The effect of intensified nonverbal facilitation of swallowing on dysphagia after severe acquired brain injury: A randomised controlled pilot study

1 Introduction

Sixty-nine million (95% CI 64-74 million) individuals worldwide are estimated to sustain a traumatic brain injury (TBI) each year (Dewan et al., 2018).

The incidence of oropharyngeal dysphagia is reported to be as high as 93% in patients with severe TBI (Hansen, Larsen, & Engberg, 2008) at admission to sub-acute rehabilitation and 37–78% in patients after stroke (Martino et al., 2005). Dysphagia is a threat to eating and drinking safely in several populations putting patients at high risk of pneumonia (Martino et al., 2005; Morgan & Mackay, 1999; Woratyla, Morgan, Mackay, Bernstein, & Barba, 1995) and malnutrition (Foley, Martin, Salter, & Teasell, 2009; Mackay, Morgan, & Bernstein, 1999).

The rehabilitation of dysphagia frequently incorporates rehabilitative exercises, aiming to improve swallowing physiology in the long term (Langmore & Pisegna, 2015). There is limited evidence that interventions such as expiratory muscle strength training, the Mendelsohn Manoeuvre or Shaker exercise improve the symptoms of dysphagia (McCullough & Kim, 2013; Shaker et al., 2002; Troche et al., 2010). Furthermore, there is a paucity of evidence relating to the dosage and intensity of therapy required (Cabib et al., 2016; Langmore & Pisegna, 2015; Robbins et al., 2008). Since patients with severe acquired brain injury (ABI) suffer from serious perceptive, sensomotory and cognitive disturbances, they are challenged to follow the therapist’s verbal guidance in executing these exercises (Cherney & Halper, 1996; Morgan & Mackay, 1999; Neumann, 1993). For patients with severe brain injury and other patients with neurological swallowing disorders, Coombes developed an interprofessional approach, the Facial Oral Tract Therapy^® (F.O.T.T.), for assessing and treating problems with safe swallowing, eating, oral hygiene, breathing, voice and articulation. This concept is a complex rehabilitation intervention and uses structured tactile input and nonverbal facilitation techniques to allow for effective function in meaningful daily life activities (Hansen & Jakobsen, 2010). F.O.T.T. aims to improve function that is as normal as possible with the goal of maximum participation. For description of the methods and techniques in F.O.T.T., see Appendix.

There is, however, a lack of evidence about the active ingredients in F.O.T.T. (Hansen & Jakobsen, 2010). A pilot study investigated the effect of several interventions included in the F.O.T.T. concept on swallowing rate, alertness and swallowing ability in 10 patients with tracheostomy (Seidl, Nusser-Müller-Busch, Hollweg, Westhofen, & Ernst, 2007). Several interventions were used including positioning, oral stimulation, facilitation of swallowing, deflating and capping the tracheostomy tube. There was a statistically significant improvement in the outcome measures after an intervention period of three weeks. However, the sample was small, and the lack of a control group makes the results inconclusive.

From clinical experience, patients with severe ABI in the sub-acute stage, often show a pattern of “pumping-like” jaw movements before swallowing. The mandible moves rhythmically up and down in biting-like movements, the tongue moves anterio-posteriorly and sometimes the lips are open. It is described from patients with other neurological diagnoses, that when swallowing is preceded by “pumping-like” jaw movements, that laryngeal elevation is delayed, incomplete, or missing (Argolo, Sampaio, Pinho, Melo, & Nobrega, 2015; Daniels, 2000; Robbins, Levine, Maser, Rosenbek, & Kempster, 1993; Saito, Hayashi, Nakazawa, & Ota, 2016; Sonies, Parent, Morrish, & Baum, 1988; Veis & Logemann, 1985). This is contrary to healthy individuals, where the mandible remains stable during the pharyngeal stage of swallowing, allowing transport movements of the tongue and elevation and anterior movement of the hyoid bone and the larynx (Dodds, 1989; Palmer, Rudin, Lara, & Crompton, 1992; Shaw & Martino, 2013). Furthermore, a well-coordinated oral and pharyngeal stage contributes to a functional coordination between breathing and swallowing, which is important for protection of the airway (Bautista, Sun & Pilowsky, 2014).

