evidence about the utility of ultrasound-enhanced thrombolysis (sonothrombolysis) in patients with acute ischemic stroke (AIS) is conflicting. We aimed to evaluate the safety and efficacy of sonothrombolysis in patients with AIS with large vessel occlusion, by analyzing individual patient data of available randomized-controlled clinical trials.

METHODS

We included all available randomized-controlled clinical trials comparing sonothrombolysis with or without addition of microspheres (treatment group) to intravenous thrombolysis alone (control group) in patients with AIS with large vessel occlusion. The primary outcome measure was the rate of complete recanalization at 1 to 36 hours following intravenous thrombolysis initiation. We present crude odds ratios (ORs) and ORs adjusted for the predefined variables of age, sex, baseline stroke severity, systolic blood pressure, and onset-to-treatment time.

RESULTS

We included 7 randomized controlled clinical trials that enrolled 1102 patients with AIS. A total of 138 and 134 confirmed large vessel occlusion patients were randomized to treatment and control groups respectively. Patients randomized to sonothrombolysis had increased odds of complete recanalization compared with patients receiving intravenous thrombolysis alone (40.3% versus 22.4%; OR, 2.17 [95% CI, 1.03-4.54]; adjusted OR, 2.33 [95% CI, 1.02-5.34]). The likelihood of symptomatic intracranial hemorrhage was not significantly different between the 2 groups (7.3% versus 3.7%; OR, 2.03 [95% CI, 0.68-6.11]; adjusted OR, 2.55 [95% CI, 0.76-8.52]). No differences in the likelihood of asymptomatic intracranial hemorrhage, 3-month favorable functional and 3-month functional independence were documented.

CONCLUSIONS

Sonothrombolysis was associated with a nearly 2-fold increase in the odds of complete recanalization compared with intravenous thrombolysis alone in patients with AIS with large vessel occlusions. Further study of the safety and efficacy of sonothrombolysis is warranted.

Large Vessel Occlusion Stroke Detection in the Prehospital Environment

Purpose of Review

Endovascular therapy for acute ischemic stroke secondary to large vessel occlusion (LVO) is time-dependent. Prehospital patients with suspected LVO stroke should be triaged directly to specialized stroke centers for endovascular therapy. This review describes advances in LVO detection among prehospital suspected stroke patients.

Recent Findings

Clinical prehospital stroke severity tools have been validated in the prehospital setting. Devices including EEG, SSEPs, TCD, cranial accelerometry, and volumetric impedance phase-shift-spectroscopy have recently published data regarding LVO detection in hospital settings. Mobile stroke units bring thrombolysis and vessel imaging to patients.

Summary

The use of a prehospital stroke severity tool for LVO triage is now widely supported. Ease of use should be prioritized as there are no meaningful differences in diagnostic performance amongst tools. LVO diagnostic devices are promising, but none have been validated in the prehospital setting. Mobile stroke units improve patient outcomes and cost-effectiveness analyses are underway.

Transcranial Doppler to evaluate postreperfusion therapy following acute ischemic stroke: A literature review

Cerebral vessel recanalization therapy, either intravenous thrombolysis or mechanical thrombectomy, is the main treatment that can significantly improve clinical outcomes after acute ischemic stroke. The degree of recanalization and cerebral reperfusion of the ischemic penumbra are dependent on cerebral hemodynamics. Currently, the main imaging modalities to assess reperfusion are MRI and CT perfusion. However, these imaging techniques cannot predict reperfusion-associated complications and are not readily available in many centers. It is also not feasible to repeat them frequently for sequential assessments, which is important because of the changing nature of cerebral hemodynamics following stroke. Transcranial Doppler sonography (TCD) is a valid, safe, and inexpensive technique that can assess recanalized vessels and reperfused tissue in real-time at the bedside. Post thrombectomy reocclusion, hyperperfusion syndrome, distal embolization, and remote infarction result in poor outcomes after mechanical or intravenous reperfusion therapy. Managing blood pressure following these endovascular treatments can also be a dilemma. TCD has an important role, with major clinical implications, in evaluating cerebral hemodynamics and collateral vessel status, guiding clinicians in making individualized decisions based on cerebral blood flow during acute stroke care. This review summarizes the most relevant literature on the role of TCD in evaluating patients after reperfusion therapy. We also discuss the importance of performing TCD in the first few hours following thrombolytic therapy in identifying hyperperfusion syndrome and embolic signals, predicting recurrent stroke, and detecting reocclusions, all of which may help improve patient prognosis. We recommend TCD during the hyperacute phase of stroke in comprehensive stroke centers.

Trans-cranial Doppler predicts early neurologic deterioration in anterior circulation ischemic stroke after successful endovascular treatment

Background

Early neurologic deterioration (END) may occur in patients with anterior circulation ischemic stroke (ACIS) after receiving endovascular treatment (EVT). Hemodynamic insufficiency, re-occlusion, and post-re-canalization hyper-perfusion are likely to play a critical role in END. We hypothesized that hemodynamic changes can predict END in patients with ACIS post-successful EVT using trans-cranial Doppler (TCD).

Methods

We utilized a prospectively maintained database of ACIS patients treated with EVT between September 2016 and June 2018 in the Xuanwu Hospital, Capital Medical University. TCD parameters including peak systolic velocity (PSV), bilateral mean flow velocity (MFV), and pulse index (PI) were determined via the middle cerebral arteries within 72 h post-EVT. A logistic regression model was applied to detect independent predictors for END.

