Significance of Pseudo-conductive Hearing Loss and Positional Nystagmus on Perilymphatic Fistula: Are they related to third window effects?

xlomafota13 shared this article with you from Inoreader Significance of Pseudo-conductive Hearing Loss and Positional Nystagmus on Perilymphatic Fistula: Are they related to third window effects? Via pubmed: "clin exp otorhinola... Clin Exp Otorhinolaryngol. 2021 Feb 26. doi: 10.21053/ceo.2020.01942. Online ahead of print. ABSTRACT OBJECTIVES: Clinical presentation is critical to identify suspected perilymphatic fistula (PLF). To explain characteristic of PLF, it was hypothesized that a third window lesion might be involved in the pathomechanism. The purpose of this study is to investigate clinical features in PLF and figure out the relationship of third window effect and PLF. METHODS: Sixty patients underwent surgical exploration under suspicion of PLF and reinforecmenet of oval window and round window was performed. Clinical features including demographics, pure tone audiometry (PTA), and videonystagmography (VNG) were evaluated preoperatively and 1 month after operation. Surgical outcomes were analyzed according to the improvement of hearing and vestibular symptoms and signs. The conductive components of PTA (air-bone gap (ABG)) were measured, and the re lationship between ABG closure after surgery and hearing improvement was analyzed. In addition, the postoperative subjective dizziness was assessed by interview in clinic. The change of positional nystagmus was analyzed according to ABG closure and hearing improvement. RESULTS: ABG at lower frequencies (LFABG, 250 Hz, 500 Hz, 1,000 Hz) was present in 27 patients (45%). Postoperatively, the PTA was significantly improved after surgical repair. Among the patients with preoperative LFABG (n=27), 15 (55.5%) showed postoperative ABG closure and significant improvement in PTA at all frequencies compared with the patients without ABG closure (P=0.012). The subjective dizziness improved in 56 patients (91.8%). Positional nystagmus was found in 45 of 49 patients. Multiple canal involvement was more common than single canal (67% vs. 33%). The horizontal semicircular canal was most commonly involved, followed by the posterior and anterior canals. Postoperatively, the positional nystagmus disappeared, or the number of involved canals decreased in 22 of 34 (64.7%) patients. CONCLUSION: . Pseudo-conductive hearing loss at the lower frequencies and positional nystagmus originating from multiple semicircular canals were common findings in PLF. Surgical reinforcement of the RW and OW improved hearing threshold accompanied by closure of ABG. The third window lesion might explain these clinical features that indicate PLF. PMID:33677850 | DOI:10.21053/ceo.2020.01942 View on the web Inoreader. Take back control of your news feed. Follow us on Twitter and Facebook.