Teaching NeuroImages: Crying thalamus: Manifestation of acute ischemic stroke.
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ABSTRACT:
SUBMITTER: Obeidat AZ
PROVIDER: S-EPMC5331865 | biostudies-literature | 2017 Feb
REPOSITORIES: biostudies-literature
Publications
Teaching Neuro<i>Images</i>: Crying thalamus: Manifestation of acute ischemic stroke.
Obeidat Ahmed Z AZ Broderick Joseph P JP
Neurology 20170201 9
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Project description:Stroke is a major threat to life and health in modern society, especially in the aging population. Stroke may cause sudden death or severe sequela-like hemiplegia. Although computed tomography (CT) and magnetic resonance imaging (MRI) are standard diagnosis methods, and artificial intelligence models have been built based on these images, shortage in medical resources and the time and cost of CT/MRI imaging hamper fast detection, thus increasing the severity of stroke. Here, we developed a convolutional neural network model by integrating four networks, Xception, ResNet50, VGG19, and EfficientNetb1, to recognize stroke based on 2D facial images with a cross-validation area under curve (AUC) of 0.91 within the training set of 185 acute ischemic stroke patients and 551 age- and sex-matched controls, and AUC of 0.82 in an independent data set regardless of age and sex. The model computed stroke probability was quantitatively associated with facial features, various clinical parameters of blood clotting indicators and leukocyte counts, and, more importantly, stroke incidence in the near future. Our real-time facial image artificial intelligence model can be used to rapidly screen and prediagnose stroke before CT scanning, thus meeting the urgent need in emergency clinics, potentially translatable to routine monitoring.
| S-EPMC11320352 | biostudies-literature
Project description:Magnetic resonance (MR) imaging (MRI) is commonly used to diagnose, assess and monitor stroke. Accurate and timely segmentation of stroke lesions provides the anatomico-structural information that can aid physicians in predicting prognosis, as well as in decision making and triaging for various rehabilitation strategies. To segment stroke lesions, MR protocols, including diffusion-weighted imaging (DWI) and T2-weighted fluid attenuated inversion recovery (FLAIR) are often utilized. These imaging sequences are usually acquired with different spatial resolutions due to time constraints. Within the same image, voxels may be anisotropic, with reduced resolution along slice direction for diffusion scans in particular. In this study, we evaluate the ability of 2D and 3D U-Net Convolutional Neural Network (CNN) architectures to segment ischemic stroke lesions using single contrast (DWI) and dual contrast images (T2w FLAIR and DWI). The predicted segmentations correlate with post-stroke motor outcome measured by the National Institutes of Health Stroke Scale (NIHSS) and Fugl-Meyer Upper Extremity (FM-UE) index based on the lesion loads overlapping the corticospinal tracts (CST), which is a neural substrate for motor movement and function. Although the four methods performed similarly, the 2D multimodal U-Net achieved the best results with a mean Dice of 0.737 (95% CI: 0.705, 0.769) and a relatively high correlation between the weighted lesion load and the NIHSS scores (both at baseline and at 90 days). A monotonically constrained quintic polynomial regression yielded R2 = 0.784 and 0.875 for weighted lesion load versus baseline and 90-Days NIHSS respectively, and better corrected Akaike information criterion (AICc) scores than those of the linear regression. In addition, using the quintic polynomial regression model to regress the weighted lesion load to the 90-Days FM-UE score results in an R2 of 0.570 with a better AICc score than that of the linear regression. Our results suggest that the multi-contrast information enhanced the accuracy of the segmentation and the prediction accuracy for upper extremity motor outcomes. Expanding the training dataset to include different types of stroke lesions and more data points will help add a temporal longitudinal aspect and increase the accuracy. Furthermore, adding patient-specific data may improve the inference about the relationship between imaging metrics and functional outcomes.