Results

Totally, 112 EVT patients were included in this study and 80/112 patients experienced successful re-canalization with <50% residual stenosis, while 17/80 (21.3%) patients suffered END, for which vasogenic cerebral edema (11/17) was considered as a leading role and followed by symptomatic intra-cranial hemorrhage (4/17) and ischemia progression (2/17). For the 80 patients, the PSV (median: 127 cm/s vs. 116 cm/s, P = 0.039), the ratio of ipsilateral-MFV/contra-lateral-MFV (iMFV/cMFV) (median: 1.29 vs. 1.02, P = 0.036) and iMFV/mean blood pressure (MBP) (median: 0.97 vs. 0.79, P = 0.008) in END patients were higher than those of non-END. Using the receiver-operating characteristic curve to obtain cut-off values for PSV, PI, iMFV/cMFV, and iMFV/MBP for END, we found that PI ≥0.85 (odds ratio: 11.03, 95% confidence interval: 1.92–63.46, P = 0.007) and iMFV/MBP ≥0.84 (odds ratio: 9.20, 95% confidence interval: 2.07–40.84, P = 0.004) were independent predictors of END in a multivariate logistic regression model, with a sensitivity of 82.4% and 76.5% and a specificity of 42.9% and 66.7%, respectively, and had the positive predictive values of 29.0% and 38.2%, and negative predictive values of 90.0% and 91.3%, with an area under the receiver-operating characteristic curve of 0.57 and 0.71, respectively.

Conclusion

TCD examination of EVT patients may be used as a real-time tool to detect END predictors, such as the higher PI and iMFV/MBP, allowing for better post-thrombectomy management in ACIS patients.

Impact of Post-Stroke Recanalization on General and Upper Limb Functioning: A Prospective, Observational Study

The objective of this study is to assess the impact of recanalization (spontaneous and therapeutic) on upper limb functioning and general patient functioning after stroke. This is a prospective, observational study of patients hospitalized due to acute ischemic stroke in the territory of the middle cerebral artery (n = 98). Patients completed a comprehensive rehabilitation program and were followed-up for 24 weeks. The impact of recanalization on patient functioning was evaluated using the modified Rankin Scale (mRS) and Stroke Upper Limb Capacity Scale (SULCS). General and upper limb functioning improved markedly in the first three weeks after stroke. Age, gender, and National Institutes of Health Stroke Scale (NIHSS) score at admission were associated with general and upper limb functioning at 12 weeks. Successful recanalization was associated with better functioning. Among patients who underwent therapeutic recanalization, NIHSS scores ≥16.5 indicate lower general functioning at 12 weeks (sensibility = 72.4%; specificity = 78.6%) and NIHSS scores ≥13.5 indicate no hand functioning at 12 weeks (sensibility = 83.8%; specificity = 76.5%). Recanalization, either spontaneous or therapeutic, has a positive impact on patient functioning after acute ischemic stroke. Functional recovery occurs mostly within the first 12 weeks after stroke, with greater functional gains among patients with successful recanalization. Higher NIHSS scores at admission are associated with worse functional recovery.

Neurovascular disease, diagnosis, and therapy: Cervical and intracranial atherosclerosis, vasculitis, and vasculopathy

Stroke is a leading cause of death, disability, and financial burden in the United States. Perhaps more than any other disease process, the rapidity with which the diagnosis and treatment of stroke are successfully achieved is paramount to the reduction of its associated morbidity and mortality. Steno-occlusive intracranial vascular disease, the most notorious culprit of cerebral ischemia and/or hemorrhage, traces its etiology to native and embolic atherosclerosis as well as various forms of vascular inflammation, insult, and dysfunction. Distinguishing between these causes is a critical first step in the diagnosis and treatment of a patient presenting with cerebrovascular compromise. In this chapter, we delineate the clinical and imaging features of cervical and intracranial atherosclerosis, vasculitis, and vasculopathy, along with the evidence behind the treatments which comprise their current-day standard of care. The modern imaging armamentarium is diverse and complex, with contrast-enhanced and non-contrast MR angiography, CT angiography, digital subtraction angiography, and ultrasound; each playing an important role in providing rapid insight into the patient's disease process. Understanding these imaging techniques and their application in the acute setting is critical for the provider caring for stroke patients.

Low dosis of alteplase, for ischemic stroke after Enchanted and its determinants, a single center experience

BACKGROUND

Low-dose alteplase (LrtPA) has been shown not to be inferior to the standard-dose (SrtPA) with respect to death/disability.

OBJECTIVE

We aim to evaluate the percentage of patients treated with LrtPA at our center after the ENCHANTED trial and the factors associated with the use of this dosage.

METHODS

Prospective study in consecutive patients with an acute stroke admitted between June 2016 and November 2018.

RESULTS

160 patients were treated with intravenous thrombolysis, 50% female; mean age 65.4±18.5 years. Of these, 48 patients (30%) received LrtPA. In univariate analysis, LrtPA was associated with patient's age (p=0.000), previous modified Rankin scale scores (mRS) (p<0.000), hypertension (p=0.076), diabetes mellitus (p=0.021), hypercholesterolemia (p=0.19), smoking (p=0.06), atrial fibrillation (p=0.10), history of coronary artery disease (p=0.06), previous treatment with antiplatelet agents (p<0.000), admission International Normalized Ratio-INR (p=0.18), platelet count (p=0.045), leukoaraiosis on neuroimaging (p<0.003), contraindications for thrombolytic treatment (p=0.000) and endovascular treatment (p=0.027). Previous relevant bleedings were determinants for treatment with LrtPA. Final diagnosis on discharge of stroke mimic was significant (p=0.02) for treatment with SrtPA. In multivariate analysis, mRS (OR: 2.21; 95%CI 1.37‒14.19), previous antiplatelet therapy (OR: 11.41; 95%CI 3.98‒32.70), contraindications for thrombolysis (OR: 56.10; 95%CI 8.81‒357.80), leukoaraiosis (OR: 4.41; 95%CI 1.37‒14.10) and diagnosis of SM (OR: 0.22; 95%CI 0.10‒0.40) remained independently associated.

