Use of the maximal phonation test for the screening of dysphagia in stroke patients: a preliminary study.

Abstract

Dysphagia is a commonly developed complication after stroke and may lead to pneumonia. Several screening tests for dysphagia have been introduced, but no consensus has been reached regarding the test that best detects dysphagia or swallowing difficulties. Maximum phonation time (MPT) can measure laryngeal and pharyngeal function indirectly by providing a means of assessing vocal cord integrity. Because vocal cords play a role in sound production and also protect the airways, we considered MPT might be used to screen for penetration and aspiration into airways in stroke patients. The purpose of this study was to investigate the ability of MPT to differentiate between stroke patients with or without penetration/aspiration and the relationships between MPT and videofluoroscopic swallowing study (VFSS) findings and those of other swallowing screening tests. Prospective observational study. Korean tertiary hospital. One hundred six Patients with acute stroke patients with suspected dysphagia referred for VFSS from January 2016 to December 2017. MPT differences among a normal group, a penetration group, and an aspiration group were analyzed, and correlations between MPT and age, Penetration Aspiration Scale (PAS), American Speech-Language-Hearing Association National Outcome Measurement System Swallowing Scale (ASHA-NOMS), Functional Dysphagia Scale (FDS) scores were investigated. MPTs were found to be significantly different in normal, penetration, and aspiration groups in stroke patients (P<0.01). Furthermore, MPT was highly correlated with PAS, ASHA-NOMS, and FDS scores. ROC analysis provided MPT cut off values for the presence of penetration and aspiration in stroke patients of 9.08 and 7.98 sec, respectively. In stroke patients, MPT could be used to detect penetration or aspirations while swallowing. and seems to have appropriate validity and sensitivity. MPT is proposed as a new screening tool for detecting dysphagia in stroke patients, especially airway aspiration.