Predictive Model of Dysphagia and Brain Lesion-Symptom Mapping in Acute Ischemic Stroke

Post-stroke dysphagia: identifying the evidence missing

Dysphagia is a high-profile dysfunction that often occurs after a stroke, with a prevalence of 50%-80%. Post-stroke dysphagia (PSD) often leads to serious complications such as pneumonia and malnutrition, reducing the quality of life and leading to poor prognosis or even death. PSD causes these adverse physical and psychological impairments to patients, which becomes a challenge for both patients and physicians. This review intends to contribute to the international debate on evidence-based options on Stroke Rehabilitation and to better understand the need for further research on PSD and summarizing evidence on some of the most relevant topics and clarifying its clinical practice value for Neurology, stroke rehabilitation experts, rehabilitation and nursing staff, as well as patients. The article identifies and discusses the gaps in knowledge on PSD and elaborates on current evidence concerning the selection of subjects, examination methods, patient data extraction and analysis, classification of stroke lesions, details of dysphagia, significance of results, and neuromodulation of dysphagia, from the perspective of rehabilitation physicians. The review identified a set of 10 points and parameters for the international debate on PSD, namely: stroke onset, cognitive impairment, feeding method, contrast medium, swallowing reflex delay, swallowing evaluation form, division of brainstem, multiple stroke sites, basal ganglia lesions and neuromodulation techniques. The article explores available evidence on factors associated with dysphagia and stroke site. Although there is plenty of evidence exploring the correlation between stroke site and swallowing disorders, the pathophysiological mechanisms between the two are complex, and expert interpretations of the evidence and clinical opinions vary on which swallowing abnormalities occur. The study generates evidence on current evidence-based options on Stroke Rehabilitation and a better understanding of the need for further research on Post-Stroke Dysphagia. Taking a patient-centric approach, the ultimate goal is to generate on how can available evidence influence policy or practice or research or clinical education. The article provides a structured discussion clarifying key points on the relationship between stroke lesions and swallowing dysfunctions and contributes to clarifying the gaps in evidence to further improve the quality of life of the patients suffering from Post-Stroke Dysphagia.

Individualized prediction of stroke-associated pneumonia for patients with acute ischemic stroke

Background

Stroke-associated pneumonia (SAP) remains a neglected area despite its high morbidity and mortality. We aimed to establish an easy-to-use model for predicting SAP.

Methods

Two hundred seventy-five acute ischemic stroke (AIS) patients were enrolled, and 73 (26.55%) patients were diagnosed with SAP. T-test, Chi-square test and Fisher's exact test were used to investigate the associations of patient characteristics with pneumonia and its severity, and multivariable logistic regression models were used to construct a prediction scale.

Results

Three variables with the most significant associations, including age, NGT placement, and right cerebral hemisphere lesions combined with gender, were used to construct a stroke-associated pneumonia prediction scale with high accuracy (AUC = 0.93). Youden index of our SAP prediction model was 0.77. The sensitivity and specificity of our SAP prediction model were 0.89 and 0.88, respectively.

Conclusion

We identified the best predictive model for SAP in AIS patients. Our study aimed to be as clinically relevant as possible, focusing on features that are routinely available. The contribution of selected variables is visually displayed through SHapley Additive exPlanations (SHAP). Our model can help to distinguish AIS patients of high-risk, provide specific management, reduce healthcare costs and prevent life-threatening complications and even death.

Cerebral small vessel disease is an independent determinant of dysphagia after acute stroke

BACKGROUND

The high incidence of dysphagia after acute stroke is likely the result of cumulative effects of the stroke and pre-stroke brain health. While cerebral small vessel disease (cSVD) is recognized as a marker of compromised brain health, it's unclear which neuroanatomical pathologies of cSVD impact post-stroke dysphagia. We assessed the relation between cSVD pathologies, i.e., brain atrophy, white matter hyperintensities (WMH), perivascular spaces, as markers for brain integrity at the time of the stroke, and acute post-stroke dysphagia measured with the Modified Barium Swallow Study (MBSS).