CONCLUSIONS

Following the ENCHANTED trial, LrtPA was restricted to 30% of our patients. The criteria that clinicians apply are based mostly on clinical variables that may increase the risk of brain or systemic hemorrhage or exclude the patient from treatment with lytic drugs.

A Review of the use of Transcranial Doppler Waveform Morphology for Acute Stroke Assessment

Acute ischemic stroke is a source of long-term disability in the United States, of which a large portion of cases are a result of large vessel occlusion (LVO). LVO strokes have high rates of morbidity and mortality due to difficulty of treatments in achieving recanalization. Recently, however, results of randomized clinical trials have shown that treatment options are expanding in both availability and efficacy. As these methods of intervention become more optimal, so must the preceding methods of assessment. Transcranial Doppler (TCD) ultrasound is a non-invasive method of evaluating cerebral hemodynamics, and has a long history in stroke assessment. Despite the importance of information provided by a TCD exam, its utilization in the acute stroke workflow has remained low because of its dependence on expert analysis. Here, we review the evolution of morphological analysis of TCD waveforms for the indication, localization, and monitoring of acute LVO.

Plasmin Generation Potential and Recanalization in Acute Ischaemic Stroke; an Observational Cohort Study of Stroke Biobank Samples

Rationale: More than half of patients who receive thrombolysis for acute ischaemic stroke fail to recanalize. Elucidating biological factors which predict recanalization could identify therapeutic targets for increasing thrombolysis success.

Hypothesis: We hypothesize that individual patient plasmin potential, as measured by in vitro response to recombinant tissue-type plasminogen activator (rt-PA), is a biomarker of rt-PA response, and that patients with greater plasmin response are more likely to recanalize early.

Methods: This study will use historical samples from the Barcelona Stroke Thrombolysis Biobank, comprised of 350 pre-thrombolysis plasma samples from ischaemic stroke patients who received serial transcranial-Doppler (TCD) measurements before and after thrombolysis. The plasmin potential of each patient will be measured using the level of plasmin-antiplasmin complex (PAP) generated after in-vitro addition of rt-PA. Levels of antiplasmin, plasminogen, t-PA activity, and PAI-1 activity will also be determined. Association between plasmin potential variables and time to recanalization [assessed on serial TCD using the thrombolysis in brain ischemia (TIBI) score] will be assessed using Cox proportional hazards models, adjusted for potential confounders.

Outcomes: The primary outcome will be time to recanalization detected by TCD (defined as TIBI ≥4). Secondary outcomes will be recanalization within 6-h and recanalization and/or haemorrhagic transformation at 24-h. This analysis will utilize an expanded cohort including ~120 patients from the Targeting Optimal Thrombolysis Outcomes (TOTO) study.

Discussion: If association between proteolytic response to rt-PA and recanalization is confirmed, future clinical treatment may customize thrombolytic therapy to maximize outcomes and minimize adverse effects for individual patients.

Predictors of the pulsatility index in the middle cerebral artery of acute stroke patients

Cervical and transcranial Doppler (TCD) are widely used as non-invasive methods in the evaluation of acute ischemic stroke (AIS) patients. High-grade carotid artery stenosis induces haemodynamic changes such as collateral flow and a so-called post-stenotic flow pattern of the middle cerebral artery (MCA), which appears flattened, with a reduction of the velocity difference between systole and diastole. We studied the influence of carotid artery stenosis and other variables on the flow pattern in the MCA using the pulsatility index (PI), a quantitative TCD parameter reflecting the flow spectrum in a large of cohort AIS patients. We performed ultrasound examinations of 1825 AIS patients at the CHUV from October 2004 to December 2014. We extracted patient characteristics from the ASTRAL registry. Carotid stenosis severity was classified as < 50%, 50–70%, 70–90% and > 90%, or occlusion, according to Doppler velocity criteria. We first determined variables associated with stenosis grade. Then we performed a multivariate analysis after adjusting for baseline differences, using MCA PI as dependent variable. Carotid stenosis > 70% (− 0.07) and carotid stenosis > 90%, or occlusion (− 0.14) and left side (− 0.02) are associated with lower MCA PI values. Age (+0.006 PI units per decade), diabetes (+0.07), acute ischemic changes on initial CT (+0.03) and severe plaque morphology (+0.18) are associated with higher MCA PI values. We found a number of clinical and radiological conditions that significantly influence the PI of the MCA, including high-grade ipsilateral carotid stenosis in AIS patients. We provide for the first time a quantitative evaluation of the effect of these influencing factors from a large cohort of AIS patients.

Effect of Recanalization on Cerebral Edema, Long-Term Outcome, and Quality of Life in Patients with Large Hemispheric Infarctions

OBJECTIVES

Space-occupying cerebral edema is the main cause of mortality and poor functional outcome in patients with large cerebral artery occlusion (LVO). We aimed to determine whether recanalization of LVO would augment cerebral edema volume and the impact on functional outcome and quality of life (QoL).

MATERIALS AND METHODS

Prospectively, 43 patients with large middle cerebral artery territory infarction or NIHSS ≥ 12 on admission were enrolled. The degree of recanalization (partial and complete versus no recanalization) was assessed by computed tomography (CT)-angiography or Duplex ultrasound more than 24 h after symptom onset. Cerebral edema volume was measured on follow up CTs by computer-based planimetry. Mortality, functional outcome (by modified Ranking Scale (mRS) and Barthel Index (BI)) were assessed at discharge and 12 months, and QoL (by SF-36 and EQ-5D-3L) at 12 months.

