Composite arterial and venous collateral score on single-phase CTA predicts 90-day outcomes in anterior circulation large-vessel occlusion stroke.

Background: Collateral circulation influences clinical outcomes in patients with acute ischemic stroke due to anterior circulation large-vessel occlusion (LVO). While both arterial and venous collateral assessments on single-phase computed tomography angiography (CTA) have prognostic value, they have traditionally been evaluated independently.

Purpose: We developed the CTA Collateral Impairment Score (CCIS), a composite measure incorporating arterial (Tan) and venous (Cortical Venous Opacification Score (COVES)) scores, and investigated its association with 90-day functional outcomes.

Hemispheric atrophy as a predictor for naming recovery following left hemisphere ischemic stroke.

Numerous large-scale epidemiological studies investigating the trajectory of cognitive recovery after ischemic stroke have presented data suggesting an immediate drop in cognition acutely post-stroke followed by persistent, accelerated decline over time when averaged as a group. We sought to further examine this trend, speculating that the average persistent decline may be a reflection of two subgroups with vastly different prognoses: 1) a minority experiencing decline secondary to neurodegenerative processes like vascular dementia and Alzheimer's disease, and 2) a majority without marked progressive brain atrophy who typically see improvement. Our team thus investigated atrophy's association with language recovery, hypothesizing that declining naming performance in the year after left hemisphere ischemic stroke would be correlated to atrophy of the contralesional hemisphere.

Neural Bases of Language Recovery After Stroke Can Only Be Fully Understood Through Longitudinal Studies of Individuals.

Despite decades of intense interest and investment in cognitive science, there remains a not only incomplete but also highly inconsistent body of evidence regarding how adult brains recover from even the most focal injuries associated with stroke. In this paper, I provide a broad narrative review of the studies of post-stroke aphasia recovery that have sought to identify the mechanisms of language recovery through longitudinal functional imaging. I start with studies that used functional imaging in groups of neurotypical individuals that have revealed areas of the brain that are reliably activated by language tasks and are functionally connected, referred to here as the "language network.

Interobserver and Intraobserver Variability in the Assessment of Prolonged Venous Transit in Anterior Circulation Large-Vessel Occlusion Ischemic Stroke.

Background And Purpose: Prolonged venous transit (PVT) on time-to-maximum (Tmax) perfusion maps has been associated with worse outcomes in patients with acute ischemic stroke due to anterior circulation large-vessel occlusion (AIS-LVO). The qualitative nature of PVT assessment introduces potential variability, and its reproducibility has not been systematically evaluated.

Materials And Methods: In a retrospective study of patients with confirmed AIS-LVO, 2 board-certified neuroradiologists independently reviewed pretreatment Tmax maps to assess PVT in the posterior superior sagittal sinus and torcula.

Elucidating White Matter Contributions to the Cognitive Architecture of Affective Prosody Recognition: Evidence from Right Hemisphere Stroke.

: Successful discourse relies not only on linguistic but also on prosodic information. Difficulty recognizing emotion conveyed through prosody (receptive affective aprosodia) following right hemisphere stroke (RHS) significantly disrupts communication participation and personal relationships. Growing evidence suggests that damage to white matter in addition to gray matter structures impairs affective prosody recognition.

Cognitive impairment in cerebral venous congestion: The need for improved assessment tools - a literature review.

ObjectiveCognitive impairment is increasingly recognized in patients with cerebral venous congestion (CVC), yet the cognitive tools used are largely adapted from stroke and dementia research. This review examines current literature on cognitive function in CVC, including conditions such as cerebral venous sinus thrombosis (CVST), idiopathic intracranial hypertension (IIH), and dural arteriovenous fistulas (dAVFs). Special emphasis is placed on the limitations of common screening tools like the Montreal Cognitive Assessment (MoCA) and Mini-Mental State Examination (MMSE).

Partial least squares multimodal analysis of brain network correlates of language deficits in aphasia.

Lesion-symptom mapping techniques are essential to determine brain regions critical for language functions. However, high collinearity in neuroimaging and behavioural data remains a challenge for distinguishing neural substrates supporting multiple language domains (shared variance) and those subserving specific language functions (unique variance). Here, we employed a novel approach to multimodal lesion-symptom mapping using multivariate partial least squares regression to delineate the latent structure of lesion-behavioural mapping in aphasia and decompose the shared and unique neural determinants of language impairments.

Acute temporal lesions are associated with phonological word verification errors.

Background: Within the dual stream model for language, the bilateral dorsal superior temporal gyrus (STG) is associated with spectro-temporal analysis while the mid-post superior temporal sulcus is associated with processing of higher-level phonological codes. However, the true lateralization of functions needed for phonological discrimination at the word level remains unsettled. The aim of the present work was to determine if individuals with acute stroke primarily involving the left STG and middle temporal gyrus (MTG) demonstrated poorer discrimination (') between phonologically related words in a word-picture verification task than those with left hemisphere lesions outside the temporal lobe and compared to those with right hemisphere stroke.