METHODS

We conducted a retrospective, observational study of 40 individuals with an acute first-ever ischemic stroke. We segmented T1-weighted images into gray matter, white matter, and cerebrospinal fluid (CSF) to derive brain atrophy estimates. We scored the presence and severity of periventricular and deep WMH using the Fazekas scale and counted perivascular spaces in the basal ganglia following standard guidelines. Swallow impairments were determined with the Modified Barium Swallow Impairment Profile (MBSImP), Penetration-Aspiration Scale, and timing measures (oral (OTT), and pharyngeal transit times (PTT)). We performed regression to assess the relation between cSVD pathologies and swallowing while controlling for the stroke overlap with the right and left corticobulbar tracts, stroke volume, and the number of days between the MRI and MBSS.

RESULTS

Worse brain atrophy and more severe periventricular WMH were related to more severe MBSImP pharyngeal total scores, and worse deep WMH were related to aspiration events. More severe perivascular spaces in the basal ganglia were related to longer OTT and PTT, with a high explanatory value (27.5% and 25.1%, respectively), even when controlling for chronological age.

CONCLUSIONS

Our results suggest that several aspects of pre-stroke brain health impact dysphagia severity after acute stroke independent of the stroke site and size. These findings contribute to our understanding of mechanisms underlying the variability of post-stroke dysphagia and emphasize the importance of brain structural integrity before the stroke. Future larger studies are warranted.

Incidence and Risk Factors for Dysphagia Following Cerebellar Stroke: a Retrospective Cohort Study

The cerebellum is known to play a supportive role in swallowing-related functions; however, wide discrepancies about the incidence rate of swallowing disorders following cerebellar strokes exist within the literature. This study aimed to investigate the incidence rate of dysphagia and the factors which may affect the presence of dysphagia and clinical recovery in individuals diagnosed with cerebellar stroke. A retrospective chart audit of 1651 post-stroke patients (1049 males and 602 females) admitted with a cerebellar stroke to a comprehensive tertiary hospital in China was conducted. Data on demographics, medical, along with swallowing function assessment were collected. Differences between dysphagic and non-dysphagic groups were evaluated using t-tests and Pearson's chi-square test. Univariate logistic regression analysis was performed to establish factors associated with the presence of dysphagia. A total of 11.45% of participants were identified with dysphagia during inpatient admission. Individuals with mixed types of stroke, multiple lesions in the cerebellum, and ages older than 85 years old were more likely to develop dysphagia. Moreover, the prognosis of dysphagia following a cerebellar stroke was associated with lesions in different parts of the cerebellum. The cumulative recovery rates from the best to worse were the right hemisphere group, the cerebellum vermis or peduncle group, and both the hemisphere group and the left hemisphere group, respectively.

Using status of secondary prevention medications in post-stroke dysphagia patients: time to raise awareness and develop special formulations

Post-stroke dysphagia (PSD) is an increasingly common complication of stroke. Despite its intuitively unfavorable impact on secondary prevention medication use, limited awareness is available regarding this issue. Herein, a cross-sectional survey was conducted to determine the current use, patient-perceived needs and preferences for secondary prevention medications among PSD patients. To emphasize the unique context related to dysphagia, we recruited Chinese stroke patients with a duration of less than 5 years. These patients were initially categorized into PSD respondents with and without dysphagia. Among the 3490 eligible respondents, 42.7% reported experiencing dysphagia after stroke. Those PSD respondents were more likely to consume multiple medications and suffer from anticoagulants-associated gastrointestinal bleeding as compared to non-PSD ones (p < 0.001). More crucially, 40.2% of them had frequent difficulty in swallowing pills, 37.1% routinely crushed solid oral dosage forms (SODFs), and 23.5% coughed frequently when taking SODFs. In consequence, 87.4% responded a need for PSD-specific formulations where safe swallowing, easy swallowing, and reduced medication frequency were preferred pharmaceutical factors. These findings demonstrate an unsatisfactory situation and definite needs for PSD patients in using secondary prevention medications. Awareness should be increased to develop PSD-specific formulations for safe and effective secondary prevention.