RESULTS

Mean cerebral edema volume was 333±141 ml without recanalization (n=13, group 1) and 276±140 ml with partial or complete recanalization (n=30, group 2, p= 0.23). There were no significant differences in mortality at discharge (38% versus 23%), at 12 months (58% versus 48%), in functional outcome at discharge (mRS 0-3: 0% both; mRS 4-5: 62% versus 77%) and at 12 months (mRS 0-3: 0% versus 11%; mRS 4-5: 42% versus 41%). The BI improved significantly from discharge to 12 months only in group 2 (p=0.001). Mean physical component score in SF-36 was 25.6±6.4, psychological component score was 41.9±14.1. In the EQ-5D-3L, most patients reported problems with activities of daily living, reduced mobility, and selfcare.

CONCLUSIONS

Recanalization of a large cerebral artery occlusion in the anterior circulation territories is not associated with amplification of post-ischemic cerebral edema but may be correlated with better long-term functional outcome. QoL was low and mainly dependent on physical disability. The association between recanalization, collateral status and development of cerebral edema after LVO and the effect on functional outcome and quality of life should be explored in a larger patient population.

Transcranial Doppler ultrasonography in neurological surgery and neurocritical care

Transcranial Doppler (TCD) ultrasonography is an inexpensive, noninvasive means of measuring blood flow within the arteries of the brain. In this review, the authors outline the technology underlying TCD ultrasonography and describe its uses in patients with neurosurgical diseases. One of the most common uses of TCD ultrasonography is monitoring for vasospasm following subarachnoid hemorrhage. In this setting, elevated blood flow velocities serve as a proxy for vasospasm and can herald the onset of ischemia. TCD ultrasonography is also useful in the evaluation and management of occlusive cerebrovascular disease. Monitoring for microembolic signals enables stratification of stroke risk due to carotid stenosis and can also be used to clarify stroke etiology. TCD ultrasonography can identify patients with exhausted cerebrovascular reserve, and after extracranial-intracranial bypass procedures it can be used to assess adequacy of flow through the graft. Finally, assessment of cerebral autoregulation can be performed using TCD ultrasonography, providing data important to the management of patients with severe traumatic brain injury. As the clinical applications of TCD ultrasonography have expanded over time, so has their importance in the management of neurosurgical patients. Familiarity with this diagnostic tool is crucial for the modern neurological surgeon.

Transcranial Doppler as a Predictor of Ischemic Events in Vertebral Artery Dissection

BACKGROUND AND PURPOSE

Transcranial Doppler (TCD) helps identify patients with carotid dissections at risk of ischemic events (IEs). There is paucity of data identifying independent predictors of IE in vertebral arterial dissection (VAD). We sought to investigate the clinical and ultrasound predictors of IE.

METHODS

Patients with VAD admitted between June 2017 and February 2020 were evaluated clinically and with TCD; sonographic curves, microembolic signals (MES), and the breath-holding index (BHI) test were applied. Covariates found on univariate screen (P < .25) were included in a multivariable linear regression to identify independent predictors of IEs.

RESULTS

Of 88 patients with 100 VAD, 75 (85.2%) were females with a mean age 37.9 ± 7.5 years. All patients received antiplatelet treatment. TCD monitoring lasted an average of 21 ± 2.1 minutes. TCD was abnormal in 23 cases (26.1%); 21 patients had abnormal sonographic curves in the vertebral/basilar arteries, while in 4 cases, MES were present and in 5 (4.5%), BHI was abnormal. None of the patients with a normal TCD had an IE. Six strokes occurred during follow up. On univariate analysis, male sex, diabetes, dyslipidemia, a previous myocardial infarct, migraine, time of consultation to the ER, bilateral VAD, MES, BHI abnormalities, post stenotic flow in the basilar artery (PFB), and basilar/vertebral velocities were significantly associated with the risk of IEs. In the multivariate analysis, only the presence of PFB was a significant predictor of IE (OR: 68.6, 95% CI 5-937, <.001).

CONCLUSIONS

TCD in VAD predicts patients at high risk of IE.

Reliability of the Modified TICI Score among Endovascular Neurosurgeons

BACKGROUND AND PURPOSE

The modified TICI score is the benchmark for quantifying reperfusion after mechanical thrombectomy. There has been limited investigation into the reliability of this score. We aim to identify intra-rater and inter-rater reliability of the mTICI score among endovascular neurosurgeons.

MATERIALS AND METHODS

Four independent endovascular neurosurgeons (raters) reviewed angiograms of 67 patients at 2 time points. κ statistics assessed inter- and intrarater reliability and compared raters'-versus-proceduralists' scores. Reliability was also assessed for occlusion location and by dichotomizing modified TICI scores (0-2a versus 2b-3).

RESULTS

Interrater reliability was moderate-to-substantial, weighted κ = 0.417-0.703, overall κ = 0.374 (P < .001). The dichotomized modified TICI score had moderate-to-substantial interrater agreement, κ statistics = 0.468-0.715, overall κ = 0.582 (P < .001). Intrarater reliability was moderate-to-almost perfect, weighted κ = 0.594-0.81. The dichotomized modified TICI score had substantial-to-almost perfect reliability, κ = 0.632-0.82. Proceduralists had fair-to-moderate agreement with raters, weighted κ = 0.348-0.574, and the dichotomized modified TICI score had fair-to-moderate agreement, κ = 0.365-0.544. When proceduralists and raters disagreed, proceduralists' scores were higher in 79.6% of cases. M1 followed by ICA occlusions had the highest agreement.

