| Autor: |
Castellucci A; ENT Unit, Department of Surgery, Azienda USL-IRCCS di Reggio Emilia, 42123 Reggio Emilia, Italy., Malara P; Audiology & Vestibology Service, Centromedico, 6500 Bellinzona, Switzerland., Martellucci S; ENT Unit, Santa Maria Goretti Hospital, Azienda USL di Latina, 04100 Latina, Italy., Alfarghal M; Otorhinolaryngology-Head and Neck Section, Surgery Department, King Abdulaziz Medical City, Jeddah 21556, Saudi Arabia., Brandolini C; Otorhinolaryngology and Audiology Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Policlinico S. Orsola-Malpighi, 40138 Bologna, Italy., Piras G; Department of Otology and Skull Base Surgery, Gruppo Otologico, Casa Di Cura Privata 'Piacenza' S.P.A., 29121 Piacenza, Italy., Armato E; Faculty of Medicine, University of Lorraine, 54000 Vandoeuvre-lès-Nancy, France., Ruberto RR; Audiology and Ear Surgery Unit, Azienda USL-IRCCS di Reggio Emilia, 42123 Reggio Emilia, Italy., Brizzi P; Audiology and Ear Surgery Unit, Azienda USL-IRCCS di Reggio Emilia, 42123 Reggio Emilia, Italy., Presutti L; Otorhinolaryngology and Audiology Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Policlinico S. Orsola-Malpighi, 40138 Bologna, Italy., Ghidini A; ENT Unit, Department of Surgery, Azienda USL-IRCCS di Reggio Emilia, 42123 Reggio Emilia, Italy. |
| Abstrakt: |
Surgical plugging of the superior semicircular canal (SSC) represents an effective procedure to treat disabling symptoms in superior canal dehiscence (SCD), despite resulting in an impaired vestibulo-ocular reflex (VOR) gain for the SSC. On the other hand, SSC hypofunction on video head impulse test (vHIT) represents a common finding in patients with SCD exhibiting sound/pressure-induced vertigo, a low-frequency air-bone gap (ABG), and enhanced vestibular-evoked myogenic potentials (VEMPs). "Spontaneous canal plugging" has been assumed as the underlying process. Nevertheless, missing/mitigated symptoms and/or near-normal instrumental findings would be expected. An endolymphatic flow dissipation has been recently proposed as an alternative pathomechanism for SSC VOR gain reduction in SCD. We aimed to shed light on this debate by comparing instrumental findings from 46 ears of 44 patients with SCD exhibiting SSC hypofunction with post-operative data from 10 ears of 10 patients with SCD who underwent surgical plugging. While no difference in SSC VOR gain values was found between the two groups ( p = 0.199), operated ears developed a posterior canal hypofunction ( p = 0.002). Moreover, both ABG values ( p = 0.012) and cervical/ocular VEMP amplitudes ( p < 0.001) were significantly higher and VEMP thresholds were significantly lower ( p < 0.001) in ears with SCD compared to operated ears. According to our data, canal VOR gain reduction in SCD should be considered as an additional sign of a third window mechanism, likely due to an endolymphatic flow dissipation. |
