The impact of lesion location on dysphagia incidence, pattern and complications in acute stroke. Part 1: dysphagia incidence, severity and aspiration

Revealing Goal-Directed Neural Control of the Pharyngeal Phase of Swallowing

Swallowing is considered a three-phase mechanism involving the oral, pharyngeal, and esophageal phases. The pharyngeal phase relies on highly coordinated movements in the pharynx and larynx to move food through the aerodigestive crossing. While the brainstem has been identified as the primary control center for the pharyngeal phase of swallowing, existing evidence suggests that the higher brain regions can contribute to controlling the pharyngeal phase of swallowing to match the motor response to the current context and task at hand. This suggests that the pharyngeal phase of swallowing cannot be exclusively reflexive or voluntary but can be regulated by the two neural controlling systems, goal-directed and non-goal-directed. This capability allows the pharyngeal phase of swallowing to adjust appropriately based on cognitive input, learned knowledge, and predictions. This paper reviews existing evidence and accordingly develops a novel perspective to explain these capabilities of the pharyngeal phase of swallowing. This paper aims (1) to integrate and comprehend the neurophysiological mechanisms involved in the pharyngeal phase of swallowing, (2) to explore the reflexive (non-goal-directed) and voluntary (goal-directed) neural systems of controlling the pharyngeal phase of swallowing, (3) to provide a clinical translation regarding the pathologies of these two systems, and (4) to highlight the existing gaps in this area that require attention in future research. This paper, in particular, aims to explore the complex neurophysiology of the pharyngeal phase of swallowing, as its breakdown can lead to serious consequences such as aspiration pneumonia or death.

Factors associated with oropharyngeal dysphagia and unsuccessful nasogastric tube removal after endovascular thrombectomy for anterior circulation stroke

PURPOSE

To identify the predictive variables for post-stroke dysphagia (PSD) among anterior circulation large vessel occlusion (LVO) stroke patients who underwent endovascular thrombectomy (EVT).

METHODS

This retrospective cohort study enrolled hospitalized patients with anterior LVO stroke who underwent EVT between January 1, 2018 and October 31, 2022. PSD was defined as the unsuccessful removal of the nasogastric (NG) tube. Factors, such as premorbid characteristics, laboratory results, EVT, rehabilitation-related parameters, and neuro-imaging, were analyzed for correlations to PSD at 4 and 12 weeks.

RESULTS

The study enrolled 136 patients, with a mean age of 72.9 ± 13.0 years, and 59 patients (43.4%) were male. At 4 weeks, 47.1% of the patients needed an NG tube, and at 12 weeks, 16.2% still required an NG tube. We found that lower albumin, lower body mass index (BMI), higher initial and 24-h post-EVT National Institute of Health Stroke Scale (NIHSS) scores, stroke-associated pneumonia, poor initial sitting balance and ability to sit up, insula or frontal operculum lesions, and bilateral hemisphere involvement were all associated with PSD at both 4 and 12 weeks in the univariate logistic regression. Multivariate analysis revealed that significant predictors of unsuccessful NG tube removal at 4 weeks included lower BMI (adjusted OR [aOR] 0.73, p = 0.005), hemorrhagic transformation (aOR 4.01, p = 0.0335), higher NIHSS scores at 24 h post-EVT (aOR 1.13, p = 0.0288), poor initial sitting ability (aOR 0.52, p = 0.0231), insular cortex ischemia (aOR 7.26, p = 0.0056), and bilateral hemisphere involvement (aOR 41.19, p < 0.0001). At 12 weeks, lower BMI (aOR 0.78, p = 0.0098), poor initial sitting balance (aOR 0.57, p = 0.0287), insular cortex lesions (aOR 4.83, p = 0.0092), and bilateral hemisphere involvement (aOR 4.07, p = 0.0139) remained significant predictors.

CONCLUSIONS

In patients with anterior LVO following EVT, PSD was associated with lower BMI, higher NIHSS scores, poor initial sitting balance and sitting ability, insular lesions, and bilateral hemisphere involvement.

Pharyngeal Electrical Stimulation prior to extubation - Reduction of extubation failure rate in acute stroke patients?

PURPOSE

The aim of our study was to assess if PES before extubation can minimize the extubation failure risk in orally intubated, mechanically ventilated stroke patients at high risk of severe dysphagia.

MATERIALS AND METHODS

Thirty-two ICU patients were prospectively enrolled in this study presenting with a high risk for dysphagia as defined by a DEFISS (Determine Extubation Failure In Severe Stroke) risk score and compared 1:1 to a retrospective matched patient control group. The prospective patient group received PES prior to extubation. Endpoints were need for reintubation, swallowing function as assessed with FEES, pneumonia incidence and length of stay after extubation.

RESULTS

Post-extubation, the Fiberoptic Endoscopic Dysphagia Severity Score (FEDSS, 4.31 ± 1.53vs.5.03 ± 1.28;p = 0.047) and reintubation rate within 72 h (9.4vs.34.4%;p = 0.032) were significantly lower in the PES group than in the historical control group. Pulmonary infections after extubation were less common in PES-treated patients although this difference was not significant (37.5vs.59.4%;p = 0.133). Time from extubation to discharge was significantly shorter after PES compared with the control group (14.09 ± 11.58vs.26.59 ± 20.49 days;p = 0.003).

CONCLUSIONS

In orally intubated and mechanically ventilated stroke patients at high risk of severe dysphagia, PES may improve swallowing function, reduce extubation failure risk and decrease time from extubation to discharge. Further research is required.

Correlation between lesion location and dysphagia characteristics in post-stroke patients

OBJECTIVE

To assess the correlation between lesion location and swallowing function characteristics in post-stroke dysphagia (PSD) patients.

MATERIALS AND METHODS

We enrolled 133 PSD. The patients were divided into supratentorial and infratentorial stroke groups. We compared the measurements in the videofluoroscopic swallowing study (VFSS) with 3ml and 5 ml of diluted and thickened barium liquid data between supratentorial and brainstem stroke groups. We further compared the difference of VFSS measurements between patients with left hemispheric or right hemispheric lesions (further divided into unilateral hemispheric cortical and subcortical subgroups) and brianstem leison stroke group.To explore the lesion location's effect on different bolus volume, the VFSS measurements of 3ml and 5ml in each subgroups were compared respectively. The measurements of VFSS included the oral transit time, soft palate elevation duration, hyoid bone movement duration (HMD), UES opening duration, pharyngeal transit duration (PTD), stage of ansition duration, and laryngeal closure duration (LCD), the upper esophageal sphincter opening (UESO), hyoid bone superior horizontal displacement, and hyoid bone anterior horizontal displacement. General swallowing function was assessed using the Penetration Aspiration Scale (PAS) and Functional Oral Intake Scale (FOIS). We performed the paired t-test, Spearman's correlation, and Kruskal-Wallis test analysis to characterize the parameters among the groups.

RESULTS

Fifty-eight patients were assessed in the final analysis. The HMD (p = 0.019), PTD (p = 0.048) and LCD (p = 0.013) were significantly different between the supratentorial and brainstem lesion groups in 5ml volume. The HMD was significantly different (p = 0.045) between the left cortical and brainstem lesion groups. Significant differences in the HMD (p = 0.037) and LCD (p = 0.032) between the left subcortical and brainstem lesion groups were found in 5ml volume bolus. There was no group different when taking the 3ml volume bolus. Regarding the relationship between food bolus volume and swallowing functions, only the UESO demonstrated a significant difference in the subcortical lesion of the right hemisphere (p = 0.0032) compared the 3 ml and 5 ml volume bolus. The PTD demonstrated a moderate correlation with the PAS scores (r = 0.38, p = 0.0044). The HMD (r = 0.32, p = 0.018) and LCD (r = 0.29, p = 0.039) demonstrated weak correlations with the PAS scores. We did not identify any correlation between the VFSS parameters and FOIS scores in each subgroup level.

CONCLUSION

The PSD with brainstem lesion shows more sever dysfunction in the pharyngeal phases. The left hemisphere was engaged in both the oral and pharyngeal phases. Lesions in the bilateral cortical, subcortical, and brainstem regions may impair sensory input.

Transient postictal dysphagia in older adults with focal structural epilepsy

OBJECTIVE

Seizures can cause transient neurological symptoms, such as hemiparesis and aphasia. However, temporary swallowing changes leading to postictal dysphagia have not been previously described. Therefore, this study evaluated the presence of swallowing disorders following seizure. In addition, dysphagia severity and duration of any recovery from dysphagic symptoms were investigated.

METHODS

The local clinical database of all fiberoptic endoscopic evaluation of swallowing (FEES) examinations performed from 2008 to 2019 was screened for patients diagnosed with seizures, but excluding patients with intensive care unit admission or intubation >24 h. Patient charts were evaluated to identify preexisting dysphagia or potential concurrent medical causes for dysphagia, including hyponatremia, increased intracranial pressure, sepsis, or other encephalopathies associated with infections, or other possible causes at the time of admission. Patients receiving >.5 defined daily doses of benzodiazepines or neuroleptics were also excluded. Age, sex, seizure semiology and etiology, comorbidities, concurrent pneumonia, and dysphagia course during hospitalization were evaluated as predictors of the occurrence of dysphagia or its potential duration.

