The Initiation of Swallowing Can Indicate the Prognosis of Disorders of Consciousness: A Self-Controlled Study

Swallowing Assessment in Post-Comatose Patients: A Feasibility Study on the SWADOC Tool

Background: After a severe brain injury and a coma, patients may develop disorders of consciousness (DoC), frequently accompanied by severe dysphagia. The evaluation and therapy of swallowing are therefore essential aspects of their management. Objectives: This study aims to evaluate the SWallowing Assessment in Disorders of Consciousness (SWADOC) tool in the assessment of swallowing in post-comatose patients. Here, we validate its quantitative items, describe preliminary results and identify limitations. Methods: Fourteen post-comatose patients were repeatedly evaluated with the Simplified Evaluation of CONsciousness Disorders (SECONDs) and with the SWADOC. Results: The internal consistency of the oral and pharyngeal subscales of the SWADOC was good. The test-retest reliability showed that all items, all subscores and the total score were stable except for two items (endo-buccal secretions and bronchial congestion). A comparison to the Facial Oral Tract Therapy Swallowing Assessment of Saliva (F.O.T.T-SAS) confirmed that scoring with the SWADOC offers a greater potential for quantitative observations in assessing swallowing abilities among patients with DoC. The SECONDs scores and SWADOC total scores showed a significant positive correlation (τ = 0.78, p < 0.001). Conclusions: This study provides preliminary but encouraging results on the psychometric properties of the SWADOC tool. It shows that this tool is relevant and feasible as a bedside assessment of dysphagia in patients with DoC.

Feeding modality evolution in traumatic brain injury patients with severe alteration of consciousness: A observational study

The aim of this study was to compare feeding modalities and the level of consciousness in patients with a severe brain injury during reeducation and rehabilitation. The clinical data of vegetative state or minimal conscious state due to severe traumatic brain injury hospitalized in a coma arousal unit were collected from 2012 to 2019. Feeding modalities were evaluated clinically and with functional endoscopy evaluation of swallowing or video fluoroscopy and functional oral intake scale. Evolution of consciousness was evaluated using Wessex Head Injury Matrix scale (WHIM). Comparison between WHIM score and feeding modalities were performed at admission and at discharge of the arousal unit. Of the 93 patients considered, 33 were included corresponding to inclusion criteria (traumatic brain injury, disorder of consciousness and age > 18 years). The mean age was 44.8 ± 16.8 years, and there were 6 females for 27 males. At admission, all patients were fed by gastrostomy (n = 25) or by nasogastric tube (n = 8) and 27 had a tracheostomy. At discharge, 10 patients keep an exclusive alimentation by gastrostomy (Group 1, G1) as 23 had exclusive oral feeding (Group 2, G2). The score of the WHIM at admission was identical in both groups (21.7 ± 10.9 (G1) vs. 21.0 ± 15.33 (G2) (ns)). At discharge, WHIM increased to 38.3 ± 15.4 in G1 and to 49.8 ± 9.7 in G2 (P < .05). WHIM score was significantly higher in G2 than in G1 (P < .05). There was a positive correlation between functional oral intake scale and WHIM at discharge. Our results demonstrated that recovery of oral feeding in patients with a severe traumatic brain injury appeared in those who had the better improvement of consciousness level.

Prognosis prediction for impaired consciousness recovery in stroke patients using videofluoroscopic swallowing study: A retrospective observational study