Early flexible endoscopic evaluation of swallowing after mechanical thrombectomy in stroke patients

OBJECTIVE

The aims of the study were to (1) characterize the findings of flexible endoscopic evaluation of swallowing (FEES) in stroke patients undergoing mechanical thrombectomy (MT); (2) analyse the screening performance of the Standardized Swallowing Assessment (SSA); and (3) study the impact of FEES-defined dysphagia on 3-month outcomes.

METHODS

This single-centre study was based on a local registry of consecutive acute ischaemic stroke patients undergoing MT during a 1-year period. Patients received FEES within 5 days of admission regardless of the result of dysphagia screening. We compared baseline demographic and clinical characteristics of patients with and without FEES-defined dysphagia. We collected 3-month modified Rankin Scale (mRS) and individual index values of the European Quality of Life 5 Dimensions (EQ-5D-iv). Using univariable and multivariable regression analyses we predicted 3-month outcomes for presence of dysphagia and for FEES-defined dysphagia severity.

RESULTS

We included 137 patients with a median age of 74 years, 43.1% were female, median NIHSS was 12 and successful recanalization was achieved in 92.7%. Stroke-associated pneumonia occurred in 8% of patients. FEES-defined dysphagia occurred in 81% of patients. Sensitivity of the SSA as a dysphagia screening was 67%. Presence of dysphagia and increasing severity of dysphagia were independently associated with increasing 3-month mRS score. Increasing dysphagia severity dysphagia was independently associated with lower EQ-5D-iv.

INTERPRETATION

Early FEES-defined dysphagia occurs in four in every five patients undergoing MT. SSA has a suboptimal dysphagia screening performance. Presence of dysphagia and increasing dysphagia severity predict worse functional outcome and worse health-related quality-of-life.

Research hotspots and frontiers in post-stroke dysphagia: a bibliometric analysis study

Background

Dysphagia is a common complication of stroke that can result in serious consequences. In recent years, more and more papers on post-stroke dysphagia have been published in various journals. However, there is still a lack of bibliometric analysis of post-stroke dysphagia. This study visually analyzes the global research situation of post-stroke dysphagia from 2013 to 2022, aiming to explore the current research status, frontier trends, and research hotspots in this field.

Methods

Articles and reviews relevant to post-stroke dysphagia were obtained and retrieved from the Web of Science core collection database in the last 10 years (from 2013 to 2022). CiteSpace and Microsoft Excel 2019 were used for bibliographic analysis.

Results

A total of 1,447 articles were included in the analysis. The number of publications showed an overall upward trend, from 72 in 2013 to 262 in 2022. The most influential authors, institutions, journals, and countries were Hamdy S, University of London, Dysphagia, and the People's Republic of China. An analysis of keywords and the literature indicated that current studies in the field of post-stroke dysphagia focused on dysphagia and aspiration, dysphagia classification, dysphagia rehabilitation, and daily living.

Conclusion

This bibliometric analysis reveals the latest advancements and emerging trends in the field of post-stroke dysphagia, spanning the years 2013 to 2022. It highlights the paramount importance of conducting large-scale randomized controlled trials examining the efficacy of dysphagia screening protocols and non-invasive intervention techniques in improving the quality of life for these patients. Such research efforts hold significant academic implications for the development of evidence-based treatment strategies in this field.

