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.

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)

Laryngeal configuration and constriction during two types of whispering.

Laryngeal functioning during the production of whispered speech is not well understood. The efficacy of whispering as a means of voice rest is a common clinical concern that is unresolved. This investigation examined vocal-fold configuration, glottal size, and airway constriction by supraglottal structures during whispering. Ten normally speaking adults produced consonant-vowel syllables with three different vowels while whispering in low-effort and high-effort manners. The larynx was visualized through fiberoptic endonasolaryngoscopy, and the views were recorded on videotape. Analysis and descriptions of the data revealed that low-effort and high-effort whispering were differentiated to a small extent by vocal-fold adjustments and to a somewhat larger degree by supraglottal constriction. However, for each dependent variable, individual subject differences tended to be considerably larger than any systematic effects due to whisper type or vowel.

The effect of pharyngeal flap surgery on the movements of the lateral pharyngeal walls.

Observations of prepharyngeal and postpharyngeal flap degrees of lateral pharyngeal wall movement seem to indicate that some individuals have the ability to alter patterns of lateral pharyngeal wall motion. However, most of the subjects did not show changes in lateral pharyngeal wall motion, and in those who did show changes, the effects of speech therapy could not be excluded. Therefore, the suggestion that pharyngeal flaps should be "tailored" to the size of the gap in the velopharyngeal sphincter seems valid. Or, to put it differently, it seems likely that in many individuals, if the pharyngeal flap constructed is not as broad as the velopharyngeal gap, velopharyngeal insufficiency and hypernasality are likely to persist because most often the lateral pharyngeal wall movement will not adapt to the presence of a new structure in the pharynx.

Laryngeal behavior during stuttering.

Laryngeal behavior associated with 101 stutterings (part-work repetitions, sound prolongations, and broken words) produced by a group of 10 stutterers was observed by means of a flexible fiberoptic naso-laryngoscope. Results indicated that 60% of part-word repetitions were different from fluent productions of the same speech segment in terms of laryngeal behavior, and 72% of sound prolongations were similar to fluent productions of the same speech segment. Findings indicate that there are differences in laryngeal behavior among the various types of stutterings.

Patterns of velopharyngeal closure in subjects with repaired cleft palate and normal speech: a multi-view videofluoroscopic analysis.

Thirty subjects with repaired palatal clefts and normal speech ranging in age from 2 to 12 years were examined in multiple videofluoroscopic projections in order to assess velopharyngeal closure in three dimensions. The following points became evident from the results of this study: 1. All 30 subjects exhibited contact between the superior border of the velum and the adenoid mass in the nasopharynx. Often, a sharp levator eminance was not formed due to the small space between the velum at rest and the adenoids. Thus, there was little room for the velum to elevate. 2. All 30 subjects showed good localized medial movement of the LAPW at the approximate plane of the hard palate. 3. 10 out of 30 subjects, 33%, had a Passavant's Ridge during speech. All 10 of these subjects utilized the ridge as a point of closure, as well as the adenoids. 4. The observed patterns of closure were consistent across varied consonant utterances. 5. The mechanism of velopharyngel closure in this group of subjects is essentially the same as for normal adult speakers and differs only anatomically due to a lack of verticle head growth in children. Thus, in spite of the presence of adenoids and the lack of verticle head development, the basic sphincteric mechanism of velopharyngeal colsure is utilized in these subjects.

A new therapeutic technique for the treatment of velopharyngeal incompetence.

A new therapeutic technique for the treatment of velopharyngeal incompetence during speech was administered to four subjects ranging in age from four to 19 years. The technique is an operant procedure designed to utilize successive approximation to competent speech via competent blowing or whistling closure mechanisms. The technique is based on cinefluoroscopic observations of normals utilizing the same closure mechanism for speech, blowing and whistling plus videofluoroscopic observations of cleft-palate subjects who were capable of attaining normal closure patterns for blowing and whistling, but not for speech. It is speculated that speech incompetence in individuals who can achieve closure during blowing and whistling is a result of an error in learning.

Selective movement of the lateral aspects of the pharyngeal walls during velopharyngeal closure for speech, blowing, and whistling in normals.

The frontal and lateral cinefluorographic views of five normal subjects performing speech, blowing, and whistling tasks were synchronized in order to observe where the greatest degree of medial movement in the lateral aspects of the pharyngeal walls was occurring in relation to structures observed in lateral view. The results of the synchronization procedure indicates that for all five subjects, maximum medial excursion in the lateral walls of the pharynx occurred at the level of the full length of the velum and hard palate, well below the levator eminance. It is hypothesized that this observed interaction may be due to the select contraction of those fibers of the superior constrictor muscle which enter the velum via the lateral walls and those fibers attached to the pterygoid plates as well as levator muscle activity. It is also suggested that definitive physiological data must be obtained from further study of combined EMG and fluoroscopic procedures.