title: The Incidence of Early Postoperative Conductive Hearing Loss after Microvascular Decompression of Hemifacial Spasm.
abstract: Objectives To evaluate the incidence and discuss the pathogenesis of early postoperative conductive hearing loss (CHL) after microvascular decompression (MVD) for hemifacial spasm (HFS). Design Pre- and postoperative audiogram data and brainstem auditory evoked potentials (BAEPs) from patients who had underwent MVD for HFS were analyzed. Setting The study was conducted at the University of Pittsburgh Medical Center. Participants MVD for HFS patients who had pre- and postoperative audiogram data, BAEP data, and normal structure of the external and middle ear were included in the study. Main Outcome Measures CHL was diagnosed if there was an air-bone gap in pure tone audiometry of at least 10 dB at 0.5, 1, 2, or 4 kHz. Results The incidence of early postoperative CHL in the ipsilateral ear was 18.7% postoperatively. No CHL was observed in the contralateral side. No significant relationship between CHL and intraoperative BAEP changes was found. Demographic parameters were not significantly different between groups with and without CHL. Conclusions Early postoperative CHL is a significant complication after MVD. Fluid entering the mastoid air cells and/or bone-dust deposition during craniotomy may result in CHL. Long-term audiograms will be needed to evaluate the risk factors that lead to permanent CHL.
authors.affiliation: Department of Neurological Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Ying
authors.affiliation: Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, United States ; Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States.
authors.forename: Parthasarathy
authors.initials: P
authors.lastname: Thirumala
authors.affiliation: Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, United States.
authors.forename: Paul
authors.initials: P
authors.lastname: Gardner
authors.affiliation: Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, United States.
authors.forename: Miguel
authors.initials: M
authors.lastname: Habeych
authors.affiliation: Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, United States.
authors.forename: Donald
authors.initials: D
authors.lastname: Crammond
authors.affiliation: Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, United States.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Balzer
keywords: air-bone gap; brainstem auditory evoked potentials; conductive hearing loss; hemifacial spasm; microvascular decompression