Acute Dysphagia Following Reperfusion Therapies: A Prospective Pilot Cohort Study

Dysphagia is a well-documented sequela of stroke. Recent advancements in medical treatments for stroke include reperfusion therapies (endovascular thrombectomy (EVT) and thrombolysis). As outcomes following reperfusion therapies are typically measured via general functional scales, the pattern and progression of acute dysphagia following reperfusion therapies is less known. To determine the progression of acute dysphagia (0-72 h) following reperfusion therapies and relationships between various stroke parameters and dysphagia, twenty-six patients were prospectively recruited across two EVT and thrombolysis centres in Brisbane, Australia. Dysphagia was screened via the Gugging Swallowing Screen (GUSS) at the bedside at three timepoints: 0-24 h, 24-48 h, and 48-72 h post-reperfusion therapies. Across three groups (EVT only, thrombolysis only, or both), the incidence of any dysphagia within the first 24 h of reperfusion therapy was 92.31% (n = 24/26), 91.30% (n = 21/23) by 48 h, and 90.91% (n = 20/22) by 72 h. Fifteen patients presented with severe dysphagia at 0-24 h, 10 at 24-48 h, and 10 at 48-72 h. Whilst dysphagia was not significantly correlated to infarct penumbra/core size, dysphagia severity was significantly related to the number of passes required during EVT (p = 0.009).Dysphagia continues to persist in the acute stroke population despite recent advancements in technology aimed to reduce morbidity and mortality post-stroke. Further research is required to establish protocols for management of dysphagia post-reperfusion therapies.

Disconnection-Based Prediction of Poststroke Dysphagia

BACKGROUND AND PURPOSE

Dysphagia is a common deficit after a stroke and is associated with serious complications. It is not yet fully clear which brain regions are directly related to swallowing. Previous lesion symptom mapping studies may have overlooked structural disconnections that could be responsible for poststroke dysphagia. Here, we aimed to predict and explain the relationship between poststroke dysphagia and the topologic distribution of structural disconnection via a multivariate predictive framework.

MATERIALS AND METHODS

We enrolled first-ever ischemic stroke patients classified as full per-oral nutrition (71 patients) and nonoral nutrition necessary (43 patients). After propensity score matching, 43 patients for each group were enrolled (full per-oral nutrition group with 17 women, 68 ± 15 years; nonoral nutrition necessary group with 13 women, 75 ± 11 years). The structural disconnectome was estimated by using the lesion segmented from acute phase diffusion-weighted images. The prediction of poststroke dysphagia by using the structural disconnectome and demographics was performed in a leave-one-out manner.

RESULTS

Using both direct and indirect disconnection matrices of the motor network, the disconnectome-based prediction model could predict poststroke dysphagia above the level of chance (accuracy = 68.6%, permutation P = .001). When combined with demographic data, the classification accuracy reached 72.1%. The edges connecting the right insula and left motor strip were the most informative in prediction.

CONCLUSIONS

Poststroke dysphagia could be predicted by using the structural disconnectome derived from acute phase diffusion-weighted images. Specifically, the direct and indirect disconnection within the motor network was the most informative in predicting poststroke dysphagia.

The assessment of dysphagia after stroke: state of the art and future directions

Dysphagia is a major complication following an acute stroke that affects the majority of patients. Clinically, dysphagia after stroke is associated with increased risk of aspiration pneumonia, malnutrition, mortality, and other adverse functional outcomes. Pathophysiologically, dysphagia after stroke is caused by disruption of an extensive cortical and subcortical swallowing network. The screening of patients for dysphagia after stroke should be provided as soon as possible, starting with simple water-swallowing tests at the bedside or more elaborate multi-consistency protocols. Subsequently, a more detailed examination, ideally with instrumental diagnostics such as flexible endoscopic evaluation of swallowing or video fluoroscopy is indicated in some patients. Emerging diagnostic procedures, technical innovations in assessment tools, and digitalisation will improve diagnostic accuracy in the future. Advances in the diagnosis of dysphagia after stroke will enable management based on individual patterns of dysfunction and predisposing risk factors for complications. Progess in dysphagia rehabilitation are essential to reduce mortality and improve patients' quality of life after a stroke.

