Developmental changes in pharyngeal swallowing acoustics: a comparison of adults and children

Shared and Separate Neuromuscular Underpinnings of Swallowing and Motor Speech Development in the School-Age Years

PURPOSE

Despite co-occurrence of swallowing and speech disorders in childhood, there is limited research on shared and separate neuromuscular underpinnings of these functions. The purpose of this study was to (a) compare neuromuscular control of swallowing and speech between younger and older children and (b) determine similarities and differences in neuromuscular control of swallowing and speech.

METHOD

Twenty-six typically developing children (thirteen 7- to 8-year-olds and thirteen 11- to 12-year-olds) completed this cross-sectional study. Neuromuscular control was evaluated using surface electromyography of submental muscles and superior and inferior orbicularis oris muscles during parallel tasks of swallowing and speech. Outcome measures included normalized mean amplitude, burst duration, time to peak amplitude, and bilateral synchrony, which were examined using mixed-effects models.

RESULTS

For normalized mean amplitude, burst duration, and time to peak amplitude, there were significant two- and three-way interactions between muscle group, task, and age group, indicating that older and younger children demonstrated different muscle activation patterns, and these patterns varied by muscle and task. No differences were noted between groups for bilateral synchrony. For parallel tasks, children demonstrated different magnitudes of normalized mean amplitude and time to peak amplitude of speech and swallowing. However, they demonstrated a similar pattern: increases in magnitude as task complexity increased.

CONCLUSIONS

Children continue to demonstrate refinement of their neuromuscular control of swallowing and speech between 7-8 and 11-12 years of age, and there are both shared and separate elements of neuromuscular control between these two vital functions. To improve generalizability of findings, future research should include longitudinal analysis of swallowing and speech development, as well as measures of central neurophysiology.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.23796258.

Using an Automated Speech Recognition Approach to Differentiate Between Normal and Aspirating Swallowing Sounds Recorded from Digital Cervical Auscultation in Children

Use of machine learning to accurately detect aspirating swallowing sounds in children is an evolving field. Previously reported classifiers for the detection of aspirating swallowing sounds in children have reported sensitivities between 79 and 89%. This study aimed to investigate the accuracy of using an automatic speaker recognition approach to differentiate between normal and aspirating swallowing sounds recorded from digital cervical auscultation in children. We analysed 106 normal swallows from 23 healthy children (median 13 months; 52.1% male) and 18 aspirating swallows from 18 children (median 10.5 months; 61.1% male) who underwent concurrent videofluoroscopic swallow studies with digital cervical auscultation. All swallowing sounds were on thin fluids. A support vector machine classifier with a polynomial kernel was trained on feature vectors that comprised the mean and standard deviation of spectral subband centroids extracted from each swallowing sound in the training set. The trained support vector machine was then used to classify swallowing sounds in the test set. We found high accuracy in the differentiation of aspirating and normal swallowing sounds with 98% overall accuracy. Sensitivity for the detection of aspiration and normal swallowing sounds were 89% and 100%, respectively. There were consistent differences in time, power spectral density and spectral subband centroid features between aspirating and normal swallowing sounds in children. This study provides preliminary research evidence that aspirating and normal swallowing sounds in children can be differentiated accurately using machine learning techniques.

Advances in Swallowing Neurophysiology across Pediatric Development: Current Evidence and Insights

Purpose of Review

This review article analyzes current evidence on the neurophysiology of swallowing during development and offers expert opinion on clinical implications and future research directions.

Recent Findings

In the past five years, basic and clinical research has offered advances in our understanding of pediatric swallowing neurophysiology. Animal models have elucidated the role of brainstem circuits and the peripheral and central nervous system in neonatal swallowing. Recent human studies have further showcased that fetal and infant swallowing require cerebral inputs in order to develop functionally. Finally, neurophysiological and neuroimaging studies are starting to better define these cerebral inputs, as well as neuroplastic adaptations that may be needed for optimal feeding development.

Summary

The neural development of swallowing is a complex and dynamic process. Continued research is needed to better understand influences on swallowing neural development, which can be essential for improving prevention, diagnosis, and interventions for pediatric dysphagia.

Oral Feeding Challenges in Children With Tracheostomy Can Improve Feeding Outcomes, Even With the Finding of Aspiration

It has been suggested that oral feeding trial has therapeutic implications for improving oral-motor and swallowing function in infants and young children fed via an enteral tube or gastrostomy. This study aimed to investigate whether oral feeding challenges in children with tracheostomy could improve feeding outcomes, even with the finding of aspiration compared to those who did not receive oral feeding at all. Children (age <7 years) with tracheostomy who had thin fluid aspiration on videofluoroscopic swallowing study (VFSS) were included in this retrospective study. Enrolled children were then divided into two feeding method groups according to the physician's decision at the time of VFSS: oral feeding (OF) group and non-oral feeding (NOF) group. Data were obtained from 47 children (median age: 49.75 months, interquartile range [IQR]: 24.08-79.42). The incidence of pneumonia within 1 year after the VFSS was not different between NOF (n = 17) and OF (n = 30) groups. In OF group, 11 subjects achieved full oral feeding and 16 subjects were in partial oral feeding status 1 year after the VFSS. On the contrary, only one subject achieved full oral feeding and 5 subjects were in partial oral feeding status in NOF group (p < 0.001). Initial and follow-up penetration-aspiration scale on VFSS were different only in the OF group (p = 0.003). These results suggest that oral feeding challenges might be attempted even with the findings of aspiration in infants or young children with tracheostomy.