Complications and outcome after acute stroke. Does dysphagia matter?

Pilot Study on an Acoustic Measurements System of the Swallowing Function Using an Acoustic-Emissions Microphone

The goal of this study is to evaluate the swallowing functions of people with dysphagia using an acoustic microphone sensor. As a basic investigation towards this end, we measured the swallowing sounds using an acoustic emissions microphone sensor (AE sensor), then analyzed the frequency range of the measured signals, and we examined the method for obtaining the necessary information to evaluate the swallowing functions. For the measurement, two types of sensors, i.e., a condenser throat microphone and an AE sensor, were employed to measure the swallowing sounds. The acoustic signals obtained were subjected to spectral analysis using the wavelet transformation, and a comparison was performed between the measurable ranges of the acoustic signals obtained by the AE and the acoustic sensors. The results from the wavelet transformation of the acoustic signals obtained by the AE sensor indicated that acoustic signals generated during swallowing contained frequency information of 3 kHz and higher, which were not measurable with the acoustic sensor used in the experiment. In addition, we proposed a method of evaluating swallowing sounds using a novel approach based on the probability distribution. From the analysis results, it was found that the distance between the theoretical values and the measured values has a high correlation with the sample viscosity. Furthermore, it was found that the data measured with the AE sensor more sensitively reflected the difference in the sample viscosity. We were thus able to demonstrate the possibility of evaluating the swallowing function via the proposed method.

Differences in brain networks during consecutive swallows detected using an optimized vertex-frequency algorithm

Patients with dysphagia can have higher risks of aspiration after repetitive swallowing activity due to the "fatigue effect". However, it is still unknown how consecutive swallows affect brain activity. Therefore, we sought to investigate differences in swallowing brain networks formed during consecutive swallows using a signal processing on graph approach. Data were collected from 55 healthy people using electroencephalography (EEG) signals. Participants performed dry swallows (i.e., saliva swallows) and wet swallows (i.e., water, nectar-thick, and honey thick swallows). After standard pre-processing of the EEG time series, brain networks were formed using the time-frequency-based synchrony measure, while signals on graphs were formed as a line graph of the brain networks. For calculating the vertex frequency information from the signals on graphs, the proposed algorithm was based on the optimized window size for calculating the windowed graph Fourier transform and the graph S-transform. The proposed algorithms were tested using synthetic signals and showed improved energy concentration in comparison to the original algorithm. When applied to EEG swallowing data, the optimized windowed graph Fourier transform and the optimized graph S-transform showed that differences exist in brain activity between consecutive swallows. In addition, the results showed higher differences between consecutive swallows for thicker liquids.

Measurement of Oxygen Desaturation Is Not Useful for the Detection of Aspiration in Dysphagic Stroke Patients

Background

Dysphagia is one of the most dangerous symptoms of acute stroke. Various screening tools have been suggested for the early detection of this condition. In spite of conflicting results, measurement of oxygen saturation (SpO₂) during clinical swallowing assessment is still recommended by different national guidelines as a screening tool with a decline in SpO₂ ≥2% usually being regarded as a marker of aspiration. This paper assesses the sensitivity of SpO₂ measurements for the evaluation of aspiration risk in acute stroke patients.

Methods

Fifty acute stroke patients with moderate to severe dysphagia were included in this study. In all patients, fiberoptic endoscopic evaluation of swallowing (FEES) was performed according to a standardised protocol. Blinded to the results of FEES, SpO₂ was monitored simultaneously. The degree of desaturation during/after swallows with aspiration was compared to the degree of desaturation during/after swallows without aspiration in a swallow-to-swallow analysis of each patient. To minimise potential confounders, every patient served as their control.

Results

In each subject, a swallow with and a swallow without aspiration were analysed. Overall, aspiration seen in FEES was related to a minor decline in SpO₂ (mean SpO₂ without aspiration 95.54 ± 2.7% vs. mean SpO₂ with aspiration 95.28 ± 2.7%). However, a significant desaturation ≥2% occurred only in 5 patients during/after aspiration. There was no correlation between aspiration/dysphagia severity or the amount of aspirated material and SpO₂ levels.

Conclusions

According to this study, measurement of oxygen desaturation is not a suitable screening tool for the detection of aspiration in stroke patients.

Recommendation of Nasogastric Tube Removal in Acute Stroke Patients Based on Videofluoroscopic Swallow Study

Objective

To evaluate the safety of nasogastric tube (NGT) removal and change to oral feeding with a food thickener for acute stroke patients in whom a videofluoroscopic swallow study (VFSS) confirmed thin liquid aspiration.

Methods

We retrospectively examined data of 199 patients with first stroke who were diagnosed with dysphagia from 2011 to 2015. Swallowing function was evaluated using VFSS. Patients included in this study were monitored for 4 weeks to identify the occurrence of aspiration pneumonia. The penetration-aspiration scale (PAS) was used to assess VFSS findings. The patients were divided into thin-liquid aspiration group (group 1, n=104) and no thin-liquid aspiration group (group 2, n=95).

Results

The feeding method was changed from NGT feeding to oral feeding with food thickener (group 1) and without food thickener (group 2). The PAS scores of thin and thick liquids were 6.46±0.65 and 1.92±0.73, respectively, in group 1 and 2.65±0.74 and 1.53±0.58, respectively, in group 2. Aspiration pneumonia developed in 1.9% of group 1 and 3.2% of group 2 (p=0.578), with no significant difference between the groups.

Conclusion

We concluded that removing the NGT and changing to oral feeding with a food thickener is a safe food modification for acute stroke patients with thin liquid aspiration. Therefore, we recommend that VFSS should be conducted promptly in acute stroke patients to avoid unnecessary prolonged NGT feeding.

Prevalence of swallowing dysfunction screened in Swedish cohort of COPD patients

Background

COPD is a common problem associated with morbidity and mortality. COPD may also affect the dynamics and coordination of functions such as swallowing. A misdirected swallow may, in turn, result in the bolus entering the airway. A growing body of evidence suggests that a subgroup of people with COPD is prone to oropharyngeal dysphagia. The aim of this study was to evaluate swallowing dysfunction in patients with stable COPD and to determine the relation between signs and symptoms of swallowing dysfunction and lung function (forced expiratory volume in 1 second percent predicted).

Methods

Fifty-one patients with COPD in a stable phase participated in a questionnaire survey, swallowing tests, and spirometry. A post-bronchodilator ratio of the forced expiratory volume in 1 second/best of forced vital capacity and vital capacity <0.7 was used to define COPD. Swallowing function was assessed by a questionnaire and two swallowing tests (water and cookie swallow tests).