CONCLUSIONS

The modified TICI score is a practical metric for assessing reperfusion after mechanical thrombectomy, though not without limitations. Agreement improved when scores were dichotomized around the clinically relevant threshold of successful revascularization. Interrater reliability improved with time, suggesting that formal training of interventionalists may improve reporting reliability. Agreement of the modified TICI scale is best with M1 and ICA occlusion and becomes less reliable with more distal or posterior circulation occlusions. These findings should be considered when developing research trials.

No benefit of flat head positioning in early moderate-severe acute ischaemic stroke: a HeadPoST study subgroup analysis

Background

Although the Head Positioning in acute Stroke Trial (HeadPoST) showed no effect of the flat head position (FP; vs sitting up head position (SUP)) on functional outcome, we hypothesised that it could still offer benefits if commenced early in those with acute ischaemic stroke (AIS) of at least moderate severity.

Methods

Subgroup analysis of HeadPoST in participants with National Institutes of Health Stroke Scale (NIHSS) scores ≥7, ≥10 and ≥14, randomised to FP or SUP <4.5 hours of AIS onset on functional outcomes defined by a shift in scores on the modified Rankin scale (mRS) and death/disability (mRS scores 3–6), and any cardiovascular serious adverse event. Logistic regression analyses were undertaken adjusted for study design and baseline risk factors.

Results

There was no significant differential treatment effect in patient subgroups defined by increasing baseline NIHSS scores: adjusted OR and 95% CI for ordinal shift and binary (3–6) mRS scores: for NIHSS ≥7 (n=867) 0.92 (0.67 to 1.25) and 0.74 (0.52 to 1.04); NIHSS ≥ 10 (n=606) 0.80 (0.58 to 1.10) and 0.77 (0.49 to 1.19); NIHSS ≥14 (n=378) 0.82 (0.54 to 1.24) and 1.22 (0.69 to 2.14).

Conclusions

Early FP had no significant effect in patients with moderate–severe AIS.

Trial registration number

NCT02162017.

Cerebral haemodynamics with head position changes post-ischaemic stroke: A systematic review and meta-analysis

The effects of upright postures on the cerebral circulation early post-ischaemic stroke are not fully understood. We conducted a systematic review and meta-analysis to investigate the effects of head positioning on cerebral haemodynamics assessed by imaging methods post-ischaemic stroke. Of the 21 studies included (n = 529), 15 used transcranial Doppler. Others used near-infrared, diffuse correlation spectroscopy and nuclear medicine modalities. Most tested head positions between 0° and 45°. Seventeen studies reported changes in CBF parameters (increase at lying-flat or decrease at more upright) in the ischaemic hemisphere with position change. However, great variability was found and risk of bias was high in many studies. Pooled data of two studies ≤24 h (n = 28) showed a mean increase in cerebral blood flow (CBF) velocity of 8.5 cm/s in the ischaemic middle cerebral artery (95%CI,-2.2-19.3) from 30° to 0°. The increase found ≤48 h (n = 50) was of 2.3 cm/s (95%CI,-4.6-9.2), while ≤7 days (n = 38) was of 8.4 cm/s (95%CI, 1.8-15). Few very early studies (≤2 days) tested head positions greater than 30° and were unable to provide information about the response of acute stroke patients to upright postures (sitting, standing). These postures are part of current clinical practice and knowledge on their effects on cerebral haemodynamics is required.

Effect of Age on Arterial Recanalization and Clinical Outcome in Thrombolyzed Acute Ischemic Stroke in CLOTBUST Cohort

Background and Aims:

Despite the evidence from randomized clinical trials, the effectiveness of intravenous tissue recombinant plasminogen activator (IV-tPA) for elderly patients (≥80 yrs) with acute ischemic stroke (AIS) is often an important consideration in clinical practice. We evaluated the effect of older age on arterial recanalization, timing of recanalization and outcome in thrombolysed AIS patients.

Methods:

Consecutive AIS patients treated with IV-tPA and transcranial Doppler (TCD) examination within 3 hours of symptom-onset were included. Thrombolysis in Brain Ischemia (TIBI) flow-grading system was used to interpret TCD findings of persistent occlusion, re-occlusion and complete recanalization within 2 hours of IV-tPA bolus. Poor functional outcome was defined by modified Rankin score of 3 or more. Univariate and multiple logistic regression analyses were performed to assess the effect of age on clinical and TCD outcome measures.

Results:

The study included 361 patients (elderly = 85, <80 yrs = 276). Median age was 68 years (range 18-91 years). Compared to the elderly, younger patients (<80 years) were more females (63.5% versus 41.3%), had higher baseline National Institute of Health Stroke Scale score (17.5 versus 16.0 points) and shorter time from symptom-onset to IV-tPA bolus (median 136.6 versus 139.7 minutes). No significant differences were noted between the site of arterial occlusion, TCD outcome measures or time of complete recanalization between the 2 groups. More patients aged < 80 years achieved good functional outcome (51.9% versus 31.8% in the older age group; P = 0.004). IV-tPA induced recanalization and symptomatic intracranial hemorrhage were similar in the 2 groups. Multivariate logistic regression showed elderly age as an independent predictor of poor outcome (adjusted OR 2.5, 95%CI 1.26-4.95; P = 0.008).

Conclusion:

Elderly AIS patients achieve relatively poor functional outcome after IV-tPA despite similar rates of arterial recanalization. However, there is no increase in the hemorrhagic risk. Perhaps, decision for IV thrombolysis in elderly patients should be made cautiously.

