Neural Mechanisms of Swallowing Dysfunction and Apraxia of Speech in Acute Stroke

Establishment and validation of early prediction model for post-stroke dysphagia

BACKGROUND

Stroke is a leading cause of death and disability worldwide, with dysphagia being a common complication that worsens patient outcomes.

METHODS

Data from 200 stroke patients (development cohort) and 50 stroke patients (validation cohort) were analyzed to develop a nomogram for predicting post-stroke dysphagia (PSD). Risk factors were identified through univariate analysis, Least Absolute Shrinkage and Selection Operator (LASSO) regression, and multivariate logistic regression.

RESULTS

Univariate analysis revealed substantial differences in age, body mass index (BMI), diabetes, atrial fibrillation, National Institute of Health Stroke Scale (NIHSS) score, Activities of Daily Living (ADL) score, lesion site, stroke type, and several laboratory indicators across the groups. Further analysis of individual NIHSS items showed significant differences in consciousness level, best gaze, facial palsy, motor arm, motor leg, dysarthria, etc. LASSO regression identified three predictors: ADL score, motor leg, and dysarthria. Multivariable logistic regression revealed that ADL score [0.96 (0.94-0.97)], motor leg [5.70 (2.14-15.22)], and dysarthria [5.26 (2.00-13.82)] were independent risk factors for PSD. The prediction model's AUC was 0.915 (0.874-0.955), with a sensitivity of 0.920 (0.867-0.973), specificity of 0.800 (0.722-0.878), positive predictive value (PPV) of 0.821 (0.750-0.892), negative predictive value (NPV) of 0.909 (0.849-0.969), and F1 score of 0.859. External validation yielded an AUC of 0.995 (0.984-1.000).

CONCLUSIONS AND IMPLICATIONS

ADL score, motor leg, and dysarthria are independent predictors of PSD. The prediction model based on these factors shows high accuracy, sensitivity, balance, consistency, and clinical applicability. This nomogram can support decision-making for ultra-early rehabilitation care, ultimately improving patient prognosis.

Evidence for Intermittent Theta Burst Transcranial Magnetic Stimulation for Dysphagia after Stroke: A Systematic Review and Meta-analysis

Dysphagia is the most common serious complication after stroke, with an incidence of about 37-78%, which seriously affects the independence of patients in daily life and clinical recovery. Repetitive transcranial magnetic stimulation (rTMS), as a non-invasive neuromodulation technique, is an emerging option for post-stroke dysphagia. Theta burst stimulation (TBS) is a new mode of transcranial magnetic stimulation that simulates the frequency of pulses released in the hippocampus.Intermittent theta burst stimulation (iTBS) has been shown to increase cortical excitability and improve swallowing function in patients. Our study sought to summarize existing clinical randomized controlled trials to provide evidence-based medical evidence for the clinical use of iTBS. A computer search was conducted on 4 Chinese (Chinese Biomedical Literature Database, VIP Information Resource System, CNKI, and Wanfang Medical Science) and 4 English (including Cochrane Library, Embase, PubMed, Web of Science) databases to retrieve all randomized controlled trials in Chinese and English that explored the effects of Intermittent Theta Burst Stimulation for post-stroke dysphagia. The retrieval years are from database construction to 23 November 2023. The primary outcome measure was a change in Penetration/Aspiration Scale (PAS), Standardized Swallowing Assessment (SSA) and Functional Oral Intake Scale (FOIS), Secondary outcomes included Fiberoptic Endoscopic Dysphagia Severity Scale (FEDSS), water-swallowing test (WST) etc. A meta-analysis by Standardized Mean Difference (SMD) and 95% confidence interval (CI) was performed with RevMan 5.3. we appraise risk of bias(RoB) of each study with the Cochrane RoB tool. Detailed instructions for using the Cochrane RoB tool are provided in the Cochrane Handbook for Systematic Reviews of Interventions (The Cochrane Handbook). Nine studies were obtained from eight databases after screening by inclusion and exclusion criteria, 567 patients from 9 studies were included in the meta-analysis, and one study was included in the qualitative analysis due to different control groups. Two of the nine studies had an unclear risk of bias, and four studies were at low risk. The results showed that iTBS significantly improved SSA, PAS, FOIS, and PAS scores in stroke patients compared to the control group(P < 0.05), and promoted swallowing function recovery. Our systematic review provides the first evidence of the efficacy of iTBS in improving dysphagia in stroke patients. However, the number of available studies limits the persuasiveness of the evidence and further validation by additional randomized controlled trials is needed.

Change of Cerebral Hemodynamic Signals during the Process of Swallowing Water, Acetic Acid Solution and Salt Solution in Healthy Adults: An fNIRS Study

BACKGROUND

The aim of this preliminary study was to investigate the similarities and differences in cortical activation patterns during the swallowing of water, acetic acid solution and salt solution in healthy adults using functional near-infrared spectroscopy (fNIRS).

