Clinical inter-rater reliability of postural control techniques.

Effectiveness of postural control techniques to compensate for oropharyngeal dysphagia have been recommended and used by several clinicians. However, the inter-rater reliability of these techniques is not well understood. The purpose of this study was to clarify the ambiguity of postural control techniques using statistical analyses. A total of 50 clinicians involved in dysphagia treatment participated in this study, where a healthy male served as the simulated patient. The following clinically used postures were measured by two investigators on two separate days: chin down, right/left incline, and right/left rotation. Postural angles were measured twice by two investigators on each day. Data obtained for the angle of each posture were visually displayed. Data from both investigators were assessed for each posture using the Youden plot, which analyzes data variability for systematic errors and accidental errors separately. The correlation coefficient for examining the measurement error between investigators was calculated. The results showed considerable variation between clinicians regarding the postures used, and significant differences were noted each day. The correlation coefficient for a total of four measurements was more often lower on Day 2 than that on Day 1. The details of the instructions provided by clinicians were not fixed, and the same specified posture was not reproduced even when instructions were provided to the same subject. These findings suggest poor inter-rater reliability because of the variability of selected postures when using statistical analyses. Therefore, standardized postures need to be developed that can be easily measured and reproduced.

Comparison of three types of tongue pressure measurement devices.

A new tongue pressure device consisting of a simple and safe disposable probe and manometer has been developed. This report describes a study that examined the validity of the new device, comparing it to a widely used tongue pressure manometer, the Iowa Oral Performance Instrument (IOPI), and to the stable adhered three air-filled bulbs manometry system. The first test compared maximum tongue pressure measured with the new device and the IOPI (13 male, 9 female, 25.0 years). The second test compared maximum tongue pressure and swallowing tongue pressure measured with the new device and the three-bulb device (13 male, 9 female, 31.0 years). Significant correlations of maximum tongue pressure were found between the new device and the IOPI in the first test (p < 0.05). In the second test, significant correlations of maximum tongue pressure were found between the new device at the anterior and middle sensors (p < 0.05) but not at the posterior sensor of the three-bulb device. Significant correlations of swallowing tongue pressure between the new device and the three-bulb device were found (p < 0.05). These findings demonstrate that the measurements by the new simple tongue pressure device are closely equivalent to those of the IOPI and three-bulb devices, demonstrating that the new device is capable of accurately measuring the pressure generated by the whole tongue.

Normal muscular activity during swallowing as measured by surface electromyography.

OBJECTIVES: Speech-language pathologists use surface electromyography biofeedback as a tool to facilitate swallowing treatment, particularly to improve swallowing strength and coordination. The present study sought to establish normative data of swallowing muscular activity as measured by surface electrodes in order to compare the performance of patients with dysphagia to normal swallow performance. METHODS: Thirty normal young (18 to 25 years of age) and elderly (60 or more years of age) subjects swallowed 3 bolus volumes (5, 10, and 20 mL) in 2 conditions: swallow-to-command and swallow-when-ready. Swallow muscular activity was measured in microvolts with a portable biofeedback unit. RESULTS: There were significant differences between the 2 swallowing conditions in both age groups. Neither age nor bolus volume had a significant effect on the findings. CONCLUSIONS: In using surface electromyography biofeedback as an adjunct to swallowing rehabilitation, it may be more beneficial to use swallow-to-command techniques if one is interested in measuring maximum effort, regardless of patient age or volume selected.

Comparison of surface electromyographic (sEMG) activity of submental muscles between the head lift and tongue press exercises as a therapeutic exercise for pharyngeal dysphagia.

OBJECTIVE: The present study compared surface electromyographic (sEMG) activity obtained from the submental muscle group for a tongue press and a head lift exercise as potential therapeutic exercises for dysphagic elderly. MATERIALS AND METHODS: Fifty-three healthy volunteers with a mean age of 35.3 participated in this study. Subjects were required to perform an isometric task, pressing their tongue against the hard palate, and an isotonic task requiring sustained lingual force against the hard palate. Pressure sensors were used to measure the amount of lingual pressure against the hard palate. Submental sEMG data from these tasks were compared with those obtained from the isometric and isotonic aspects of a head lift exercise. RESULTS: No sEMG differences were identified between the isometric tongue press task and head lift exercise. Isotonic tongue press exercises resulted in significantly higher maximum and mean sEMG values compared with the isotonic head lift exercise (p < 0.05). The submental sEMG activity from the tongue press exercise was equal (isometric) to, or greater (isotonic) than comparable muscle activation obtained during the head lift exercise. CONCLUSIONS: The tongue press exercise may be less strenuous than the head lift exercise while achieving the same therapeutic effect.

