Device-facilitated I-PRO therapy transitioned a single patient, who was more than 2 years post brainstem stroke, with profound dysphagia to functional swallowing. The patient received nutrition and hydration solely by G-tube and could manage secretions only by expectoration when I-PRO intervention was initiated. Other treatments, such as UES dilatation, were performed post maintenance to demonstrate that changes observed at the end of the intervention period resulted primarily from the MOST-facilitated I-PRO intervention. The oropharyngeal swallow is a complex, multifaceted function comprising the combined effort of multiple muscles, end organs, and 5 cranial nerves. In this case study, several of these separate end organs, including the tongue, pharyngeal constrictors, and cricopharyngeus, undergo change via a simple, nonspecific task focusing the patient on a single organ, the tongue (including intrinsic and extrinsic muscles). Although the tongue is the primary applicator of force to drive a bolus through the oral and pharyngeal spaces, it is not the only driving force. The base of tongue and pharyngeal wall constrictors apply pressure on all sides of the bolus to propel it through the hypopharynx and UES. Positive and negative changes observed in swallowing-related outcomes, including postswallow residue score, kinematic durations, and pharyngeal pressures, reflect this complex anatomic-physiologic process.
The goal in application of the novel MOST device, with a patient more than 2 years post brainstem stroke, was a return to functional swallowing compared with normal or premorbid swallowing abilities. Clinical significance, as it relates to this goal, was the primary concern for this patient. In similar chronic cases, the goals are typically a return to function, which is more important to the patient in regard to improvements in QOL than statistical measures of change.
In isolation, the increase in semisolid cricopharyngeal residue post I-PRO intervention may seem unhelpful at first glance, in terms of bolus clearance. However, improved pharyngeal bolus clearance is apparent when viewed in light of the diminishing residue both in the valleculae and posteriorly along the pharyngeal wall and increased residue moving inferiorly through the pyriform sinuses to the cricopharyngeus, combined with greater pressure generation clearing material from the upper pharynx. By the end of intervention, a single, second swallow in head-turned position afforded the best clearance of pharyngeal residue; whereas pre intervention, J.B. required 4 to 5 swallows to minimize residue, which added a fatigue factor to swallowing. Changes observed in timing between initiation of airway protection (beginning of laryngeal vestibule closure) and the point where the bolus enters the pharynx () further suggest that movements generated with increased pressure by the tongue musculature may affect associated structures innervated by different cranial nerves, centers, and/or pattern generators. In this case, the decrease in time between the beginning of laryngeal vestibule closure and the point when the bolus enters the pharynx is evidence of improved airway protection, as the laryngeal vestibule is closing nearer to the time that the bolus enters the pharynx. I-PRO therapy not only facilitated gains in swallow function, but also a change in lingual anatomy as well; there was an 8.37% increase in total tongue volume, indicative of a reversal in potential muscle atrophy.
Gains made in pharyngeal pressure patterns, though improved following I-PRO therapy, did not reach normative levels and did not return to a typical presentation as seen on the spatiotemporal plots ( and ). However, there was return to functional swallowing abilities. Notably, the minimum UES pressure dropped to levels below the normative data. It is possible that the patient developed a compensatory strategy to open the UES in the setting of relatively low hypopharyngeal pressures and hyolaryngeal excursion by using means other than those clinically measured. This gives new insight to oropharyngeal pressure patterns that are needed for a safe swallow, namely high hypopharyngeal pressures, that are evidently influenced by oral pressures in the setting of low UES pressures.
Clinically, the most significant outcomes from the patient's point of view are in the changes that affect daily life. This patient enthusiastically reported a complete return to premorbid activities post intervention. At baseline, this profound dysphagia was perceived as a complete burden, because all food and drink were restricted (). Post intervention, there was no more perceived burden because diet was completely unrestricted. The patient's perception of restriction and resultant burden were directly related to her perception of enjoyment and motivation to participate in premorbid activities including any sort of food or drink.
A potential confounding factor was the initiation of oral intake during the intervention period, as the act of swallowing promotes swallowing. However, until week 4 of the intervention period, the patient was unable to safely take anything by mouth. The decision to initiate oral intake was clinically warranted by improvements in objective, radiographic, and instrumental findings comparing data collected at baseline to week 4 of the intervention period. This case study included the inconsistent design of an 8-week intervention, 5-week detraining period, 9-week therapeutic maintenance period, and it examined just one patient's participation in MOST-facilitated I-PRO strengthening therapy. The final UES dilatation, which occurred after the maintenance period, is also a potential confounding factor related to the patient's oral intake. However, the patient initiated oral intake 18 weeks before the dilatation and discontinued the use of her G-tube 14 weeks prior to the dilatation. Diet advancement did occur as a consequence of I-PRO intervention alone, however the UES dilatation further broadened the patient's diet advancement.
From the patient's perspective, QOL also improved as she was able to swallow her own saliva and no longer carried a spittoon; the latter was certainly a challenge for social acceptability. She also gained back 15 lbs, of her lost 25 lbs, by the end of the intervention; this weight gain was initially perceived as being unattainable. Perhaps most important, she expressed great surprise, satisfaction, and pleasure in her new oral intake status.
This patient, who was more than 2 years post stroke, made enormous gains in her ability to swallow her secretions and re-initiate oral intake without the risk of airway invasion, by virtue of increasing tongue strength and improving oral control using I-PRO therapy. Despite other previous and intensive traditional therapies performed in the 25 months prior to initiating I-PRO therapy, MOST-facilitated I-PRO therapy resulted in the greatest gains in terms of QOL. Additionally, the MOST device provided the patient immediate knowledge of performance and automatically recorded any and all lingual press repetition and pressure data each time J.B. used the device. This afforded improved reliability and patient compliance by eliminating more crude/less reliable recording and reporting methods such as daily logs or therapy journals.
The potential for improvement with I-PRO therapy hinges on fundamental principles of exercise,15
including repetition, overload, and therapy duration. At 8 weeks, this single patient continued to demonstrate improvements and may have continued to improve beyond the period of this study. However, the upper limit of I-PRO therapy duration is not well-defined. Further research is needed to determine the optimal I-PRO therapy regimen as well as various patient populations that could potentially benefit from this therapy.
Gains made using MOST-facilitated I-PRO therapy demonstrate an important argument for functionality as a goal for swallowing therapy. Even though the patient did not reach normal values for lingual or pharyngeal pressures following therapy, she was able to augment her swallowing pressure patterns to safely and enjoyably (ie, with reduced patient-perceived effort) swallow a bolus. Novel technologies and applications, such as the MOST device and high-resolution manometry, offer new solutions and documentation of methods for swallowing intervention and have the potential to quantify gains not previously achievable or detectable.