Transcutaneous Auricular Vagus Nerve Stimulation for Meniere Disease: Randomized Trial Controlled

Pure tone thresholds.

Time Frame: Change from Baseline level of Pure tone thresholds at 12-weeks post-therapy.

The pure tone thresholds was performed in a sound-attenuated, double-walled booth with circumaural headphones (Sennheiser HD 280 for frequencies from 250 to 8000 Hz and Sennheiser HD 200 for frequencies from 8000 to 14000 Hz; Sennheiser, Old Lyme, USA) on a certified and calibrated audiometric system (Interacoustics, Middelfart, Denmark). Thresholds were measured using a probe-detection paradigm with pure tones presented for 250 ms at frequencies of 250, 500, 1000, 2000, 4000, 8000 Hz for each ear. To determine the LDL, the volume was set to 75 dB at 1000 Hz and then continuously raised in 5 dB steps (every 5 s) until the subject gave the signal that this volume was uncomfortable. When the volume exceeded 110 dB the test was stopped to prevent any hearing damage. The severity of hearing impairment was calculated as mild (20-40 dB), moderate (41-70 dB), severe (71-95 dB) and profound (\>95 dB). Normal hearing was defined as pure-tone thresholds less than 20 dB.

Tinnitus Handicap Inventory (THI)

Time Frame: Change from Baseline scores of THI at 12-weeks post-therapy.

The THI is a 25-items, self-reported questionnaire regarding tinnitus handicap in daily life. The questionnaire comprises a 12-item functional subscale, an 8-item emotional subscale, and a 5-item catastrophic subscale. The three answer options are "yes," "sometimes," and "no," with scores of 4, 2, and 0, respectively. The overall score is the sum of 25 items (Range: 0-100). Higher scores equate to greater severity of tinnitus symptoms. measure the subjective tinnitus symptoms.

Dizziness Handicap Inventory (DHI)

Time Frame: Change from Baseline scores of DHI at 12-weeks post-therapy.

The DHI is 25-items self-reported questionnaire that used to evaluate the functional, emotional, and physical impact of dizziness on patients' daily life. Among the overall 25 items of questions, 9 items are emotional related, 9 items are functional related, and 7 items are physical related questions. The three answer options are "yes," "sometimes," and "no," with scores of 4, 2, and 0, respectively. The overall score is the sum of 25 items (Range: 0-100). Higher scores equate to greater severity of dizziness symptoms.

Visual analogue scale (VAS)

Time Frame: Change from Baseline scores of VAS of aural fullness at 12-weeks post-therapy.

The VAS scale of aural fullness consists of a 100 mm straight line with defined endpoints ("no aural fullness" and "worst aural fullness imaginable") on which the patients were asked to mark their experienced aural fullness (results in mm) at the actual time ("VAS now"). The higher VAS score (Range: 0-100) is correlated with a severe aural fullness.