| S-EPMC9949513 | biostudies-literature
Project description:Background and objectivesEmotional and cognitive deficits are prevalent in strokes involving the thalamus. In contrast to cognitive deficits, emotional deficits have not been studied prospectively in isolated thalamic stroke.MethodsIn 37 ischemic thalamic stroke patients (57.0 [50.0; 69.5] years [median (Q1; Q3)], 21 males, 5 anterior, 12 paramedian, 20 inferolateral vascular territory), and 37 non-stroke control patients matched for age and sex, we prospectively examined depression, anxiety, activities of daily living, and quality of life at 1, 6, 12, and 24 months post-stroke using the Hospital-Anxiety-and-Depression Scale (HADS), Nürnberger-Alters-Alltagsaktivitäten scale (NAA), and Short Form-36 (SF36) questionnaire. Voxel-based lesion-symptom mapping (VLSM) and lesion-subtraction analyzes were performed to determine associations between questionnaire scores and thalamic stroke topography.ResultsAt 1 month post-stroke, anterior thalamic stroke patients had higher depression scores [8.0 (7.5; 10.5)] than paramedian [4.5 (1.0; 5.8)] and inferolateral [4.0 (1.0; 7.0)] thalamic stroke patients. Furthermore, anterior thalamic stroke patients had higher anxiety scores [11.0 (8.0; 14.5)] than their matched controls [2.5 (2.0; 2.5)], paramedian [4.5 (1.0; 5.8)] and inferior [4.0 (1.0; 7.0)] thalamic stroke patients. Depression and anxiety scores in anterior thalamic stroke patients remained high across the follow-up [depression: 9.0 (3.5; 13,8); anxiety:10.05 (2.8, 14.5)].Physical health assessed by SF36 was intact in anterior [1 month post-stroke: T-score = 55.9 (37.0; 57.6)] but reduced in inferolateral [44.5(32.4; 53.1)] thalamic stroke, whereas mental health was reduced in anterior thalamic stroke [32.0 (29.8; 47.3)].VLSM confirmed that voxels in the anterior thalamus around Montreal Neurological Institute (MNI) coordinates X = -8, Y = -12, Z = 2 were more often affected by the stroke in depressed (HADS-score ≥ 8) than non-depressed (HADS-score < 8) patients and voxels around coordinates X = -10, Y = -12, Z = 2 were more often affected in anxious (HADS-score ≥ 8) than non-anxious (HADS-score < 8) patients.ConclusionAnterior, but not paramedian or inferolateral thalamic stroke was associated with depression and anxiety. Even though our results are mostly significant in the left thalamus, this observation on stroke laterality might be confounded by the fact that the right hemisphere was underrepresented in our study.
| S-EPMC10493383 | biostudies-literature
Project description:Stroke remains a leading cause of disability in the United States. Despite recent advances, interventions to reduce damage and enhance recovery after stroke are lacking. P2X4R, a receptor for adenosine triphosphate (ATP), regulates activation of myeloid immune cells (infiltrating monocytes/macrophages and brain-resident microglia) after stroke injury. However, over-stimulation of P2X4Rs due to excessive ATP release from dying or damaged neuronal cells can contribute to ischemic injury. Therefore, we pharmacologically inhibited P2X4R to limit the over-stimulated myeloid cell immune response and improve both acute and chronic stroke recovery. We subjected 8-12-week-old male and female wild type mice to a 60 min right middle cerebral artery occlusion (MCAo) followed by 3 or 30 days of reperfusion. We performed histological, RNA sequencing, behavioral (sensorimotor, anxiety, and depressive), and biochemical (Evans blue dye extravasation, western blot, quantitative PCR, and flow cytometry) analyses to determine the acute (3 days after MCAo) and chronic (30 days after MCAo) effects of P2X4R antagonist 5-BDBD (1 mg/kg P.O. daily x 3 days post 4 h of MCAo) treatment. 5-BDBD treatment significantly (p < .05) reduced infarct volume, neurological deficit (ND) score, levels of cytokine interleukin-1 beta (IL-1β) and blood brain barrier (BBB) permeability in the 3-day group. Chronically, 5-BDBD treatment also conferred progressive recovery (p < .05) of motor balance and coordination using a rotarod test, as well as reduced anxiety-like behavior over 30 days. Interestingly, depressive-type behavior was not observed in mice treated with 5-BDBD for 3 days. In addition, flow cytometric analysis revealed that 5-BDBD treatment decreased the total number of infiltrated leukocytes, and among those infiltrated leukocytes, pro-inflammatory cells of myeloid origin were specifically reduced. 5-BDBD treatment reduced the cell surface expression of P2X4R in flow cytometry-sorted monocytes and microglia without reducing the total P2X4R level in brain tissue. In summary, acute P2X4R inhibition protects against ischemic injury at both acute and chronic time-points after stroke. Reduced numbers of infiltrating pro-inflammatory myeloid cells, decreased surface P2X4R expression, and reduced BBB disruption are likely its mechanism of neuroprotection and neuro-rehabilitation.