Results

Sixty-five percent of the patients reported subjective signs and symptoms of swallowing dysfunction in the questionnaire and 49% showed measurable ones in the swallowing tests. For the combined subjective and objective findings, 78% had a coexisting swallowing dysfunction. No significant difference was found between male and female patients.

Conclusion

Swallowing function is affected in COPD patients with moderate to severe airflow limitation, and the signs and symptoms of this swallowing dysfunction were subjective, objective, or both.

Functional connectivity patterns of normal human swallowing: difference among various viscosity swallows in normal and chin-tuck head positions

Consuming thicker fluids and swallowing in the chin-tuck position has been shown to be advantageous for some patients with neurogenic dysphagia who aspirate due to various causes. The anatomical changes caused by these therapeutic techniques are well known, but it is unclear whether these changes alter the cerebral processing of swallow-related sensorimotor activity. We sought to investigate the effect of increased fluid viscosity and chin-down posture during swallowing on brain networks. 55 healthy adults performed water, nectar-thick, and honey thick liquid swallows in the neutral and chin-tuck positions while EEG signals were recorded. After pre-processing of the EEG timeseries, the time-frequency based synchrony measure was used for forming the brain networks to investigate whether there were differences among the brain networks between the swallowing of different fluid viscosities and swallowing in different head positions. We also investigated whether swallowing under various conditions exhibit small-world properties. Results showed that fluid viscosity affects the brain network in the Delta, Theta, Alpha, Beta, and Gamma frequency bands and that swallowing in the chin-tuck head position affects brain networks in the Alpha, Beta, and Gamma frequency bands. In addition, we showed that swallowing in all tested conditions exhibited small-world properties. Therefore, fluid viscosity and head positions should be considered in future swallowing EEG investigations.

Prediction of Pneumonia in Acute Stroke Patients Using Tongue Pressure Measurements

Swallowing dysfunction caused by stroke is a risk factor for aspiration pneumonia. Tongue pressure measurement is a simple and noninvasive method for evaluating swallowing dysfunction. We have hypothesized that low tongue pressure may be able to predict pneumonia occurrence in acute stroke patients. Tongue pressure was measured using balloon-type equipment in 220 acute stroke patients. The modified Mann Assessment of Swallowing Ability (MASA) score was evaluated independently on the same day. Tongue pressure was measured every week thereafter. An improvement in tongue pressure was observed within the first 2 weeks. Receiver operating curve analysis was performed to determine the ability of tongue pressure to predict modified MASA score <95, which suggests swallowing dysfunction. The optimal cutoff for tongue pressure was 21.6 kPa (χ2 = 45.82, p<0.001, sensitivity 95.9%, specificity 91.8%, area under the curve = 0.97). The tongue pressure was significantly lower in patients with pneumonia than in those without pneumonia. Using a Cox proportional hazard model for pneumonia onset with a cutoff tongue pressure value of 21.6 kPa and adjustment for age, sex, and National Institutes of Health Stroke Scale score at admission, the tongue pressure had additional predictive power for pneumonia onset (hazard ratio, 7.95; 95% confidence interval, 2.09 to 52.11; p = 0.0013). In the group with low tongue pressure, 27 of 95 patients showed improvement of tongue pressure within 2 weeks. Pneumonia occurred frequently in patients without improvement of tongue pressure, but not in patients with improvement (31/68 and 2/27, p<0.001). Tongue pressure is a sensitive indicator for predicting pneumonia occurrence in acute stroke patients.

Intermittent Oroesophageal Tube Feeding via the Airway in Patients With Dysphagia

Objective

To investigate the feasibility of the use of the oropharyngeal airway (OPA) during intermittent oroesophageal tube (IOET) feeding.

Methods

Ten patients, who were evaluated using the videofluoroscopic swallowing study (VFSS), were enrolled. One patient withdrew from the study during the study period. Tube insertion time with and without OPA use was recorded in the same patients in a random order during the VFSS. Patients who could safely undergo IOET feeding were then randomly allocated to 2 groups (OPA and non-OPA). Satisfaction Questionnaire with Gastrostomy Feeding (SAGA-8) scores and pneumonia incidence were assessed on the 3rd and 10th day after the VFSS. Non-parametric analysis was used for statistical analyses.

Results

The IOET insertion time was significantly shorter in the OPA group than in the non-OPA group (17.72±5.79 vs. 25.41±10.41 seconds; p=0.017). Complications were not significantly different between the 2 groups (p=0.054). Furthermore, although there were no significant differences in the SAGA-8 scores (25.50±2.38 vs. 21.40±3.13; p=0.066), which reflect the patient/caregiver satisfaction and the ease of tube insertion, patients in the OPA group tended to be more satisfied with the feeding procedure.

Conclusion

Although the small size of the study cohort is a limitation of our study, the use of the OPA appears to be beneficial during IOET feeding in patients with dysphagia.

The Relationship Between Tongue Pressure and Oral Dysphagia in Stroke Patients

Objective

To evaluate the relationships between tongue pressure and different aspects of the oral-phase swallowing function.

Methods

We included 96 stroke patients with dysphagia, ranging in age from 40 to 88 years (mean, 63.7 years). Measurements of tongue pressure were obtained with the Iowa Oral Performance Instrument, a device with established normative data. Three trials of maximum performance were performed for lip closure pressure (LP), anterior hard palate-to-tongue pressure (AP), and posterior hard palate-to-tongue pressure (PP); buccal-to-tongue pressures on both sides were also recorded (buccal-to-tongue pressure, on the weak side [BW]; buccal-to-tongue pressure, on the healthy side [BH]). The average pressure in each result was compared between the groups. Clinical evaluation of the swallowing function was performed with a videofluoroscopic swallowing study.

Results

The average maximum AP and PP values in the intact LC group were significantly higher than those in the inadequate lip closure group (AP, p=0.003; PP, p<0.001). AP and PP showed significant relationships with bolus formation (BF), mastication, premature bolus loss (PBL), tongue to palate contact (TP), and oral transit time (OTT). Furthermore, LP, BW, and BH values were significantly higher in the groups with intact mastication, without PBL and intact TP.

Conclusion

These findings indicate that the tongue pressure appears to be closely related to the oral-phase swallowing function in post-stroke patients, especially BF, mastication, PBL, TP and OTT.

Age, Body Mass Index, and White Blood Cell Count Predict the Resumption of Oral Intake in Subacute Stroke Patients

OBJECTIVE

To identify the predictors for the resumption of oral feeding at discharge among tube feeding-dependent stroke patients admitted to rehabilitation wards.

MATERIALS AND METHODS

This study was a retrospective analysis of 107 stroke patients (mean age, 72.1 years) dependent on tube feeds at admission to a rehabilitation ward. Data analyzed included demographic information, severity of impairments, functional independence, body mass index, nutritional and inflammatory laboratory markers at admission, and videofluoroscopic examination findings, if conducted. The variables were compared between the groups with and without resumption of oral intake. The predictive factors for resumption of oral intake were analyzed by using a stepwise multiple logistic regression model.

