Reevaluating the notion of “within normal limits” in tympanometry: implications for alternobaric vertigo and more

Abstract

This editorial explores the notion of "within normal limits" (WNL) in tympanometry, focusing on its limitations in identifying conditions such as alternobaric vertigo (AV) and ground-level alternobaric vertigo (GLAV). Tympanometry is a simple diagnostic instrument that measures middle ear (ME) pressure, compliance, ear canal volume, and the width of tympanogram. While WNL ranges are based on average values from the population, they often do not account for individual differences, leading to possible misdiagnoses. Conditions such as AV, caused by asymmetric ME pressure, can show symptoms even when tympanometry results are within normal ranges. The editorial suggests a more thorough diagnostic approach that includes detailed patient histories, dynamic testing methodologies, and additional hearing and balance tests to improve diagnostic accuracy and patient outcomes. Symmetry in tympanometry data is crucial, and the Valsalva maneuver should be avoided due to potential harm. Future research should aim to improve diagnostic criteria and develop personalized approaches to better understand and manage ME issues.