Surface electromyographic studies of swallowing in normal children, age 4-12 years

Objectives: Surface electromyographic (sEMG) studies were performed on 100 normal children, age 4-12 years, to establish normative database for duration and amplitude of muscle activity during swallowing and continuous drinking. Study design: Prospective observational study of healthy volunteers. Methods: Parameters evaluated during swallowing include the timing and amplitude (in μV) of activity of m. orbicularis oris, masseter, submental and infrahyoid (laryngeal strap muscles (LSM)) groups covered by platisma. Four tests were examined: voluntary single swallows of saliva ("dry" swallow), voluntary single water swallows as normal, voluntary single swallows of excessive amount of water (up to 15ml), continuous drinking of 50ml of water (duration and number of swallows). Duration of muscle activity during swallowing (mean plus standard deviation (S.D.)) was measured for two age groups: 4-8 and 9-12 years old. The group of 40 adults, age 18-30 years, was taken as a control group. Results: Normative data for duration and amplitude of muscle activity during single swallowing and continuous drinking are established for healthy children. The duration of muscle activity during swallows and drinking in all tests showed decrease with the age, and this tendency is statistically significant (one-dimensional analysis of variance, SPSS, χ² criterion, 95% confidence interval). There was no statistically significant difference in amplitude (range) measurements between children and adults (P=0.05). There was no statistically significant difference between male and female children duration of muscle activity during single swallowing and continuous drinking in all age groups (P≥0.05). Conclusion: Surface EMG of swallowing is a simple and reliable noninvasive method for screening evaluation of swallowing with low level of discomfort of the examination. The normative timing of events data can be used for evaluation of complaints and symptoms, as well as for comparison purposes in pre- and postoperative stages and in electromyography (EMG) monitoring during ENT or neurological treatment. These parameters represent normal deglutition, and can be used to identify abnormalities in pediatric patients, and provide a basis for comparison of swallowing performance, both within and between patients.