RESULTS

At discharge, 69.2% (74 of 107) of the patients resumed oral intake. There were significant differences in age, the Functional Independence Measure, body mass index, serum albumin, C-reactive protein, white blood cell count, and duration of stroke onset at admission between the 2 groups. Multiple logistic regression analysis identified age (odds ratio [OR] .55; 95% confidence interval [CI] .31-.95), body mass index (OR 1.34; 95% CI 1.12-1.60), and white blood cell count (OR .76; 95% CI .60-.97) as significant predictors for the resumption of oral intake in these patients.

CONCLUSION

Older age, lower body mass index, and higher white blood cell count were significant independent negative predictors for the resumption of oral feeding among stroke patients dependent on tube feeding at admission to rehabilitation wards.

Cross-Cultural Adaptation and Validation of the Italian Version of SWAL-QOL

The aim of the study was to evaluate the reliability and validity of the Italian SWAL-QOL (I-SWAL-QOL). The study consisted of five phases: item generation, reliability analysis, normative data generation, validity analysis, and responsiveness analysis. The item generation phase followed the five-step, cross-cultural, adaptation process of translation and back-translation. A group of 92 dysphagic patients was enrolled for the internal consistency analysis. Seventy-eight patients completed the I-SWAL-QOL twice, 2 weeks apart, for test-retest reliability analysis. A group of 200 asymptomatic subjects completed the I-SWAL-QOL for normative data generation. I-SWAL-QOL scores obtained by both the group of dysphagic subjects and asymptomatic ones were compared for validity analysis. I-SWAL-QOL scores were correlated with SF-36 scores in 67 patients with dysphagia for concurrent validity analysis. Finally, I-SWAL-QOL scores obtained in a group of 30 dysphagic patients before and after successful rehabilitation treatment were compared for responsiveness analysis. All the enrolled patients managed to complete the I-SWAL-QOL without needing any assistance, within 20 min. Internal consistency was acceptable for all I-SWAL-QOL subscales (α > 0.70). Test-retest reliability was also satisfactory for all subscales (ICC > 0.7). A significant difference between the dysphagic group and the control group was found in all I-SWAL-QOL subscales (p < 0.05). Mild to moderate correlations between I-SWAL-QOL and SF-36 subscales were observed. I-SWAL-QOL scores obtained in the pre-treatment condition were significantly lower than those obtained after swallowing rehabilitation. I-SWAL-QOL is reliable, valid, responsive to changes in QOL, and recommended for clinical practice and outcome research.

Additional effects of acupuncture on early comprehensive rehabilitation in patients with mild to moderate acute ischemic stroke: a multicenter randomized controlled trial

BACKGROUND

Acupuncture is not considered a conventional therapy for post-stroke sequelae but it might have some additional positive effects on early rehabilitation. We conducted this trial to determine whether acupuncture has additional effects in early comprehensive rehabilitation for acute ischemic stroke and dysfunctions secondary to stroke.

METHODS

Two hundred fifty patients were randomized into two groups: acupuncture (AG) or no acupuncture (NAG). Eighteen acupuncture treatment sessions were performed over a 3-week period. The primary outcome was blindly measured with National Institutes of Health Stroke Scale (NIHSS) at week 1, week 3, and week 7. Secondary outcomes included: Fugl-Meyer Assessment (FMA) for motor function, bedside swallowing assessment (BSA) and videofluoroscopic swallowing study (VFSS) for swallowing function, the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) for cognitive function, and the adverse reaction of acupuncture for safety assessment.

RESULTS

Significant improvements from acupuncture treatment were observed in NIHSS (p < 0.001), VFSS (p < 0.001), MMSE (p < 0.001), MoCA (p = 0.001), but not obtained from FMA (p = 0.228). Changes from baseline of all above variables (except FMA) also had the same favorable results. A significant improvement in FMA lower extremity subscale appeared in AG (p = 0.020), but no significant difference was found for the upper extremity subscale (p = 0.707). More patients with swallowing disorder recovered in AG (p = 0.037). Low incidence of mild reaction of acupuncture indicated its safety.

CONCLUSIONS

This trial showed acupuncture is safe and has additional multi-effect in improving neurologic deficits, swallowing disorder, cognitive impairment, and lower extremity function, but has no significant improvement for upper extremity function during this short-term study period.

TRIAL REGISTRATION

Chictr.org ChiCTR-TRC -12001971 (March 2012).

Therapeutic effect of acupuncture combining standard swallowing training for post-stroke dysphagia: A prospective cohort study

OBJECTIVE

To assess the therapeutic effect of acupuncture combining standard swallowing training for patients with dysphagia after stroke.

METHODS

A total of 105 consecutively admitted patients with post-stroke dysphagia in the Affiliated Hospital of Gansu University of Chinese Medicine were included: 50 patients from the Department of Neurology and Rehabilitation received standard swallowing training and acupuncture treatment (acupuncture group); 55 patients from the Department of Neurology received standard swallowing training only (control group). Participants in both groups received 5-day therapy per week for a 4-week period. The primary outcome measures included the scores of Videofluoroscopic Swallow Study (VFSS) and the Standardized Swallowing Assessment (SSA); the secondary outcome measure was the Royal Brisbane Hospital Outcome Measure for Swallowing (RBHOMS), all of which were assessed before and after the 4-week treatment.

RESULTS

A total of 98 subjects completed the study (45 in the acupuncture group and 53 in the control group). Significant differences were seen in VFSS, SSA and RBHOMS scores in each group after 4-week treatment as compared with before treatment (P<0.01). Comparison between the groups after 4-week treatment showed that the VFSS P=0.007) and SSA scores (P=0.000) were more significantly improved in the acupuncture group than the control group. However, there was no statistical difference (P=0.710) between the acupuncture and the control groups in RBHOMS scores.

CONCLUSIONS

Acupuncture combined with the standard swallowing training was an effective therapy for post-stroke dysphagia, and acupuncture therapy is worth further investigation in the treatment of post-stroke dysphagia.

Proposed Use of Thickener According to Fluid Intake on Videofluoroscopic Swallowing Studies: Preliminary Study in Normal Healthy Persons

OBJECTIVE

To examine the characteristics and changes in the pharyngeal phase of swallowing according to fluid viscosity in normal healthy persons, to help determine fluid intake methods in more detail than the use of standardized fluid.