RESULTS

We identified 41 patients with dysphagia following a seizure, without evidence of any concurrent cause of swallowing dysfunction. These patients all presented with focal structural epilepsy, they had a mean age of 79 ± 11.3 years (range = 44-95 years), and 21 were women. The mean Elixhauser Comorbidity Score was 4.8. Hospital-acquired pneumonia was detected in 21 patients (51.2%). FEES diagnosed mild and severe dysphagia in 21 (51.2%) and 20 (48.8%) patients, respectively. Dysphagia improved significantly (p = .001) during hospitalization, persisting for an average of 3.9 days (median = 3 days, SD = 2.07 days, range = 1-8 days).

SIGNIFICANCE

Dysphagia is a potential transient neurological deficit following seizure. Our findings suggest that older patients, with focal structural epilepsy, are at risk for postictal dysphagia. Further studies are needed to ascertain the prevalence, complications, and predictors of postictal dysphagia. Dysphagia screening may improve early detection in patients with relevant risk factors, as well as reduce the occurrence of aspiration pneumonia.

Prevalence and Risk Factors of Poststroke Dysphagia: A Meta-Analysis

INTRODUCTION

In patients with stroke, poststroke dysphagia (PSD) is a common complication that plays an important role in morbidity and mortality. The aim of this paper was to assess the prevalence and risk factors of PSD using a systemic review and meta-analysis.

METHODS

PubMed, Embase, Cochrane Library, and Web of Science databases were systematically searched for potentially eligible studies published until September 2023. Further, the pooled incidence and risk factors for PSD were determined using a random-effects model. Overall, 58 studies involving 37,404 patients with acute stroke were selected for the meta-analysis.

RESULTS

The pooled incidence of PSD in patients with acute stroke was 42% (95% confidence interval [CI]: 36-48%), which is the highest in South America (47%) and lowest in Asia (37%). Notably, older age (odds ratio [OR]: 2.13; 95% CI: 1.53-2.97; p < 0.001), hypertension (OR: 1.23; 95% CI: 1.06-1.44; p = 0.007), diabetes mellitus (OR: 1.22; 95% CI: 1.04-1.44; p = 0.014), stroke history (OR: 1.26; 95% CI: 1.04-1.53; p = 0.019), and atrial fibrillation (OR: 1.58; 95% CI: 1.02-2.44; p = 0.039) were found to be associated with an increased risk of PSD. Conversely, sex differences, smoking, alcoholism, obesity, hyperlipidemia, ischemic heart disease, stroke type, and the hemisphere affected were not associated with the risk of PSD.

CONCLUSION

The abstract reports the prevalence of PSD in patients with acute stroke and identified potential risk factors for PSD, including older age, hypertension, diabetes mellitus, stroke history, and atrial fibrillation.

Health Factors Associated With Development and Severity of Poststroke Dysphagia: An Epidemiological Investigation

BACKGROUND

Dysphagia after stroke is common and can impact morbidity and death. The purpose of this population-based study was to determine specific epidemiological and health risk factors that impact development of dysphagia after acute stroke.

METHODS AND RESULTS

Ischemic and hemorrhagic stroke cases from 2010 and 2015 were identified via chart review from the GCNKSS (Greater Cincinnati Northern Kentucky Stroke Study), a representative sample of ≈1.3 million adults from southwestern Ohio and northern Kentucky. Dysphagia status was determined on the basis of clinical assessments and necessity for alternative access to nutrition via nasogastric or percutaneous endoscopic gastrostomy tube placement. Comparisons between patients with and without dysphagia were made to determine differences in baseline characteristics and premorbid conditions. Multivariable logistic regression determined factors associated with increased risk of dysphagia. Dysphagia status was ascertained from 4139 cases (1709 with dysphagia). Logistic regression showed that increased age, Black race, higher National Institutes of Health Stroke Scale score at admission, having a hemorrhagic stroke (versus infarct), and right hemispheric stroke increased the risk of developing dysphagia after stroke. Factors associated with reduced risk included history of high cholesterol, lower prestroke modified Rankin Scale score, and white matter disease.

CONCLUSIONS

This study replicated previous findings of variables associated with dysphagia (older age, worse stroke, right-sided hemorrhagic lesions), whereas other variables identified were without clear biological rationale (eg, Black race, history of high cholesterol, and presence of white matter disease) and should be investigated in future studies to determine biological relevance and potential influence in stroke recovery.

The Cortical and Subcortical Neural Control of Swallowing: A Narrative Review

Swallowing is a sophisticated process involving the precise and timely coordination of the central and peripheral nervous systems, along with the musculatures of the oral cavity, pharynx, and airway. The role of the infratentorial neural structure, including the swallowing central pattern generator and cranial nerve nuclei, has been described in greater detail compared with both the cortical and subcortical neural structures. Nonetheless, accumulated data from analysis of swallowing performance in patients with different neurological diseases and conditions, along with results from neurophysiological studies of normal swallowing have gradually enhanced understanding of the role of cortical and subcortical neural structures in swallowing, potentially leading to the development of treatment modalities for patients suffering from dysphagia. This review article summarizes findings about the role of both cortical and subcortical neural structures in swallowing based on results from neurophysiological studies and studies of various neurological diseases. In sum, cortical regions are mainly in charge of initiation and coordination of swallowing after receiving afferent information, while subcortical structures including basal ganglia and thalamus are responsible for movement control and regulation during swallowing through the cortico-basal ganglia-thalamo-cortical loop. This article also presents how cortical and subcortical neural structures interact with each other to generate the swallowing response. In addition, we provided the updated evidence about the clinical applications and efficacy of neuromodulation techniques, including both non-invasive brain stimulation and deep brain stimulation on dysphagia.

The neurorehabilitation of post-stroke dysphagia: Physiology and pathophysiology

Swallowing is a complex process involving the precise contractions of numerous muscles of the head and neck, which act to process and shepherd ingested material from the oral cavity to its eventual destination, the stomach. Over the past five decades, information from animal and human studies has laid bare the complex network of neurones in the brainstem, cortex and cerebellum that are responsible for orchestrating each normal swallow. Amidst this complexity, problems can and often do occur that result in dysphagia, defined as impaired or disordered swallowing. Dysphagia is common, arising from multiple varied disease processes that can affect any of the neuromuscular structures involved in swallowing. Post-stroke dysphagia (PSD) remains the most prevalent and most commonly studied form of dysphagia and, as such, provides an important disease model to assess dysphagia physiology and pathophysiology. In this review, we explore the complex neuroanatomical processes that occur during normal swallowing and PSD. This includes how strokes cause dysphagia, the mechanisms through which natural neuroplastic recovery occurs, current treatments for patients with persistent dysphagia and emerging neuromodulatory treatments.

The relationship between dysphagia and the localisation of brain lesion in stroke: is the involvement of the pons and medulla important?

OBJECTIVES

The presence of dysphagia in stroke is associated with mortality and morbidity. The aim of this retrospective study is to present the relationship between dysphagia and the demographic characteristics of the patient, and the type and localisation of brain lesion in the acute period in stroke patients with dysphagia.

MATERIALS AND METHODS

The data of 284 patients who had stroke-related dysphagia, had a disease duration 1-3 months, had no history of swallowing dysfunction before the event, and had their brain MRI/CT reports in the hospital were included.

RESULTS

The rate of tube-dependent oral areas was higher in the lesions located in the pons and the medulla than in the lesions located in the MCA cortex, the basal ganglia, and the cerebellum (p ˂ 0.001, p = 0.032 and p = 0.011, respectively) and the percentage of those fed with NG + TPN + PEG was statistically significantly higher (p = 0.002, p = 0.032 and p = 0.011, respectively). History of pneumonia was found to be statistically significantly higher in the lesions located in the pons and the medulla than in the lesions located in the MCA cortex, ACA cortex, PCA cortex, the basal ganglia, periventricular white matter, the thalamus, the cerebellum, and the midbrain (p ˂ 0.001, p = 0.005, p = 0.023, p ˂ 0.001, p = 0.023, p = 0.001, p = 0.011 and p = 0.023, respectively).

CONCLUSION

In conclusion, although lesion localisation in the acute period in patients with dysphagia varied in terms of clinical swallowing evaluation findings, weight loss, pneumonia history, the rate of tube-dependent intake, were shown to be higher in patients who had lesions in the pons and the medulla, which is a finding that should be considered in the clinical follow-up of acute stroke patients with lesions in the pons and the medulla.

Swallowing performance in older adults: Associated cognitive, neuroanatomical and demographic factors

BACKGROUND

Swallowing problems are frequently seen in older adults, especially in individuals with cognitive impairment (CI). The brain plays a crucial role in both cognition and swallowing. Using magnetic resonance imaging (MRI) data, researchers identified regions associated with swallowing. However, it is not yet fully elucidated which factors influence the swallowing performance in older adults.

OBJECTIVES

The current study investigated which factors, such as cognitive function, neuroanatomical factors (e.g., the cortical thickness and volume of specific brain regions) and demographical factors are associated with swallowing performance in older adults. Secondly, it was investigated whether there is a difference in neuroanatomical factors between individuals with and without CI.

RESEARCH DESIGN AND METHODS

In total, 15 CI individuals (73.1 ± 9.1 years; 46.7% male) and 48 non-CI controls (69.0 ± 5.1 years; 29.2% male) were included. The repetitive saliva swallowing test (RSST) was performed, and an MRI scan was acquired from the participants.

RESULTS

Multivariate linear regression analysis showed that the cortical thickness of the right supramarginal gyrus and female gender were positively associated, and a higher age was negatively associated with the RSST in older adults (p < .05). CI was not significantly associated with swallowing performance. Furthermore, it was found that the cortical volume differs more frequently between CI and non-CI than the cortical thickness.