| S-EPMC7242087 | biostudies-literature
Project description: Not available
| S-EPMC5562967 | biostudies-literature
Project description:Studies have demonstrated that computed tomography (CT) angiography source images (CTA-SI) acquired under near-steady-state contrast concentration provide infarct core estimates equivalent to diffusion-weighted images (DWI). We sought to test this relationship using our current CTA protocol optimized for faster scan acquisition.Forty-eight consecutive acute ischemic stroke patients met the following criteria: fast-acquisition CTA and magnetic resonance imaging (MRI) within 9 hours of symptom onset, CTA-to-MRI interval under 2 hours, and anterior circulation vessel occlusion. Collaterals were graded on CTA, and lesion volumes were calculated on CTA-SI, DWI, and MR mean transit time (MTT) maps.The mean CTA-to-MRI interval was 36 minutes (± 18 minutes). In paired analysis, lesion volumes on CTA-SI were significantly larger than on DWI (45.6 cm3 vs. 29.9 cm3; P < .0001). In 14 (29.2%) cases, there was major CTA-SI overestimation (>25 cm3 difference) of the DWI lesion. Lower collateral score (P = .001), higher National Institutes of Health stroke scale (NIHSS) score (P = .01), older age (P = .01), and proximal occlusion (P < .05) were univariate predictors of major overestimation, with collateral score being the only independent predictor. The interobserver agreement was worse for CTA-SI than for DWI (P < .001 for limits of agreement).CTA-SI performed using a fast-acquisition protocol overestimates the infarct core on DWI. Substantial differences are observed in over 25% of cases, and are associated with reduced collateralization.
| S-EPMC3248622 | biostudies-literature
Project description:PurposeTo test whether the relationship between acute ischemic infarct size on concurrent computed tomographic (CT) angiography source images and diffusion-weighted (DW) magnetic resonance images is dependent on the parameters of CT angiography acquisition protocols.Materials and methodsThis retrospective study had institutional review board approval, and all records were HIPAA compliant. Data in 100 patients with anterior-circulation acute ischemic stroke and large vessel occlusion who underwent concurrent CT angiography and DW imaging within 9 hours of symptom onset were analyzed. Measured areas of hyperintensity at acute DW imaging were used as the standard of reference for infarct size. Information regarding lesion volumes and CT angiography protocol parameters was collected for each patient. For analysis, patients were divided into two groups on the basis of CT angiography protocol differences (patients in group 1 were imaged with the older, slower protocol). Intermethod agreement for infarct size was evaluated by using the Wilcoxon signed rank test, as well as by using Spearman correlation and Bland-Altman analysis. Multivariate analysis was performed to identify predictors of marked (?20%) overestimation of infarct size on CT angiography source images.ResultsIn group 1 (n=35), median hypoattenuation volumes on CT angiography source images were slightly underestimated compared with DW imaging hyperintensity volumes (33.0 vs 41.6 mL, P=.01; ratio=0.83), with high correlation (?=0.91). In group 2 (n=65), median volume on CT angiography source images was much larger than that on DW images (94.8 vs 17.8 mL, P<.0001; ratio=3.5), with poor correlation (?=0.49). This overestimation on CT angiography source images would have inappropriately excluded from reperfusion therapy 44.4% or 90.3% of patients eligible according to DW imaging criteria on the basis of a 100-mL absolute threshold or a 20% or greater mismatch threshold, respectively. Atrial fibrillation and shorter time from contrast material injection to image acquisition were independent predictors of marked (?20%) infarct size overestimation on CT angiography source images.ConclusionCT angiography protocol changes designed to speed imaging and optimize arterial opacification are associated with significant overestimation of infarct size on CT angiography source images.