METHODS

Eighteen right-handed healthy adults were recruited and fNIRS was used to measure changes in concentrations of oxygenated hemoglobin (HbO2) and deoxygenated hemoglobin (HbR) in 35 channels during the swallowing of water, acetic acid solution and salt solution. The task-based experiment used a block-design in which participants alternated between resting blocks of 30 s and task blocks (swallowing water, acetic acid solution, or salt solution) of 30 s, repeated six times. Participants remained still during the resting blocks and performed a swallowing action every 6 s during the task blocks. Data preprocessing was conducted using NirSpark software and statistical analyses were performed using either one-sample or paired t-tests to compare differences in cortical activation in healthy participants between swallowing a water and acetic acid solution, as well as swallowing a water and salt solution.

RESULTS

Compared to the resting state, nine brain regions, including primary somatosensory cortex (S1), primary motor cortex (M1), dorsolateral prefrontal cortex (DLPFC), Wernicke's area, premotor cortex (PMC), supplementary motor area (SMA), inferior frontal cortex (IFC), orbitofrontal cortex (OFC) and frontopolar area, were commonly activated during the process of swallowing water, acetic acid solution, and salt solution. The DLPFC, Broca's area, PMC and SMA showed higher activation levels during the swallowing of acetic acid solution when compared to swallowing water, with statistically significant differences (p < 0.05). The frontopolar area and OFC exhibited higher activation during the swallowing of salt solution when compared to water, also with statistically significant differences (p < 0.05).

CONCLUSIONS

Multiple brain regions were activated during the swallowing of water, acetic acid solution and salt solution in healthy adults. Moreover, swallowing acetic acid solution leads to stronger activation of DLPFC, Broca's area, PMC and SMA, while swallowing salt solution leads to stronger activation of the frontopolar area and OFC.

Clinical outcomes associated with speech, language and swallowing difficulties post-stroke

BACKGROUND

 There is a lack of prospective research in South Africa's speech therapy private sector, specifically, in the acute stroke population. There is a need to understand the quality of speech therapy services and outcomes post-stroke in the private sector.

OBJECTIVES

 This prospective cohort study investigated associations between speech, language, and swallowing conditions (i.e. dysarthria, apraxia of speech, aphasia, dysphagia), and outcomes post-stroke (i.e. length of hospital stay [LOS], degree of physical disability according to the Modified Rankin Scale [mRS], functional level of oral intake according to the Functional Oral Intake Scale [FOIS], dehydration, weight loss, aspiration pneumonia, mortality).

METHOD

 A prospective design was used to determine the incidence of speech, language, and swallowing conditions post-stroke. Convenience sampling was used to select participants (N = 68). Various statistical tests were used and the alpha level was set at Bonferroni correction p  0.01.

RESULTS

 Co-occurring speech, language, and swallowing conditions frequently occurred post-stroke (88%). Participants who were referred to speech therapy later than 24 h post-admission (52.94%) stayed in hospital for a median of 3 days longer than those who were referred within 24 h (p = 0.042). Dysphagia was significantly associated with moderate to severe physical disability (p  0.01). Dysphagia with aspiration was significantly associated with poor functional level of oral intake, at admission and at discharge (p  0.01). At discharge, aspiration pneumonia was significantly associated with severe physical disability (p  0.01, r = 0.70).

CONCLUSION

 In South Africa's private sector, co-occurring speech, language, and swallowing conditions commonly occurred post-stroke, and dysphagia was strongly associated with physical disability and poor functional level of oral intake. Length of hospital stay was increased by delayed speech therapy referrals.Contribution: This article contributes data on speech therapy services, communication and swallowing disorders post-stroke, and outcomes in South Africa's private sector.

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.

Swallowing Apraxia Post Ischemic Stroke

A 55-year-old male patient with a known medical history of diabetes mellitus type 2 and treated lymphoma was first admitted with a sudden left-sided facial asymmetry and mouth deviation to the left side with no other neurological symptoms. A Computerized Tomography (CT) scan of the brain showed acute infarct and small left basal ganglia old lacunar infarction. He was discharged on a dual antiplatelet. One week later, the patient's condition had worsened and, therefore, was admitted with an impression of ischemic stroke. A bedside swallowing assessment, VFSS, and FEES study were conducted to diagnose this case. The bedside assessment did not reveal any sensory or motor deficits in his oral cavity and the FEES examination was also unable to rule out pharyngeal dysphagia. However, a videofluoroscopic swallowing study (VFSS) revealed a significant dysfunction of oral preparation and oral phases and presented difficulty initiating the pharyngeal phase. Given these features, we believe that this swallowing difficulty is caused by swallowing apraxia. This case provides additional information and understanding on management from the swallowing side.

Modulating swallowing-related functional connectivity and behavior via modified pharyngeal electrical stimulation: A functional near-infrared spectroscopy evidence

Introduction

Modified pharyngeal electrical stimulation (mPES) is a novel therapeutic modality for patients with neurogenic dysphagia. However, the underlying neural mechanism remains poorly understood. This study aimed to use functional near-infrared spectroscopy (fNIRS) to explore the influence of mPES on swallowing-related frequency-specific neural networks and ethology.