METHODS

This was a prospective observational study involving 10 normal healthy adults. While the participants sequentially took in fluids with 10 different viscosities changes in the pharyngeal phase of the swallowing process were monitored using videofluoroscopic swallowing studies (VFSS). Twenty parameters of the pharyngeal phase, including epiglottis contact, laryngeal elevation, pharyngeal constriction, and upper esophageal sphincter opening, were determined and compared.

RESULTS

No significant viscosity-based changes in epiglottis contact, laryngeal elevation, or upper esophageal sphincter-opening duration of the pharyngeal phase were observed. However, pharyngeal transit time and time from the start of the pharyngeal phase to peak pharyngeal constriction were significantly delayed upon intake of fluid with viscosities of 150.0 centipoise (cP) and 200.0 cP.

CONCLUSION

VFSS analysis of fluid intake may require the use of fluids of various concentrations to determine a suitable viscosity of thickener mixture for each subject.

Rapid Aspiration Screening for Suspected Stroke: Part 1: Development and Validation

OBJECTIVE

To develop and validate a nurse-administered screening tool to identify aspiration risk in patients with suspected stroke.

DESIGN

Validity study comparing evidence-based swallowing screening items with the videofluoroscopic swallowing study (VFSS) results.

SETTING

A certified primary stroke center in a major metropolitan medical facility.

PARTICIPANTS

Consecutive patients (N=250) admitted with suspected stroke.

INTERVENTIONS

Patients were administered evidence-based swallowing screening items by nurses. A VFSS was completed within 2 hours of swallowing screening.

MAIN OUTCOME MEASURES

Validity relative to identifying VFSS-determined aspiration for each screening item and for various combinations of items.

RESULTS

Aspiration was identified in 29 of 250 participants (12%). Logistic regression revealed that age (P=.012), dysarthria (P=.001), abnormal volitional cough (P=.030), and signs related to the water swallow trial (P=.021) were significantly associated with aspiration. Validity was then determined on the basis of the best combination of significant items for predicting aspiration. The results revealed that age >70 years, dysarthria, or signs related to the water swallow trial (ie, cough, throat clear, wet vocal quality, and inability to continuously drink 90mL water) yielded 93% sensitivity and 98% negative predictive value.

CONCLUSIONS

The final validated tool, Rapid Aspiration Screening for Suspected Stroke, is a valid nurse-administered tool to detect risk of aspiration in patients presenting with suspected stroke.

Post-stroke dysphagia: A review and design considerations for future trials

Post-stroke dysphagia (a difficulty in swallowing after a stroke) is a common and expensive complication of acute stroke and is associated with increased mortality, morbidity, and institutionalization due in part to aspiration, pneumonia, and malnutrition. Although most patients recover swallowing spontaneously, a significant minority still have dysphagia at six months. Although multiple advances have been made in the hyperacute treatment of stroke and secondary prevention, the management of dysphagia post-stroke remains a neglected area of research, and its optimal management, including diagnosis, investigation and treatment, have still to be defined.

Dysphagia in Acute Stroke: Incidence, Burden and Impact on Clinical Outcome

Background

Reported frequency of post-stroke dysphagia in the literature is highly variable. In view of progress in stroke management, we aimed to assess the current burden of dysphagia in acute ischemic stroke.

Methods

We studied 570 consecutive patients treated in a tertiary stroke center. Dysphagia was evaluated by using the Gugging Swallowing Screen (GUSS). We investigated the relationship of dysphagia with pneumonia, length of hospital stay and discharge destination and compared rates of favourable clinical outcome and mortality at 3 months between dysphagic patients and those without dysphagia.

Results

Dysphagia was diagnosed in 118 of 570 (20.7%) patients and persisted in 60 (50.9%) at hospital discharge. Thirty-six (30.5%) patients needed nasogastric tube because of severe dysphagia. Stroke severity rather than infarct location was associated with dysphagia. Dysphagic patients suffered more frequently from pneumonia (23.1% vs. 1.1%, p<0.001), stayed longer at monitored stroke unit beds (4.4±2.8 vs. 2.7±2.4 days; p<0.001) and were less often discharged to home (19.5% vs. 63.7%, p = 0.001) as compared to those without dysphagia. At 3 months, dysphagic patients less often had a favourable outcome (35.7% vs. 69.7%; p<0.001), less often lived at home (38.8% vs. 76.5%; p<0.001), and more often had died (13.6% vs. 1.6%; p<0.001). Multivariate analyses identified dysphagia to be an independent predictor of discharge destination and institutionalization at 3 months, while severe dysphagia requiring tube placement was strongly associated with mortality.

Conclusion

Dysphagia still affects a substantial portion of stroke patients and may have a large impact on clinical outcome, mortality and institutionalization.

Validation and Cultural Adaptation of the Arabic Version of the Eating Assessment Tool (EAT-10)

BACKGROUND AND OBJECTIVES

The Eating Assessment Tool (EAT-10) is a 10-item self-administered questionnaire. It is a noninvasive tool to measure patients' perception of their swallowing problems. The purposes of the present study were to develop an Arabic version of the EAT-10 and to evaluate its validity, consistency, and reliability in the Arabic-speaking population with oropharyngeal dysphagia.

SETTING AND DESIGN

This was a prospective study carried out at the Communication and Swallowing Disorders Unit, King Saud University, Riyadh, Saudi Arabia.

SUBJECTS AND METHODS

The Arabic EAT-10 was administered to 138 patients with oropharyngeal dysphagia and 83 control subjects. Internal consistency and test-retest reliability were evaluated. Content and clinical validity were studied, and the EAT-10 results were compared across patients and control groups.

RESULTS

The Arabic EAT-10 showed excellent internal consistency (Cronbach's α = 0.92). Also, good test-retest reliability was found for the total scores of the Arabic EAT-10 (intraclass correlation = 0.73). There was a significant difference in Arabic EAT-10 scores between the oropharyngeal dysphagia group and the control group (p < 0.001).

CONCLUSION

This study demonstrated that the Arabic EAT-10 is a valid tool that can be used for screening of dysphagia-related problems in an Arabic-speaking population.

A statistical analysis of cervical auscultation signals from adults with unsafe airway protection

Background

Aspiration, where food or liquid is allowed to enter the larynx during a swallow, is recognized as the most clinically salient feature of oropharyngeal dysphagia. This event can lead to short-term harm via airway obstruction or more long-term effects such as pneumonia. In order to non-invasively identify this event using high resolution cervical auscultation there is a need to characterize cervical auscultation signals from subjects with dysphagia who aspirate.

Methods

In this study, we collected swallowing sound and vibration data from 76 adults (50 men, 26 women, mean age 62) who underwent a routine videofluoroscopy swallowing examination. The analysis was limited to swallows of liquid with either thin (<5 cps) or viscous (≈300 cps) consistency and was divided into those with deep laryngeal penetration or aspiration (unsafe airway protection), and those with either shallow or no laryngeal penetration (safe airway protection), using a standardized scale. After calculating a selection of time, frequency, and time-frequency features for each swallow, the safe and unsafe categories were compared using Wilcoxon rank-sum statistical tests.

