Topic
Our Early Experience with Testosterone Injection in the Thyroarytenoid Muscle for Lowering the Vocal Pitch in Vocal Fold Sulcus
Authors
Nupur Kapoor Nerurkar, Zainab Nagree, Aman Bansal, Bhavini Verma

Back ground: A deep, low pitched voice, is often socially perceived as a marker of masculinity and authority. Various conditions are responsible for an abnormally high vocal pitch such as puberphonia, vocal fold sulcus, scarring and in the situation where a trans-man does not achieve adequate pitch-lowering following systemic testosterone therapy, to name a few. Besides voice modulation, the main intervention that may be used to lower pitch is a relaxation laryngeal framework surgery. However, this often decreases the pitch dramatically. Recent case reports have shown a drop in pitch with testosterone (T) injections into the thyroarytenoid muscle (TAM), offering a promising alternative that may mitigate the limitations associated with framework surgery.
Our aim was to study the outcomes of injecting testosterone into the thyroarytenoid muscle with respect to decreasing the vocal pitch in cases with vocal fold sulcus.

Methods: We present a case series of 11 cis male patients with bilateral vocal fold sulcus and a high-pitched voice. All patients were evaluated pre and post procedure (1 month and 3 months) using fundamental frequency (F0), maximum phonation time (MPT), stroboscopy and serum testosterone levels.
The patients were injected with a total of 30 milligrams of testosterone enanthate bilaterally ( 15 mg each vocal fold) into the TAM. A total of 7 patients were operated by laser assisted sulcus release (LASR) surgery under general anaesthesia for bilateral vocal fold sulcus at the time of injection. There were 2 previously operated patients of LASR who had a residual complaint of persistent high pitch for which they were injected with in-office testosterone. All these patients ( N=9) were included in the LASR+T group, while two patients were injected in-office for bilateral vocal fold sulcus.
Results: In a total of 11 patients the average drop in pitch was 31 Hz (mean pre F0: 223.2 Hz; mean post F0: 192.1 Hz) at 1 month post TAM testosterone injection, which was sustained at 3 months. Using the paired t-test the pitch drop was statistically significant (t =3.23, p < 0.05) with a large effect size (Cohen’s d=0.97). The MPT showed an improvement of 2.5 seconds (mean pre MPT 10.2 seconds; mean post MPT 12.7 seconds) at 1 month which was a statistically significant increase using the paired t test (t= 2.23, p <0.05). Serum testosterone levels remained within normal limits at all time points.

Conclusion: In this first case- series of testosterone injection in the TAM in 11 vocal fold sulcus patients, there was a significant drop in the F0 pitch along with a significant increase in the MPT, at the 3-month period, without systemic hormonal alteration. This minimally invasive technique may serve as a safe and effective alternative to framework surgery in selected patients with high-pitched voice due to vocal fold sulcus and related conditions. However, larger studies with longer follow-up are required to validate these findings.