Identification of swallowing events from sEMG Signals Obtained from Healthy Adults.

Surface electromyography (sEMG) is being used with increasing frequency to identify the occurrence of swallowing, to describe swallow physiology, and to treat impaired swallowing function in dysphagic patients. Despite this increased utilization, limited information is available regarding the validity and reliability of investigators and clinicians to interpret sEMG data in reference to swallowing. This study examines the validity and interjudge reliability of swallow identification using sEMG records obtained from healthy adults. Validity and reliability estimates were compared between experienced and naïve judges in the identification of swallows from graphic sEMG records. Multiple validity estimates were high, indicating a strong degree of accuracy in identification of swallows versus nonswallow movements from sEMG traces. Experienced judges were more accurate than naïve judges (classification accuracy: experienced = 90% vs. naïve = 81%; p = 0.006, kappa: experienced = 0.89 vs. naïve 0.62; p = 0.008). Judges in both groups were more likely to classify swallows as nonswallow movements (false negatives) than to classify nonswallow movements as swallows (false positives). Interjudge reliability estimates indicated a high degree of agreement among judges in the identification of swallows versus nonswallow movements from the sEMG signal, with higher agreement among experienced judges (average kappa coefficient: experienced = 0.75 vs. naïve = 0.51). These results suggest that the sEMG graphic record is a valid and reliable tool for identifying normal swallows and that experience with this technique results in better identification and interjudge agreement.

Reinstituting oral feeding in tube-fed adult patients with dysphagia.

Feeding tubes are valuable assets in the rehabilitation of adult patients with dysphagia. Feeding tubes may be placed in response to perceived risks of airway compromise or insufficient nutrient intake. However, not all patients require long-term enteral feeding. With intensive dysphagia therapy, many patients will experience resolving deficits or improvement in swallowing ability. These patients require an appropriate strategy to transition from tube to oral feeding. This article reviews some of the basic characteristics of dysphagia and identifies specific swallowing difficulties in 2 groups of patients who often benefit from temporary enteral feeding: stroke survivors and patients treated for head and neck cancer. Specific suggestions are offered for clinical strategies to reinstitute oral feeding in these groups of tube-fed patients.

Psychometric testing of the McGill Ingestive Skills Assessment.

The goal of this study was to determine the psychometric properties of the McGill Ingestive Skills Assessment. Interrater and intrarater reliability and score stability were tested using repeated administration of this test. The Functional Independence Measure and Modified Mini-Mental State Examination, as well as patient characteristics, were used to determine the validity of the assessment. One hundred and two persons with ingestive skill loss of neurologic origin were evaluated. Intraclass correlations for interrater, intrarater reliability and stability reached or surpassed 0.80 for most subscales. In validity testing, significant relationships were found between McGill Ingestive scores and Functional Independence Measure and Mini-Mental scores, as well as with patient characteristics. It is concluded that the McGill Ingestive Skills Assessment approaches or meets levels of reliability necessary for assessing patients and is valid for adults with neurogenic feeding difficulties residing in tertiary care facilities.

Biomechanical correlates of surface electromyography signals obtained during swallowing by healthy adults.

PURPOSE: The purpose of this study was to describe biomechanical correlates of the surface electromyographic signal obtained during swallowing by healthy adult volunteers. METHOD: Seventeen healthy adults were evaluated with simultaneous videofluoroscopy and surface electromyography (sEMG) while swallowing 5 mL of liquid barium sulfate. Three biomechanical swallowing events were analyzed: hyoid elevation, pharyngeal constriction, and opening-closing of the pharyngoesophageal segment. For each biomechanical event and from the sEMG signal, the authors identified onset, peak, and offset time points. From these points, duration measures were calculated. Means and 95% confidence intervals were calculated for each measure. Subsequently, correlations were evaluated between timing aspects of the sEMG traces and each biomechanical event. RESULTS: Swallow onset in the sEMG signal preceded the onset of all biomechanical events. All biomechanical events demonstrated a strong correspondence to the sEMG signal. The strongest relationship was between hyoid elevation-anterior displacement and the sEMG signal. CONCLUSIONS: These results suggest that the sEMG signal is a useful indicator of major biomechanical events in the swallow. Future studies should address the impact of age and disease processes, as well as bolus characteristics, on the biomechanical correlates of sEMG signals obtained during swallowing.

The impact of rheologically controlled materials on the identification of airway compromise on the clinical and videofluoroscopic swallowing examinations.