Results

Our analysis found that few of our chosen features varied in magnitude between safe and unsafe swallows with thin swallows demonstrating no statistical variation. We also supported our past findings with regard to the effects of sex and the presence or absence of stroke on cervical ausculation signals, but noticed certain discrepancies with regards to bolus viscosity.

Conclusions

Overall, our results support the necessity of using multiple statistical features concurrently to identify laryngeal penetration of swallowed boluses in future work with high resolution cervical auscultation.

Ischemia, Immunosuppression and Infection--Tackling the Predicaments of Post-Stroke Complications

The incidence of stroke has risen over the past decade and will continue to be one of the leading causes of death and disability worldwide. While a large portion of immediate death following stroke is due to cerebral infarction and neurological complications, the most common medical complication in stroke patients is infection. In fact, infections, such as pneumonia and urinary tract infections, greatly worsen the clinical outcome of stroke patients. Recent evidence suggests that the disrupted interplay between the central nervous system and immune system contributes to the development of infection after stroke. The suppression of systemic immunity by the nervous system is thought to protect the brain from further inflammatory insult, yet this comes at the cost of increased susceptibility to infection after stroke. To improve patient outcome, there have been attempts to lessen the stroke-associated bacterial burden through the prophylactic use of broad-spectrum antibiotics. However, preventative antibiotic treatments have been unsuccessful, and therefore have been discouraged. Additionally, with the ever-rising obstacle of antibiotic-resistance, future therapeutic options to reverse immune impairment after stroke by augmentation of host immunity may be a viable alternative option. However, cautionary steps are required to ensure that collateral ischemic damage caused by cerebral inflammation remains minimal.

Effects of non-invasive brain stimulation on post-stroke dysphagia: A systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

The primary aim of this review is to evaluate the effects of non-invasive brain stimulation on post-stroke dysphagia.

METHODS

Thirteen databases were systematically searched through July 2014. Studies had to meet pre-specified inclusion and exclusion criteria. Each study's methodological quality was examined. Effect sizes were calculated from extracted data and combined for an overall summary statistic.

RESULTS

Eight randomized controlled trials were included. These trials revealed a significant, moderate pooled effect size (0.55; 95% CI=0.17, 0.93; p=0.004). Studies stimulating the affected hemisphere had a combined effect size of 0.46 (95% CI=-0.18, 1.11; p=0.16); studies stimulating the unaffected hemisphere had a combined effect size of 0.65 (95% CI=0.14, 1.16; p=0.01). At long-term follow up, three studies demonstrated a large but non-significant pooled effect size (0.81, p=0.11).

CONCLUSIONS

This review found evidence for the efficacy of non-invasive brain stimulation on post-stroke dysphagia. A significant effect size resulted when stimulating the unaffected rather than the affected hemisphere. This finding is in agreement with previous studies implicating the plasticity of cortical neurons in the unaffected hemisphere.

SIGNIFICANCE

Non-invasive brain stimulation appears to assist cortical reorganization in post-stroke dysphagia but emerging factors highlight the need for more data.

Practical Assessment of Dysphagia in Stroke Patients

Objective

To develop a quantitative and organ-specific practical test for the diagnosis and treatment of dysphagia based on assessment of stroke patients.

Methods

An initial test composed of 24 items was designed to evaluate the function of the organs involved in swallowing. The grading system of the initial test was based on the analysis of 50 normal adults. The initial test was performed in 52 stroke patients with clinical symptoms of dysphagia. Aspiration was measured via a videofluoroscopic swallowing study (VFSS). The odds ratio was obtained to evaluate the correlation between each item in the initial test and the VFSS. A polychotomous linear logistic model was used to select the final test items.

Results

Eighteen of 24 initial items were selected as significant for the final tests. These 18 showed high initial validity and reliability. The Spearman correlation coefficient for the total score of the test and functional dysphagia scale was 0.96 (p<0.001), indicating a statistically significant positive correlation.

Conclusion

This study was carried out to design a quantitative and organ-specific test that assesses the causes of dysphagia in stroke patients; therefore, this test is considered very useful and highly applicable to the diagnosis and treatment of dysphagia.

Instrumentos de rastreio para disfagia orofaríngea no acidente vascular encefálico

RESUMO Objetivo: Identificar os parâmetros presentes nos instrumentos de rastreio para a disfagia orofaríngea no acidente vascular encefálico, publicados na literatura. Estratégia de pesquisa: Para a seleção dos estudos, foram utilizados os descritores: transtornos de deglutição, acidente vascular cerebral, rastreio, screening, avaliação e disfagia. Foram consultadas as bases de dados MEDLINE, Embase, LILACS, SciELO e biblioteca Cochrane. Critérios de seleção: Foram selecionados artigos em inglês, português e espanhol, publicados até dezembro de 2014, cuja abordagem metodológica referisse instrumentos de rastreio para a disfagia orofaríngea, elaborados para indivíduos adultos com acidente vascular encefálico. Os parâmetros utilizados nos diferentes instrumentos de rastreio foram agrupados por igualdade e/ou semelhança. Foi realizada análise descritiva e calculada a frequência dos parâmetros encontrados. Resultados: Foram encontrados 688 artigos e, após consideração dos critérios de inclusão e exclusão, 23 artigos foram efetivamente analisados. Dos 20 instrumentos encontrados, 90% utilizaram algum tipo de oferta via oral no rastreio para a disfagia, sendo a maioria, a água. Foram encontrados 19 parâmetros distintos, não relacionados à oferta de alimento e 12 parâmetros relacionados à oferta de alimento. Conclusão: Não há consenso, entre os estudos, sobre os parâmetros mais sensíveis e específicos para compor o método de rastreio para disfagia orofaríngea na população com acidente vascular encefálico.

Effectiveness of Neuromuscular Electrical Stimulation on Patients With Dysphagia With Medullary Infarction

OBJECTIVE

To evaluate and compare the effects of neuromuscular electrical stimulation (NMES) acting on the sensory input or motor muscle in treating patients with dysphagia with medullary infarction.

DESIGN

Prospective randomized controlled study.

SETTING

Department of physical medicine and rehabilitation.

PARTICIPANTS

Patients with dysphagia with medullary infarction (N=82).

INTERVENTIONS

Participants were randomized over 3 intervention groups: traditional swallowing therapy, sensory approach combined with traditional swallowing therapy, and motor approach combined with traditional swallowing therapy. Electrical stimulation sessions were for 20 minutes, twice a day, for 5d/wk, over a 4-week period.