CONCLUSION

A thinner cortex of the right supramarginal gyrus and being an older female are associated with poorer swallowing performance. Secondly, cortical volume was more often found to differ between CI and non-CI individuals than cortical thickness.

Exploring the neural mechanisms underlying achalasia: A study of functional connectivity and regional brain activity

BACKGROUND AND AIMS

The pathophysiology of achalasia, which involves central nuclei abnormalities, remains unknown. We investigated the resting-state functional MRI (rs-fMRI) features of patients with achalasia.

METHODS

We applied resting-state functional MRI (rs-fMRI) to investigate the brain features in patients with achalasia (n = 27), compared to healthy controls (n = 29). Focusing on three regions of interest (ROIs): the dorsal motor nucleus of the vagus (DMV), the nucleus ambiguus (NA), and the nucleus of the solitary tract (NTS), we analyzed variations in resting-state functional connectivity (rs-FC), fractional amplitude of low-frequency fluctuations (fALFF), and regional homogeneity (ReHo).

RESULTS

Achalasia patients demonstrated stronger functional connectivity between the NA and the right precentral gyrus, left postcentral gyrus, and left insula. No significant changes were found in the DMV or NTS. The fMRI analysis showed higher rs-FC values for NA-DMV and NA-NTS connections in achalasia patients. Achalasia patients exhibited decreased fALFF values in the NA, DMV, and NTS regions, as well as increased ReHo values in the NA and DMV regions. A positive correlation was observed between fALFF values in all six ROIs and the width of the barium meal. The NTS fALFF value and NA ReHo value displayed a positive correlation with integrated relaxation pressure (IRP), while the ReHo value in the right precentral gyrus showed an inverse correlation with the height of the barium meal.

CONCLUSIONS

Abnormal rs-FC and regional brain activity was found in patients with achalasia. Our study provides new insights into the pathophysiology of achalasia and highlights the potential of rs-fMRI in improving the diagnosis and treatment of this condition.

Dysphagia and pulmonary complications in acute cerebrovascular disease: A retrospective observational study

INTRODUCTION

Dysphagia is a common post-stroke complication, which may result in serious pulmonary sequelae. Early detection of dysphagia and aspiration risk can reduce morbidity, mortality and length of hospitalization.

OBJECTIVES

This study aims to identify association between dysphagia and acute cerebrovascular disease, and evaluate the prevalence and impact of pulmonary complications on readmissions and mortality.

MATERIAL AND METHODS

Retrospective observational study based on 250 clinical records of patients with acute cerebrovascular disease: clinical history, neurological examination, imaging and Gugging Swallowing Screen in the first 48h. Patients were followed for 3 months via medical records to estimate 3-month mortality and readmissions.

RESULTS

Out of 250 clinical records analyzed, 102 (40.8%) were evaluated for dysphagia. The prevalence of dysphagia was 32.4%. The risk was higher in older patients (p<0.001), in severe stroke (p<0.001) and in the hemorrhagic subtype (p=0.008). An association was found with dysarthria and aphasia (p=0.003; p=0.017). Respiratory tract infections occurred in 14.4% of all patients (GUSS group 11.8% versus no GUSS group 16.2%), and in 75% of those with severe dysphagia (p<0.001). Mortality at 3 months was 24.2% in dysphagic patients, especially high in the severe dysphagia group (75%, p<0.001).

CONCLUSIONS

The type of cerebrovascular disease, NIHSS and GCS scores, age, dysarthria, and aphasia were significant associated factors to dysphagia. The prevalence of respiratory tract infections was higher in patients with no GUSS record, and no statistical significance was observed in related readmissions. Mortality at 3 months was superior in the severe dysphagia group.

Health factors associated with development and severity of post-stroke dysphagia: an epidemiological investigation

Background and Purpose

Dysphagia is a common post-stroke occurrence and has been shown to impact patients' morbidity and mortality. The purpose of this study was to use a large population-based dataset to determine specific epidemiological and patient health risk factors that impact development and severity of dysphagia after acute stroke.

Methods

Using data from the Greater Cincinnati Northern Kentucky Stroke Study, GCNKSS, involving a representative sample of approximately 1.3 million people from Southwest Ohio and Northern Kentucky of adults (age ≥18), ischemic and hemorrhagic stroke cases from 2010 and 2015 were identified via chart review. Dysphagia status was determined based on bedside and clinical assessments, and severity by necessity for alternative access to nutrition via nasogastric (NG) or percutaneous endoscopic gastrostomy (PEG) tube placement. Comparisons between patients with and without dysphagia were made to determine differences in baseline characteristics and pre-morbid conditions. Multivariable logistic regression was used to determine factors associated with increased risk of developing dysphagia.

Results

Dysphagia status was ascertained from 4139 cases (1709 with dysphagia). Logistic regression showed: increased age, Black race, higher NIHSS score at admission, having a hemorrhagic stroke (vs infarct), and right hemispheric stroke increased risk of developing dysphagia after stroke. Factors associated with reduced risk included history of high cholesterol, lower pre-stroke mRS score, and white matter disease.

Conclusions

This study replicated many previous findings of variables associated with dysphagia (older age, worse stroke, right sided hemorrhagic lesions), while other variables identified were without clear biological rationale (e.g. Black race, history of high cholesterol and presence of white matter disease). These factors should be investigated in future, prospective studies to determine biological relevance and potential influence in stroke recovery.

Repetitive transcranial magnetic stimulation for stroke rehabilitation: insights into the molecular and cellular mechanisms of neuroinflammation

Stroke is a leading cause of mortality and disability worldwide, with most survivors reporting dysfunctions of motor, sensation, deglutition, cognition, emotion, and speech, etc. Repetitive transcranial magnetic stimulation (rTMS), one of noninvasive brain stimulation (NIBS) techniques, is able to modulate neural excitability of brain regions and has been utilized in neurological and psychiatric diseases. Moreover, a large number of studies have shown that the rTMS presents positive effects on function recovery of stroke patients. In this review, we would like to summarized the clinical benefits of rTMS for stroke rehabilitation, including improvements of motor impairment, dysphagia, depression, cognitive function, and central post-stroke pain. In addition, this review will also discuss the molecular and cellular mechanisms underlying rTMS-mediated stroke rehabilitation, especially immune regulatory mechanisms, such as regulation of immune cells and inflammatory cytokines. Moreover, the neuroimaging technique as an important tool in rTMS-mediated stroke rehabilitation has been discussed, to better understanding the mechanisms underlying the effects of rTMS. Finally, the current challenges and future prospects of rTMS-mediated stroke rehabilitation are also elucidated with the intention to accelerate its widespread clinical application.

Relationship between post-stroke dysphagia and pharyngeal sensory impairment

BACKGROUND

Post-stroke dysphagia (PSD) is common and can lead to serious complications. Pharyngeal sensory impairment is assumed to contribute to PSD. The aim of this study was to investigate the relationship between PSD and pharyngeal hypesthesia and to compare different assessment methods for pharyngeal sensation.

METHODS

In this prospective observational study, fifty-seven stroke patients were examined in the acute stage of the disease using Flexible Endoscopic Evaluation of Swallowing (FEES). The Fiberoptic Endoscopic Dysphagia Severity Scale (FEDSS) and impaired secretion management according to the Murray-Secretion Scale were determined, as well as premature bolus spillage, pharyngeal residue and delayed or absent swallowing reflex. A multimodal sensory assessment was performed, including touch-technique and a previously established FEES-based swallowing provocation test with different volumes of liquid to determine the latency of swallowing response (FEES-LSR-Test). Predictors of FEDSS, Murray-Secretion Scale, premature bolus spillage, pharyngeal residue, and delayed or absent swallowing reflex were examined with ordinal logistic regression analyses.

RESULTS

Sensory impairment using the touch-technique and the FEES-LSR-Test were independent predictors of higher FEDSS, Murray-Secretion Scale, and delayed or absent swallowing reflex. Decreased sensitivity according to the touch-technique correlated with the FEES-LSR-Test at 0.3 ml and 0.4 ml, but not at 0.2 ml and 0.5 ml trigger volumes.

CONCLUSIONS

Pharyngeal hypesthesia is a crucial factor in the development of PSD, leading to impaired secretion management and delayed or absent swallowing reflex. It can be investigated using both the touch-technique and the FEES-LSR-Test. In the latter procedure, trigger volumes of 0.4 ml are particularly suitable.

Predicting Failure to Recover Swallowing in Patients with Severe Post-stroke Dysphagia: The DIsPHAGIc Score

In post-stroke dysphagia, early identification of patients at highest risk of failing swallowing recovery (SR) would be useful to decide which of them should undergo percutaneous endoscopic gastrostomy. The studies on this subject were numerous but generally based on small statistical samples. In this retrospective study, 1232 patients with ischemic or hemorrhagic stroke (73.7 ± 13.0 years, 51% men) were assessed: 593 non-dysphagic, 351 partially dysphagic and 288 totally dysphagic. Among the latter, 45.1% could not recover oral intake. A score to assess the risk of failing SR was obtained from the group with total dysphagia, and further 210 patients with total post-stroke dysphagia were utilized for validation. A regular progression of stroke severity markers, complications and mortality was observed from non-dysphagic, to partially dysphagic, up to totally dysphagic patients. Among the latter, seven variables were independently associated with failure of SR, and formed the "DIsPHAGIc score": cerebral lesion Diameter ≥ 6 cm (+ 1), left frontal Ischemia (- 1), Partial anterior circulation syndrome (- 1), Hypoxia (+ 1), Antiplatelet drug (+ 1), GCS verbal reaction < 4 (+ 1), Internal capsule ischemia (- 1). The area under the ROC curve was 0.79 (95% CI 0.74-0.85). For total scores ≥ 2 there was a high risk of failing SR, with specificity 76.9%, sensitivity 72.1% and accuracy 74.7%. The application of the DIsPHAGIc score to the validation sample provided almost identical results. The evolution of post-stroke dysphagia towards irreversibility can be predicted by a simple, reproducible and robust scoring system based on 7 variables commonly available during hospitalization.