| S-EPMC3267077 | biostudies-literature
Project description:ObjectivesConcise "synthetic" review of the state of the art of management of acute ischemic stroke.Data sourcesAvailable literature on PubMed.Study selectionWe selected landmark studies, recent clinical trials, observational studies, and professional guidelines on the management of stroke including the last 10 years.Data extractionEligible studies were identified and results leading to guideline recommendations were summarized.Data synthesisStroke mortality has been declining over the past 6 decades, and as a result, stroke has fallen from the second to the fifth leading cause of death in the United States. This trend may follow recent advances in the management of stroke, which highlight the importance of early recognition and early revascularization. Recent studies have shown that early recognition, emergency interventional treatment of acute ischemic stroke, and treatment in dedicated stroke centers can significantly reduce stroke-related morbidity and mortality. However, stroke remains the second leading cause of death worldwide and the number one cause for acquired long-term disability, resulting in a global annual economic burden.ConclusionsAppropriate treatment of ischemic stroke is essential in the reduction of mortality and morbidity. Management of stroke involves a multidisciplinary approach that starts and extends beyond hospital admission.
| S-EPMC7540624 | biostudies-literature
Project description:Intra-arterial therapy (IAT) for acute ischemic stroke refers to endovascular catheter-based approaches to achieve recanalization using mechanical clot disruption, locally injected thrombolytic agents or both. IAT may be used in addition to intravenous tissue plasminogen activator (tPA) or in patients who do not qualify for tPA, usually because they are outside the approved 3-h timeframe window or have contraindications, such as elevated international normalized ratio or partial thromboplastin time. Recanalization rates correlate with clinical improvement, and with the newest catheters it is possible to achieve recanalization in roughly 80% of patients treated. However, while the catheters are approved by the Food and Drug Administration, there are still no randomized trial data demonstrating the role of current IAT therapy vs either tPA or standard management. IAT is reserved for patients with large artery occlusions in the basilar, distal carotid, or proximal middle cerebral arteries. Imaging the penumbra using magnetic resonance imaging or computed tomographic perfusion is currently the most frequently used way to identify patients who might benefit. However, the imaging and clinical criteria for identifying which patients benefit, and perhaps more importantly those who will do poorly despite IAT, remain unclear.
| S-EPMC3250276 | biostudies-other
Project description:Tenecteplase is a fibrinolytic drug with higher fibrin specificity and longer half-life than the standard stroke thrombolytic, alteplase, permitting the convenience of single bolus administration. Tenecteplase, at 0.5 mg/kg, has regulatory approval to treat ST-segment-elevation myocardial infarction, for which it has equivalent 30-day mortality and fewer systemic hemorrhages. Investigated as a thrombolytic for ischemic stroke over the past 15 years, tenecteplase is currently being studied in several phase 3 trials. Based on a systematic literature search, we provide a qualitative synthesis of published stroke clinical trials of tenecteplase that (1) performed randomized comparisons with alteplase, (2) compared different doses of tenecteplase, or (3) provided unique quantitative meta-analyses. Four phase 2 and one phase 3 study performed randomized comparisons with alteplase. These and other phase 2 studies compared different tenecteplase doses and effects on early outcomes of recanalization, reperfusion, and substantial neurological improvement, as well as symptomatic intracranial hemorrhage and 3-month disability on the modified Rankin Scale. Although no single trial prospectively demonstrated superiority or noninferiority of tenecteplase on clinical outcome, meta-analyses of these trials (1585 patients randomized) point to tenecteplase superiority in recanalization of large vessel occlusions and noninferiority in disability-free 3-month outcome, without increases in symptomatic intracranial hemorrhage or mortality. Doses of 0.25 and 0.4 mg/kg have been tested, but no advantage of the higher dose has been suggested by the results. Current clinical practice guidelines for stroke include intravenous tenecteplase at either dose as a second-tier option, with the 0.25 mg/kg dose recommended for large vessel occlusions, based on a phase 2 trial that demonstrated superior recanalization and improved 3-month outcome relative to alteplase. Ongoing randomized phase 3 trials may better define the comparative risks and benefits of tenecteplase and alteplase for stroke thrombolysis and answer questions of tenecteplase efficacy in the >4.5-hour time window, in wake-up stroke, and in combination with endovascular thrombectomy.
| S-EPMC7606819 | biostudies-literature