Toward automated classification of pathological transcranial Doppler waveform morphology via spectral clustering

Cerebral Blood Flow Velocity waveforms acquired via Transcranial Doppler (TCD) can provide evidence for cerebrovascular occlusion and stenosis. Thrombolysis in Brain Ischemia (TIBI) flow grades are widely used for this purpose, but require subjective assessment by expert evaluators to be reliable. In this work we seek to determine whether TCD morphology can be objectively assessed using an unsupervised machine learning approach to waveform categorization. TCD beat waveforms were recorded at multiple depths from the Middle Cerebral Arteries of 106 subjects; 33 with Large Vessel Occlusion (LVO). From each waveform, three morphological features were extracted, quantifying onset of maximal velocity, systolic canopy length, and the number/prominence of peaks/troughs. Spectral clustering identified groups implicit in the resultant three-dimensional feature space, with gap statistic criteria establishing the optimal cluster number. We found that gap statistic disparity was maximized at four clusters, referred to as flow types I, II, III, and IV. Types I and II were primarily composed of control subject waveforms, whereas types III and IV derived mainly from LVO patients. Cluster morphologies for types I and IV aligned clearly with Normal and Blunted TIBI flows, respectively. Types II and III represented commonly observed flow-types not delineated by TIBI, which nonetheless deviate from normal and blunted flows. We conclude that important morphological variability exists beyond that currently quantified by TIBI in populations experiencing or at-risk for acute ischemic stroke, and posit that the observed flow-types provide the foundation for objective methods of real-time automated flow type classification.

Timing of Recanalization and Functional Recovery in Acute Ischemic Stroke

Background and Purpose

Although onset-to-treatment time is associated with early clinical recovery in acute ischemic stroke (AIS) patients treated with intravenous tissue plasminogen activator (tPA), the effect of the timing of tPA-induced recanalization on functional outcomes remains debatable.

Methods

We conducted a multicenter, prospective observational cohort study to determine whether early (within 1-hour from tPA-bolus) complete or partial recanalization assessed during 2-hour real-time transcranial Doppler monitoring is associated with improved outcomes in patients with proximal occlusions. Outcome events included dramatic clinical recovery (DCR) within 2 and 24-hours from tPA-bolus, 3-month mortality, favorable functional outcome (FFO) and functional independence (FI) defined as modified Rankin Scale (mRS) scores of 0–1 and 0–2 respectively.

Results

We enrolled 480 AIS patients (mean age 66±15 years, 60% men, baseline National Institutes of Health Stroke Scale score 15). Patients with early recanalization (53%) had significantly (jos-2019-01648P<0.001) higher rates of DCR at 2-hour (54% vs. 10%) and 24-hour (63% vs. 22%), 3-month FFO (67% vs. 28%) and FI (81% vs. 39%). Three-month mortality rates (6% vs. 17%) and distribution of 3-month mRS scores were significantly lower in the early recanalization group. After adjusting for potential confounders, early recanalization was independently associated with higher odds of 3-month FFO (odds ratio [OR], 6.19; 95% confidence interval [CI], 3.88 to 9.88) and lower likelihood of 3-month mortality (OR, 0.34; 95% CI, 0.17 to 0.67). Onset to treatment time correlated to the elapsed time between tPA-bolus and recanalization (unstandardized linear regression coefficient, 0.13; 95% CI, 0.06 to 0.19).

Conclusions

Earlier tPA treatment after stroke onset is associated with faster tPA-induced recanalization. Earlier onset-to-recanalization time results in improved functional recovery and survival in AIS patients with proximal intracranial occlusions.

Neuro-ultrasonography

Transcranial Doppler ultrasonography (TCD) is a noninvasive, bedside, portable tool for assessment of cerebral hemodynamics. Modern TCD head frames allow continuous hands-free emboli detection for risk stratification and assessment of treatment efficacy in several cardiovascular diseases. Identifying a focal stenosis, arterial occlusion, and monitoring the treatment effect of intravenous tissue plasminogen activator can easily be accomplished by assessing TCD waveforms and determining prestenotic and poststenotic mean flow velocities. TCD is an excellent screening tool for vasospasm in aneurysmal subarachnoid hemorrhage. The use of intraoperative TCD during carotid endarterectomy and stenting allows optimal intraoperative hemodynamic management. Other applications are also discussed.

Cerebral Hemodynamic Evaluation After Cerebral Recanalization Therapy for Acute Ischemic Stroke

Cerebral recanalization therapy, either intravenous thrombolysis or mechanical thrombectomy, improves the outcomes in patients with acute ischemic stroke (AIS) by restoring the cerebral perfusion of the ischemic penumbra. Cerebral hemodynamic evaluation after recanalization therapy, can help identify patients with high risks of reperfusion-associated complications. Among the various hemodynamic modalities, magnetic resonance imaging (MRI), computed tomography perfusion, and transcranial Doppler sonography (TCD) are the most commonly used. Poststroke hypoperfusion is associated with infarct expansion, while hyperperfusion, which once was considered the hallmark of successful recanalization, is associated with hemorrhagic transformation. Either the hypo- or the hyperperfusion may result in poor clinical outcomes. Individual blood pressure target based on cerebral hemodynamic evaluation was crucial to improve the prognosis. This review summarizes literature on cerebral hemodynamic evaluation and management after recanalization therapy to guide clinical decision making.

Validation of a basic neurosonology laboratory for detecting cervical carotid artery stenosis

INTRODUCTION

Most of the cases of ischaemic stroke in our setting are of atherothrombotic origin. Detecting intracranial and cervical carotid artery stenosis in patients with ischaemic stroke is therefore essential. Ultrasonography has become the tool of choice for diagnosing carotid artery stenosis because it is both readily accessibility and reliable. However, use of this technique must be validated in each laboratory. The purpose of this study is to validate Doppler ultrasound in our laboratory as a means of detecting severe carotid artery stenosis.

