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Biomedical subjects

Catriona M Steele

Publications and source records attributed to Catriona M Steele.

7 recordsLinked to original sources
PubMed2006

The influence of orolingual pressure on the timing of pharyngeal pressure events.

This study explored the influence of two methods of effortful swallow execution on the timing of pharyngeal pressure events. Participants were asked to either emphasize or minimize tongue-to-palate contact during performance of the maneuver. Twenty healthy participants were evaluated using concurrent submental surface electromyography (sEMG), orolingual manometry, and pharyngeal manometry. Each subject performed three repetitions of three counterbalanced tasks (noneffortful dry swallows, effortful dry swallows with tongue-to-palate emphasis, and effortful dry swallows with tongue-to-palate de-emphasis). Four variables were measured: Onset Lag vs. sEMG Peak, Peak Lag vs. sEMG Peak, Total Duration, and Percent Rise Time to Peak. Compared to noneffortful swallows, the effortful swallow task elicited significantly earlier onsets and peaks of pharyngeal pressures relative to the submental sEMG peak. Total pressure event durations were greater and rise times were significantly shorter. When comparing the two methods of effortful swallow execution, a longer latency to peak proximal pharyngeal pressure was found in the tongue-to-palate emphasis condition. These results support the interpretation that the effortful swallow maneuver involves generation of higher velocity bolus driving forces that propel the bolus into and through the pharynx with greater efficiency and that pressure is then sustained to facilitate more complete bolus clearance.

Adult↗
PubMed2006

An analysis of lingual contribution to submental surface electromyographic measures and pharyngeal pressure during effortful swallow.

OBJECTIVE: To evaluate the influence of tongue-to-palate pressures on submental muscle contraction and oral and pharyngeal pressure dynamics during effortful swallowing maneuver. DESIGN: Comparative analysis of 2 task strategies on biomechanic measures of swallowing. SETTING: Research laboratory in a free-standing research facility. PARTICIPANTS: Consecutive volunteer sample of 20 healthy participants (age range, 20-35 y). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Peak amplitude of submental surface electromyography and orolingual and pharyngeal manometric pressure at 4 locations. RESULTS: General linear model analysis of variance revealed statistically significant greater amplitudes for the tongue emphasis condition of effortful swallow at all measured sensors (P<.004). CONCLUSIONS: Tongue-to-palate emphasis during execution of effortful swallowing increases amplitudes of submental surface electromyography, orolingual pressure, and upper pharyngeal pressure to a greater degree than a strategy of inhibiting tongue-to-palate emphasis.

Adult↗
PubMed2005

Does barium influence tongue behaviors during swallowing?

The validity of videofluoroscopic swallowing assessments rests on the understanding that thin, nectar-, honey-, and spoon-thick radiopaque liquids resemble nonopaque liquids, both in their consistency and in the variations in swallowing that they elicit. Tongue movements during sequential swallows of opaque and nonopaque liquids were studied in 8 healthy participants in 2 age groups (<30 years, >50 years) using electromagnetic midsagittal articulography. Differences included smaller sip size, longer oropharyngeal transit times, and greater variability in tongue movement patterns with opaque liquids compared to nonopaque liquids, but effect sizes for these differences were small. Transit times were significantly longer for older participants than younger participants. We recommend matching radiopaque bolus size in videofluoroscopy to the patient's habitually preferred sip mass for comparator nonopaque liquids.

Adult↗
PubMed2004

Influence of bolus consistency on lingual behaviors in sequential swallowing.

Thickened liquids are a commonly recommended intervention for dysphagia. Previous research has documented differences in temporal aspects of bolus transit for paste versus liquid consistencies; however, the influence of liquid viscosity on tongue movements during swallowing remains unstudied. We report an analysis of the influence of bolus consistency on lingual kinematics during swallowing. Electromagnetic midsagittal articulography was used to trace tongue body and dorsum movement during sequential swallows of three bolus consistencies: thin, nectar-thick, and honey-thick liquids. Rheological profiling was conducted to characterize viscosity and density differences among six liquids (two of each consistency). Eight healthy volunteers participated; four were in a younger age cohort (under age 30) and four were over the age of 50. The primary difference observed across the liquids of interest was a previously unreported phenomenon of sip-mass modulation; both flavor and density appeared to influence sip-sizing behaviors. Additionally, significantly greater variability in lingual movement patterns was observed in the older subject group. Systematic variations in lingual kinematics related to bolus consistency were restricted to the variability of downward tongue dorsum movement. Otherwise, the present analysis failed to find empirical evidence of significant modulations in tongue behaviors across the thin to honey-thick consistency range.

Adult↗
PubMed2004

Use of electromagnetic midsagittal articulography in the study of swallowing.

The tongue functions as the primary articulator during the oropharyngeal stages of swallowing. However, detailed descriptions of the kinematics and spatiotemporal variability of tongue behaviors during swallowing are limited to a handful of analyses of data from the X-ray microbeam database. In this article, a new technique, electromagnetic midsagittal articulography (EMMA), is introduced for the high-resolution description of oral articulatory movements during swallowing. Data from 8 healthy, nondysphagic participants are used to illustrate the methods used for data collection and analysis. Movement data were collected for 3 fleshpoint positions on the tongue (blade, body, dorsum) during sequences of repeated discrete water swallows, and were characterized for variables of spatiotemporal variability and 4 discrete kinematic parameters (movement amplitude, peak velocity, duration, and kinematic stiffness). These data show that the movement trajectories measured using EMMA are consistent with descriptions from previous X-ray microbeam studies, indicating that EMMA is a feasible method for the detailed study of tongue movements during swallowing.

Adult↗
PubMed2003

The rheology of liquids: a comparison of clinicians' subjective impressions and objective measurement.

Texture-modified diets are commonly prescribed for patients with dysphagia; it is therefore important to demonstrate that clinicians form accurate impressions of the rheological (flow) properties of the items that they recommend for their clients. We explored the correlation between objective rheological measurement and clinicians' subjective impressions of liquid consistency, rated on the bases of product labeling and sampling. Ten liquids, ranging from thin through nectar-thick and honey-thick to spoon-thick consistencies, were selected for study. Rheological analysis was conducted using a CarriMed CSL Controlled Stress Rheometer. Fifty speech-language pathologists ranked the liquids in order of perceived viscosity, based on their interpretation of the product packaging and label. Product nomenclature proved insufficient to accurately represent the consistency class to which each liquid belonged. A second group of 16 speech-language pathologists rated the perceived relative viscosity and density of nectar-thick and honey-thick juice items in blinded two-point discrimination tests of stirring-resistance, oral manipulation, and vessel weight. Physical sampling of these two products enabled clinicians to reliably perceive relative viscosity and density differences between the nectar- and honey-thick items.

Deglutition Disorders↗