Neural basis of dysphagia in stroke: A systematic review and meta-analysis

Objectives

Dysphagia is a major cause of stroke infection and death, and identification of structural and functional brain area changes associated with post-stroke dysphagia (PSD) can help in early screening and clinical intervention. Studies on PSD have reported numerous structural lesions and functional abnormalities in brain regions, and a systematic review is lacking. We aimed to integrate several neuroimaging studies to summarize the empirical evidence of neurological changes leading to PSD.

Methods

We conducted a systematic review of studies that used structural neuroimaging and functional neuroimaging approaches to explore structural and functional brain regions associated with swallowing after stroke, with additional evidence using a live activation likelihood estimation (ALE) approach.

Results

A total of 35 studies were included, including 20 studies with structural neuroimaging analysis, 14 studies with functional neuroimaging analysis and one study reporting results for both. The overall results suggest that structural lesions and functional abnormalities in the sensorimotor cortex, insula, cerebellum, cingulate gyrus, thalamus, basal ganglia, and associated white matter connections in individuals with stroke may contribute to dysphagia, and the ALE analysis provides additional evidence for structural lesions in the right lentiform nucleus and right thalamus and functional abnormalities in the left thalamus.

Conclusion

Our findings suggest that PSD is associated with neurological changes in brain regions such as sensorimotor cortex, insula, cerebellum, cingulate gyrus, thalamus, basal ganglia, and associated white matter connections. Adequate understanding of the mechanisms of neural changes in the post-stroke swallowing network may assist in clinical diagnosis and provide ideas for the development of new interventions in clinical practice.

Effects of Insular Cortex on Post-Stroke Dysphagia: A Systematic Review and Meta Analysis

Objective: To investigate the relationship of lobar and deep brain regions with post-stroke dysphagia (PSD). Method: The databases of Medline, Embase, Web of Science, and Cochrane Library were searched from the establishment to May 2022. Studies that investigated the effects of lesions in lobar and deep brain regions on swallowing function after stroke were screened. The primary outcomes were PSD-related brain regions (including aspiration-related and oral transit time-related brain regions). The secondary outcomes were the incidence rate of PSD. The brain regions with the most overlap in the included studies were considered to be most relevant to PSD, and were presented as percentages. Data were compared utilizing the t-tests for continuous variables and χ2 for frequency-based variables. Result: A total of 24 studies and 2306 patients were included. The PSD-related lobar and deep brain regions included the insular cortex, frontal lobe, temporal gyrus, basal ganglia, postcentral, precentral, precuneus, corona radiate, etc. Among these brain regions, the insular cortex was most frequently reported (taking up 54.2%) in the included studies. Furthermore, the total incidence rate of PSD was around 40.4%, and the incidence of male was nearly 2.57 times as much as that of female (χ2 = 196.17, p < 0.001). Conclusions: In lobar and deep brain regions, the insular cortex may be most relevant to PSD and aspiration, which may be a potentially promising target in the treatment of PSD.

Efficacy and Safety of Mirror Therapy for Post-stroke Dysphagia: A Systematic Review and Meta-Analysis

Background

Post-stroke dysphagia is a common symptom after stroke and one of the most frequent and severe complications of stroke. Over the recent years, mirror therapy has generated significant research interest as a non-invasive therapeutic and rehabilitative intervention for post-stroke dysphagia and has been investigated in several randomized controlled trials in single center.

Objective

In this study, we aimed to evaluate the efficacy and safety of mirror therapy for post-stroke dysphagia.

