Postural Facial Deformation and Virtual Fit of Non-Invasive Ventilation Mask in Amyotrophic Lateral Sclerosis: A Case-Control Observational Pilot Study

Abstract

Background: Use of a non-invasive ventilation (NIV) mask in patients with bulbar amyotrophic lateral sclerosis (bALS) is difficult for several reasons including pressure injuries and air leaks depending on posture. We used three-dimensional scanning to analyze the facial deformations in different postures in patients with bALS compared to those of healthy participants, then adjusted the masks virtually to examine the possible effects on user compliance. Methods: We conducted a prospective observational study with two groups, i.e., 14 bALS patients and 14 healthy participants. Three-dimensional scans of facial deformation when changing posture (sitting to supine and sitting to lateral decubitus) were performed on all participants. The extent of postural deformations was analyzed using the ALS Functional Rating Scale-Revised subscore and Urimal Test of Articulation and Phonation. In addition, the participants were virtually fitted with an NIV mask to calculate the horizontal distance, to identify possible complications with the NIV mask. This trial is registered with ClinicalTrials.gov (NCT04798183). Findings: The anteroposterior directional difference at the oral area was significantly greater in the bALS group than in the healthy group when changing posture from sitting to supine, and lateral deviation of the oral area was significantly greater compared in the bALS group than in the healthy group when changing posture from sitting to lateral decubitus. The extent of facial deformations, particularly of the oral region, was significantly related to the clinical scores. The virtual application of the NIV mask to the participants showed a significant change in the chin, cheek, and nasolabial fold according to the postural change. Interpretation: We showed that in patients with bALS, use of NIV masks can encounter several difficulties in different postures, and thereby reduce mask compliance. Different regions of the face were prone to complications in different postures in virtual fitting and this effect should be carefully considered when applying NIV masks. Clinical Trial Registration Details: Registered on the ClinicalTrials.gov (NCT04798183). Funding Information: This study was supported by the Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital. Declaration of Interests: The authors have no conflicts of interest. Ethics Approval Statement: Approved by the Institutional Review Board of a local Ethical Committee Pusan National University Yangsan Hospital, 05-2021-034). All participants gave informed consent.