To address the lack of evidence for the effect of F.O.T.T. on swallowing ability and pumping like jaw movements, we decided to perform a definitive trial. In order to design this trial, we needed to investigate the feasibility of the intervention, recruitment rate, outcome measures and trial size. The primary objectives of this pilot study were therefore: 1) to estimate the recruitment rate based on the inclusion criteria and recruitment method, 2) to determine the feasibility of intensifying existing levels of F.O.T.T. in a clinical setting, 3) to determine the feasibility of administering the outcome measures, 4) to obtain preliminary data of effect size to inform estimates of sample size for a definitive trial.

2 Materials and methods

3 Results

We included a total of 10 patients during the project period. There were no significant differences between groups in age, days to inclusion, EFA or GCS at baseline. There were more males in the control group than the intervention group. GCS and EFA scores show that the included patients were severely brain damaged (Table 1).

Participants were enrolled over a period of 32 months. There were periods of several months where we were unable to include patients. Patients, that otherwise would have met the inclusion criteria for pumping jaw movements and PAS-score worse than 3, could not be included due to restlessness and/ or agitated behaviour, prevalent in patients in the sub-acute stage following severe ABI. These patients would not have tolerated the positioning required for measuring and intervention and they would not have tolerated the electrodes for the EMBI measurement.

Written consent was obtained for all patients fulfilling the inclusion- and exclusion criteria, no patients withdrew from the study and there were no dropouts.

The intensified intervention was feasible, one patient received the target of 30 additional treatments, one received 29, two received 27 and one received 25. The reasons for missing treatment were increased agitation or motor restlessness, deterioration of medical conditions and the transfer to another department for a single patient due to hydrocephalus.

The intervention with two extra treatments per day was very intensive for the patients, who often seemed tired. It was a challenge to incorporate the intensified treatment in an interprofessional setting whilst ensuring that the patient had adequate rest.

Table 2 shows the changes in the Penetration Aspiration Scale and Functional Oral Intake Scale for both groups. There were no significant differences in score changes between groups in these outcomes.

There was a reduction in the mean value for maximum laryngeal elevation in the control group throughout the treatment (negative outcome) whereas it increased in the intervention group during facilitation when compared to the pre- and post-treatment periods (positive outcome) (Fig. 1a).

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Fig.1

(a) Maximum laryngeal elevation during swallows; (b) Speed of laryngeal elevation; (c) Swallowing frequency; (d) Pumping frequency.

The median speed of laryngeal elevation during swallows fell during treatment and post-treatment in the control group (negative outcome), whereas it increased in the intervention group during treatment (positive outcome) compared with the pre- and post-treatment periods. (Fig. 1b).

Median swallowing frequency increased in both groups during treatment (positive outcome) compared with the pre- and post-treatment phases (Fig. 1c).

Median pumping frequency increased in both groups during treatment (negative outcome) but more greatly in the control group (Fig. 1d).

There were no observed adverse events as a result of the intervention but there was an adverse reaction in the form of increased patient fatigue during some of the interventions. There were no important changes to methods following trial commencement.

This study has provided evidence that PAS and FOIS are both feasible outcome measures to measure dysphagia in a definitive study. The study also demonstrated that it is possible to measure swallowing frequency and swallowing specific parameters using the EMBI system in patients with severe acquired brain damage, that are not restless or agitated. The inclusion criteria and organisational restraints limited the inclusion rate to three patients a year, which was considerably lower than anticipated. The study has additionally shown that intensifying therapy with two treatments a day is challenging both in terms of organization, but also in terms of patient fatigue and changing arousal.

One of the principal reasons explaining the slow inclusion rate was a lack of patients that met the inclusion criteria. It would improve patient inclusion if the inclusion criteria were widened by removing the age limit and patients were included at multiplecentres.

The intensification of treatment proved to be challenging both from an organizational perspective, but also from a patient perspective. The organizational challenge could be met by finding financial and human resources to provide the intensified therapy, for example during weekends and evenings. The greatest challenge is however to ensure that the patient has a high enough arousal level to benefit from the intensified therapy. Patients with severe ABI suffer from low and fluctuating arousal due to disorders of consciousness (Giacino, Fins, Laureys, & Schiff, 2014) that may inhibit or prevent motor learning (Goldfine & Schiff, 2011). Level of consciousness may confound the relationship between the amount of exercise and functional swallowing recovery.

