Dysphagia; Surface Electromyography; Fiberoptic Endoscopy; Swallowing

FEES: Fiberoptic endoscopic evaluation of swallowing; sEMG: Surface electromyography; GERD: Gastroesophageal reflux disease; MDADI: MD Anderson Dysphagia Inventory.

Dysphagia, or difficulty in swallowing, is described as a medical problem, whereby it is problematic to propagate the food bolus from the oral cavity to the stomach. Structural or functional abnormalities may cause such difficulties. Dysphagia can be secondary to defects in three phases of swallowing: oral, pharyngeal and esophageal phases [1,2]. The most common descriptions in literature describes dysphagia as being a common complaint among older individuals, with a primarily high incidence in the elderly population. The term for the aforementioned changes is presbyphagia, and it refers to changes in swallowing mechanism of otherwise healthy adults (>65 years) and occurs in 30%-40% or even 60% of patients in nursing homes [3,4]. A completely different group of patients suffering from dysphagia are those with concomitant neurological disorders, more precisely those diagnosed with neurodegenerative diseases (more than 80% of this patient group presents with dysphagia), after stroke (more than 30%), Parkinson’s (52%-82%), or Alzheimer’s (84%) [2,5-7].

Dysphagia is a very general concern amongst patients, and in recent years it is more noticeable in the younger population. Based on western guidelines, we decided to form a team dedicated to the broader diagnosis of problems swallowing in order to develop guidelines for the Polish population. This will provide consistent feedback for therapy management and rehabilitation in specific patient groups with disorders from various phases of swallowing. The main idea of this project is that patients who report to us with dysphagia will continue treatment in our department and not get sent to further specialists. We would like to create a specialized team that will be able to provide the unmet needs of the patient while delivering comprehensive care and control of the disease management.

The aim of the study is to present preliminary data from the conducted diagnostic tests for patients suffering from swallowing disorders, which can be used for the development of future guidelines in the Polish population.

In the Department of Otolaryngology, Head and Neck Surgery and Oncological Otolaryngology in Poznan we conducted research on a group of 92 patients with suspected dysphagia. Out of this group, 52 were males and 40 females, age ranged from 35 to 72, with the average age of 58 years. (median-61.5; SD-11.2). Criteria of inclusion were: no prior history of operations in the head and neck region, and no history of neurological disorders. Each patient complained of persistent or periodic swallowing disorders which had lasted at least 6 months. Every patient took part in a full examination according to the developed algorithm: questionnaire-MDADI ( MD Anderson Dysphagia Inventory ) [8] FEES (Fiberoptic Endoscopic Evaluation of Swallowing), surface electromyography (sEMG) and registration of respiratory patterns with the use of Digital Swallowing Workstation from KayPENTAX. Examination was carried out during standard appointment in outpatient clinic, followed by signing of the dedicated consent form.

The questionnaire consists 20 questions about the patient’s swallowing ability. The questions are divided into 3 subgroups: emotional, functional and physical, except for the first question (was scored individually). There are five possible answers for each question (strongly agree, agree, no opinion, disagree, strongly disagree; scored on a scale 1 to 5 and were summed). The patient must choose only one answer [8]. The integrate system allows the physician to capture an image, and objectively measure key physiologic parameters related to swallowing, with real-time visual feedback. Every examination consisted of full documentation of swallowing from the oral cavity to the throat with the ingestion of different foods including liquids, softfoods, and solid-foods. The swallowing reports generated were further correlated with respiratory patterns and surface EMG.

The patients were asked to be seated, with all electrodes and cannulas placed according to the accepted guidelines [9,10] and later asked to swallow food bolus in the following intervals: a) 20 mL liquid (milk)-the volume could be consumed at once if physiologic function of swallowing was preserved [11]; b) teaspoon of soft-food; c) half a biscuit solid food chewed and swallowed at once. The examination has been assessed, autonomously by two physicians and speech therapist. The presence of food retention within the mucosa of the hypoharynx, piriformis sinus or entrance to the esophagus was considered as positive (+), while the lack of it as negative (−). During each bite there was simultaneous registering and analysis of initial muscular contraction. The results were collected by the surface electrodes and registered in microvolts (mV) from sEMG. Reports were conducted from the initial muscular contraction, maximal peak contraction, and end of contraction for each food type consumed separately. Analysis was also done for the duration (in seconds) of the muscular contraction. In addition, each patient has a simultaneous registration of respiratory phases, which could be further used in correlation with the different stages of swallowing for each food type, but wasn’t considered in this study.

The statistical calculations Chi-square test and description statistics were performed using the Statistica v12. p-values lower than 0.05 were considered as statistically significant.

Data was collected from the 92 individuals using the above mentioned study design and the following preliminary results were obtained. In 38 patients (41.3%) symptoms of gastroesophageal reflux disease (GERD) were apparent in the endoscopic examination. These patients had been referred to gastroenterologist, and 13 of them returned with confirmation of GERD. In 50 patients (54.3%) chronic inflammation of the larynx in the endoscopic image was observed. In the assessment of retention for particular food types, it was clear that 56 patients (60.8%) had fluid retention, 66 patients (71.7%) had retention of soft food and 50 patients (54.3%) had retention of solid food. In group of individuals with chronic inflammation, 40 patients had retention of fluids, 44 had soft food retention and 32 had solid food retention, what stated 80%, 88% and 64% respectively. In this group of patients, there was strong statistical correlation (p<0.05) between retention of each types of food a presence of chronic laryngitis. Among patients with endoscopic signs of GERD, retention of fluid and soft food was present in 73.7% and 78.9% respectively. Fluid retention in FEES in correlation with GERD symptoms turned out to be statistically significant (p<0.05) (Table 1).

