Post-extubation dysphagia and dysphonia amongst adults with COVID-19 in the Republic of Ireland: A prospective multi-site observational cohort study.

OBJECTIVES: This study aims to (i) investigate post-extubation dysphagia and dysphonia amongst adults intubated with SARS-COV-2 (COVID-19) and referred to speech and language therapy (SLT) in acute hospitals across the Republic of Ireland (ROI) between March and June 2020; (ii) identify variables predictive of post-extubation oral intake status and dysphonia and (iii) establish SLT rehabilitation needs and services provided to this cohort. DESIGN: A multi-site prospective observational cohort study. PARTICIPANTS: One hundred adults with confirmed COVID-19 who were intubated across eleven acute hospital sites in ROI and who were referred to SLT services between March and June 2020 inclusive. MAIN OUTCOME MEASURES: Oral intake status, level of diet modification and perceptual voice quality. RESULTS: Based on initial SLT assessment, 90% required altered oral intake and 59% required tube feeding with 36% not allowed oral intake. Age (OR 1.064; 95% CI 1.018-1.112), proning (OR 3.671; 95% CI 1.128-11.943) and pre-existing respiratory disease (OR 5.863; 95% CI 1.521-11.599) were predictors of oral intake status post-extubation. Two-thirds (66%) presented with dysphonia post-extubation. Intubation injury (OR 10.471; 95% CI 1.060-103.466) and pre-existing respiratory disease (OR 24.196; 95% CI 1.609-363.78) were predictors of post-extubation voice quality. Thirty-seven per cent required dysphagia intervention post-extubation, whereas 20% needed intervention for voice. Dysphagia and dysphonia persisted in 27% and 37% cases, respectively, at hospital discharge. DISCUSSION: Post-extubation dysphagia and dysphonia were prevalent amongst adults with COVID-19 across the ROI. Predictors included iatrogenic factors and underlying respiratory disease. Prompt evaluation and intervention is needed to minimise complications and inform rehabilitation planning.

Dysphagia, Dysphonia, and Dysarthria Outcomes Among Adults Hospitalized With COVID-19 Across Ireland.

OBJECTIVE: To investigate the presence, degree, predictors, and trajectory of dysphagia, dysphonia, and dysarthria among adults hospitalized with COVID-19 across the Republic of Ireland (ROI) during the first wave of the pandemic. STUDY DESIGN: Prospective observational cohort study. METHODS: Adults with confirmed COVID-19 who were admitted into 14 participating acute hospitals across ROI and referred to speech and language therapy between March 1st and June 30th, 2020 were recruited. Outcomes obtained at initial SLT evaluation and at discharge were oral intake status (Functional Oral Intake Scale), perceptual voice quality (GRBAS), and global dysarthria rating (Dysarthria Severity Scale). RESULTS: Data from 315 adults were analyzed. At initial SLT assessment, 84% required modified oral diets, and 31% required tube feeding. There were high rates of dysphonia (42%) and dysarthria (23%). History of intubation (OR 19.959, 95% CI 6.272, 63.513; P = .000), COVID-19 neurological manifestations (OR 3.592, 95% CI 1.733, 7.445; P = .001), and age (OR 1.034; 95% CI 1.002, 1.066; P = .036) were predictive of oral intake status. History of intubation was predictive of voice quality (OR 4.250, 95% CI 1.838, 9.827; P = .001) and COVID-19 neurological manifestations were predictive of dysarthria (OR 2.275; 95% CI 1.162, 4.456; P = .017). At discharge, there were significant improvements in oral intake (Z = -7.971; P = .000), voice quality (Z = -5.971; P = .000), and dysarthria severity (Z = -2.619; P = .009), although need for modified oral intake (59%), dysphonia (23%), and dysarthria (14%) persisted. CONCLUSION: Dysphagia, dysphonia, and dysarthria were widespread among adults hospitalized with COVID-19 and they persisted for many at discharge. Prompt SLT evaluation is required to minimize complications. LEVEL OF EVIDENCE: 3 Laryngoscope, 132:1251-1259, 2022.

Species-Specific Functions of Twinfilin in Actin Filament Depolymerization.

Twinfilin is a highly conserved member of the actin depolymerization factor homology (ADF-H) protein superfamily, which also includes ADF/Cofilin, Abp1/Drebrin, GMF, and Coactosin. Twinfilin has a unique molecular architecture consisting of two ADF-H domains joined by a linker and followed by a C-terminal tail. Yeast Twinfilin, in conjunction with yeast cyclase-associated protein (Srv2/CAP), increases the rate of depolymerization at both the barbed and pointed ends of actin filaments. However, it has remained unclear whether these activities extend to Twinfilin homologs in other species. To address this, we purified the three mouse Twinfilin isoforms (mTwf1, mTwf2a, mTwf2b) and mouse CAP1, and used total internal reflection fluorescence microscopy assays to study their effects on filament disassembly. Our results show that all three mouse Twinfilin isoforms accelerate barbed end depolymerization similar to yeast Twinfilin, suggesting that this activity is evolutionarily conserved. In striking contrast, mouse Twinfilin isoforms and CAP1 failed to induce rapid pointed end depolymerization. Using chimeras, we show that the yeast-specific pointed end depolymerization activity is specified by the C-terminal ADF-H domain of yeast Twinfilin. In addition, Tropomyosin decoration of filaments failed to impede depolymerization by yeast and mouse Twinfilin and Srv2/CAP, but inhibited Cofilin severing. Together, our results indicate that Twinfilin has conserved functions in regulating barbed end dynamics, although its ability to drive rapid pointed end depolymerization appears to be species-specific. We discuss the implications of this work, including that pointed end depolymerization may be catalyzed by different ADF-H family members in different species.

A novel mode of capping protein-regulation by twinfilin.

Cellular actin assembly is controlled at the barbed ends of actin filaments, where capping protein (CP) limits polymerization. Twinfilin is a conserved in vivo binding partner of CP, yet the significance of this interaction has remained a mystery. Here, we discover that the C-terminal tail of Twinfilin harbors a CP-interacting (CPI) motif, identifying it as a novel CPI-motif protein. Twinfilin and the CPI-motif protein CARMIL have overlapping binding sites on CP. Further, Twinfilin binds competitively with CARMIL to CP, protecting CP from barbed-end displacement by CARMIL. Twinfilin also accelerates dissociation of the CP inhibitor V-1, restoring CP to an active capping state. Knockdowns of Twinfilin and CP each cause similar defects in cell morphology, and elevated Twinfilin expression rescues defects caused by CARMIL hyperactivity. Together, these observations define Twinfilin as the first 'pro-capping' ligand of CP and lead us to propose important revisions to our understanding of the CP regulatory cycle.