Publications by authors named "Jeffrey B Palmer"

Objective: During the mastication of solid food, the tongue pushes the bolus laterally to place it onto occlusal surfaces as the jaw is opened. This movement is referred to as tongue-pushing (TP). TP has an important role in efficient chewing, but its kinematic mechanisms remain unclear.

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Understanding bolus flow patterns in swallowing (rheology, the study of flow) is fundamental to assessment and treatment of dysphagia. These patterns are complex and poorly understood. A liquid swallow is typically biphasic, including air, so the actual bolus has both liquid and gas phases.

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Article Synopsis
  • * Results showed that while there were no significant differences in the maximum or minimum pharyngeal volumes between the two liquids, the timing of volume changes varied: thick liquids led to an earlier and more rapid decrease in volume compared to thin liquids.
  • * The findings suggest that the differences in swallowing mechanics for thick versus thin liquids are related to how the tongue moves to push the bolus and clear the throat, which could have implications for dysphagia treatment strategies.
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Pharyngeal residue, the material that remains in the pharynx after swallowing, is an important marker of impairments in swallowing and prandial aspiration risk. The goals of this study were to determine whether the 2D area of post-swallow residue accurately represents its 3D volume, and if the laterality of residue would affect this association. Thirteen patients with dysphagia due to brainstem stroke completed dynamic 320-detector row computed tomography while swallowing a trial of 10 ml honey-thick barium.

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Objectives: To assess the effect of age on swallowing with a focus on structural movement, timing and duration of physiologic events.

Design: Cross-sectional study.

Setting: Tertiary University Medical Center.

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Older adults may evidence changes in swallowing physiology. Our goals were to identify dysphagia risk in community-dwelling older adults with no history of dysphagia, and to compare swallowing physiology and safety between older and younger adults. Thirty-two older adults with no history of dysphagia were prospectively recruited and completed the Dysphagia Handicap Index (DHI), two trials of a 3 oz.

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To evaluate timing and duration differences in airway protection and esophageal opening after oral intubation and mechanical ventilation for acute respiratory distress syndrome (ARDS) survivors versus age-matched healthy volunteers. Orally intubated adult (≥ 18 years old) patients receiving mechanical ventilation for ARDS were evaluated for swallowing impairments via a videofluoroscopic swallow study (VFSS) during usual care. Exclusion criteria were tracheostomy, neurological impairment, and head and neck cancer.

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This study investigated the effects of Mendelsohn maneuver with three-dimensional kinematic analysis. Nine female speech-language pathologists (nine females, mean ± SD 27.1 ± 3.

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Objective: When eating solids, stage II transport (St2Tr) propels triturated food into the pharynx for bolus formation and storage before swallowing. Although the existence of St2Tr is acknowledged, the reason for its existence remains unclear. Understanding it may facilitate development of food appropriate for individuals with dysphagia.

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Rationale: Nearly 60% of patients who are intubated in intensive care units (ICUs) experience dysphagia after extubation, and approximately 50% of them aspirate. Little is known about dysphagia recovery time after patients are discharged from the hospital.

Objectives: To determine factors associated with recovery from dysphagia symptoms after hospital discharge for acute respiratory distress syndrome (ARDS) survivors who received oral intubation with mechanical ventilation.

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Food oral processing and pharyngeal food passage cannot be observed directly from the outside of the body without instrumental methods. Videofluoroscopy (x-ray video recording) reveals the movement of oropharyngeal anatomical structures in two dimensions. By adding a radiopaque contrast medium, the motion and shape of the food bolus can be also visualized, providing critical information about the mechanisms of eating, drinking, and swallowing.

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Communication and swallowing disorders are common after stroke. Targeted surveillance followed by prompt evaluation and treatment is of paramount importance. The overall goals of rehabilitation for impaired swallowing and communication and swallowing deficits may differ based on the specific deficits caused by the stroke but the main goal is always to improve the patient's everyday interpersonal interactions and optimize participation in society.

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Few studies have examined the intensity of muscle activity during swallowing in healthy humans. We examined selected hyoid muscles using fine wire intramuscular electromyography (EMG) during swallowing of four food consistencies. Thirteen healthy adults were studied using videofluorography and EMG of the anterior belly of digastric (ABD), geniohyoid (GH), sternohyoid (SH), and masseter (MA; surface electrodes) while ingesting thin liquid (three trials) and solid food of three consistencies (banana, tofu, and cookie, three trials each).

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Swallowing is one of the basic activities in humans. The pharynx functions as an airway and a food channel, and a pharyngeal swallow usually occurs after bolus transport from the oral cavity. However, direct fluid infusion through a catheter into the hypopharynx produces a pharyngeal swallow without the oral stage in experimental situations.