MAIN OUTCOME MEASURES

Swallowing function was evaluated by the water swallow test and Standardized Swallowing Assessment, oral intake was evaluated by the Functional Oral Intake Scale, quality of life was evaluated by the Swallowing-Related Quality of Life (SWAL-QOL) Scale, and cognition was evaluated by the Mini-Mental State Examination (MMSE).

RESULTS

There were no statistically significant differences between the groups in age, sex, duration, MMSE score, or severity of the swallowing disorder (P>.05). All groups showed improved swallowing function (P≤.01); the sensory approach combined with traditional swallowing therapy group showed significantly greater improvement than the other 2 groups, and the motor approach combined with traditional swallowing therapy group showed greater improvement than the traditional swallowing therapy group (P<.05). SWAL-QOL Scale scores increased more significantly in the sensory approach combined with traditional swallowing therapy and motor approach combined with traditional swallowing therapy groups than in the traditional swallowing therapy group, and the sensory approach combined with traditional swallowing therapy and motor approach combined with traditional swallowing therapy groups showed statistically significant differences (P=.04).

CONCLUSIONS

NMES that targets either sensory input or motor muscle coupled with traditional therapy is conducive to recovery from dysphagia and improves quality of life for patients with dysphagia with medullary infarction. A sensory approach appears to be better than a motor approach.

Decoding human swallowing via electroencephalography: a state-of-the-art review

Swallowing and swallowing disorders have garnered continuing interest over the past several decades. Electroencephalography (EEG) is an inexpensive and non-invasive procedure with very high temporal resolution which enables analysis of short and fast swallowing events, as well as an analysis of the organizational and behavioral aspects of cortical motor preparation, swallowing execution and swallowing regulation. EEG is a powerful technique which can be used alone or in combination with other techniques for monitoring swallowing, detection of swallowing motor imagery for diagnostic or biofeedback purposes, or to modulate and measure the effects of swallowing rehabilitation. This paper provides a review of the existing literature which has deployed EEG in the investigation of oropharyngeal swallowing, smell, taste and texture related to swallowing, cortical pre-motor activation in swallowing, and swallowing motor imagery detection. Furthermore, this paper provides a brief review of the different modalities of brain imaging techniques used to study swallowing brain activities, as well as the EEG components of interest for studies on swallowing and on swallowing motor imagery. Lastly, this paper provides directions for future swallowing investigations using EEG.

The Effects of the VFSS Timing After Nasogastric Tube Removal on Swallowing Function of the Patients With Dysphagia

OBJECTIVE

To evaluate the effects of the videofluoroscopic swallowing study (VFSS) timing after the nasogastric tube (NGT) removal on swallowing function of the patients with dysphagia.

METHODS

This study was conducted on 40 NGT-fed patients with dysphagia. To assess the patients' swallowing function, VFSS was performed twice using a 5-mL 35% diluted barium solution. For the initial examination, VFSS was performed immediately after the NGT removal (VFSS 1). For the second examination, VFSS was performed five hours after the NGT removal (VFSS 2). We used the functional dysphagia scale (FDS) to assess swallowing function. In the FDS, a significant difference in the four items in the oral phase, seven items in the pharyngeal phase, and total scores were assessed (p<0.05). We also used modified penetration-aspiration scale (mPAS) to compare the two examinations (p<0.05).

RESULTS

A paired t-test was performed to confirm the statistical significance of the two examinations (p<0.05). The overall swallowing function was assessed as better in VFSS 2 than in VFSS 1. In the FDS, significant differences in the residue in valleculae (p=0.002), the residue in pyriform sinuses (p=0.001), the coating of pharyngeal wall after swallow (p=0.001), and the total scores (p<0.001) were found between the two examinations. Also, in the mPAS that assessed the degree of penetration-aspiration, a significant difference was found between the two examinations (p<0.001).

CONCLUSION

The results of this study confirmed that the timing of the VFSS after the NGT removal affects the swallowing function. Thus, to accurately assess the swallowing function, VFSS must be performed in NGT-fed patients after they have rested for a certain period following the removal of their NGT.

Dysphagia May Be an Independent Marker of Poor Outcome in Acute Lateral Medullary Infarction

BACKGROUND AND PURPOSE

The functional recovery after the lateral medullary infarction (LMI) is usually good. Little is known about the prognostic factors associated with poor outcome following acute LMI. The aim of this study was to identify the factors associated with poor long-term outcome after acute LMI, based on experiences at a single center over 11 years.

METHODS

A consecutive series of 157 patients with acute LMI who were admitted within 7 days after symptom onset was evaluated retrospectively. Clinical symptoms were assessed within 1 day after admission, and outcomes were evaluated over a 1-year period after the initial event. The lesions were classified into three vertical types (rostral, middle, and caudal), and the patients were divided into two groups according to the outcome at 1 year: favorable [modified Rankin Scale (mRS) score ≤1] and unfavorable (mRS score ≥2).

RESULTS

Of the 157 patients, 93 (59.2%) had a favorable outcome. Older age, hypertension, dysphagia, requirement for intensive care, and pneumonia were significantly more prevalent in the unfavorable outcome group. The frequencies of intensive care (13%) and mortality (16.7%) were significantly higher in the rostral lesion (p=0.002 and p=0.002). Conditional logistic regression analysis revealed that older age and initial dysphagia were independently related to an unfavorable outcome at 1 year [odds ratio (OR)=1.04, 95% confidence interval (95% CI)=1.001-1.087, p=0.049; OR=2.46, 95% CI=1.04-5.84, p=0.041].

CONCLUSIONS

These results suggest that older age and initial dysphagia in the acute phase are independent risk factors for poor long-term prognosis after acute LMI.

Dysphagia Screening: Contributions of Cervical Auscultation Signals and Modern Signal-Processing Techniques

Cervical auscultation is the recording of sounds and vibrations caused by the human body from the throat during swallowing. While traditionally done by a trained clinician with a stethoscope, much work has been put towards developing more sensitive and clinically useful methods to characterize the data obtained with this technique. The eventual goal of the field is to improve the effectiveness of screening algorithms designed to predict the risk that swallowing disorders pose to individual patients' health and safety. This paper provides an overview of these signal processing techniques and summarizes recent advances made with digital transducers in hopes of organizing the highly varied research on cervical auscultation. It investigates where on the body these transducers are placed in order to record a signal as well as the collection of analog and digital filtering techniques used to further improve the signal quality. It also presents the wide array of methods and features used to characterize these signals, ranging from simply counting the number of swallows that occur over a period of time to calculating various descriptive features in the time, frequency, and phase space domains. Finally, this paper presents the algorithms that have been used to classify this data into 'normal' and 'abnormal' categories. Both linear as well as non-linear techniques are presented in this regard.

