FEES-based assessment of pharyngeal hypesthesia-Proposal and validation of a new test procedure.

BACKGROUND: Intact pharyngeal sensation is essential for a physiological swallowing process, and conversely, pharyngeal hypesthesia can cause dysphagia. This study introduces and validates a diagnostic test to quantify pharyngeal hypesthesia. METHODS: A total of 20 healthy volunteers were included in a prospective study. Flexible endoscopic evaluation of swallowing (FEES) and a sensory test were performed both before and after pharyngeal local anesthesia. To test pharyngeal sensation, a small tube was positioned transnasally in the upper third of the oropharynx with contact to the lateral pharyngeal wall. Increasing volumes of blue-dyed water were injected through the tube, and the latency of swallowing response (LSR) was determined by two independent raters from the endoscopic video recording. Three trials were performed for each administered volume starting with 0.1 mL and increased by 0.1 mL up to 0.5 mL. KEY RESULTS: The average LSR without anesthesia was 2.24 ± 0.80 s at 0.1 mL, 1.79 ± 0.84 s at 0.2 mL, 1.29 ± 0.62 s at 0.3 mL, 1.17 ± 0.41 s at 0.4 mL, and 1.19 ± 0.52 s at 0.5 mL. With anesthesia applied, the average LSR was 2.65 ± 0.62 s at 0.1 mL, 2.64 ± 0.49 s at 0.2 mL, 2.44 ± 0.65 s at 0.3 mL, 2.10 ± 0.80 s at 0.4 mL, and 2.18 ± 0.85 s at 0.5 mL. LSR was significantly longer following anesthesia at 0.2 mL (t = -3.82; P = .001), 0.3 mL (t = -4.65; P < .000), 0.4 mL (t = -5.77; P < .000), and 0.5 mL (t = -3.49; P = .005). CONCLUSION AND INFERENCES: Pharyngeal hypesthesia can be quantified with sensory testing using LSR. Suitable volumes to distinguish between normal and impaired pharyngeal sensation are 0.2 mL, 0.3 mL, 0.4 mL and 0.5 mL. Experimentally induced pharyngeal anesthesia represents a valid model of sensory dysphagia.

Substance P Saliva Reduction Predicts Pharyngeal Dysphagia in Parkinson's Disease.

Introduction: Although patients with Parkinson's disease (PD) often suffer from oropharyngeal dysphagia, knowledge about the underlying pathophysiological mechanisms is limited. Substance P (SP) is a localization-independent neurotransmitter of the entire nervous system. Reduced levels of SP were found in saliva of patients with impaired cough reflex and in advanced stages of PD. The aim of the study was to investigate SP in PD patients in order to gain further insights into the underlying pathophysiology of PD-related dysphagia and to evaluate the potential of SP as a biomarker for early dysphagia. Methods: Flexible endoscopic evaluation of swallowing (FEES) was used to objectively assess pharyngeal swallowing function. From a cohort of 105 consecutive PD patients 20 subjects were recruited: in 10 of them pharyngeal dysphagia was excluded by FEES, the other 10 subjects showed signs of early pharyngeal dysphagia defined as hypopharyngeal sensory deficit with mild to moderate vallecular residues after swallowing solid consistencies. Analysis of the Substance P level in saliva of the 20 included PD patients was performed in the clinical on state condition by ELISA-type immunoassay. Significant differences were calculated by using the Mann-Whitney test. Results: Twenty PD patients with a mean age of 69.5 ± 12.5 years (8 female) were included in the study. No significant differences were found regarding gender, age, UPDRS III, Hoehn and Yahr stage, disease duration, and Levodopa equivalent dose between the non-dysphagic and dysphagic subjects. Dysphagia was mainly characterized by unrecognized residues in the valleculae without any aspiration risk for all of the tested consistencies in FEES and was thereby scored as mild in all cases. Saliva SP concentrations were significantly lower in PD patients with pharyngeal dysphagia compared to those with a normal pharyngeal swallowing function (9,644 vs. 17,591 pg/mL; p = 0.001). Conclusion: Reduced saliva SP concentrations may predict early pharyngeal swallowing dysfunction in PD patients. This finding supports the hypothesis that an impaired SP mediated neurotransmission has a significant impact for the development of dysphagia in PD patients. Larger studies are needed to confirm SP as a clinical useful biomarker for early detection of PD-related dysphagia.

Intubation, tracheostomy, and decannulation in patients with Guillain-Barré-syndrome-does dysphagia matter?

