Ultrasound: an emerging modality for the dysphagia assessment toolkit?

PURPOSE OF REVIEW: Videofluoroscopy (VFSS) and fibreoptic endoscopic evaluation of swallowing (FEES) are established instrumental techniques to support differential diagnosis and treatment of oropharyngeal dysphagia. Whilst their value is undisputed, each tool is not without limitations. The COVID-19 pandemic has restricted access to VFSS and FEES leading clinicians to explore alternative or augmentative tools to support swallowing assessment.Ultrasound (US) is an established tool for visualisation of head and neck anatomy, including structures implicated in swallowing. Although US has been utilised in swallowing research for many years, its application has not translated into common clinical practice. This review presents and debates the evidence for and against use of US for clinical swallowing assessment. RECENT FINDINGS: Evaluation of swallowing muscle morphometry and measurement of isolated swallowing kinematics are two primary uses of US in swallowing assessment that have been identified in the literature. Use of US to detect bolus flow, aspiration and residues is in its early stages and needs further research. SUMMARY: US shows promise as an adjunctive modality to support assessment of swallowing. With standardisation, these measurements may have potential for transition into clinical care. Reliability and validity testing and development of normative data are imperative to ensure its use as an evidence-based instrumentation.

Enhanced rapid review of the applicability of ultrasound in the assessment of sucking, swallowing and laryngeal function in the paediatric population.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has renewed interest in the use of ultrasound (US) amongst dysphagia-trained clinicians working with infants and children. US is a portable, minimally intrusive tool which carries reduced risk of aerosol-generation provoked by other instrumental swallowing assessment tools such as fibreoptic endoscopic evaluation of swallowing (FEES). For this reason, US could be a valuable addition to the dysphagia assessment toolkit. A recently published rapid review of US evidence for the assessment of swallowing and laryngeal function in the adult population provided a framework for this neonatal and paediatric review. AIMS: This enhanced rapid review aimed to establish the applicability of US as an instrumental assessment tool for sucking, swallowing and laryngeal function in the neonatal and paediatric populations. METHODS & PROCEDURES: A rapid review of six electronic databases was conducted to identify articles using US to assess sucking, swallowing or laryngeal function in the selected populations, compared with varied reference tests. Abstract screening was completed according to pre-defined inclusion/exclusion criteria with 10% of articles assessed by a second screener. Data was extracted from the included studies using a pre-developed form. A modified QUADAS-2 tool was used to assess study quality. Results from the included studies were summarised and grouped into sucking, swallowing and laryngeal function data. OUTCOMES & RESULTS: Twelve studies using US in the assessment of swallowing and/or laryngeal function met inclusion criteria. No studies using US for assessment of sucking met the inclusion criteria. All were peer-reviewed, primary studies across a range of clinical populations and with a wide geographical spread. Five studies had an overall low risk of bias. Seven studies had at least one domain where risk of bias was judged as high. All studies had high applicability. The two studies assessing swallowing differed in terms of aims and use of US. The studies assessing laryngeal function predominately investigated vocal fold movement and laryngeal pathology. Sensitivity and specificity data were provided or calculated from raw data for nine of the laryngeal function studies (respective ranges of 75%-100% and 80%-100%). CONCLUSIONS & IMPLICATIONS: Emerging evidence exists to support the use of US as adjunct to clinical assessment of swallowing and laryngeal function in the neonatal and paediatric population. A paucity of evidence to support use of US in the assessment of sucking exists. Further research is needed to establish evidence-based assessment and analysis protocols as well as development of paediatric data.