Pre and post operative voice analysis after medialization thyroplasty in cases of unilateral vocal fold paralysis

The present study was undertaken to assess the efficacy of medialization thyroplasty on outcome of voice quality in vocal cord paralysis by analyzing the voice. A total 19 patients with vocal cord paralysis of different etiologies were included in the study. Preoperative voice analysis was done by voice recordings, GRBAS score, maximum phonation time (MPT) and acoustic analysis using Dr Speech software (University version 4.0) using habitual fundamental frequency (F0), jitter %, shimmer % and normalized noise energy (NNE) as parameters. 18 patients underwent type 1 or medialization thyroplasty alone and 1 patient had undergone medialization thyroplasty along with arytenoids adduction. Post operative voice analysis was done using same parameters. There was post operative improvement of voice in 16 patients whereas 3 patients showed no significant improvement. Mean preoperative MPT was 4.8947 s and post operative was 13 s. Mean preoperative GRBAS score was 76.1579 and post operative was 30. On acoustic analysis, mean preoperative habitual fundamental frequency (F0), jitter %, shimmer % and NNE was 278.16 Hz, 1.7, 6.81 and 1.81 dB respectively whereas post operative mean was 132.37 Hz, 0.41, 1.65 and 123.38 dB respectively. Thyroplasty offers good voice outcome in patients of uncompensated vocal cord paralysis. Improvement can be documented in terms of perceptual evaluation of voice and acoustic analysis as well as maximum phonation time in addition to voice recording.