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.

Acupuncture combined with balloon dilation for post-stroke cricopharyngeal achalasia: A meta-analysis of randomized controlled trials

Background

The purpose of this study was to systematically evaluate the effectiveness of acupuncture combined with balloon dilatation in patients with post-stroke cricopharyngeal achalasia (CPA) according to the effective rate, videofluoroscopy swallowing study (VFSS) score and standardized swallowing function assessment scale (SSA) score through Meta-analysis.

Methods

English and Chinese language literature published before July 24,2022 were searched in ten electronic databases. The identified articles were screened, data were extracted, and the methodological quality of the included trials was assessed. Using RevMan 5.4.1 software to perform Meta-analysis.

Results

10 studies with 517 patients with post-stroke CPA were included. Meta-analysis showed that the effective rate of the experience group was higher than that of the control group [OR = 0.62; 95% CI (2.32, 13.05); I 2 = 0%; p = 0.0001]. Compared to the control group, the SSA score was lower in the experience group [MD = -4.22; 95% CI (-4.57, -3.87); I 2 = 42%; p < 0.00001]. In terms of VFSS scores, the experience group showed greater efficacy differences than control group [MD = 1.53; 95% CI (1.32, 1.75); I 2 = 0%; p < 0.00001]. The subgroup analysis of VFSS score based on the average course of disease (<1 month vs. ≥1 month) showed no significant difference. The subgroup analysis based on average age (>60 years vs. ≤60 years) showed the VFSS score of the experience group was significantly higher than that of the control group, and the effect may be better in the subgroup older than 60 years. The subgroup analysis based on the treatment course (>30 days vs. ≤30 days) showed the VFSS score of the experience group was significantly higher than that of the control group, and the effect may be better in the subgroup the treatment course>30 days.

Conclusion

Acupuncture combined with balloon dilatation may be an effective method for treating post-stroke CPA. Compared with balloon dilatation, acupuncture combined with balloon can significantly improve the swallowing function of patients, and it is also effective for patients of different courses, ages, and treatment course, while patients over 60 years old and the treatment course over 30 days may have better clinical outcomes.

Dysphagia assessment in ischemic stroke after mechanical thrombectomy: When and how?

Background

Dysphagia is a frequent symptom in acute ischemic stroke (AIS). Endovascular treatment (EVT) has become the standard of care for acute stroke secondary to large vessel occlusion. Although standardized guidelines for poststroke dysphagia (PSD) management exist, they do not account for this setting in which patients receive EVT under general anesthesia. Therefore, the aim of this study was to evaluate PSD prevalence and severity, as well as an appropriate time point for the PSD evaluation, in patients undergoing EVT under general anesthesia (GA).

Methods

We prospectively included 54 AIS patients undergoing EVT under GA. Fiberoptic Endoscopic Evaluation of Swallowing (FEES) was performed within 24 h post-extubation in all patients. Patients presenting significant PSD received a second FEES-assessment to determine the course of dysphagia deficits over time. Dysphagia severity was rated according the Fiberoptic Dysphagia Severity Scale (FEDSS).

Results

At first FEES (FEES 1) assessment, performed in the median 13 h (IQR 5-17) post-extubation, 49/54 patients (90.7%) with dysphagia were observed with a median FEDSS of 4 (IQR 3-6). Severe dysphagia requiring tube feeding was identified in 28/54 (51.9%) subjects, whereas in 21 (38.9%) patients early oral diet with certain food restrictions could be initiated. In the follow up FEES examination conducted in the median 72 h (IQR 70-97 h) after initial FEES 34/49 (69.4%) patients still presented PSD. Age (p = 0.030) and ventilation time (p = 0.035) were significantly associated with the presence of PSD at the second FEES evaluation. Significant improvement of dysphagia frequency (p = 0.006) and dysphagia severity (p = 0.001) could be detected between the first and second dysphagia assessment.

Conclusions

PSD is a frequent finding both immediately within 24 h after extubation, as well as in the short-term course. In contrast to common clinical practice, to delay evaluation of swallowing for at least 24 h post-extubation, we recommend a timely assessment of swallowing function after extubation, as 50% of patients were safe to begin oral intake. Given the high amount of severe dysphagic symptoms, we strongly recommend application of instrumental swallowing diagnostics due to its higher sensitivity, when compared to clinical swallowing examination. Furthermore, advanced age, as well as prolonged intubation, were identified as significant predictors for delayed recovery of swallowing function.

Cerebral control of swallowing: An update on neurobehavioral evidence

This review aims to update the current knowledge on the cerebral control of swallowing. We review data from both animal and human studies spanning across the fields of neuroanatomy, neurophysiology and neuroimaging to evaluate advancements in our understanding in the brain's role in swallowing. Studies have collectively shown that swallowing is mediated by multiple distinct cortical and subcortical regions and that lesions to these regions can result in dysphagia. These regions are functionally connected in separate groups within and between the two hemispheres. While hemispheric dominance for swallowing has been reported in most human studies, the laterality is inconsistent across individuals. Moreover, there is a shift in activation location and laterality between swallowing preparation and execution, although such activation changes are less well-defined than that for limb motor control. Finally, we discussed recent neurostimulation treatments that may be beneficial for dysphagia after brain injury through promoting the reorganization of the swallowing neural network.

The efficacy and safety of catheter balloon dilatation in the treatment of dysphagia after stroke: A protocol for systematic review and meta-analysis

BACKGROUND

Dysphagia is a serious complication after stroke, which has a significant influence on the health as well as life quality of global people. Patients with dysphagia tend to be a higher risk rate of an aspiration than general person. Catheter balloon dilatation is an additional therapy for treating dysphagia in recent years, which can improve the symptom of achalasia of cricopharyngeal muscle. This research will be used for confirming the efficacy and safety of the catheter balloon dilatation for resolving dysphagia.

METHODS

We intend to search literature related to the research in different databases, for instance, China National Knowledge Infrastructure, Wanfang Data, PubMed, Cochrane Library, and Embase up to January 2022. Literature selection, data collection, as well as assessment of bias risk, will be carried out by 2 independent researchers. Data analysis will be conducted by using Stata and review manager 5.4.

RESULTS

The results will be submitted to a peer-reviewed journal.

CONCLUSION

The research will verify whether or not catheter balloon dilatation can improve dysphagia by submitting high-quality data syntheses.

REGISTRATION NUMBER

CRD42022358433.

Case report: A complicated course of Collet-Sicard syndrome after internal carotid artery dissection and lenticulo-striatal artery infarction

A 40-year-old Caucasian man presented with sudden onset of left-sided hemiparesis associated with dysphonia, dysphagia, and right-sided weakness on shoulder elevation and head rotation. The clinical examination revealed deviation of the tongue to the right, absence of right-sided gag reflex, right-sided palatal and vocal cord paresis, and weakness of the right trapezius and sternocleidomastoid muscles; all were in addition to left-sided brachiocephalic-accentuated hemiparesis. The diagnostic examination revealed dissection of the right carotid artery with occlusion of the middle cerebral artery and infarction in the lenticular-striatal artery territory. Mechanical thrombectomy with stent angioplasty of the right internal carotid artery was performed. The paresis of the left side of the body completely regressed within a week after symptom onset, but the dysphonia, weakness of the right trapezius and sternocleidomastoid muscles, and especially dysphagia persisted and regressed slowly but gradually. The patient required percutaneous gastric tube feeding for the next 12 weeks, possibly because of involvement of subcortical white matter tracts. The constellation of symptoms and clinical findings were consistent with Collet-Sicard syndrome, an extremely rare disorder caused by direct compression of the caudal cranial nerves at the base of the skull.

Swallowing function after acute ischemic stroke: Development and validation of a novel clinical prognostic model

Background

Predicting the duration of dysphagia after acute ischemic stroke (AIS) is important for clinical treatment decisions.

Objective

The purpose of this study is to assess the swallowing function of AIS patients and to develop and validate a prognostic model for the need for nasogastric tube (NGT) in these patients.

Materials and methods

We included 554 AIS patients during 2018–2019 as the development group and had 186 AIS patients as the external validation group. The primary end point of the study was the retention of NGT in patients 1 week after admission (Functional Oral Intake Scale ≤ 4). Swallowing function and stroke-associated pneumonia (SAP) at 1 month post-onset were also the objectives of this study. The volume-viscosity swallow test (V-VST) was used to assess the patient’s impaired swallowing function. The Predictive model was built by logistic regression.

Results

Overall, a total of 104 patients required indwelling NGT at 1 week of AIS onset in development group. The final prognostic model includes 5 variables: age (OR: 1.085, 95%CI: 1.049–1.123), neutrophil-to-lymphocyte ratio (NLR) (OR: 1.332, 95%CI: 1.090–1.626), NIHSS (OR: 1.092, 95%CI: 1.025–1.164), history of drinking (OR: 2.532, 95%CI: 1.452–4.417) and stroke location (Subtentorial vs. Supratentorial, OR: 1.954, 95%CI: 1.088–3.509). The prediction model had an AUC of 0.810, while the external validation group was 0.794.