We were able to administer the outcome measures on all patients that were included in the project. The only missing data were due to a faulty cable in the EMBI system for a single patient. FOIS and EFA require knowledge of the patient to make valid scores. This was not always the case, due to sick leave or vacation of the primary therapist and may have affected the data quality. The PAS assessment using FEES is acknowledged as gold standard for the evaluation of oropharyngeal dysphagia. Due to the invasive nature of the endoscopic examination, this outcome was only used at baseline and at the end of the intervention. A single measure, however, can vary according to the patient’s daily context and arousal and a definitive study would need to control for the patient’s level of arousal. There is some evidence, that the body position and the swallowing of different consistencies do influence swallowing specific parameters (Schultheiss, Wolter, Schauer, Nährstedt, & Seidl, 2015). Even though, the EMBI was feasible and robust in terms of patient positioning, two of the patients had difficulties staying in the neutral side lying resting position, due to muscle tone and respiratory issues. Measures made using the EMBI system in the two rest periods with different positioning may not be comparable.

The FOIS scores showed little change in few participants during the study. A scale of this type reflects relevant changes in abilities in daily life activities but would require a substantial increase in the sample size to achieve statistical significance. An adequately powered definitive randomised trial could implement this score as it more broadly reflects eating function (Crary et al., 2005). Participants in this study had more severe perceptive, cognitive and sensorimotor problems than patients with stroke in the FOIS sensitivity study (Crary et al., 2005) which may explain the relatively smaller changes in the FOIS score in this study.

The total PAS scores improved in both groups during the study period and was significantly different from baseline in the intervention group. Despite no published studies of sensitivity for this measure, it seemed to be sensitive to changes in this study. Whether the PAS is helpful in describing and measuring the severity of airway invasion when swallowing saliva or consistencies has been questioned for several reasons (Steele & Grace-Martin, 2017). The PAS produces a score for each consistency. Using only the worst scores increases the risk of skewing the score, whereas the mean value does not reflect the distribution of the scores. Furthermore, the question has been raised, whether it is more dangerous for the patient to have a PAS score of 3, where penetrated material remains above the vocal folds without being expelled (and thereby the risk for subsequent aspiration), or a score of 6, where an aspiration is followed by a subsequent effective cough. Despite these challenges in interpreting the PAS scores, this measure together with FEES remains the best available clinical tool to measure aspiration and penetration and, in the light of this study, will be a prioritised choice of secondary outcome in a future definitivestudy.

The swallowing specific parameters show a tendency for the swallowing frequency, the maximum elevation of larynx and the speed of laryngeal elevation to improve within the intervention group during the intervention phase. Furthermore, the frequency of pumping jaw movements during intervention decreased. These results appear to reflect the clinical experience of the facilitation of swallowing and these measures therefore seem to be valid in quantifying swallowing kinematics non-invasively. Future studies should investigate the relationship of these parameters to aspiration and penetration risk in patients with brain injury and whether there is a solid learning effect of the intervention reflected in an increase in eating ability measured using FOIS at a 3-month follow-up.

A controlled study in a population of patients with severe ABI in an intensive rehabilitation clinic is very challenging. The patients in our study reflected the heterogeneous nature of this patient population with varying diagnoses, symptoms and severities. All patients were medicated with pharmaceutics that can potentially influence arousal, tone and production of saliva, which might have influenced the swallowing frequency. Their ability to swallow may also vary due to other factors such as infections and level of consciousness. Some of the challenges of creating matched groups in a randomised design could be met using stratification techniques, but the greatest challenge in working with this patient group is the extent to which the intervention can be controlled in a sub-acute clinical setting.

Funding

The study was supported by the Danish Occupational Therapist Association (FF 2–13–3), the Glostrup Hospitals Research grant and Department of Neurorehabilitation, TBI Unit, Rigshospitalet.

Authors’ contributions

DJ, THP, ROS and CS modified the study design from Müller. DJ and THP initiated the study and were responsible for collection of data and monitoring the process. CS, CR and DJC analysed the data. DJ and DJC drafted the manuscript. All authors critically reviewed and contributed to the draft, revised and approved the manuscript.

Conflict of interest

Daniela Jakobsen is a certified F.O.T.T.^® senior instructor and teaches F.O.T.T.^® courses. The other authors declare no potential conflicts of interest with respect to the research, authorship or publication of this article.