Effectiveness of Non-invasive Brain Stimulation in Dysphagia Subsequent to Stroke: A Systemic Review and Meta-analysis

The objective of this study is to assess the efficacy and safety of non-invasive brain stimulation (NIBS) in patients with dysphagia subsequent to stroke. A systematic search of the literature published by Medline (January 1, 1976 through June 21, 2013), EMBASE (January 1, 1985 through June 21, 2013), and the Cochrane Library (January 1, 1987 through June 21, 2013) was conducted for all relevant articles related to NIBS, dysphagia, and cerebrovascular disorders (CVD). Two reviewers (S.N.Y and S.B.P) independently evaluated the eligibility of retrieved data according to the selection criteria and assessed methodological quality of the studies using the 'assessing risk of bias' table recommended in the Cochrane Handbook for Systematic Reviews of Interventions (version 5.0.2). Six randomized controlled trials (59 intervention groups and 55 placebo groups) were identified as addressing the use of NIBS for dysphagia after CVD and were included in the meta-analysis. The function scale score improvement of dysphagia in patients treated with NIBS was statistically significant compared with that of patients who underwent sham stimulation (standardized mean difference = 1.08, 95 % confidence intervals = 0.29-1.88, p = 0.008; I (2) = 72 %). A subgroup analysis based on the type of intervention (three repetitive transcranial magnetic stimulation (rTMS) studies and three transcranial direct current stimulation (tDCS) studies) revealed a statistically significant beneficial effect of NIBS compared with sham stimulation in the rTMS group, but not in the tDCS group. When the results were examined based on intervention site (ipsilesional vs. contralesional site stimulation), no statistically significant difference was noted between two groups. No complications of NIBS were reported in this analysis.

Effect of Repetitive Transcranial Magnetic Stimulation According to the Stimulation Site in Stroke Patients With Dysphagia

Objective

To investigate the effect of repetitive transcranial magnetic stimulation (rTMS) according to the stimulation site in subacute stroke patients with dysphagia.

Methods

This study was designed as a matched comparative study. Twenty-four patients who had dysphagia after ischemic stroke were recruited, and they were divided into two groups after matching for age and stroke lesion. The patients in group A received rTMS over the brain cortex where motor evoked potential (MEP) was obtained from the suprahyoid muscle. Group B received rTMS over the brain cortex where MEP was obtained from the abductor pollicis brevis muscle. rTMS was performed at 110% of MEP threshold, 10 Hz frequency for 10 seconds, and then repeated every minute for 10 minutes. Dysphagia status was measured by the Functional Dysphagia Scale (FDS), the Penetration-Aspiration Scale (PAS), and the Dysphagia Outcome and Severity Scale (DOSS) using the results of a videofluoroscopic swallowing study. These evaluations were measured before, immediately, and 4 weeks after rTMS.

Results

Group A showed significant improvement compared to group B in the DOSS score immediately and 4 weeks after rTMS. There were no significant differences in the changes of FDS and PAS scores between groups A and B immediately and 4 weeks after rTMS.

Conclusion

rTMS over a hot spot for the suprahyoid muscle caused more improvement in swallowing function when compared to that over the interconnected site.

Clinical and fiberoptic endoscopic assessment of swallowing in patients with chronic obstructive pulmonary disease

Introduction: Chronic obstructive pulmonary disease is characterized by progressive and partially reversible obstruction of pulmonary airflow.

Aim: To characterize swallowing in patients with chronic obstructive pulmonary disease and correlate the findings with the degree chronic obstructive pulmonary disease, heart and respiratory rate, oxygen saturation, and smoking.

Method: We conducted a prospective cohort study of 19 patients (12 men and 7 women; age range, 50–85 years) with confirmed medical diagnosis of chronic obstructive pulmonary disease. This study was performed in 2 stages (clinical evaluation and functional assessment using nasolaryngofibroscopy) on the same day. During both stages, vital signs were checked by medical personnel.

Results: Clinical evaluation of swallowing in all patients showed the clinical signs of cough. The findings of nasolaryngofibroscopy highlighted subsequent intraoral escape in 5 patients (26.5%). No patient had tracheal aspiration. There was no association of subsequent intraoral escape with degree of chronic obstructive pulmonary disease, heart and respiratory rate, oxygen saturation, or smoking.

Conclusion: In patients with chronic obstructive pulmonary disease, there was a prevalence of oral dysphagia upon swallowing and nasolaryngofibroscopy highlighted the finding of subsequent intraoral escape. There was no correlation between intraoral escape and the degree of chronic obstructive pulmonary disease, heart and respiratory rate, oxygen saturation, or smoking.

Characteristics of Dry Chin-Tuck Swallowing Vibrations and Sounds

OBJECTIVE

The effects of the chin-tuck maneuver, a technique commonly employed to compensate for dysphagia, on cervical auscultation are not fully understood. Characterizing a technique that is known to affect swallowing function is an important step on the way to developing a new instrumentation-based swallowing screening tool.

METHODS

In this study, we recorded data from 55 adult participants who each completed five saliva swallows in a chin-tuck position. The resulting data were processed using previously designed filtering and segmentation algorithms. We then calculated nine time-, frequency-, and time-frequency-domain features for each independent signal.

RESULTS

We found that multiple frequency- and time-domain features varied significantly between male and female subjects as well as between swallowing sounds and vibrations. However, our analysis showed that participant age did not play a significant role on the values of the extracted features. Finally, we found that various frequency features corresponding to swallowing vibrations did demonstrate statistically significant variation between the neutral and chin-tuck positions but sounds showed no changes between these two positions.

CONCLUSION

The chin-tuck maneuver affects many facets of swallowing vibrations and sounds and its effects can be monitored via cervical auscultation.

SIGNIFICANCE

These results suggest that a subject's swallowing technique does need to be accounted for when monitoring their performance with cervical auscultation-based instrumentation.

Reliability of ultrasound evaluation of hyoid-larynx approximation with positional change

We evaluated the reliability of ultrasound evaluation of hyoid-larynx approximation with positional change. Twenty healthy volunteers (10 men, 10 women) participated in this study. The distance between the hyoid bone and thyroid cartilage was measured by ultrasound in both the sitting and supine positions. Hyoid-larynx approximation was defined as the shortest distance between the lower tip of the hyoid bone and the upper end of the thyroid cartilage during swallowing. The transducer was placed in a longitudinal position above the midline of the larynx, which allowed visualization of the hyoid bone and thyroid cartilage. Patients were given 5 mL of water and swallowed. The measurement was repeated three times to enable averaging in each position. Using the mean distance at rest and the shortest distance during swallowing, we calculated relative laryngeal elevation. There was no significant difference in resting distance between the hyoid bone and thyroid cartilage with positional change or gender, with identical relative laryngeal elevation. However, there was a negative correlation between the resting and approximation distance and body mass index. In conclusion, ultrasound evaluation in healthy volunteers revealed no difference in hyoid-laryngeal approximation on swallowing in either the supine or sitting position. This finding is likely to be of value in the investigation of dysphagia.