The impact of brain-derived neurotrophic factor gene polymorphisms on post-stroke naming in aphasia.

Post-stroke aphasia, or language deficits after stroke, afflicts 20-30% of survivors and often persists into the chronic phase. The protein brain-derived neurotrophic factor has been identified as important for neuroplasticity, and is regulated by the brain-derived neurotrophic factor gene. A patient's brain-derived neurotrophic factor genotype may influence their post-stroke aphasia recovery.

Integrating perfusion imaging derived venous outflow and tissue-level collateral parameters in a comprehensive clinical model enhances prognostication in large vessel occlusion stroke.

Arterial inflow restoration and collateral status have been significantly correlated with functional outcomes in AIS-LVO patients undergoing mechanical thrombectomy (MT). CT perfusion imaging biomarkers, including prolonged venous transit (PVT), cerebral blood volume (CBV) index, and hypoperfusion intensity ratio (HIR), have emerged as reliable pretreatment adjunct parameters of comprehensive flow assessment. However, their absolute and comparative effectiveness in improving prognostic prediction remains unclear when used in conjunction with clinical and arterial inflow parameters.

Perfusion imaging parameters predict long-term clinical outcome in isolated posterior cerebral artery occlusion stroke patients.

BackgroundIsolated posterior cerebral artery (PCA) occlusions, which account for 5% of ischemic strokes, significantly impact patient quality of life due to effects on the thalamus and visual cortex. Current guidelines for acute treatment and the prognostic utility of perfusion imaging in PCA strokes remain limited and underexplored.MethodsWe conducted a retrospective analysis of 21 patients with isolated PCA occlusions from January 2017 to March 2023 at two comprehensive medical institutions.

The relative cerebral blood volume (rCBV) <42% is independently associated with prolonged hospitalization in anterior circulation large vessel occlusion.

BackgroundThe pretreatment rCBV <42% lesion volume on CT Perfusion (CTP) has recently been shown to predict 90-day functional outcomes in stroke patients. However, its association with length of stay (LOS) has not yet been explored. This study aims to assess the relationship between rCBV <42% and prolonged LOS, defined as 7 days or longer.

The Pattern of Phonological, Semantic, and Circumlocution Naming Errors for Nouns and Verbs in Primary Progressive Aphasia.

Background: In the diagnostic criteria for lvPPA (Gorno-Tempini et al., 2011), "speech (phonologic) errors in spontaneous speech and naming" is a secondary criterion, but studies of naming error patterns in PPA have not found evidence to support this criterion. Furthermore, only a few studies have examined naming error patterns in PPA.

The Cortical Vein Opacification Score Is Independently Associated with Good and Excellent Functional Outcomes at 90 Days in Patients with Minor Stroke with Anterior Circulation Large-Vessel Occlusion: A Multicenter Study.

Background And Purpose: There is currently no consensus on the most appropriate emergent treatment for patients with acute ischemic stroke secondary to large-vessel occlusion and minor stroke. These patients were excluded from prior randomized controlled trials assessing the efficacy of mechanical thrombectomy in large-vessel occlusion, making it challenging to determine the best treatment approach. Therefore, identifying markers that can predict functional outcomes would be invaluable for triaging these patients for mechanical thrombectomy.

White Matter Hyperintensity Load Independent From the Stroke Lesion Is Associated With Chronic Aphasia Severity and Treatment Outcome.

Background: Although many studies have suggested that white matter hyperintensity (WMH) severity predicts naming and aphasia severity in chronic poststroke aphasia, there are inconsistencies in the literature. WMHs are typically symmetrical in neurotypical controls, and measuring WMH in the contralateral hemisphere is likely the best option to estimate brain health independently from the stroke lesion and avoid measurement contamination from stroke-related gliosis. In this study, we aimed to clarify the discrepancies in the literature by testing whether WMH rating methods are related to clinical outcomes.

Prolonged Venous Transit as a Superior Predictor of Functional Outcomes in Successfully Reperfused Large Vessel Occlusions: Comparative Analysis With Cerebral Blood Volume Index and Hypoperfusion Intensity Ratio.

Background: Collateral status plays a crucial role in outcomes after acute ischemic stroke due to large vessel occlusion. Tissue-level collaterals and venous outflow are key components following mechanical thrombectomy. This study evaluates the predictive performance of prolonged venous transit (PVT), cerebral blood volume index, and hypoperfusion intensity ratio in determining 90-day functional outcomes.

Impact of White Matter Hyperintensities on Nonverbal Cognition Through Structural Disconnections in Poststroke Aphasia.

