Abstract
Objectives: This study aimed to determine the positive predictive value of our NMD Suspicion Criteria in the diagnosis of NMDs. Other clinical factors routinely examined in our voice and swallowing examinations were also investigated to see if they had a significant association with the diagnosis of NMDs. Methods: This study retrospectively investigated the medical charts of patients who visited our Voice and Swallowing outpatient clinic between 2013 and 2022. Patients with previously diagnosed NMDs were excluded from the analysis. Among the remaining patients, we included those that were referred to neurologists for further evaluation due to suspicion of having an NMD based on the NMD Suspicion Criteria. The patients were then divided into groups according to the status of their diagnosis within 2 years of referral as "diagnosed", "denied", or "observed". These three groups of patients were then compared according to the following clinical findings; velopharyngeal insufficiency (VPI), tongue atrophy, impaired tongue movement, dysarthria, vocal fold mobility impairment, dysphagia, involuntary movement, gait disturbances, weight loss, and a sense of fatigue in order to see if they were significantly associated with the diagnosis of NMDs. Results: Of 3769 outpatients without a confirmed diagnosis of NMDs, 37 were referred to neurologists for suspected NMDs, and 19 (51%) were diagnosed with NMDs. VPI and impaired tongue movement were significant diagnostic factors for NMDs (p = 0.014, 0.033). VPI during speech (p = 0.045) was more strongly associated with the diagnosis of NMDs than VPI during swallowing (p = 0.076). Fatigue was a significant related factor for other diseases (non-NMDs) causing Voice and Swallowing problems (p = 0.049). Conclusions: In the outpatient clinic setting, suspicion of NMD should be raised, particularly when VPI and impaired tongue movement are observed, prompting a thorough assessment of velopharyngeal closure during both speech and swallowing.