Conclusion

In stroke patients, it is very important to decide early whether to indwell a NGT. The nomogram will support decision making for NGT insertion and help these patients recover from their condition.

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.

Characteristics of dysphagia among different lesion sites of stroke: A retrospective study

Objective

This study aims to compare the characteristics of dysphagia among different lesion sites and explore the possible risk factors that are relevant to penetration and aspiration after stroke.

Materials and methods

Data on patients with post-stroke dysphagia were collected. Major measures of the videofluoroscopic swallowing study included pharyngeal transit duration (PTD), pharyngeal response duration (PRD), soft palate elevation duration (SED), stage transition duration (STD), hyoid bone anterior-horizontal displacement (HAD), hyoid bone superior-horizontal displacement (HSD), upper esophageal sphincter opening (UESO), Pharyngeal Residual Grade (PRG), and Penetration Aspiration Scale (PAS). Included patients were divided into supratentorial (deep or lobar intracerebral) and infratentorial stroke groups. The Kruskal–Wallis test, Spearman’s correlation analysis, and multivariate logistic regression analyses were used to test the difference and the correlation between those measures. Time-to-event endpoints (oral feeding) were analyzed by the Kaplan–Meier method.

Results

A total of 75 patients were included in this study. Significant differences were demonstrated in PTD, PRD, SED, STD, HAD, HSD, UESO, PAS, and PRG between supratentorial and infratentorial stroke groups (p < 0.05). The PRG score of the lobar intracerebral subgroup was significantly higher (p < 0.05) than that of the deep intracerebral and lobar + deep intracerebral stroke subgroups, while HSD was significantly shorter (p < 0.01). Spearman’s correlation analysis revealed that PAS was related to PTD, PRG, HAD, and UESO (p < 0.05). Multivariate logistic regression analysis demonstrated that HAD and PRG may be risk factors for penetration and aspiration (p < 0.05). Kaplan–Meier survival plot showed that there was a significant difference in time to oral feeding between supratentorial and infratentorial stroke groups (p < 0.01).

Conclusion

Infratentorial stroke may lead to worse swallowing function as compared with supratentorial stroke, and lobar intracerebral stroke may be worse than deep intracerebral stroke. Suitable preventive measures may be considered for patients with higher PRG scores and shorter HSD to avoid penetration and aspiration.

Single Nucleotide Polymorphisms May Increase the Risk of Aspiration Pneumonia in Post-Stroke Patients with Dysphagia

This study aimed to evaluate whether genetic polymorphism is associated with an increased risk of infection, specifically post-stroke aspiration pneumonia. Blood samples were obtained from a total of 206 post-stroke participants (males, n = 136; mean age, 63.8 years). Genotyping was performed for catechol-O-methyltransferase (rs4680, rs165599), dopamine receptors (DRD1; rs4532, DRD2; rs1800497, DRD3; rs6280), brain-derived neurotrophic factor (rs6265), apolipoprotein E (rs429358, rs7412), and the interleukin-1 receptor antagonist gene (rs4251961). The subjects were stratified into two groups, aged < 65 (young) and ≥ 65 (elderly). Functional parameters and swallowing outcomes were measured at enrollment and at 3 months post-onset. The primary outcome was the incidence of aspiration pneumonia. Analysis of the association between genetic polymorphisms and aspiration pneumonia history showed that a minor C rs429358 allele was associated with the occurrence of aspiration pneumonia in the young group, both in the additive and the dominant models (odds ratio: 4.53; 95% CI: 1.60−12.84, p = 0.004). In the multivariable analysis, the minor C rs429358 allele increased the risk of post-stroke aspiration pneumonia in young stroke patients by 5.35 (95% CI: 1.64−20.88). In contrast, no such association was observed in the elderly group. Apolipoprotein E polymorphism may affect the risk of post-stroke aspiration pneumonia.

Profiles of Swallowing Impairment in a Cohort of Patients With Reduced Tongue Strength Within 3 Months of Cerebral Ischemic Stroke

PURPOSE

Patients with poststroke dysphagia may experience inefficient bolus clearance or inadequate airway protection. Following a stroke, impairments in lingual pressure generation capacity are thought to contribute to oropharyngeal dysphagia. The goal of our study was to determine whether similar profiles of swallowing impairment would be seen across a cohort of patients with reduced tongue strength within 3 months after cerebral ischemic stroke.

METHOD

The sample comprised six adults with reduced tongue strength (i.e., maximum anterior isometric pressure < 40 kPa). Participants underwent a videofluoroscopy according to a standard protocol. Post hoc blinded ratings were completed using the Analysis of Swallowing Physiology: Events, Kinematics and Timing Method and coded as "typical" versus "atypical" (i.e., within vs. outside the healthy interquartile range) in comparison to published reference values.

RESULTS

The videofluoroscopies suggested that having reduced tongue strength did not translate into a common profile. Of the six participants, two showed Penetration-Aspiration Scale (PAS) scores of ≥ 3 on thin liquids, associated with incomplete laryngeal vestibule closure (LVC). Another two participants displayed PAS scores of 2 (transient penetration), but these were not associated with incomplete LVC. Pharyngeal residue, above the healthy 75th percentile, was seen for three participants. Five participants presented with atypical reductions in hyoid XY peak position.

CONCLUSIONS

In this cohort of adults within 3 months of cerebral ischemic stroke, reductions in tongue strength presented alongside a variety of changes in swallowing physiology. There was no straightforward relationship linking reduced tongue strength to particular patterns of impairment on videofluoroscopy.

Prevalence of dysphagia and risk of pneumonia and mortality in acute stroke patients: a meta-analysis

Background

Post-stroke dysphagia (PSD) has been associated with high risk of aspiration pneumonia and mortality. However, limited evidence on pooled prevalence of post-stroke dysphagia and influence of individual, disease and methodological factors reveals knowledge gap. Therefore, to extend previous evidence from systematic reviews, we performed the first meta-analysis to examine the pooled prevalence, risk of pneumonia and mortality and influence of prognostic factors for PSD in acute stroke.

Methods

Our search was conducted in CINAHL, Cochrane Library, EMBASE, Ovid-Medline, PubMed, and Web of Science an initial search in October 2020 and a follow-up search in May 2021. Data synthesis was conducted using the Freeman-Tukey double-arcsine transformation model for the pooled prevalence rate and the DerSimonian-Lard random-effects model for prognostic factors and outcomes of PSD.

Results

The pooled prevalence of PSD was 42% in 42 studies with 26,366 participants. PSD was associated with higher pooled odds ratio (OR) for risk of pneumonia 4.08 (95% CI, 2.13–7.79) and mortality 4.07 (95% CI, 2.17–7.63). Haemorrhagic stroke 1.52 (95% CI, 1.13–2.07), previous stroke 1.40 (95% CI, 1.18–1.67), severe stroke 1.38 (95% CI, 1.17–1.61), females 1.25 (95% CI, 1.09–1.43), and diabetes mellitus 1.24 (95% CI, 1.02–1.51) were associated with higher risk of PSD. Males 0.82 (95% CI, 0.70–0.95) and ischaemic stroke 0.54 (95% CI, 0.46–0.65) were associated with lower risk of PSD. Haemorrhagic stroke, use of instrumental assessment method, and high quality studies demonstrated to have higher prevalence of PSD in the moderator analysis.

Conclusions

Assessment of PSD in acute stroke with standardized valid and reliable instruments should take into account stroke type, previous stroke, severe stroke, diabetes mellitus and gender to aid in prevention and management of pneumonia and thereby, reduce the mortality rate.

Trial registration

https://osf.io/58bjk/?view_only=26c7c8df8b55418d9a414f6d6df68bdb.

Supplementary information

The online version contains supplementary material available at 10.1186/s12877-022-02960-5.

Transcranial Magnetic Stimulation for Improving Dysphagia After Stroke: A Meta-Analysis of Randomized Controlled Trials

Background

Rehabilitation of post-stroke dysphagia is an urgent clinical problem, and repetitive transcranial magnetic stimulation (rTMS) has been widely used in the study of post-stroke function. However, there is no reliable evidence-based medicine to support the effect of rTMS on post-stroke dysphagia. This review aims to evaluate the effectiveness and safety of rTMS on post-stroke dysphagia.

Methods

English-language literature published before December 20, 2021, were searched in six electronic databases. Identified articles were screened, data were extracted, and the methodological quality of included trials was assessed. Meta-analysis was performed using RevMan 5.3 software. The GRADE method was used to assess the quality of the evidence.

Results

A total of 10 studies with 246 patients were included. Meta-analysis showed that rTMS significantly improved overall swallowing function (standardized mean difference [SMD]−0.76, 95% confidence interval (CI)−1.07 to−0.46, p < 0.0001, n = 206; moderate-quality evidence), Penetration Aspiration Scale (PAS) (mean difference [MD]−1.03, 95% CI−1.51 to−0.55, p < 0.0001, n = 161; low-quality evidence) and Barthel index scale (BI) (MD 23.86, 95% CI 12.73 to 34.99, p < 0.0001, n = 136; moderate-quality evidence). Subgroup analyses revealed that (1) rTMS targeting the affected hemisphere and targeting both hemispheres significantly enhanced overall swallowing function and reduced aspiration. (2) Low-frequency rTMS significantly enhanced overall swallowing function and reduced aspiration, and there was no significant difference between high-frequency rTMS and control group in reducing aspiration (p = 0.09). (3) There was no statistical difference in the dropout rate (low-quality evidence) and adverse effects (moderate-quality evidence) between the rTMS group and the control group.

Conclusion

rTMS improved overall swallowing function and activity of daily living ability and reduced aspiration in post-stroke patients with good acceptability and mild adverse effects.