Methods

Twenty-two healthy right-handed volunteers participated in the study. Each participant was randomly assigned to either the sham or the mPES group and provided a 10-min intervention program every day for 5 days. Oxyhemoglobin and deoxyhemoglobin concentration changes verified by fNIRS were recorded on days 1, 3, and 5. Five characteristic frequency signals (0.0095-2 Hz) were identified using the wavelet transform method. To calculate frequency-specific functional connectivity, wavelet phase coherence (WPCO) was adopted. Furthermore, behavioral performance was assessed pre- and post-mPES using a 150 ml-water swallowing stress test.

Results

Compared with sham stimulation on day 1, the significantly decreased WPCO values were mainly associated with the dorsolateral prefrontal lobe, Broca's area, and middle temporal lobe. Compared with the sham mPES on day 1, the mPES showed a noticeable effect on the total swallow duration. Compared with the baseline, the WPCO values on days 3 and 5 showed a stepwise decrease in connectivity with the application of mPES. Furthermore, the decreased WPCO was associated with a shortened time per swallow after mPES.

Conclusions

The mPES could modulate swallowing-related frequency-specific neural networks and evoke swallowing cortical processing more efficiently. This was associated with improved performance in a water swallowing stress test in healthy participants.

The effectiveness of psychoeducational interventions on family function among families after stroke: A meta-analysis

AIMS

This meta-analysis aimed to synthesize the available evidence on the effectiveness of psychoeducational interventions on family function among families after stroke.

BACKGROUND

Family function may be improved by psychoeducational intervention, but findings about the effect of psychoeducation on family function among families after stroke have been mixed.

METHODS

This was a meta-analysis carried out by searching five international electronic databases, including Cochrane Library, PubMed, EMBASE, Web of Science and CINAHL, as well as four national electronic databases, including Chinese Biological Medicine (CBM), China National Knowledge Infrastructure (CNKI), VIP and Wanfang. Two groups of researchers screened the studies independently, assessed the quality of the studies and extracted data. Meta-analysis was performed by using the RevMan 5.3 software.

RESULTS

Five studies on psychoeducational interventions were included. Pooled analysis of these studies showed a small effect of the interventions on improving family function (WMD: -0.13, 95% CI: -0.24 to -0.01, P < 0.05). Subgroup analysis showed significant differences between the psychoeducation and control groups at 1 month postintervention (WMD: -0.12, 95% CI: -0.18 to -0.05, P < 0.05) and more than 6 months postintervention (WMD: -0.14, 95% CI: -0.24 to -0.04, P < 0.05). The psychoeducational interventions also had positive effect on improving the problem solving (WMD: -0.22, 95% CI: -0.14 to -0.03, P < 0.05) and communication (WMD: -0.23, 95% CI: -0.41 to -0.05, P < 0.05) functions of the family. There were significant differences in the group of dyad intervention (WMD: -0.14, 95% CI: -0.25 to -0.02, P < 0.05) and the group using face to face method (WMD: -0.58, 95% CI: -0.84 to -0.32, P < 0.05).

CONCLUSIONS

Synthesized results demonstrated the favourable effect of psychoeducational interventions on the improvement of the family function among families after stroke, especially in terms of family problem solving and family communication. Future psychoeducational intervention research design should consider the combination of multiple intervention methods and the applicable population of intervention.

Effectiveness of Multidisciplinary Nursing Based on Fever, Blood Sugar, and Swallowing Function Management in Patients with Acute Stroke

Purpose

The aim of this study was to assess the effectiveness of multidisciplinary nursing based on fever, blood sugar, and swallowing function management in patients with acute stroke (AS).

Methods

A total of 200 AS patients who were treated in our hospital from January 2016 to January 2020 were recruited and randomized at a ratio of 1 : 1 into a control group and a study group. The control group received standardized early rehabilitation nursing, and the study group received multidisciplinary nursing based on fever, blood sugar, and swallowing function management plus standardized early rehabilitation nursing. The patients were also assigned different blood glucose levels upon admission to a high blood glucose group or a normal blood glucose group. The clinical endpoint is clinical efficacy.

Results

Multidisciplinary nursing resulted in better clinical outcomes and treatment efficiency in the patients in the study group versus standardized early rehabilitation nursing. When compared with the control group, the patients in the study group showed lower National Institute of Health Stroke Scale (NIHSS) scores, higher Barthel Index (BI) scores, lower fasting blood glucose levels and body temperature 24 hours after admission, a lower incidence of swallowing dysfunction and aspiration pneumonia 30 days after nursing, and lower C-reactive Protein (CRP) levels 7 days after nursing. The NIHSS scores of the high blood glucose group were significantly higher than those of the normal blood glucose group.

Conclusion

Multidisciplinary nursing based on fever, blood sugar, and swallowing function management for patients with AS improves the clinical outcome and treatment efficiency, restores the swallowing function and blood glucose level, and ameliorates the long-term prognosis of patients.