Background: Nonverbal cognitive deficits in poststroke aphasia remain poorly understood. They may result from direct stroke damage or disconnections of preserved cortical regions due to white matter injury, which may be worsened by white matter hyperintensities (WMH). Here, we examined the prevalence of nonverbal cognitive deficits in chronic poststroke aphasia and whether WMH-related disconnections contribute to these deficits beyond those caused by stroke lesions.

Prolonged Venous Transit Independently Predicts Worse Functional Outcomes at Discharge in Successfully Reperfused Patients with Large Vessel Occlusion Stroke.

Background And Purpose: Venous outflow (VO) impairment predicts unfavorable outcomes in patients with acute ischemic stroke caused by large vessel occlusion (AIS-LVO). Prolonged venous transit (PVT), a visual qualitative VO marker on CT perfusion (CTP) time to maximum (Tmax) maps, has been associated with 90-day mortality despite successful reperfusion. This study investigates the association between PVT and modified Rankin Scale (mRS) score at discharge among AIS-LVO patients who have undergone successful reperfusion.

Discourse Measures From the Modern Cookie Theft Picture Description Are Sensitive to Mild Communication Deficits Not Captured by the Western Aphasia Battery-Revised Aphasia Quotient.

Purpose: The Western Aphasia Battery-Revised (WAB-R) is often used for diagnosis of aphasia. However, persons scoring above the WAB-R diagnostic cutoff may still present with language difficulties indicative of aphasia. Identification of residual language challenges is critical for treatment referral or inclusion in research.

Hypoperfusion regions linked to National Institutes of Health Stroke Scale scores in acute stroke.

Background: The National Institutes of Health Stroke Scale (NIHSS) is widely used to assess stroke severity. While prior studies have identified subcortical regions where infarcts correlate with NIHSS scores, stroke symptoms can also arise from hypoperfusion, not just infarcts. Understanding the potential for neurological recovery post-reperfusion is essential for guiding treatment decisions.

Novel Insights into Viewer-Centered Versus Stimulus-Centered Hemispatial Neglect: A Cross-Sectional Behavioral and Imaging Study of Acute Stroke.

Hemispatial neglect is common after stroke but is often evaluated only after right hemisphere (RH) stroke. We sought to determine the prevalence of two types of neglect, viewer-centered neglect (VCN) and stimulus-centered neglect (SCN), after left hemisphere (LH) and RH strokes. Additionally, we identified lesion load in each vascular territory and areas of hypoperfusion, estimated with FLAIR hyperintense vessels (FVHs) that contribute to neglect.

Relative improvement in language vs. motor functions with reperfusion therapies for large vessel occlusion.

When weighing potential risks versus benefits of reperfusion therapy, the functions likely to recover if blood flow can be restored should be considered. Because deep and motor areas often infarct relatively early in acute stroke, we hypothesized that reperfusion therapies improve predominantly cortical functions more than motor function. In this retrospective review of a prospectively collected database of patients with acute stroke due to large vessel occlusion, we evaluated percent improvement (mean change in score/maximum score) for different items of the National Institutes of Health Score Scale with and without endovascular thrombectomy (EVT), and/or intravenous thrombolysis.

Larger Perfusion Mismatch Volume Is Associated With Longer Hospital Length of Stay in Medium Vessel Occlusion Stroke.

Background And Purpose: Prolonged length of stay (LOS) following a stroke is associated with unfavorable clinical outcomes. Factors predicting LOS in medium vessel occlusion (MeVO), impacting up to 40% of acute ischemic stroke (AIS) cases, remain underexplored. This study aims to investigate the predictors of LOS in AIS-MeVO.

Cerebral blood volume index in the era of thrombectomy-treated large and medium vessel ischemic strokes.

The cerebral blood volume index (CBV index) is a perfusion-based marker of collateral status. Several real-world data analyses from observational stroke cohorts have established relationships between this parameter and a range of favorable and unfavorable stroke outcomes. In this review, an overview is provided of the CBV index, within the context of thrombectomy-treated large vessel and medium vessel occlusion ischemic strokes.

Factors Associated With Prolonged Venous Transit in Large Vessel Occlusion Acute Ischemic Strokes.

Background And Purpose: Prolonged venous transit (PVT), derived from computed tomography perfusion (CTP) time-to-maximum (T) maps, reflects compromised venous outflow (VO) in acute ischemic stroke due to large vessel occlusion (AIS-LVO). Poor VO is associated with worse clinical outcomes, but pre-treatment markers predictive of PVT are not well described.

Methods: We conducted a retrospective analysis of 189 patients with anterior circulation AIS-LVO who underwent baseline CT evaluation, including non-contrast CT, CT angiography, and CTP.