Neurogenic Dysphagia in Subdural Hematoma

INTRODUCTION

Dysphagia is a common and severe symptom of traumatic brain injury (TBI) affecting up to 78% of patients. It is associated with pneumonia, increased morbidity, and mortality. Although subdural hematoma (SDH) accounts for over 50% of TBI, the occurrence of dysphagia in this subtype has not been investigated yet.

METHODS

All patients with SDH admitted to the author's institution between the years 2007 and 2020 were included in the study. Patients with SDH and clinical suspicion for dysphagia received a clinical swallowing assessment by a speech and language pathologist (SLP). Furthermore, the severity of dysphagia was rated according to swallowing disorder scale. Functional outcome was evaluated by the Glasgow outcome scale (GOS).

RESULTS

Out of 545 patients with SDH, 71 patients had dysphagia (13%). The prevalence of dysphagia was significantly lower in the surgical arm compared to the conservative arm (11.8 vs. 21.8%; OR 0.23; p = 0.02). Independent predictors for dysphagia were GCS <13 at admission (OR 4.17; p < 0.001), cardiovascular disease (OR 2.29; p = 0.002), and pneumonia (OR 2.88; p = 0.002), whereas the operation was a protective factor (OR 0.2; p < 0.001). In a subgroup analysis, right-sided SDH was an additional predictor for dysphagia (OR 2.7; p < 0.001). Overall, patients with dysphagia improved significantly under the SLP treatment from the initial diagnosis to hospital discharge (p < 0.01). However, a subgroup of patients with the most severe grade of dysphagia showed no significant improvement. Patients with dysphagia had significantly worse outcomes (GOS 1-3) compared to those without dysphagia (48.8 vs. 26.4%; p < 0.001).

CONCLUSION

Dysphagia is a frequent symptom in SDH, and the early identification of dysphagia is crucial regarding the initiation of treatment and functional outcome. Surgery is effective in preventing dysphagia and should be considered in high-risked patients.

Theta burst stimulation versus high-frequency repetitive transcranial magnetic stimulation for poststroke dysphagia: A randomized, double-blind, controlled trial

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) of high-frequency (10 Hz) on suprahyoid motor cortex has been an evidence-based treatment for poststroke dysphagia. Intermittent theta burst stimulation (iTBS) can be performed in 3 minutes compared with 20 ± 5 minutes for 10 Hz rTMS. This study aimed to ensure the clinical efficacy, safety, and tolerability of iTBS compared with 10 Hz rTMS for patients with poststroke dysphagia.

METHOD

In this randomized, double-blind, single-center, controlled trial, 47 participants were randomly assigned to iTBS (n = 24) and rTMS (n = 23) group. Each participant received iTBS or rTMS daily at suprahyoid motor cortex of affected hemisphere for 10 consecutive days. The outcomes were assessed at baseline, immediately, and 2 weeks after intervention, including water-swallowing test, standardized swallowing assessment, Mann assessment of swallowing ability, Murray Secretion Scale, Yale Pharyngeal Residue Severity Rating Scale, Penetration-Aspiration Scale, and motor evoked potential (MEP) of bilateral suprahyoid muscle.

RESULTS

There were no significant differences between groups. There was a significant improvement on all rating scales and MEP after rTMS and iTBS. No significant differences on water-swallowing test, Mann assessment of swallowing ability, standardized swallowing assessment, Murray Secretion Scale scores, and MEP were observed between groups. In particular, there was significant differences on Penetration-Aspiration Scale scores (viscous liquid: mean difference = 1.016; 95% CI: 0.32-1.71; effect size: 0.360; P = .005) and the residue rate of pyriform fossa (viscous liquid: mean difference = 0.732; 95% CI: 0.18-1.28; effect size: 0.248; P = .010) in between-group. Comparing the differences over the changes of all rating scales, only the residue rate of epiglottis valley between groups was found to be significantly different (dilute liquid: mean difference = -0.567; 95% CI: -0.98 to -0.15; P = .009). There was no severe adverse effect and high dropout rates in both groups.

CONCLUSION

The clinical efficacy, safety, and tolerability of iTBS showed non-inferior to 10 Hz rTMS for patients with poststroke dysphagia. The present study can be used to improve the clinicians' knowledge and clinical decision skills on iTBS and rTMS for poststroke dysphagia.

Total magnetic resonance imaging of cerebral small vessel disease burden predicts dysphagia in patients with a single recent small subcortical infarct

Background

This study was performed to identify the association between the total magnetic resonance imaging burden of small vessel disease and the occurrence of post-stroke dysphagia in patients with a single recent small subcortical infarct (RSSI).

Methods

We retrospectively identified all patients with a magnetic resonance imaging-confirmed single RSSI. The water-swallowing test and volume-viscosity swallow test were performed within the first 24 h following admission to assess swallowing. Demographic and clinical data were extracted from our stroke database. Based on brain magnetic resonance imaging, we independently rated the presence of cerebral microbleeds, lacunes, white matter hyperintensities and enlarged perivascular spaces. The presence of each small vessel disease feature was summed to determine the total small vessel disease burden, ranging from 0 to 4.

Results

In total, 308 patients with a single RSSI were enrolled. Overall, 54 (17.5%) were diagnosed with post-stroke dysphagia. The risk factors related to post-stroke dysphagia included the following: older age, higher National Institute of Health Stroke Scale scores, higher C-reactive protein level and higher fibrinogen level. Based on multiple logistic regression, National Institute of Health Stroke Scale scores and total small vessel disease burden were independent risk factors of post-stroke dysphagia in patients with a single RSSI, after adjusting for age, gender, history of hypertension, C-reactive protein level and fibrinogen level.

Conclusions

Dysphagia in patients with a single RSSI was associated with a more severe total small vessel disease burden as reflected by MRI. Total MRI of cerebral small vessel disease burden may predict dysphagia in these patients. Furthermore, more severe total small vessel disease burden was associated with systemic inflammation.

Oropharyngeal dysphagia in elderly persons: Etiology, pathophysiology and symptomatology

Swallowing disorders can occur at any age, although they occur more often in old age when the physiology of swallowing changes due to aging. Oropharyngeal dysphagia is a very common clinical condition affecting 13% of the total population over 65 years of age and 51% of institutionalized older people. Given that oropharyngeal dysphagia can lead to increased morbidity and mortality in the elderly, it is necessary to prevent the occurrence of dysphagia in this population group as much as possible. In relation to this, the paper aims to provide insight into contemporary research into the etiology, pathophysiology, and symptomatology of oropharyngeal dysphagia in the elderly. In this review study, the electronic databases of Google Scholar Advanced Search and the Consortium of Serbian Libraries for Unified Procurement - KoBSON were searched. The following keywords and phrases were used in the search: swallowing, dysphagia, oropharyngeal dysphagia, aging, age and dysphagia, etiology of oropharyngeal dysphagia, the clinical picture of oropharyngeal dysphagia, pathophysiology of oropharyngeal dysphagia. This systematic review and meta-analysis of papers showed significant progress in the effective diagnostic approach of oropharyngeal dysphagia during the last years but also a significant lack of knowledge about adequate modifications of drugs applied during the treatment of patients with dysphagia. A good understanding of the etiology, pathophysiology, and symptomatology of oropharyngeal dysphagia would eliminate the harmful effects of pharmacological substances on the function of swallowing, given that the elderly, on the advice of a doctor, use them daily.

Neural correlates in the development of and recovery from dysphagia after supratentorial stroke: A prospective tractography study

•

Stroke may lead to unilateral or bilateral CBT changes regardless of dysphagia.

•

Poor fractional anisotropy of the unaffected sides relates to limited recovery.

•

Swallowing recovery may depend on the integrity of the unaffected CBT.

•

Bi-hemispheric reorganization of the CBT is associated with swallowing recovery.

Background

Methods

Results

Conclusions

Electromyographic study assessing swallowing function in subacute stroke patients with respiratory muscle weakness

BACKGROUND

Dysphagia has been reported to be associated with the descent of the hyolaryngeal complex. Further, suprahyoid muscles play a greater role than infrahyoid muscles in elevation of the hyolarngeal complex. Respiratory muscle training (RMT) can improve lung function, and expiratory muscle strength training can facilitate elevation of the hyoid bone and increase the motor unit recruitment of submental muscles during normal swallowing. This study aimed to investigate the surface electromyography (sEMG) of the swallowing muscles, bilaterally, and the effect of RMT on swallowing muscles in stroke patients with respiratory muscle weakness.

METHODS

Forty patients with first episode of unilateral stroke were included in this retrospective controlled trial. After exclusion of 11 patients with respiratory muscle strength stronger than 70% of the predicted value, 15 were allocated to the RMT group and 14 to the control group. However, eventually, 11 patients in RMT group and 11 patients in control group completed the study. The sEMG of the orbicularis oris, masseter, submental, and infrahyoid muscles were recorded during dry swallowing, water swallowing (2 mL), and forced exhalation against a threshold breathing trainer set at different intensities, at baseline and after 6-week RMT.

RESULTS

Regarding the sEMG of submental muscles, there were significant between-group differences on the latency of the unaffected side (P = .048), significant change from baseline force on the unaffected side (P = .035), and significant between-side difference (P = .011) in the RMT group during dry swallowing. Significant change in the duration from baseline was observed on the affected side of the RMT group when blowing was set at 50% maximal expiratory pressure (MEP; P = .015), and on the unaffected side of the control group when blowing set at 15% MEP (P = .005). Significant difference was observed in the duration between 50% MEP and 15% MEP after 6-week program in the control group (P = .049).