Prognosis prediction of impaired consciousness is clinically important for establishing therapeutic strategies, determining a rehabilitative goal and functional outcome, and estimating rehabilitative therapy duration. In this study, we investigated the prognosis prediction value of videofluoroscopic swallowing study (VFSS) in recovery of impaired consciousness in stroke patients. Fifty-one patients with impaired consciousness who underwent VFSS during the early stage of stroke between 2017 and 2021 were recruited in this retrospective study. VFSS were performed using modified Logemann protocol, and bonorex was used as the liquid contrast medium. The penetration-aspiration scale (PAS) was graded for all patients, and they were classified into 2 groups depending on the presence of aspiration on liquid material: the aspiration-positive group with a PAS score ≥ 6, and the aspiration-negative group with a PAS score < 6. The coma recovery scale-revised (CRS-R) was used to evaluate patients' conscious state at the time of VFSS and 3 months after. Statistical analysis was performed using independent t test and Pearson's correlation. The increase in total CRS-R score from time of VFSS to 3 months later was greater in aspiration-negative group than in aspiration-positive group (P < .05). A moderate negative correlation was observed between liquid PAS score and the increase in total CRS-R score (r = -0.499, P < .05). Among 6 CRS-R subscales, a strong negative correlation was observed between liquid PAS score and the communication score increase (r = -0.563, P < .05), while moderate negative correlations were detected between liquid PAS score and the increases in auditory (r = -0.465, P < .05), motor (r = -0.372, P < .05), oromotor (r = -0.426, P < .05), and arousal (r = -0.368, P < .05) scores. We observed that patients without aspiration on videofluoroscopic swallowing study showed better recovery of impaired consciousness, and the degree of penetration and aspiration had a predictive value for impaired consciousness prognosis in the early stage of stroke.

Feasibility study of the Nox-T3 device to detect swallowing and respiration pattern in neurologically impaired patients in the acute phase

Dysphagia is a frequent complication in neurologically impaired patients, which can lead to aspiration pneumonia and thus prolonged hospitalization or even death. It is essential therefore, to detect and assess dysphagia early for best patient care. Fiberoptic endoscopic and Videofluoroscopy evaluation of swallowing are the gold standard exams in swallowing studies but neither are perfectly suitable for patients with disorders of consciousness (DOC). In this study, we aimed to find the sensitivity and specificity of the Nox-T3 sleep monitor for detection of swallowing. A combination of submental and peri-laryngeal surface electromyography, nasal cannulas and respiratory inductance plethysmography belts connected to Nox-T 3 allows recording swallowing events and their coordination with breathing, providing time-coordinated patterns of muscular and respiratory activity. We compared Nox-T3 swallowing capture to manual swallowing detection on fourteen DOC patients. The Nox-T3 method identified swallow events with a sensitivity of 95% and a specificity of 99%. In addition, Nox-T3 has qualitative contributions, such as visualization of the swallowing apnea in the respiratory cycle which provide additional information on the swallowing act that is useful to clinicians in the management and rehabilitation of the patient. These results suggest that Nox-T3 could be used for swallowing detection in DOC patients and support its continued clinical use for swallowing disorder investigation.

Links Between Swallowing and Consciousness: A Narrative Review

This literature review explores a wide range of themes addressing the links between swallowing and consciousness. Signs of consciousness are historically based on the principle of differentiating reflexive from volitional behaviors. We show that the sequencing of the components of swallowing falls on a continuum of voluntary to reflex behaviors and we describe several types of volitional and non-volitional swallowing tasks. The frequency, speed of initiation of the swallowing reflex, efficacy of the pharyngeal phase of swallowing and coordination between respiration and swallowing are influenced by the level of consciousness during non-pathological modifications of consciousness such as sleep and general anesthesia. In patients with severe brain injury, the level of consciousness is associated with several components related to swallowing, such as the possibility of extubation, risk of pneumonia, type of feeding or components directly related to swallowing such as oral or pharyngeal abnormalities. Based on our theoretical and empirical analysis, the efficacy of the oral phase and the ability to receive exclusive oral feeding seem to be the most robust signs of consciousness related to swallowing in patients with disorders of consciousness. Components of the pharyngeal phase (in terms of abilities of saliva management) and evoked cough may be influenced by consciousness, but further studies are necessary to determine if they constitute signs of consciousness as such or only cortically mediated behaviors. This review also highlights the critical lack of tools and techniques to assess and treat dysphagia in patients with disorders of consciousness.