A comparative analysis of DBSCAN, K-means, and quadratic variation algorithms for automatic identification of swallows from swallowing accelerometry signals

BACKGROUND

Cervical auscultation with high resolution sensors is currently under consideration as a method of automatically screening for specific swallowing abnormalities. To be clinically useful without human involvement, any devices based on cervical auscultation should be able to detect specified swallowing events in an automatic manner.

METHODS

In this paper, we comparatively analyze the density-based spatial clustering of applications with noise algorithm (DBSCAN), a k-means based algorithm, and an algorithm based on quadratic variation as methods of differentiating periods of swallowing activity from periods of time without swallows. These algorithms utilized swallowing vibration data exclusively and compared the results to a gold standard measure of swallowing duration. Data was collected from 23 subjects that were actively suffering from swallowing difficulties.

RESULTS

Comparing the performance of the DBSCAN algorithm with a proven segmentation algorithm that utilizes k-means clustering demonstrated that the DBSCAN algorithm had a higher sensitivity and correctly segmented more swallows. Comparing its performance with a threshold-based algorithm that utilized the quadratic variation of the signal showed that the DBSCAN algorithm offered no direct increase in performance. However, it offered several other benefits including a faster run time and more consistent performance between patients. All algorithms showed noticeable differentiation from the endpoints provided by a videofluoroscopy examination as well as reduced sensitivity.

CONCLUSIONS

In summary, we showed that the DBSCAN algorithm is a viable method for detecting the occurrence of a swallowing event using cervical auscultation signals, but significant work must be done to improve its performance before it can be implemented in an unsupervised manner.

Does the addition of specific acupuncture to standard swallowing training improve outcomes in patients with dysphagia after stroke? a randomized controlled trial

OBJECTIVE

To assess the effect of adding acupuncture to standard swallowing training for patients with dysphagia after stroke.

DESIGN

Single-blind randomized controlled trial.

SETTING

Inpatient and outpatient clinics.

SUBJECTS

A total of 124 patients with dysphagia after stroke were randomly divided into two groups: acupuncture and control.

INTERVENTIONS

The acupuncture group received standard swallowing training and acupuncture treatment. In comparison, the control group only received standard swallowing training. Participants in both groups received six days of therapy per week for a four-week period.

MAIN MEASURES

The primary outcome measures included the Standardized Swallowing Assessment and the Dysphagia Outcome Severity Scale. The secondary outcome measures included the Modified Barthel Index and Swallowing-Related Quality of Life, which were assessed before and after the four-week therapy period.

RESULTS

A total of 120 dysphagic subjects completed the study (60 in acupuncture group and 60 in control group). Significant differences existed in the Standardized Swallowing Assessment, Dysphagia Outcome Severity Scale, Modified Barthel Index, and Swallowing-Related Quality of Life scores of each group after the treatment (P < 0.01). After the four-week treatment, the Standardized Swallowing Assessment (mean difference - 2.9; 95% confidence interval (CI) - 5.0 to - 0.81; P < 0.01), Dysphagia Outcome Severity Scale (mean difference 2.3; 95% CI 0.7 to 1.2; P < 0.01), Modified Barthel Index (mean difference 17.2; 95% CI 2.6 to 9.3; P < 0.05) and Swallowing-Related Quality of Life scores (mean difference 31.4; 95% CI 3.2 to 11.4; P < 0.01) showed more significant improvement in the acupuncture group than the control group.

CONCLUSIONS

Acupuncture combined with the standard swallowing training may be beneficial for dysphagic patients after stroke.

Oropharyngeal Dysphagia: neurogenic etiology and manifestation

To determine the type, severity and manifestation of dysphagia in patients with neurogenic etiology. Clinical documentation was done on the different etiologies, its manifestation, assessment findings and management strategies taken for patients with neurogenic oropharyngeal dysphagia who were referred for assessment and management of dysphagia over a period of three months in a tertiary care teaching hospital. Flexible endoscopic examination was done in all the patients. The severity of dysphagia in these patients were graded based on Gugging Swallowing Screen (GUSS). A total of 53 patients with neurogenic oropharyngeal dysphagia were evaluated by an otolaryngologist and a speech language pathologist over a period of three months. The grading of severity based on GUSS for these patients were done. There were 30 patients with recurrent laryngeal nerve injury due to various etiologies, one patient with Neurofibroma-vestibular schwanoma who underwent surgical excision, 16 patients with stroke, two patients with traumatic brain injury, two patients with Parkinsonism and two patients with myasthenia gravis. The manifestation of dysphagia was mainly in the form of prolonged masticatory time, oral transit time, and increased number of swallows required for each bolus, cricopharyngeal spasms and aspiration. Among the dysphagia patients with neurogenic etiology, dysphagia is manifested with a gradual onset and is found to have a progressive course in degenerative disorders. Morbidity and mortality may be reduced with early identification and management of neurogenic dysphagia.

A comparative analysis of swallowing accelerometry and sounds during saliva swallows

BACKGROUND

Accelerometry (the measurement of vibrations) and auscultation (the measurement of sounds) are both non-invasive techniques that have been explored for their potential to detect abnormalities in swallowing. The differences between these techniques and the information they capture about swallowing have not previously been explored in a direct comparison.

METHODS

In this study, we investigated the differences between dual-axis swallowing accelerometry and swallowing sounds by recording data from adult participants and calculating a number of time and frequency domain features. During the experiment, 55 participants (ages 18-65) were asked to complete five saliva swallows in a neutral head position. The resulting data was processed using previously designed techniques including wavelet denoising, spline filtering, and fuzzy means segmentation. The pre-processed signals were then used to calculate 9 time, frequency, and time-frequency domain features for each independent signal. Wilcoxon signed-rank and Wilcoxon rank-sum tests were utilized to compare feature values across transducers and patient demographics, respectively.

RESULTS

In addition to finding a number of features that varied between male and female participants, our statistical analysis determined that the majority of our chosen features were statistically significantly different across the two sensor methods and that the dependence on within-subject factors varied with the transducer type. However, a regression analysis showed that age accounted for an insignificant amount of variation in our signals.

CONCLUSIONS

We conclude that swallowing accelerometry and swallowing sounds provide different information about deglutition despite utilizing similar transduction methods. This contradicts past assumptions in the field and necessitates the development of separate analysis and processing techniques for swallowing sounds and vibrations.