CONCLUSIONS

A 6-week RMT can improve the electric signal of the affected swallowing muscles with more effect on the unaffected side than on the affected side during dry swallowing. Furthermore, RMT with 50% MEP rather than 15% MEP can facilitate greater submental muscle activity on the affected side in stroke patients with respiratory muscle weakness.

Voxel-based lesion symptom mapping analysis for dysphagia in stroke patients with isolated cerebellar lesions

Because the cerebellum plays a role in motor coordination, timing, sequencing, and feedback, it is hypothesized to be involved in swallowing-related functions. The role of the cerebellum in deglutition has become increasing evident, but the exact nature of this role remains inconclusive because of limited data from pure cerebellar lesions. Therefore, we conducted location analysis in isolated cerebellar lesions to complement previous findings and provide additional information. We reviewed 40 stroke patients with isolated cerebellar lesion. Lesion location and volume were measured on brain magnetic resonance images. We generated statistical maps of lesions related to VDS using voxel-based lesion symptom mapping (VLSM). We also created an overlay map of subgroups according to VDS score, those who have low risk and those who have high risk. Patients with cerebellar lesion had difficulty swallowing, both in the oral and pharyngeal phases. Multivariate analysis of cognitive function was selected as an independent predictor. In the group of high-risk patients, the overlay map showed some bilateral asymmetry, with a wider distribution in the left hemisphere and involvement of deep cerebellar nuclei. Using VLSM, we found that lesion location was associated with dysphagia. Although these results were not statistically significant, they showed a lesion pattern with predominant distribution in the left posterior lobe. Our results suggest that damage to the posterior lobe of the left cerebellum tends be related to severity of dysphagia in patients with isolated cerebellar lesion.

Structural Connectivity Affecting Aspiration After Stroke

Aspiration after stroke is associated with pneumonia and mortality. In this study, we investigated brain structural connectivity associated with aspiration after unilateral supratentorial stroke. Patients on oral feeding after stroke were divided into liquid aspiration (22 patients) and normal (18 patients) groups based on videofluoroscopic swallowing studies. Voxel-based lesion-symptom mapping and voxel-wise group comparison of fractional anisotropy, mode of anisotropy, and mean diffusivity maps were conducted. Voxel-based lesion-symptom mapping revealed no significant lesion differences between groups. The aspiration group showed significantly increased fractional anisotropy and mode of anisotropy in the anterior limb and the genu of the internal capsule in the right hemisphere. In contrast, the normal group showed significantly increased mean diffusivity, mainly in the superior longitudinal fasciculus in the right hemisphere (P < 0.05). Degeneration of the internal capsule in the right hemisphere was found to affect aspiration after stroke.

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

Background and purpose: Early recognition and management of post-stroke dysphagia (PSD) based on MRI may reduce the incidence of complications. Combining clinical symptoms with applications of MRI, we aimed to identify the risk factors of PSD, develop a prediction scale with high accuracy and map key dysphagia brain areas.

Methods: A total of 275 acute ischemic stroke patients were enrolled in this study, and 113 (41.1%) patients were diagnosed with PSD. All patients underwent the water-swallowing test (WST) and volume-viscosity swallow test (V-VST) within first 24 h following admission to assess swallowing. Vascular factors were evaluated and MRI brain scans were obtained within 3 days after symptom onset for each participant admitted to the hospital. T-test, chi-squared test and Fisher’s exact test were used to investigate the associations of various patient characteristics with dysphagia, and multivariable logistic regression models were used to construct a prediction scale. Scale accuracy was assessed using receiver operating characteristic (ROC) analysis. We extracted white matter hyperintensities for each patient as potential brain lesions. Voxel-based lesion-symptom mapping (VLSM) was used to identify key brain areas for dysphagia.

Results: Risk factors related with PSD were older age, history of atrial fibrillation, higher fasting blood glucose, NIH stroke scale, TOAST classification, progressive stroke, middle cerebral artery lesion and anterior cerebral artery lesion. Three variables with most significant associations, including NIH stroke scale, TOAST classification and progressive stroke, combined with age and gender, were used to construct a dysphagia prediction scale with high accuracy (AUC = 0.86). VLSM identified left inferior parietal gyrus as a key brain region for PSD.

Conclusion: Risk factors of PSD were identified and a predictive model of dysphagia was constructed intelligently and automatically. The left inferior parietal gyrus was identified as a key brain area for dysphagia, which provides a new symptom-based treatment target for early rehabilitation in the future.

Noninvasive Brain Stimulation for Poststroke Dysphagia: A Meta-Analysis for Randomized Controlled Trials

BACKGROUND

Past research has indicated that repetitive transcranial magnetic stimulation (rTMS) on the pharyngeal motor cortex may be beneficial to poststroke dysphagic patients. In addition, some studies have supported that transcranial direct current stimulation (tDCS) over the pharyngeal motor cortex can improve swallowing function in poststroke dysphagia. However, some studies showed that rTMS and tDCS show no effect on poststroke dysphagia. This study aims to make a meta-analysis to investigate the therapy effect of rTMS and tDCS on poststroke dysphagia in randomized controlled trials (RCTs).

METHODS

We searched for studies published before March 2021 in databases (PubMed, Web of Science, MEDLINE, EMBASE, and Google Scholar). Meta-analysis was made to compute the results of included studies using STATA 12.0 software.

RESULTS

The present study shows a significant increase in the swallowing function in poststroke dysphagia given rTMS compared to those given sham rTMS (standardized mean difference [SMD] = 1.08, 95% confidence interval [CI] = 0.37-1.80, I2 = 81.2%, p < 0.001). In addition, the study shows a significant increase in the swallowing function in poststroke dysphagia given tDCS (combined or not combined with conventional swallowing therapy), compared to those given sham tDCS (combined or not combined with conventional swallowing therapy) (SMD = 1.43, 95% CI = 0.73-2.13, I2 = 77.6%, p < 0.001).

CONCLUSIONS

The study demonstrates that rTMS and tDCS over the pharyngeal motor cortex show therapy effects on poststroke dysphagia. Many more large-scale, blinded RCTs are essential to investigate the effect of rTMS and tDCS on poststroke dysphagia.

The Role of White Matter in the Neural Control of Swallowing: A Systematic Review

Background: Swallowing disorders (dysphagia) can negatively impact quality of life and health. For clinicians and researchers seeking to improve outcomes for patients with dysphagia, understanding the neural control of swallowing is critical. The role of gray matter in swallowing control has been extensively documented, but knowledge is limited regarding the contributions of white matter. Our aim was to identify, evaluate, and summarize the populations, methods, and results of published articles describing the role of white matter in neural control of swallowing.

Methods: We completed a systematic review with a multi-engine search following PRISMA-P 2015 standards. Two authors screened articles and completed blind full-text review and quality assessments using an adapted U.S. National Institute of Health's Quality Assessment. The senior author resolved any disagreements. Qualitative synthesis of evidence was completed.

Results: The search yielded 105 non-duplicate articles, twenty-two of which met inclusion criteria. Twenty were rated as Good (5/22; 23%) or Fair (15/22; 68%) quality. Stroke was the most represented diagnosis (n = 20; 91%). All studies were observational, and half were retrospective cohort design. The majority of studies (13/22; 59%) quantified white matter damage with lesion-based methods, whereas 7/22 (32%) described intrinsic characteristics of white matter using methods like fractional anisotropy. Fifteen studies (68%) used instrumental methods for swallowing evaluations. White matter areas commonly implicated in swallowing control included the pyramidal tract, internal capsule, corona radiata, superior longitudinal fasciculus, external capsule, and corpus callosum. Additional noteworthy themes included: severity of white matter damage is related to dysphagia severity; bilateral white matter lesions appear particularly disruptive to swallowing; and white matter adaptation can facilitate dysphagia recovery. Gaps in the literature included limited sample size and populations, lack of in-depth evaluations, and issues with research design.

Conclusion: Although traditionally understudied, there is sufficient evidence to conclude that white matter is critical in the neural control of swallowing. The reviewed studies indicated that white matter damage can be directly tied to swallowing deficits, and several white matter structures were implicated across studies. Further well-designed interdisciplinary research is needed to understand white matter's role in neural control of normal swallowing and in dysphagia recovery and rehabilitation.

Association of Lesion Pattern and Dysphagia in Acute Intracerebral Hemorrhage

[Figure: see text].

Tube feeding predictors after ischemic hemispheric stroke during hospitalization

PURPOSE

To verify the factors associated with the need of tube feeding (TF) during patients post-ischemic stroke hospitalization.

METHOD

This is a retrospective study with 70 adult post-ischemic hemispheric stroke adult patients hospitalized in the Neurology department at a tertiary public hospital in Santa Catarina, Brazil. We investigated associations between the need of a feeding tube during hospitalization and the variables age, gender, admission and discharge NIHSS and FOIS, length of hospital stay in days, presence of thrombolytic therapy, extensive stroke, hemisphere affected, prior stroke, pneumonia during hospitalization, presence of signs of laryngeal penetration and laryngotracheal aspiration and dysphagia in the first and last swallowing clinical evaluation.

RESULTS

A total of 33 participants used tube feeding. There was a significant relationship among tube feeding and the following parameters: NIHSS (p value .001), FOIS (p value .001), extensive stroke (p value .034), left hemisphere involvement (p value .035), pneumonia during hospitalization (p value .001), length of hospital stay in days (p value .001), signs of laryngotracheal penetration/aspiration (p value .001) and dysphagia in speech-language assessment (p value .001).

