Analysis and applications of respiratory surface EMG: report of a round table meeting

Surface electromyography (sEMG) can be used to measure the electrical activity of the respiratory muscles. The possible applications of sEMG span from patients suffering from acute respiratory failure to patients receiving chronic home mechanical ventilation, to evaluate muscle function, titrate ventilatory support and guide treatment. However, sEMG is mainly used as a monitoring tool for research and its use in clinical practice is still limited-in part due to a lack of standardization and transparent reporting. During this round table meeting, recommendations on data acquisition, processing, interpretation, and potential clinical applications of respiratory sEMG were discussed. This paper informs the clinical researcher interested in respiratory muscle monitoring about the current state of the art on sEMG, knowledge gaps and potential future applications for patients with respiratory failure.

Dystrophic Myopathy of the Diaphragm with Recurrent Severe Respiratory Failure is Congenital Myasthenic Syndrome 11

We here present the case of a patient with a congenital myasthenic syndrome (CMS) due to pathogenic variants in the RAPSN gene. During childhood he experienced recurrent episodes of respiratory failure during respiratory infections. This and other cases were reported as isolated dystrophy of the diaphragmatic musculature. In adulthood, whole exome sequencing revealed two heterozygous pathogenic variants in the RAPSN gene. This led to the revision of the diagnosis to rapsyn CMS11 (OMIM:616326, MONDO:0014588). EMG, muscle ultrasound and the revision of muscle biopsies taken in childhood support this diagnosis. After the revision of the diagnosis, treatment with pyridostigmine was started. This resulted in a reduction of fatigability and an improvement in functional abilities and quality of life.

Tongue movements and teat compression during bottle feeding: A pilot study of a quantitative ultrasound approach

Nutritive sucking is a complex process, essential to proper growth and development. The complexity of this oral sensorimotor activity includes movements of the tongue and jaw. Tongue movements during nutritive sucking can only be visualized with instrumented methods such as ultrasound. Until now, studies using ultrasound during nutritive sucking performed measurements on each individual ultrasound image frame, which was quite time-consuming. The aim of this pilot study was to automatically process ultrasound video recordings in healthy infants during bottle feeding to measure teat compression and tongue movements. Tongue movements and teat compression during bottle feeding were visualized and recorded using 2D dynamic ultrasound imaging. A custom-made semi-automated analysis-routine was developed. Teat compression was expressed as the median difference in teat diameter during the recording. Tongue movements were expressed as the displacement of the tongue along four evenly distributed image lines and the corresponding time-shifts between those lines. The recordings of 12 out of 14 participants were adequate for the analysis of tongue movements. Teat compression could be analysed in the recordings of 6 participants. The reliability of our analysis-routine was considered to be good, and the analysis-routine was more time-efficient than manual frame-by-frame analysis. This quantitative analysis-routine is a promising tool, that can be used efficiently and accurately in the future to collect normative data that can serve as reference values to distinguish normal from abnormal tongue movements in infants with feeding difficulties.