PATIENTS AND METHODS

We conducted an observational descriptive study to evaluate diagnostic tests. The results from transcranial and cervical carotid Doppler ultrasound scans conducted by neurologists were compared to those from carotid duplex scans performed by radiologists in patients diagnosed with stroke. Arteriography was considered the gold standard (MR angiography, CT angiography, or conventional arteriography).

RESULTS

Our sample included 228 patients. Transcranial and cervical carotid Doppler ultrasound showed a sensitivity of 95% and specificity of 100% for detection of carotid artery stenosis > 70%, whereas carotid duplex displayed a sensitivity of 87% and a specificity of 94%. Transcranial carotid Doppler ultrasound achieved a sensitivity of 78% and a specificity of 98% for detection of intracranial stenosis.

CONCLUSIONS

Doppler ultrasound in our neurosonology laboratory was found to be a useful diagnostic tool for detecting cervical carotid artery stenosis and demonstrated superiority to carotid duplex despite the lack of B-mode. Furthermore, this technique was found to be useful for detecting intracranial stenosis.

Sonothrombolysis with Magnetically Targeted Microbubbles

Microbubble-enhanced sonothrombolysis is a promising approach to increasing the tolerability and efficacy of current pharmacological treatments for ischemic stroke. Maintaining therapeutic concentrations of microbubbles and drugs at the clot site, however, poses a challenge. The objective of this study was to investigate the effect of magnetic microbubble targeting upon clot lysis rates in vitro. Retracted whole porcine blood clots were placed in a flow phantom of a partially occluded middle cerebral artery. The clots were treated with a combination of tissue plasminogen activator (0.75 µg/mL), magnetic microbubbles (∼10⁷ microbubbles/mL) and ultrasound (0.5 MHz, 630-kPa peak rarefactional pressure, 0.2-Hz pulse repetition frequency, 2% duty cycle). Magnetic targeting was achieved using a single permanent magnet (0.08-0.38 T and 12-140 T/m in the region of the clot). The change in clot diameter was measured optically over the course of the experiment. Magnetic targeting produced a threefold average increase in lysis rates, and linear correlation was observed between lysis rate and total energy of acoustic emissions.

STROKE34 Study Protocol: A Randomized Controlled Phase IIa Trial of Intra-Arterial CD34+ Cells in Acute Ischemic Stroke

Rationale/aim

Despite the increasing efficacy of recanalization therapies for acute ischemic stroke, a large number of patients are left with long-term functional impairment, devoid of efficacious treatments. CD34+ cells comprise a subset of bone marrow-derived mononuclear cells with the capacity to promote angiogenesis in ischemic lesions and have shown promising results in observational and in vitro studies. In this study, we aim to assess the efficacy of an autotransplant of CD34+ cells in acute ischemic stroke.

Sample size estimates

30 patients will be randomized for a power of 90% and alpha of 0.05 to detect a difference in 3 months infarct volume.

Methods and design

We will screen 18–80 years old patients with acute ischemic stroke due to occlusion of a middle cerebral artery (MCA) for randomization. Persistent arterial occlusions, contra-indications to magnetic resonance imaging (MRI), premorbid dependency, or other severe diseases will be excluded. Treatment will involve bone marrow aspiration, selection of CD34+ cells, and their administration intra-arterially in the symptomatic MCA by angiography. Patients will be randomized for treatment at 7 (±2) days, 20 (±5 days) or sham procedure, 10 in each group.

Study outcomes

The primary outcome will be infarct volume in MRI performed at 3 months. Secondary outcomes will include adverse events and multidimensional functional and neurological measures.

Discussion/conclusion

STROKE34 is a PROBE design phase IIa clinical trial to assess the efficacy of intra-arterial administration of CD34+ cells 7 and 20 days after acute ischemic stroke.

Trial registration (EU Clinical Trials Register)

2017-002456-88.

Factors Associated with Early Recovery after Intravenous Thrombolytic Therapy in Acute Ischemic Stroke

Introduction

In this study, we aimed to identify the factors associated with early neurological improvement (ENI) in acute stroke patients treated with intravenous recombinant tissue plasminogen activator (IV rt-PA), and to determine the association between ENI and outcomes at 3 months after stroke.

Methods

Patients with acute ischemic stroke who were treated with IV rt-PA within 4.5 hours of symptom onset from February 2009 to December 2016 were included in the study at the stroke center of Eskişehir Osmangazi University Medical Faculty. ENI was defined as an improvement in National Institutes of Health Stroke Scale (NIHSS) score of ≥8 points compared to the pretreatment score or an NIHSS score of 0 or 1 at 24 hours after stroke. We assessed the outcomes at 3 months after treatment using the modified Rankin Scale (mRS) score, and mRS scores of 0-1 were defined as 'very good' outcomes.

Results

ENI was observed in 43.9% of 355 patients included in the study. Very good outcome at the 3rd month was detected in 80.1% of the patients with ENI, and in 15.6% of the patients without ENI (p<0.001). Patients with ENI were younger (p=0.025), and had lower NIHSS scores (p=0.027) and higher ASPECT scores (p=0.008) than those without. The ENI group had lower serum glucose levels at the time of admission (p< 0.001). Additionally, the presence of diabetes mellitus, hypertension, and hyperdense artery sign were more frequent in the ENI group (p=0.001, p=0.024, and p<0.001, respectively). Finally, multiple regression analysis showed a significant relationship between serum glucose level, hyperdense artery sign, and ENI.

