Longitudinal analysis of surgical outcome in subjects with pulsatile tinnitus originating from the sigmoid sinus

Abstract

A dominant sigmoid sinus with either diverticulum or dehiscence (SS-Div/SS-Deh) is a common cause of pulsatile tinnitus (PT). For PT originating from SS-Div/SS-Deh, an etiology-specific and secure reconstruction using firm materials is vital for optimal outcomes. As a follow-up to our previous reports on transmastoid SS resurfacing or reshaping for SS-Div/SS-Deh, this study aimed to evaluate the long-term results of transmastoid resurfacing/reshaping. We retrospectively reviewed 20 PT patients who were diagnosed with SS-Div/SS-Deh, underwent transmastoid resurfacing/reshaping, and were followed up for more than 1 year postoperatively. For PT, immediate and long-term changes (> 1 year) in loudness and annoyance were analyzed using the visual analog scale (VAS). Additionally, pre and postoperative objective measurements of PT using transcanal sound recording and spectro-temporal analysis (TSR-STA), imaging results, and audiological findings were comprehensively analyzed. Significant improvements in PT were sustained or enhanced for > 1 year (median follow-up period: 37 months, range: 12-54 months). On TSR-STA, both peak and root mean square amplitudes decreased after surgery. Also, the average pure-tone threshold at 250 Hz improved after surgery. Thus, our long-term follow-up data confirmed that the surgical management of PT originating from SS-Div/SS-Deh is successful with regard to both objective and subjective measures.

Figure 1

(a) Schematic illustration of the surgical procedures of the transmastoid sigmoid sinus (SS) resurfacing surgery for patients with SS diverticulum (SS-Div). (b) Schematic illustration of the surgical procedures of transmastoid SS reshaping for patients with SS dehiscence (SS-Deh). A multistep reconstructive process, including external reduction (a) or compression (b) of the sigmoid sinus, reconstruction of a sound-proof barrier using a firm material (i.e., bone cement), and disconnection of the sound transmission, may be the keys to quieting PT.

Figure 2

The short-term (< 1 week) and long-term (> 1 year) changes in the Visual Analog Scale (VAS) of tinnitus loudness and tinnitus-related distress are depicted. The mean VAS loudness (a) and VAS annoyance (b) significantly decreased immediately (within 1 week of surgery) and then improved over 1 year. Compared with the short-term time point (< 1 week), mean VAS loudness (a) and VAS annoyance (b) were markedly decreased after surgery in the long-term (> 1 year). *Indicates statistical significance by the Paired t-test.

Figure 3

(a) Comparison of pre and postoperative pure tone audiometries. Of 20 patients, 6 (30%) exhibited ipsilateral pseudo-low frequency hearing loss (LFHL), as proposed by our criteria, at preoperative evaluation. Improvements in the low-frequency hearing thresholds were evident postoperatively in all 6 subjects. (b) Changes in hearing threshold at 250 Hz of 6 subjects with ipsilateral pseudo-LFHL. All subjects showed significant improvement in air-conduction hearing threshold at 250 Hz immediately after the operation. The blue circle indicates the LFHL at 250 Hz. *Indicates statistical significance by the Paired t-test.

Figure 4

Spectro-temporal analysis of signals obtained via transcanal sound recording. (a, b) Comparison of pre and postoperative peak and RMS amplitudes. (c) Three-dimensional waterfall spectrograms of the pre and post-treatment signals. *Indicates statistical significance by the Wilcoxon signed-rank sum test.