Numerous studies have suggested that the clinical evaluation of swallowing fails to adequately identify those patients who aspirate or do not aspirate on a videofluoroscopic swallowing examination. These conclusions, however, are based on comparisons between swallowed materials that were not rheologically matched. The present study used a battery of rheologically matched test materials, involving thin and thick liquids and cohesive and adhesive semisolids. Using these test items, results from a clinical swallow evaluation were compared to the results of a videofluorographic evaluation using identical test materials. Results suggest that the use of three test materials, including thin and thick liquids given in volumes of 5 and 10 ml, demonstrated the strongest associations between cough on the clinical examination and aspiration on the videofluoroscopic examination.

Initial psychometric assessment of a functional oral intake scale for dysphagia in stroke patients.

OBJECTIVE: To report on the development and psychometric evaluation of a clinical scale to document change in functional oral intake of food and liquid in stroke patients. DESIGN: Validity and reliability study. SETTING: Tertiary care, academic medical center, metropolitan stroke unit. PARTICIPANTS: Acute stroke patients (N=302). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Interrater reliability, validity, and sensitivity to change assessments were completed on a 7-point ordinal scale-the Functional Oral Intake Scale (FOIS)-developed to document the functional level of oral intake of food and liquid in stroke patients. Interrater reliability was drawn from FOIS ratings applied to dietary information from patient medical charts. Consensual validity was estimated by rankings from judges against predefined scale scores. Criterion validity was evaluated by comparison to the Modified Rankin Scale, the Modified Barthel Index, and Mann Assessment of Swallowing Ability. Cross-validation was assessed via comparison to 2 physiologic measures of swallowing function. Change in functional oral intake over time was assessed descriptively by applying the scale to dietary information from a cohort of 302 acute stroke patients followed up for 6 months. RESULTS: Interrater reliability was high, with perfect agreement on 85% of ratings. Kappa statistics ranged from .86 to .91. Consensual validity was high (.90). Criterion validity was high at onset and 1 month poststroke. Significant associations were identified between the FOIS and stroke handicap scales. The FOIS was significantly associated with 2 physiologic measures of swallowing. Scores on the FOIS from the cohort of stroke patients showed a shift toward increased oral intake over a 6-month period. CONCLUSIONS: The FOIS had adequate reliability, validity, and sensitivity to change in functional oral intake. These findings suggest that the FOIS may be appropriate for estimating and documenting change in the functional eating abilities of stroke patients over time.

Functional benefits of dysphagia therapy using adjunctive sEMG biofeedback.

This article describes a retrospective analysis of functional outcome, time in therapy, and cost per unit of functional change in patients who received therapy for pharyngeal dysphagia. Twenty-five patients presenting dysphagia following stroke and 20 patients with dysphagia following treatment for head/neck cancer completed a systematic therapy program supplemented with surface electromyographic (sEMG) biofeedback. Eighty-seven percent (39/45) of all patients increased their functional oral intake of food/liquid including 92% of stroke patients and 80% of head/neck cancer patients. Patients with dysphagia following stroke demonstrated greater improvement than those in the head/neck cancer group. Patients in the stroke group completed more therapy sessions thus increasing the total cost of therapy, but they made more functional progress resulting in lower costs per unit of functional change than patients in the head/neck cancer group. Limitations of this study are described in reference to implications for future clinical research on the efficacy of this therapy approach.

McGill Ingestive Skills Assessment (MISA): development and first field test of an evaluation of functional ingestive skills of elderly persons.

There is a lack of reliable and valid clinical assessment tools for individuals with loss of ingestive skills. The McGill Ingestive Skills Assessment (MISA) was developed to facilitate the reliable and valid bedside assessment of elderly persons with feeding difficulties. Items were generated by a literature review and selected with the collaboration of a multidisciplinary team. The first version of the MISA comprised 190 items in 7 scales, covering the domains of medical history, mealtime environment, physical characteristics of the patient, food textures consumed, solid ingestion, liquid ingestion, and behaviors related to self-feeding. The first field test for item selection included 50 individuals, aged 60 years and older, living in the community, supervised housing, and long-term care centers. After field testing, 134 items were eliminated due to poor face validity, redundancy, or poor psychometric performance. The remaining 56 items were provided with 4 response categories and were reorganized into 5 scales. The revised version was field tested to determine its preliminary psychometric properties on 33 individuals, 60 years of age and older, residing in a long-term care center. Six items were eliminated due to redundancy after the second field test. Analyses of the revised version resulted in the elimination of another 6 items that were redundant or that demonstrated poor reliability. Internal consistency of all scales is > or = 0.86 and interrater agreement is > or = 0.92. These analyses suggest that the psychometric properties of the MISA are adequate for diagnosis and treatment planning. This supports its readiness for clinical use following further reliability and validity testing with a larger sample.