Sustainability of Intravenous Alteplase Administration via Telephone-Based Consult: Data from a US Health System.

OBJECTIVES: Telephone-based consults using remote imaging review and standardization of evaluation but without visualizing the patient are an alternative to video-telestroke consults but are less well-studied. We aim to demonstrate the safety and efficacy of telephone-based acute consults in which IV tPA was administered over nearly a decade within one health system. MATERIALS AND METHODS: Clinical characteristics and outcomes were compared between a community hospital (spoke; uses telephone-based consults) and the academic comprehensive stroke center (hub; uses oversight of on-site neurology trainees) from 2008-2017. In both institutions acute therapy decisions are made by the same stroke neurologists. RESULTS: 2518 acute ischemic stroke consults were evaluated at hub and 2049 at spoke. Of these, 191 patients received IV tPA at hub and 184 at spoke. Patients at hub were younger (median (IQR): 61 (51-74) vs 69 (56-81) years, p = 0.0021) but admission National Institutes of Health Stroke Scale (NIHSS) was similar. There were no differences between door-to-needle times (69 (56-101) vs 69 (51-92) minutes, p = 0.13), last known well-to-tPA times (157 (113-202) vs 144 (110-175) minutes, p = 0.053), and rates of overall intracranial hemorrhage (ICH) after tPA (n = 23 (13.5%) vs 31 (17.0%), p = 0.35). In multivariable analyses, hospital was not an independent predictor of ICH after tPA. CONCLUSIONS: In a large dataset over nearly a decade, assessment for IV tPA administration using telephone assessment along with imaging review and emergency department standardization resulted in similar safety and outcomes as in the presence of on-site stroke/neurology expertise. Future studies are needed to confirm these findings.

Exploring the Collateral Damage of the COVID-19 Pandemic on Stroke Care: A Statewide Analysis.

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Learning Middle-Latitude Cyclone Formation up in the Air: Student Learning Experience, Outcomes, and Perceptions in a CAVE-Enabled Meteorology Class.

Cave Automatic Virtual Environment (CAVE) is a virtual reality (VR) environment that has not been fully studied due to its high cost and complexity in system integration. Previous CAVE-related studies mainly focused on comparing its effectiveness with other learning media, such as textbooks, desktop VR, or head-mounted display (HMD) VR. In this study, through the utilization of CAVE in a meteorology class, we concentrated on CAVE itself, measured how CAVE impacted learners' learning outcomes before and after using CAVE in an actual ongoing undergraduate-level class, and investigated how learners perceived their learning experiences. Quantitative data were collected to examine the students' knowledge acquisition and learning experience. We also triangulated the quantitative results with qualitative data from the interviews regarding learners' perceptions of the CAVE-enabled class and their knowledge mastery. The results indicated that their learning outcomes increased through learning with CAVE and that their perceptions of immersion, presence, and engagement significantly correlated with each other. The interview results showed a great fondness of and satisfaction with the learning experience, group collaboration, and effectiveness of the CAVE-enabled class from the learners. We also learned that the learners' learning experiences in CAVE could be further improved if we provided them with more learner-environment interaction, offered them a better sense of immersion, and reduced cybersickness. Implications of these findings are discussed.

Clinical characteristics and outcome of current standard management of central retinal artery occlusion.

BACKGROUND: To investigate the visual outcomes in acute central retinal artery occlusion (CRAO) with current standard therapy at two university teaching hospitals. METHODS: Retrospective analysis of two cohorts of CRAO patients from John Hopkins Hospital (JHH; USA), and Flinders Medical Centre (FMC; Australia), treated with current standard therapy. The outcome measures were visual acuity, and subsequent ocular and systemic ischaemic events. RESULTS: The mean follow-up period was 11.2 +/- 13.1 months in the JHH cohort and 35.4 +/- 34.9 months in the FMC cohort. The frequency distribution of vascular risk factors and the incidence of subsequent ischaemic events were similar for the patients from both institutions. All patients from JHH were treated as inpatients, whereas 79% of patients from FMC were treated as outpatients. More patients in the JHH cohort underwent paracentesis, ocular massage or were treated with intraocular hypotensive agents (76%) than in the FMC cohort (26%); however, there was no significant difference in visual outcome between the two cohorts (P = 0.114). CONCLUSION: Despite differences in management of CRAO between two institutions in different countries, visual outcomes were similar. This suggests a lack of efficacy of current standard treatment in acute CRAO.

