Biomedical subjects

G Chi-Fishman

Publications and source records attributed to G Chi-Fishman.

5 recordsLinked to original sources

PubMed2000

Motor strategy in rapid sequential swallowing: new insights.

This study examined the physiological properties and movement strategies of normal, rapid sequential swallowing during simultaneous videofluoroscopy (VFS) and submental surface electromyography (EMG). Ten subjects performed discrete (5 and 15 cc) and sequential (150 cc in tilted and upright head postures) swallowing tasks. Analyses included VFS event timing, movement/bolus passage characteristics, EMG amplitude waveforms, and peak and offset EMG amplitudes. Results revealed that sequential swallows were significantly shorter than discrete swallows in several VFS event durations, but significantly longer in pharyngeal transit and stage transition times. The hyolaryngeal system exhibited a cyclical "rise and partial fall" movement pattern during sequential swallows on VFS, corresponding to a repetitive "activation and partial deactivation" characteristic on EMG. Greater peak EMG amplitude for sequential than discrete swallows was found in 6/10 subjects. Pharyngeal bolus merging, preparatory laryngeal gestures, and penetration without aspiration were also observed in some subjects on VFS. Intersubject differences were significant in timing measures and EMG amplitude. Our findings of individual variability and subject-specific strategies for task accommodation support the notion of built-in plasticity in the deglutitive motor complex.

Adult↗

PubMed1999

Effects of physostigmine on swallowing and oral motor functions in patients with progressive supranuclear palsy: A pilot study.

The purpose of this pilot study was to investigate whether cholinergic stimulation reduces swallowing and oral motor disturbances in patients with progressive supranuclear palsy (PSP). A controlled, double-blind crossover trial of physostigmine, a centrally active cholinesterase inhibitor, and placebo was conducted. Patients were randomized to a 10-day crossover placebo-controlled double-blind trial of physostigmine at their previously determined best dose administered orally every 2 hr, six times per day. Patients were evaluated with ultrasound imaging of the oropharynx and an oral motor examination at baseline and during the third or fourth days of each study phase (placebo and drug). Under the double-blind placebo-controlled conditions, patients showed no statistically significant improvement in oral motor functions or swallow durations. Because patients with PSP have increased sensitivity to cholinergic blockade compared with control subjects, studies with newer, more potent cholinergic stimulating agents need further exploration. Suggestions for future research include the evaluation of newer direct cholinergic agonists in the treatment of the less-impaired PSP patients who may have a greater number of cholinergic neurons preserved and the evaluation of combined therapies.

Cholinesterase Inhibitors↗

PubMed1998

Lingual action in normal sequential swallowing.

Current knowledge about the flexibility in lingual motor control and performance during swallowing is incomplete. The present study aimed at gaining a better understanding of the tongue's motor flexibility and at identifying variable versus invariant lingual motor program parameters in light of changing swallowing task demands (discrete vs. sequential). Specifically, the timing and patterns of tongue-palate contact and the associated changes in tongue shape and action were examined in 5 normal adults using simultaneous electropalatography and ultrasound. Tasks for discrete swallowing included 5 and 30 cc of water; tasks for sequential swallowing involved drinking 200 cc of water at normal and fast rates. Results showed little variation in propulsive contact pattern as a function of task or subject. However, the tongue demonstrated shorter movement duration and overlapping gestures during sequential swallowing. Thus, continuous drinking was performed without changes in motor strategies per se but with changes in the timing coordination of the "drink" and "swallow" action sequences. These findings support the theory that the deglutitive lingual motor program has both invariant and variant parameters, and that movement pattern and action sequence reflect fixed elements within the structure of the motor program, but movement timing can be modified according to the demands of the task at hand.

Adult↗

PubMed1996

A new application for electropalatography: swallowing.

Electropalatography (EPG) has been applied to linguistic research and speech pathology. This study evaluated whether EPG could provide useful information on swallow-related tongue action. Specifically, the investigation focused on the quantification of tongue-palate contact patterns for swallowing and on the effects of bolus volume and consistency. Five normal subjects were tested during swallows of 5 and 30 ml of water, 5 and 30 ml of gelatin, and saliva. By segmenting the EPG time-motion sequences into four stages (prepropulsion, propulsion, full contact, withdrawal) and compartmentalizing the palate into six bins (front, central, back, lateral, medial, midline), temporal and spatial characteristics of deglutitive tongue-palate contact were revealed. Significant differences (p < 0.01) were found in contact timing across bolus sizes and consistencies for the propulsion and full contact stages. Water was propelled faster than gelatin. and 30-ml gelatin faster than 5-ml gelatin. Dry swallows had a longer full contact stage than water. Contact patterns, though not statistically analyzed at this time, appeared to vary little as a function of bolus properties. Our findings suggest potential value in using EPG to investigate the timing and patterning of abnormal tongue movements associated with disordered swallowing.

Adult↗

PubMed1994

Thermomechanical facilitation of swallowing evoked by electrical nerve stimulation in cats.

Application of a cold metal probe to the anterior faucial pillar has been reported to improve swallowing in some patients with dysphagia. Although a variety of stimuli contribute to the initiation of swallowing, the effects of a controlled, cold-thermal stimulus combined with mechanical stimulation have not been examined. It is known that simultaneous stimulation of the glossopharyngeal nerve (IX) and the superior laryngeal nerve may summate to facilitate swallowing in the cat. The goal of this study was to determine whether thermomechanical stimulation of the mucosa innervated by IX would interact with threshold electrical stimulation of the internal laryngeal nerve (ILN) to augment the swallowing response in cats. Four experimental conditions were tested over 24 trials in 4 pentobarbital-anesthetized cats. These included electrical stimulation of ILN, mechanical stimulation of the anterior faucial pillar with a thermode at ambient (room) temperature, concurrent ambient-mechanical and electrical stimulation, and concurrent cold-mechanical and electrical stimulation. Tissue was cooled to 8.9 degrees C during cold-mechanical-electrical stimulation and 25.3 degrees C during ambient-mechanical-electrical and ambient-mechanical alone stimulation. Ambient-mechanical stimulation alone did not produce swallowing. However, both forms of thermomechanical-electrical stimulation elicited a significantly greater number of swallows than did electrical stimulation alone. Therefore, mechanical stimulation with a thermode was capable of modifying the swallowing response in neurologically intact cats.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia↗