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When eating solid food, the tongue intermittently propels triturated food to the oropharynx or valleculae, where a bolus accumulates before swallowing. The tongue motion during this food transport (stage II transport, STII) is distinctly different from that during chewing, and is more similar to the oral propulsive stage of swallowing. Therefore, we tested the hypothesis that the onset of STII cycles was more likely to occur during expiration than inspiration.

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Rationale: Endotracheal intubation is associated with postextubation swallowing dysfunction, but no guidelines exist for postextubation swallowing assessments.

Objectives: We evaluated the prevalence, patient demographic and clinical factors, and intensive care unit (ICU) and hospital organizational factors associated with swallowing assessment after oral endotracheal intubation and mechanical ventilation in patients with acute lung injury (ALI).

Methods: We performed a secondary analysis of a prospective cohort study in which investigators evaluated 178 eligible patients with ALI who were mechanically ventilated via oral endotracheal tube.

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Purpose: The purpose of the study is to compare neuromuscular electrical stimulation (NMES) vs sham on leg strength at hospital discharge in mechanically ventilated patients.

Materials And Methods: We conducted a randomized pilot study of NMES vs sham applied to 3 bilateral lower extremity muscle groups for 60 minutes daily in the intensive care unit (ICU). Between June 2008 and March 2013, we enrolled adults who were receiving mechanical ventilation within the first week of ICU stay and who could transfer independently from bed to chair before hospital admission.

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Few studies have reported the activation sequence of the swallowing muscles in healthy human participants. We examined temporal characteristics of selected hyoid muscles using fine wire intramuscular electromyography (EMG). Thirteen healthy adults were studied using EMG of the anterior belly of digastric (ABD), geniohyoid (GH), sternohyoid (SH), and masseter (MA, with surface electrodes) while ingesting thin liquid, banana, tofu, and cookie (3 trials each).

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Stage II transport (St2Tr) is propulsion of triturated food into the pharynx for storage before swallowing via tongue squeeze-back against the palate. To clarify the phenomenology of St2Tr, we examined the effects of food consistency and the number of chewing cycles on the number of St2Tr cycles in a chew-swallow sequence. We recorded chew-swallow sequences in lateral projection with videofluoroscopy of 13 healthy volunteers eating 6 g of hard (shortbread cookie), and soft foods (ripe banana and tofu) with barium.

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Purpose: The purpose of this study is to evaluate demographic and clinical factors associated with self-reported dysphagia after oral endotracheal intubation and mechanical ventilation in patients with acute lung injury (ALI).

Materials And Methods: This is a prospective cohort study of 132 ALI patients who had received mechanical ventilation via oral endotracheal tube.

Results: The primary outcome was binary, whether clinically important symptoms of dysphagia at hospital discharge were reported by patients, using the Sydney Swallowing Questionnaire score 200 or more.

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Objective: We examined the temporospatial characteristics of stage I oral food transport, in which a piece of solid food is moved from the anterior oral cavity to the postcanine region for chewing. Anteroposterior transport is accomplished by carrying food posteriorly on the surface of the tongue, in contrast to the squeeze-back mechanism of stage II transport from the oral cavity to the pharynx.

Design: There were two experiments (Exp1 and Exp2): In Exp1, Twelve healthy young adults ate 2g, 4g, 6g, 8g 12g initial bolus sizes of banana and cookie; in Exp2, fourteen similar subjects ate 6g of banana and cookie with and without radiopaque tongue surface makers.

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When chewing solid food, part of the bolus is propelled into the oropharynx before swallowing; this is named stage II transport (St2Tr). However, the tongue movement patterns that comprise St2Tr remain unclear. We investigated coronal jaw and tongue movements using videofluorography.

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Objective: To evaluate the potential annual net cost savings of implementing an ICU early rehabilitation program.

Design: Using data from existing publications and actual experience with an early rehabilitation program in the Johns Hopkins Hospital Medical ICU, we developed a model of net financial savings/costs and presented results for ICUs with 200, 600, 900, and 2,000 annual admissions, accounting for both conservative- and best-case scenarios. Our example scenario provided a projected financial analysis of the Johns Hopkins Medical ICU early rehabilitation program, with 900 admissions per year, using actual reductions in length of stay achieved by this program.

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The present study examined the effect of bolus viscosity on the onset of laryngeal closure (relative to hyoid elevation), the duration of laryngeal closure, and other key events of swallowing in ten healthy volunteers. All volunteers underwent 320-row area detector computed tomography swallow studies while swallowing 10 ml of honey-thick barium (5 % v/w) and thin barium (5 % v/w) in a 45° reclining position. Three-dimensional images of both consistencies were created in 29 phases at an interval of 0.

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Background: As the population ages and critical care advances, a growing number of survivors of critical illness will be at risk for intensive care unit (ICU)-acquired weakness. Bed rest, which is common in the ICU, causes adverse effects, including muscle weakness. Consequently, patients need ICU-based interventions focused on the muscular system.

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