INTRODUCTION: Although patients with Guillain-Barré syndrome frequently require orotracheal intubation and tracheostomy, the incidence and relevance of neurogenic dysphagia prior to intubation and risk factors for prolonged requirement for a tracheal cannula have not yet been identified. METHODS: Retrospective analysis of the medical records of 88 patients was performed. Clinical characteristics were compared between intubated and nonintubated patients and between immediately decannulated and not immediately decannulated patients. RESULTS: Thirty-five (39.7%) patients required tracheostomy. Neuromuscular weakness and related respiratory insufficiency were the main reasons for intubation. In the subgroup of tracheotomized patients, immediate decannulation after completed respiratory weaning was possible in 14 (40%) patients. The severity of dysphagia, in particular pharyngolaryngeal hypesthesia, was related to the length of cannulation. DISCUSSION: Respiratory muscle weakness is the main reason for intubation, whereas neurogenic dysphagia is the main risk factor for persisting cannulation. Dysphagia after weaning is most frequently characterized by severe laryngeal sensory deficit. Muscle Nerve 59:194-200, 2019.

The Effect of Improved Dysphagia Care on Outcome in Patients with Acute Stroke: Trends from 8-Year Data of a Large Stroke Register.

BACKGROUND: Early dysphagia screening and appropriate management are recommended by current guidelines to reduce complications and case fatality in acute stroke. However, data on the potential benefit of changes in dysphagia care on patient outcome are limited. Our objective was to assess the degree of implementation of dysphagia guidelines and determine the impact of modifications in dysphagia screening and treatment practices on disease complications and outcome in stroke patients over time. METHODS: In this prospective register-based study ("Stroke Register of Northwestern Germany"), all adult stroke patients admitted to 157 participating hospitals between January, 2008 and December, 2015 were included (n = 674,423). Dysphagia incidence upon admission, the proportion of patients receiving a standardized swallowing screening, and the percentage of dysphagic patients being referred to a speech language therapist (SLT) for treatment were obtained per year. Pneumonia rate, modified Rankin Scale (mRS) at discharge, and in-hospital mortality were compared between groups of dysphagic vs. non-dysphagic patients over time. RESULTS: Screening proportions continuously increased from 47.2% in 2008 to 86.6% in 2015. But the proportion diagnosed with dysphagia remained stable with about 19%. The number of dysphagic patients receiving SLT treatment grew from 81.6 up to 87.0%. Pneumonia incidence was higher in dysphagic stroke cases (adjusted OR 5.4 [5.2-5.5], p < 0.001), accompanied by a worse mRS at discharge (adjusted OR for mRS ≥3: 3.1 [3.0-3.1], p < 0.001) and higher mortality (adjusted OR 3.1 [3.0-3.2], p < 0.001). The order of magnitude of these end points did not change over time. CONCLUSION: Although advances have been made in dysphagia care, prevalent screening and treatment practices remain insufficient to reduce pneumonia rate, improve functional outcome, and decrease case fatality in dysphagic stroke patients. More research is urgently needed to develop more effective swallowing therapies.

Introducing a Virtual Lesion Model of Dysphagia Resulting from Pharyngeal Sensory Impairment.

BACKGROUND/AIMS: Performing neurophysiological and functional imaging studies in severely affected patients to investigate novel neurostimulation techniques for the treatment of neurogenic dysphagia is difficult. Therefore, basic research needs to be conducted in healthy subjects. Swallowing is a motor function highly dependent on sensory afferent input. Here we propose a virtual peripheral sensory lesion model to mimic pharyngeal sensory impairment, which is known as a major contributor to dysphagia in neurological disease. METHODS: In this randomized crossover study on 11 healthy volunteers, cortical activation during pneumatic pharyngeal stimulation was measured applying magnetoencephalography in two separate sessions, with and without pharyngeal surface anesthesia. RESULTS: Stimulation evoked bilateral event-related desynchronization (ERD) mainly in the caudolateral pericentral cortex. In comparison to the no-anesthesia condition, topical anesthesia led to a reduction of ERD in beta (13-30 Hz) and low gamma (30-60 Hz) frequency ranges (p<0.05) in sensory but also motor cortical areas. CONCLUSIONS: Withdrawal of sensory afferent information by topical anesthesia leads to reduced response to pneumatic pharyngeal stimulation in a distributed cortical sensorimotor network in healthy subjects. The proposed paradigm may serve to investigate the effect of neuromodulatory treatments specifically on pharyngeal sensory impairment as relevant cause of neurogenic dysphagia.

