Assessment of sensitivity of acoustic reflex decay test in diagnosis of patulous eustachian tube

Abstract

Abstract Background It has long been believed that the patulous eustachian tube is a unique but uncommon condition, with an estimated incidence ranging from 0.3 to 6.6% in the general population. Hearing one’s own voice and breathing, or autophony and aerophony, are the most common symptoms of PET, along with frequent auditory fullness. Aim This study is to establish a standardized protocol for the audiological evaluation of patulous Eustachian tube using acoustic reflex decay test during different breathing tasks. Methods Between January 2022 and December 2022, the ENT department at Suez Canal University Hospitals undertook an observational case-control study. Fifty-two adult patients who present to the Suez Canal University ENT department with complaints of autophony, auditory fullness, or aerophony are diagnosed with patulous eustachian tube dysfunction through endoscopic examination of the tympanic membrane’s synchronized movement with respiration. Results The incidence rate of PET among adults was approximately 3 patients/1000 patients/year. The age of the whole studied group ranged from 20 to 60 years with mean ± SD of 37.4 ± 12.6 years. They included 23 males (44.2%) and 29 females (55.8%). The most common symptom among the studied group was aural fullness (46%), while the least common symptom was aerophony (12%); the most common risk factor among the studied patients was allergy (46.2%), while the least common was radiotherapy (3.9%); 66.7% of the patients with GERD were males, while 66.7% of the patients who lost weight were females; 58.3% of the patients with allergies were females, and also 60% of the patients with thin built were females. In the case group, there is a significant higher change of middle ear compliance in ipsilateral nostril breathing than the mouth breathing and nasal breathing. The sensitivity of the acoustic reflex decay test to diagnose PET with reference to the gold standard test is 88.5% (23/26*100), the specificity is 100% (26/26*100), and the positive predictive value is 100% (23/23*100). Conclusion The sensitivity of the acoustic reflex decay test to diagnose PET with reference to the gold standard test is high, and the specificity is very high with very good diagnostic accuracy.