Table 1: sEMG description statistics for different foods in 92 patients. p1: the start point of the muscle contraction , Peak-the maximum of muscle contraction; p2: the finish point of muscle contraction, Dt-total time of muscle contraction.

It should be emphasized that retention was recorded postprandial. Maximal muscular contraction during swallowing was recorded by sEMG and the endoscopic image recorded food debris on the mucus membranes of the throat, piriformis sinus or entrance to the esophagus. Food retention is primarily symptomatic in patients suffering from GERD or chronic inflammation of the larynx, or both simultaneously, even if the patient did not notice obvious symptoms associated with dysphagia prior to the examination

The surface electrodes were placed on the suprahyoid muscles and reports were generated for initial muscular contraction, maximal isometric muscular contraction and subsequently the end of the contraction phase, to determine when the food bolus passed. The full duration of the contraction was also documented (Table 2).

Table 2: Comparison of fluid, soft and solid food retention with GERD and chronic inflammation of the larynx.

The results obtained during the sEMG recordings give the opportunity to illustrate a number of correlations in the various phases of swallowing, which warrant further statistical analysis that is in development and will be published separately.

MDADI results-The all questions were added up and there are the results of 3 subgroups:

Emotional: 14 to 26, mean 21.4 points.

Functional: 12 to 23, mean 19.5 points.

Physical: 23 to 40, mean 30.3 points.

Total points: 53 to 92 , mean 72.4.

During the analysis of collected data we observed an interesting correlation between the results of sEMG and MDADI especially in patients suffering from GERD or chronic inflammation of the larynx. In this group of patients the points obtained in the MDADI questionnaire were below average in each subscale and in total– total scores in patients with GERD and chronic laryngitis were 62.4 and 66.5 respectively. In the same cases the data from the sEMG were slightly lower compared to the group of patient without these pathologies. We believe that constant increasing the number of patients examined, will allow us to extract interesting statistical correlations in the further studies.

Analysis of the respiratory phases revealed only a single case of non-physiological correlation with swallowing. Still, remaining a part of full swallowing examination, was excluded at this point from our study.

Dysphagia is a topic reported by patients of all age groups. As part of normal senescence, elderly patients are inherently predisposed to dysphagia. Healthcare providers will increasingly encounter patients with oropharyngeal or esophageal diseases with concomitant complaints of difficulty swallowing. Understanding the complex anatomy and physiology of swallowing is key in the diagnosis and management of swallowing disorders. Countless tools can aid in competent and complete examination of all phases of swallowing while simultaneously securing the airways from food aspirations [12]. Technological advancements in equipment significantly improve examinations, diagnosis, and short or long-term observations. FEES with superficial electromyography (sEMG) and documentation of respiratory patterns with the use of Digital Swallowing Workstation from KayPENTAX gives us such possibilities. The merits for using flexible fiberoscopy allows for significant advantages in examining patients with swallowing disorders, anatomical irregularities or aspirations of food. Using foods of various consistencies combined with food coloring dye enables a simple and direct observation regarding any changes in the oral cavity, pharyngeal and laryngeal areas. An additional advantage is the ability to use the device at various stages of treatment or during rehabilitation of the patient. It can be used to assess the progress of therapeutic intervention [13,14]. Supplementary sEMG testing using surface electrodes is very promising. We found interesting the fact, that patients with intercurrent GERD or chronic laryngitis, thus problem affecting mucosa, had slightly lower responses from the muscles in sEMG. These findings require further research, larger group of patients and searching for statistical correlations. For several years, research has been conducted worldwide for the use of surface electrodes, and results are showing good results especially in the diagnosis of dysphagia [15-18]. Vaiman et al. [19-21] has been developing standards for several years for children and adults on the basis of testing muscle activity during deglutination using surface electrodes, as a non-invasive technique in the diagnosis of dysphagia. It needs to be underlined, that creation and development of such a database for a given population requires a significantly larger and more detailed statistical analysis, which also demands more time. However, looking at Vaiman’s guidelines, there is a large space for opportunities to use this technique in the diagnosis of swallowing disorders. The first analysis and preliminary correlations which are observed, are very optimistic for the future.. A team of leading physicians from Poznan is constantly working on the formation of those standards for the Polish population.

• Dysphagia may affect patients of a wide range of ages.

• FEES with superficial electromyography and documentation of respiratory airways gives wide possibilities of swallowing disorders diagnostics.

• Authors aim to develop guidelines for Polish population which would allow to improve dysphagia diagnostics and treatment and to create a multidisciplinary team helping wide range of patients with dysphagia, including those with neurological disorders and those after extensive surgeries in head & neck region.

Observed outcomes-lower mean score in self-assessing survey- MDADI and lower sEMG score in patients with GERD and chronic laryngitis may lead to interesting conclusions but necessitate further study and statistical analysis on larger group of patients.