Pharyngolaryngeal Sensory Deficits in Patients with Middle Cerebral Artery Infarction: Lateralization and Relation to Overall Dysphagia Severity.

BACKGROUND: Dysphagia is a frequent and dangerous complication of acute stroke. Apart from a well-timed oropharyngeal muscular contraction pattern, sensory feedback is of utmost importance for safe and efficient swallowing. In the present study, we therefore analyzed the relation between pharyngolaryngeal sensory deficits and post-stroke dysphagia (PSD) severity in a cohort of acute stroke patients with middle cerebral artery (MCA) infarction. METHODS: Eighty-four first-ever MCA stroke patients (41 left, 43 right) were included in this trial. In all patients, fiberoptic endoscopic evaluation of swallowing (FEES) was performed according to a standardized protocol within 96 h after stroke onset. PSD was classified according to the 6-point fiberoptic endoscopic dysphagia severity scale. Pharyngolaryngeal sensation was semi-quantitatively evaluated by a FEES-based touch technique. RESULTS: PSD severity was closely related to the pharyngolaryngeal sensory deficit. With regards to lateralization of the sensory deficit, there was a slight but significant preponderance of sensory loss contralateral to the side of stroke. Apart from that, right hemispheric stroke patients were found to present with a more severe PSD. CONCLUSIONS: This study provides evidence that an intact sensory feedback is of utmost importance to perform nonimpaired swallowing and highlights the key role of disturbed pharyngeal and laryngeal afferents in the pathophysiology of PSD.

Increase of Substance P Concentration in Saliva after Pharyngeal Electrical Stimulation in Severely Dysphagic Stroke Patients - an Indicator of Decannulation Success?

BACKGROUND/AIMS: Substance P (SP) is a neuropeptide, likely acting as a neurotransmitter in the pharyngeal mucosa enhancing the swallow and cough reflex. Pharyngeal Electrical Stimulation (PES) induces a temporary increase of salivary SP levels in healthy adults. Previous evidence suggests that post-stroke dysphagia is related to reduced SP levels. Here, we investigated the effects of PES on SP levels in severely dysphagic stroke patients and a possible link between increase of SP and treatment success. METHODS: 23 tracheotomized stroke patients who could not be decannulated due to severe and persisting dysphagia according to endoscopic evaluation received PES for 10 minutes a day over three consecutive days in this prospective single-center study. If initial treatment failed, repetitive stimulation cycles were provided. Saliva samples were collected before and directly after each PES. RESULTS: 61% of participants were decannulated after the first treatment cycle. Increase of SP levels post-stimulation was closely related to treatment success, i.e. decannulation with 79% of successfully treated patients showing increase of SP, whereas 89% of unsuccessfully treated patients had stable or decreased SP levels. Applying logistic regression analysis, increase of SP level remained the only independent predictor of decannulation after PES. All 3 repetitively treated patients showed increased SP levels when progressing from the 1st to the 2nd cycle, two of whom were decannulated hereafter. CONCLUSIONS: The physiological mechanism of PES may consist in restoration of sensory feedback, which is known to be crucial for the execution of a safe swallow. SP possibly acts as a biomarker for indicating response to PES.

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.

Electrical pharyngeal stimulation for dysphagia treatment in tracheotomized stroke patients: a randomized controlled trial.

PURPOSE: Treatment of post-stroke dysphagia is notoriously difficult with different neurostimulation strategies having been employed with a variable degree of success. Recently, electrical pharyngeal stimulation (EPS) has been shown to improve swallowing function and in particular decrease airway aspiration in acute stroke. We performed a randomized controlled trial to assess EPS effectiveness on swallowing function in severely dysphagic tracheotomized patients. METHODS: All consecutive stroke patients successfully weaned from the respirator but with severe dysphagia precluding decannulation were screened for eligibility. Eligible patients were randomized to receive either EPS (N = 20) or sham stimulation (N = 10) over three consecutive days. Primary endpoint was ability to decannulate the patient. Swallowing function was assessed using fiberoptic endoscopy. Patients having received sham stimulation were offered EPS treatment during unblinded follow-up if required. Investigators were blinded to the patient's study group allocation. RESULTS: Both groups were well matched for age, stroke severity, and lesion location. Decannulation after study intervention was possible in 75% of patients of the treatment group and in 20% of patients of the sham group (p < 0.01). Secondary outcome parameters did not differ. No adverse events occurred. CONCLUSION: In this pilot study, EPS enhanced remission of dysphagia as assessed with fiberoptic endoscopic evaluation of swallowing (FEES), thereby enabling decannulation in 75% of patients.