CONCLUSION

Tube feeding during patients hospitalization after ischemic hemispheric stroke was predicted by the severity of stroke and signs of airway permeation.Key pointsSwallowing difficulty is one of the most common post-stroke consequences.There are few studies on the characterization of post-stroke patients with tube feeding.Tube feeding after ischemic stroke predictors were severity of stroke and signs of airway permeation.

Post-stroke dysphagia: frequency, risk factors, and topographic representation: hospital-based study

Background

The frequency of dysphagia varies considerably across literature. Post-stroke dysphagia is a common cause of increased morbidity and length of hospitalization. This study aimed to estimate the frequency, risk factors of dysphagia following first-ever ischemic or hemorrhagic stroke and its neuroradiological correlation.

Methods

Two hundred fifty patients (180 ischemic and 70 hemorrhagic strokes) with first-ever stroke were recruited within 72 h of onset. Detailed history, neurological examination, and computed tomography and/or magnetic resonance were done for each patient. Severity of stroke was evaluated by the National Institutes of Health Stroke Scale (NIHSS). Swallowing function was assessed by water swallowing test (WST) and dysphagia outcome severity scale (DOSS).

Results

Ninety-eight (39.2%) of all stroke patients had dysphagia, 57 (31.7%) of ischemic group, 41 (58.6%) of hemorrhagic group. The mean age of ischemic group with dysphagia was older than ages of non-dysphagic and older than hemorrhagic stroke with dysphagia group. The mean total NIHSS was higher in dysphagic group than non-dysphagic group in both ischemic and hemorrhagic stroke. Dysphagia in ischemic group was highly associated with diabetes mellitus (DM), hypertension (HTN), and atrial fibrillation (AF). Dysphagia was commonly associated with middle cerebral artery (MCA), brainstem, and capsular infarctions as well as with intracerebral hemorrhage (ICH) with ventricular extension. Stroke severity and lesion size were the main determinant of dysphagia severity.

Conclusions

The frequency of post-stroke dysphagia is consistent with other studies. Advanced age, DM, HTN, and AF were the main risk factors. MCA, brain stem, capsular infarctions, and ICH with ventricular extension were frequently associated with dysphagia. Stroke severity and lesion size were independent predictors of dysphagia severity.

Effects of aging on brain networks during swallowing: general linear model and independent component analyses

Swallowing disorders occur more frequently in older adults. However, the effects of the aging process on neural activation when swallowing are unclear. We aimed to identify neural regions activated during swallowing and evaluate changes in neural activation and neural networks with aging. Using a general linear model (GLM) and independent component (IC) analyses, blood oxygen level-dependent (BOLD) signals were observed in the lateral precentral gyrus, postcentral gyrus, anterior insular cortices, supramarginal gyri, and medial frontal gyrus during swallowing. The right thalamus and anterior cingulate gyri were found to be active areas by GLM and IC analyses, respectively. In the correlational analyses, age was negatively correlated with BOLD signals of the lateral precentral gyri, postcentral gyri, and insular cortices in swallowing tasks. Additionally, correlation analyses between ICs of all participants and age revealed negative correlations in the right supramarginal gyrus, both anterior cingulate cortices, putamen, and cerebellum. In the network analysis, the BOLD signal positively correlated with age in the default mode network (DMN), and was negatively correlated in the lateral precentral gyri, postcentral gyri, and insular cortices. The amplitude of low-frequency fluctuations was significantly decreased in the DMN and increased in swallowing-related areas during swallowing tasks. These results suggest that aging has negative effects on the activation of swallowing-related regions and task-induced deactivation of the DMN. These changes may be used to detect early functional decline during swallowing.

Role of rs6265 BDNF polymorphisms and post-stroke dysphagia recovery-A prospective cohort study

BACKGROUND

Previous studies suggest that specific genes may predispose some to increased risk of dysphagia in the geriatric population, but whether these genes may affect swallowing recovery after a stroke is unknown. This study investigated whether single-nucleotide polymorphisms (SNP) of the brain-derived neurotrophic factor (BDNF), catechol-O-methyl transferase, apolipoprotein E, interleukin-1 receptor antagonist, and dopamine, which have been linked to swallowing, could adversely affect the prognosis of post-stroke dysphagia.

METHODS

In this study, 218 subjects with confirmed post-stroke dysphagia were enrolled. The primary endpoint was failed recovery from nil per mouth (NPM) status with the first 3 months post-stroke.

KEY RESULTS

The Val/Val group from the rs6265, BDNF, showed higher score changes on the Functional Oral Intake Scale at 1 month. The proportion of patients with recovery from NPM status within the first 1 month was 60.8% in the Val/Val group, which was statistically higher than those in the Met allele groups (38.1%, P = .017). At 3 months, the BDNF rs6265 showed significant group differences in Modified Barium Swallow Impairment Profile^© score changes with the Val/Val allele leading to greater improvement. However, no single SNP was associated with increased risk of poor recovery with persistence of NPM at 3 months post-stroke.

CONCLUSIONS AND INFERENCES

Those with the dominant Val/Val phenotype of BDNF manifested with faster and greater improvement than the Met-phenotypes. Based on our results, the BDNF Val allele may play a positive role with faster score improvement and rapid recovery from NPM than the Met allele. Clinical Trials gov: NCT03577444 (https://clinicaltrials.gov/ct2/show/study/NCT03577444).

Classification of Stroke Patients With Dysphagia Into Subgroups Based on Patterns of Submental Muscle Strength and Skill Impairment

OBJECTIVES

To identify and characterize subgroups of stroke patients with clinical signs of dysphagia, based on swallowing-related strength and skill impairments of the submental muscle group.

DESIGN

Prospective observational study.

SETTING

Inpatient rehabilitation centers and community dwellings.

PARTICIPANTS

Individuals (N=114), including stroke patients with dysphagia (n=55) and 2 control groups including myopathic patients with dysphagia (n=19) and healthy volunteers (n=40) were included in this study.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Novel clinical assessment of strength (force generation) and skill (spatial and temporal precision of muscle activation) of the submental muscle group during swallowing and nonswallowing behaviors, using surface electromyography and dynamometry.

RESULTS

Hierarchical cluster analysis revealed 4 clusters, which could be broadly characterized as cluster 1: intact strength and skill, cluster 2: poor strength and poor nonswallowing skill, cluster 3: poor strength, and cluster 4: poor strength and poor swallowing skill. Membership in cluster was significantly associated with medical diagnosis (P<.001). The majority of healthy and myopathic participants were assigned to clusters 1 and 3, respectively, whereas stroke patients were found in all 4 clusters. Skill outcome measures were more predictive of cluster assignment than strength measures.

CONCLUSIONS

Although healthy and myopathic participants demonstrated predominantly homogeneous swallowing patterns of submental muscle function within their etiology, several subgroups were identified within stroke, possibly reflecting different subtypes of swallowing function. Future research should focus on the nature and rehabilitation needs of these subtypes. Assessment of skill in swallowing may be an important but overlooked aspect of rehabilitation.

Ischemic Lesion Location Based on the ASPECT Score for Risk Assessment of Neurogenic Dysphagia

Dysphagia is common in patients with middle cerebral artery (MCA) infarctions and associated with malnutrition, pneumonia, and mortality. Besides bedside screening tools, brain imaging findings may help to timely identify patients with swallowing disorders. We investigated whether the Alberta stroke program early CT score (ASPECTS) allows for the correlation of distinct ischemic lesion patterns with dysphagia. We prospectively examined 113 consecutive patients with acute MCA infarctions. Fiberoptic endoscopic evaluation of swallowing (FEES) was performed within 24 h after admission for validation of dysphagia. Brain imaging (CT or MRI) was rated for ischemic changes according to the ASPECT score. 62 patients (54.9%) had FEES-proven dysphagia. In left hemispheric strokes, the strongest associations between the ASPECTS sectors and dysphagia were found for the lentiform nucleus (odds ratio 0.113 [CI 0.028–0.433; p = 0.001), the insula (0.275 [0.102–0.742]; p = 0.011), and the frontal operculum (0.280 [CI 0.094–0.834]; p = 0.022). A combination of two or even all three of these sectors together increased relative dysphagia frequency up to 100%. For right hemispheric strokes, only non-significant associations were found which were strongest for the insula region. The distribution of early ischemic changes in the MCA territory according to ASPECTS may be used as risk indicator of neurogenic dysphagia in MCA infarction, particularly when the left hemisphere is affected. However, due to the exploratory nature of this research, external validation studies of these findings are warranted in future.

Post-stroke Dysphagia: Recent Insights and Unanswered Questions

PURPOSE OF REVIEW

We explored themes in recent post-stroke dysphagia literature, focusing on the following questions: (1) What does post-stroke dysphagia look like?; (2) Who gets post-stroke dysphagia?; (3) What are the consequences of post-stroke dysphagia?; and (4) How can we improve treatment of post-stroke dysphagia?

RECENT FINDINGS

There have been several improvements in quantitative descriptions of swallowing physiology using standard and new evaluation techniques. These descriptions have been correlated with lesion locations, and several factors can predict development of post-stroke dysphagia and its sequelae. Novel treatment paradigms have leveraged post-stroke neuroplastic improvements using neurostimulation and biofeedback techniques. Despite recent findings, the field is limited by lack of standardization and unanswered questions on rehabilitation variables. Our improved understanding of post-stroke dysphagia will enhance our ability to prevent, identify, and treat it. Future work should be grounded in swallowing physiology and continue refining treatments, particularly in the acute stage.