Conclusion

There is a significant relationship between ENI and very good outcome at 3 months in acute stroke patients who received IV rt-PA. Therefore, the management of factors such as serum glucose level, NIHSS score, ASPECT score and presence of hyperdense artery sign which are related to ENI, and the determination of treatment strategies according to them are important issues for achieving a better outcome in acute ischemic stroke.

Endovascular therapy versus intravenous thrombolysis in cervical artery dissection ischemic stroke - Results from the SWISS registry

INTRODUCTION

In patients with stroke attributable to cervical artery dissection, we compared endovascular therapy to intravenous thrombolysis regarding three-month outcome, recanalisation and complications.

MATERIALS AND METHODS

In a multicentre intravenous thrombolysis/endovascular therapy-register-based cohort study, all consecutive cervical artery dissection patients with intracranial artery occlusion treated within 6 h were eligible for analysis. Endovascular therapy patients (with or without prior intravenous thrombolysis) were compared to intravenous thrombolysis patients regarding (i) excellent three-month outcome (modified Rankin Scale score 0-1), (ii) symptomatic intracranial haemorrhage, (iii) recanalisation of the occluded intracranial artery and (iv) death. Upon a systematic literature review, we performed a meta-analysis comparing endovascular therapy to intravenous thrombolysis in cervical artery dissection patients regarding three-month outcome using a random-effects Mantel-Haenszel model.

RESULTS

Among 62 cervical artery dissection patients (median age 48.8 years), 24 received intravenous thrombolysis and 38 received endovascular therapy. Excellent three-month outcome occurred in 23.7% endovascular therapy and 20.8% with intravenous thrombolysis patients. Symptomatic intracranial haemorrhage occurred solely among endovascular therapy patients (5/38 patients, 13.2%) while four (80%) of these patients had bridging therapy; 6/38 endovascular therapy and 0/24 intravenous thrombolysis patients died. Four of these 6 endovascular therapy patients had bridging therapy. Recanalisation was achieved in 84.2% endovascular therapy patients and 66.7% intravenous thrombolysis patients (odds ratio 3.2, 95% confidence interval [0.9-11.38]). Sensitivity analyses in a subgroup treated within 4.5 h revealed a higher recanalisation rate among endovascular therapy patients (odds ratio 3.87, 95% confidence interval [1.00-14.95]), but no change in the key clinical findings. In a meta-analysis across eight studies (n = 212 patients), cervical artery dissection patients (110 intravenous thrombolysis and 102 endovascular therapy) showed identical odds for favourable outcome (odds ratio 0.97, 95% confidence interval [0.38-2.44]) among endovascular therapy patients and intravenous thrombolysis patients.

DISCUSSION AND CONCLUSION

In this cohort study, there was no clear signal of superiority of endovascular therapy over intravenous thrombolysis in cervical artery dissection patients, which - given the limitation of our sample size - does not prove that endovascular therapy in these patients cannot be superior in future studies. The observation that symptomatic intracranial haemorrhage and deaths in the endovascular therapy group occurred predominantly in bridging patients requires further investigation.

Neurosonology Accuracy for Isolated Acute Vestibular Syndromes

OBJECTIVES

The clinical approach to acute vestibular syndromes is often complex for the physician. Neurosonology offers a noninvasive method to study the cervicocephalic circulation when a vascular etiology is suspected. We aim to evaluate the diagnostic accuracy of a vascular neurosonological exam in isolated acute vestibular syndrome.

METHODS

All patients submitted to cerebrovascular ultrasound and magnetic resonance imaging during the period between 2011 and 2015 with acute isolated vestibular syndrome. Those with any clinical sign of brainstem lesion on presentation were excluded. All patients performed the neuroimaging study (brain computed tomography and magnetic resonance imaging) and neurologic surveillance. Neurosonological exam included all intra- and extracranial segments of the vertebrobasilar circulation. Positive ultrasound exam was defined as the presence of stenotic or occlusive disease in any of these segments related to the infarcted area.

RESULTS

A total of 108 patients were included: 60 (53.6%) were males (mean age: 60.75 years (standard deviation, 14.17)). In 27 patients (25.0%) a cerebral ischemic lesion was found to be the cause of the vertigo. Neurosonological assessment showed a sensitivity of 40.7% (95% confidence interval (CI): 22.4; 61.2), specificity of 100% (95% CI: 95.5; 100.0), positive predictive value (PPV) of 100% (95% CI: 71.5; 100.0), and negative predictive value (NPV) of 83.5% (95% CI: 74.6; 90.3).

CONCLUSIONS

Our study suggests that cerebrovascular ultrasound is a highly specific method for the diagnosis of cerebrovascular vertigo. However, its low sensitivity makes it a poor candidate for screening.

Elevated body temperature in ischemic stroke associated with neurological improvement

OBJECTIVES

Some studies suggest that high body temperature within the first few hours of ischemic stroke onset is associated with improved outcome. We hypothesized an association between high body temperature on admission and detectable improvement within 6-9 hours of stroke onset.

MATERIALS AND METHODS

Consecutive ischemic stroke patients with NIHSS scores obtained within 3 hours and in the interval 6-9 hours after stroke onset were included. Body temperature was measured on admission.

RESULTS

A total of 315 patients with ischemic stroke were included. Median NIHSS score on admission was 6. Linear regression showed that NIHSS score 6-9 hours after stroke onset was inversely associated with body temperature on admission after adjusting for confounders including NIHSS score <3 hours after stroke onset (P<.001). The same result was found in patients with proximal middle cerebral occlusion on admission.

CONCLUSIONS

We found an inverse association between admission body temperature and neurological improvement within few hours after admission. This finding may be limited to patients with documented proximal middle cerebral artery occlusion on admission and suggests a beneficial effect of higher body temperature on clot lysis within the first three hours.