Local intraarterial fibrinolysis administered in aliquots for the treatment of central retinal artery occlusion: the Johns Hopkins Hospital experience.

BACKGROUND AND PURPOSE: Central retinal artery occlusion results in acute visual loss with poor spontaneous recovery. Current standard therapies do not alter the natural history of disease. Several open-label clinical studies using continuous infusion of thrombolytic agents have suggested that local intraarterial fibrinolysis (LIF) is efficacious in the treatment of central retinal artery occlusion. The aim is to compare the visual outcome in patients with acute central retinal artery occlusion of presumed thromboembolic etiology treated with LIF administered in aliquots with that of patients treated with standard therapy. METHODS: We conducted a single-center, nonrandomized interventional study of consecutive patients with acute central retinal artery occlusion from July 1999 to July 2006. RESULTS: Twenty-one patients received LIF and 21 received standard therapy. Seventy-six percent of subjects in the LIF group had a visual acuity improvement of one line or more compared with 33% in the standard therapy group (P=0.012, Fisher exact). Multivariate logistic regression controlling for gender, history of prior stroke/transient ischemic attack, and history of hypercholesterolemia showed that patients who received tissue plasminogen activator were 36 times more likely to have improvement in visual acuity (P=0.0001) after adjusting for these covariates. Post hoc analysis showed that patients who received tissue plasminogen activator were 13 times more likely to have improvement in visual acuity of 3 lines or more (P=0.03) and 4.9 times more likely to have a final visual acuity of 20/200 or better (P=0.04). Two groin hematomas were documented in the LIF group. No ischemic strokes, retinal or intracerebral hemorrhages were documented. CONCLUSIONS: LIF administered in aliquots is associated with an improvement in visual acuity compared with standard therapy and has few side effects.

Restoring cerebral blood flow reveals neural regions critical for naming.

We identified areas of the brain that are critical for naming pictures of objects, using a new methodology for testing which components of a network of brain regions are essential for that task. We identified areas of hypoperfusion and structural damage with magnetic resonance perfusion- and diffusion-weighted imaging immediately after stroke in 87 individuals with impaired picture naming. These individuals were reimaged after 3-5 d, after a subset of patients underwent intervention to restore normal blood flow, to determine areas of the brain that had reperfused. We identified brain regions in which reperfusion was associated with improvement in picture naming. Restored blood flow to left posterior middle temporal/fusiform gyrus, Broca's area, and/or Wernicke's area accounted for most acute improvement after stroke. Results show that identifying areas of reperfusion that are associated with acute improvement of a function can reveal the brain regions essential for that function.

Combined stent placement and thrombolysis in acute vertebrobasilar ischemic stroke.

BACKGROUND AND PURPOSE: Acute vertebrobasilar ischemic stroke is often associated with high morbidity and mortality with limited therapeutic options. Endovascular treatment with thrombolysis has offered some hope for affected patients; however, overall outcomes have been less than satisfactory. In this report, we present the results of our approach in six consecutive cases of acute vertebrobasilar ischemic stroke by combined proximal vessel stent placement and thrombolysis. METHODS: Six consecutive cases were retrospectively reviewed for the clinical outcome of patients presenting to our institution with acute posterior circulation stroke who underwent cerebral revascularization including proximal arterial stent placement by using balloon-expandable coronary stents and intraarterial thrombolysis. All of these patients were initially evaluated by stroke team neurologists and imaged with MR, including diffusion-weighted imaging documenting acute posterior circulation stroke. MR angiography of the circle of Willis was also obtained. Short-term follow-up was conducted to assess National Institutes of Health stroke scores (NIHSS) and modified Rankin scores. RESULTS: In these six cases, a combined approach of proximal arterial stent placement (five cases of vertebral artery origin and one case of carotid and subclavian stent placement plus vertebral artery revascularization) and thrombolysis was performed at variable times after stroke onset (range, 30 hours to 5 days). Four of the six patients had good basilar artery recanalization (Thrombolysis in Myocardial Infarction [TIMI] grade 0-1 before tissue plasminogen activator thrombolysis and TIMI grade 2 after procedure). Four of six patients had excellent immediate recovery and were discharged to an acute rehabilitation unit or their homes with improved neurologic symptoms and functional status. Two patients died: one patient presented with coma at outset with an NIHSS of 38, and the other patient probably had reocclusion of the basilar artery within 24 hours despite initial postprocedural improvement. CONCLUSION: We demonstrate that, in the setting of acute stroke, stent placement in combination with revascularization and thrombolysis is practical and allows quick access to a clot and simultaneously increases perfusion through collaterals during the thrombolytic process. In particular, basilar thrombolysis may be facilitated by proximal vertebral stent placement as concomitant atheromatous vertebrobasilar stenosis is common.