Methods

A total of seven databases were searched comprehensively from inception to the 31 December 2021, including PubMed, the Cochrane Library, Web of Science, China National Knowledge Infrastructure (CNKI), Chinese Biomedical Literature Service System (SinoMed), Wan-fang database, and the Chinese Scientific Journals Database (VIP) from inception to 31 December 2021. The primary outcome measure was efficacy, as measured by clinical effectiveness rate. Secondary outcomes included the water swallowing test and the incidence of pneumonia. In addition, we applied the Cochrane Risk of Bias Tool to investigate the risk of bias. Potential publication bias was evaluated by applying Egger's bias indicator test and by assessing the symmetry of data when visualized as funnel plots.

Results

A total of five randomized controlled trials (135 subjects in the experimental group and control group) were found to report the application of mirror therapy for post-stroke dysphagia and were included in this study. No publication bias was detected. Meta-analysis revealed that mirror therapy had a positive effect on the rate of clinical efficacy [odds ratio (OR) = 4.22; 95% confidence interval (CI): 2.3–7.73] and the water swallowing test [mean difference (MD) = −0.76; 95% CI = −1.29 to −0.22]. Moreover, mirror therapy reduced the incidence of pneumonia (OR = 0.13; 95% CI = 0.03–0.49). Subgroup analyses indicated that mirror therapy during the acute phase was robust but was unstable during the convalescent phase. Sensitivity analysis revealed that the results generated by our meta-analysis were robust and stable.

Conclusions

Available evidence appears to suggest that mirror therapy may have a role in the management of post-stroke dysphagia but has yet to be fully confirmed. Existing evidence from clinical trials suggests that evidence relating to the safety of mirror therapy for patients with post-stroke dysphagia is not yet sufficient.

Systematic Review Registration

Identifier: CRD42022302733.

Risk factors of dysphagia in patients with ischemic stroke: A meta-analysis and systematic review

Background

Dysphagia is a common yet serious complication in stroke patients. We aimed to conduct a meta-analysis and systematic review to evaluate the risk factors of dysphagia in patients with ischemic stroke, to provide insights to the clinical treatment and nursing care of dysphagia.

Methods

We searched PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure (CNKI) and Wanfang Database, China Biomedical Literature Database (CBM) for studies on dysphagia in patients with ischemic stroke up to January 31, 2022. The quality of the literature was evaluated using the Newcastle-Ottawa scale. Meta-analysis was performed using RevMan 5.3 software.

Results

A total of 10 studies involving 4637 ischemic stroke patients were included, 1183(25.51%) patients had dysphagia after stroke. The synthesized outcomes showed that elder age (SMD = 0.42, 95%CI:0.34–0.50), hypertension (OR = 1.96, 95%CI:1.48–2.61), diabetes (OR = 1.83, 95%CI:1.47–2.28), brainstem stroke (OR = 2.12, 95%CI:1.45–3.09) were associated with dysphagia in patients with ischemic stroke (all P<0.05). There was no significant difference in the gender between dysphagia and no dysphagia patients (OR = 1.07, 95%CI:0.91–1.27, P = 0.40). Egger regression tests indicated there were no significant publication biases in the synthesized outcomes (all P>0.05).

Conclusions

Elder age, hypertension, diabetes and brainstem stroke are associated with the development of dysphagia in patients with ischemic stroke. Attention should be paid to the assessment and early intervention of those risk factors for dysphagia to improve the prognosis of stroke patients.

Net clinical benefit of anticoagulant therapy from a neurologist's perspective: A review

In this article the concept of "net clinical benefit" (NCB) is considered in the context of stroke, the role of direct oral anticoagulants in secondary prevention of cardioembolic stroke and NCB from their prescription. Practical aspects of NCB evaluation from the neurologist's point of view are presented, taking into account such factors as stroke duration and severity, features of neurological deficit (severity of residual limitations, dysphagia, motor disorders and risk of falls), neuroimaging characteristics of stroke (focal size and hemorrhagic transformation) and concomitant neurological diseases (epilepsy and dementia). In all these situations, the use of oral anticoagulants has a significant clinical benefit, which justifies the inadmissibility of refusal to prescribe them.