Screening Tools Designed to Assess and Evaluate Oropharyngeal Dysphagia in Adult Patients: A Scoping Review

Oropharyngeal Dysphagia (OD) significantly decreases a patient’s quality of life and poses a high economic burden to institutions. In this sense, evaluation and assessment are important interventions for health professionals, although current tools and instruments are multiple and are dispersed in the literature. The aim of this review was to map existing screening tools to assess and evaluate OD in adult patients, identify their relevant clinical parameters and respective contexts of use and provide a systematic approach and summary to better inform practice. A scoping review was developed guided by the JBI methodology and using PRISMA-ScR to report results published between 2014 and 2021, in English, Spanish and Portuguese. Databases included Medline, Academic Search Complete, CINAHL Complete, Scielo, Google Scholar, ScienceDirect, OpenGrey and B-On. Mendeley was used to store and screen data. A total of 33 studies were included in the study, of which 19 tools were identified, some being intervention-based tools and others an algorithm for decision. The most common context used was in the general population and older adults. Regarding clinical parameters, the most common were food consistency, presence of the cough reflex, swallowing effort, voice changes and weight. As oropharyngeal dysphagia concerns important risks for the patient, a rigorous assessment must be performed. In this sense, the review identified specific disease-related tools and more general instruments, and it is an important contribution to more efficient dysphagia screening and prevention.

Feasibility and Safety of Fiberoptic Endoscopic Evaluation of Swallowing in People with Disorder of Consciousness: A Systematic Review

People with disorders of consciousness (DoC) often receive nutrition via a feeding tube and the swallowing ability in this population is not fully understood. In particular, fiberoptic endoscopic evaluation of swallowing (FEES) with people with DoC requires further investigation. The aim of this systematic review is to collate, assess and summarise the current evidence of whether FEES is feasible and safe with people with DoC. Multiple health databases were searched in November 2019 to identify studies which used FEES with people with DoC. Data extraction included demographic information, adverse events reported and outcomes related to oral feeding. The Diagnostic Accuracy Quality Scale (DAQS) was used to assess the quality of the studies. In total only four studies were found, all of which had a high risk of bias. Many participants went from nil by mouth to some degree of oral diet sometime after the FEES was completed with low reporting of adverse events associated with FEES. This suggests a potential for the use of FEES in people with DoC. However, the evidence is low and further studies are recommended to improve understanding of FEES with people with DoC. Recommendations for clinical practice and areas for future research are outlined.

The Development and Validation of the SWADOC: A Study Protocol for a Multicenter Prospective Cohort Study

Background: After a coma, patients with severe brain injury may present disorders of consciousness (DOC). A substantial proportion of these patients also suffer from severe dysphagia. Assessment of and therapy for swallowing disabilities of patients with DOC are essential because dysphagia has major functional consequences and comorbidities. Dysphagia evaluation in patients with DOC is impeded by the lack of adapted tools. The first aim of this study was to create a new tool, the SWallowing Assessment in Disorders Of Consciousness (SWADOC), and propose a validation protocol. The SWADOC was developed to help therapists assess factors related to swallowing in patients with DOC. The second aim was to investigate the relationship between patients' level of consciousness and SWADOC items and scores. Method/Design: In this multicenter prospective cohort, 104 patients with DOC will be tested three times over five consecutive days with the SWADOC. Statistical analyses will focus on the reliability and validity of the SWADOC, especially the intrarater and interrater reliability, internal consistency, measures of dispersion, and concurrent validity with the Facial Oral Tract Therapy Swallowing Assessment of Saliva (FOTT-SAS). The level of consciousness will be assessed with the Simplified Evaluation of CONsciousness Disorders (SECONDs) and the Coma Recovery Scale-Revised (CRS-R). Discussion: The assessment of swallowing abilities among patients with DOC is the first necessary step toward the development of a customized dysphagia care plan. A validated scoring tool will be essential for clinicians to better assess dysphagia in patients with DOC and document the evolution of their disorders. Trial Registration: NCT04706689.