Variability in subcortical aphasia is due to variable sites of cortical hypoperfusion.

A variety of fluent and nonfluent aphasias have been reported after left basal ganglia stroke. It has been speculated that this heterogeneity may reflect variations in cortical hypoperfusion resulting from large vessel stenosis. To test this hypothesis, a consecutive series of 24 patients with left caudate infarct identified with diffusion-weighted imaging underwent language testing and perfusion-weighted imaging < 24h from onset of symptoms. Specific regions in perisylvian cortex were rated for the percentage of the region that was hypoperfused. Aphasia type was determined on the basis of speech fluency, comprehension, and repetition performance on the language tests. Association between aphasia type/language impairment and regions of hypoperfusion were identified with Fisher's exact tests. Results demonstrated that in patients with acute left caudate infarct, the presence and type of aphasia reflected regions of hypoperfusion, and generally followed predictions based on chronic lesion studies, regarding anatomical lesions associated with classic aphasia types.

Neural correlates of modality-specific spatial extinction.

Sites of lesions responsible for visual, tactile, and/or motor extinction have not been clearly identified. We sought to determine the frequency of extinction in various modalities immediately after acute ischemic stroke, the rate of co-occurrence of extinction across modalities, and areas of infarct and/or hypoperfusion associated with each modality of extinction. A total of 148 patients with right supratentorial stroke were studied. In Study 1, 88 patients without hemiplegia, hemianesthesia, or visual field cuts were tested within 24 hours of onset for visual, tactile, and motor extinction, and underwent magnetic resonance diffusion and perfusion imaging. Associations between modality of extinction and areas of neural dysfunction (hypoperfusion/infarct) were identified. Of the 88 patients, 19 had only tactile extinction, 8 had only visual extinction, 12 had only motor extinction, 14 had extinction in two or more modalities, and 35 had no extinction. Tactile extinction was associated with neural dysfunction in the inferior parietal lobule; visual extinction was associated with dysfunction in the visual association cortex; and motor extinction was associated with neural dysfunction in the superior temporal gyrus. In Study 2, data from 60 patients who were excluded from Study 1 because of motor deficits were analyzed in the same way to determine whether frontal lesions contributed to visual or tactile extinction. Results again demonstrated that tactile extinction is associated with inferior parietal dysfunction, and visual extinction is associated with dysfunction of the visual association cortex. Potential accounts of the results, based on the "hemisphere rivalry" model of extinction and the limited attentional capacity model, are considered.

Vestibular compensation after ganglionectomy: ultrastructural study of the tangential vestibular nucleus and behavioral study of the hatchling chick.

The tangential nucleus is a major part of the avian vestibular nuclear complex, and its principal cells are structurally distinctive neurons participating in the vestibuloocular and vestibulocollic reflexes. After unilateral peripheral vestibular lesion, a behavioral recovery of function defined as vestibular compensation is observed. Because sprouting and hypertrophy of synapses have been reported in other regions of immature animals after central nervous system injury, we investigated whether this also occurs in the vestibular nuclei during compensation. To test this hypothesis, unilateral vestibular ganglionectomy was performed on 4-6-day-old hatchlings and vestibular function was tested during the next 2 months. Degeneration and evidence for regeneration of synapses were studied in the tangential nucleus at 1, 3, 7, and 56 days after surgery. Spoon endings, large vestibular terminals on the principal somata, degenerated 1-3 days after surgery. However, the small synaptic terminals showed no significant change in the percentage or number covering the soma or in mean terminal lengths in the deafferented or contralateral tangential nucleus. Furthermore, there was no evidence of neuron death in the tangential nucleus. Vestibular compensation occurred in three stages: 0-3 days, when vestibular synapses degenerated and severe behavioral deficits were seen; 4-9 days, when primary vestibular fibers degenerated centrally and marked improvement in both the static and the dynamic symptoms were observed; and 10-56 days, when changes in neuronal morphology were not detected but the dynamic symptoms gradually improved. Accordingly, after unilateral vestibular ganglionectomy, vestibular compensation proceeded without ultrastructural evidence of sprouting or hypertrophy of axosomatic synapses in the hatchling tangential nucleus. This rapid behavioral recovery of function distinguishes the vestibular system from other sensory systems, which, in general, exhibit much less robust recovery after injury to their peripheral receptors.