Mucosal wave asymmetries in the clinical voice laboratory

Anecdotally, it has been observed that in some healthy middle-aged men, who have neither vocal complaints nor known vocal pathology, asymmetries of the mucosal wave exist when examined videostroboscopically. This may cause concern on the part of the otolaryngologist, who might consider mucosal wave asymmetries to be a forewarning of subclinical pathology and subject the patient to unnecessary, expensive, and anxiety-provoking investigations or interventions. The purpose of this study is to establish the presence of mucosal wave asymmetries in a healthy, asymptomatic subpopulation. Acoustic spectral analysis is also used to determine if the presence of subharmonics might be associated.

A prospective, cohort study design was used. The population was randomly selected, healthy, asymptomatic, nonsmoking men aged 35 to 50 years. Each subject completed acoustic spectral analysis and a medical questionnaire, followed by videostroboscopic laryngeal examination.

Thirty-seven percent of the subjects exhibited mucosal wave variations at stroboscopy, characterized as periodic lateral phase asymmetries. There was no association with the acoustic spectral parameters chosen.

Mucosal wave asymmetries may be a variance of normal. The 37% found here is expected to be very significant. Mucosal wave asymmetries are likely to be far more common in the general population than previously believed. There have been few normative data published for variations of the mucosal wave specifically for epidemiologic purposes. These results establish a starting point and justification for the normative population studies under way at our institution. Clinically, in the absence of such data, otolaryngologists may overinterpret videostroboscopic findings, leading to unnecessary investigations or interventions.