Integrated acoustic and respiratory biomarkers of dysarthria in acquired brain injury: protocol for a cross-sectional study.

Abstract

Dysarthria secondary to acquired brain injury (ABI) is a motor speech disorder characterised by impaired coordination of the respiratory, phonatory and articulatory subsystems, with a negative impact on communication and quality of life. Previous studies have largely examined these components separately, which limits understanding of their functional interactions. An integrated approach combining respiratory and acoustic-articulatory measures may improve the characterisation of dysarthria and support the identification of objective markers of severity. The aim of this study is to jointly analyse respiratory function and speech acoustic parameters in adults with ABI and to examine their association with the presence and severity of dysarthria. A cross-sectional observational study will be conducted in adults with a confirmed diagnosis of ABI, both with and without dysarthria, with an estimated sample size of 97-101 participants. The protocol will include collection of sociodemographic and clinical data, cognitive assessment using the Mini-Mental State Examination, swallowing assessment using the Eating Assessment Tool-10, acoustic and aerodynamic analyses following standardised procedures, respiratory function assessment using spirometry and perceptual evaluation of dysarthria using the Frenchay Dysarthria Assessment-2. Between-group comparisons and multivariate analyses will be performed to examine associations between respiratory, acoustic, aerodynamic and dysarthria severity measures. The study has been approved by the Ethics Committee for Research with Medicines of the Salamanca Health Area (CEIm PI 2025 04 1897-TD) and will be conducted in accordance with the Declaration of Helsinki. Written informed consent must be provided by all participants prior to inclusion. Findings will be disseminated at scientific conferences and in peer-reviewed journals. Anonymised data will be made available following publication of the main results, in compliance with data protection regulations. NCT07435155.