Outcome of Botulinum Toxin injection in Adductor Spasmodic Dysphonia

Botulinum Toxin injection is the mainstay of treatment of Adductor Spasmodic Dysphonia. However its outcomes, improvement, duration of effects and complications are matter of discussion. The aim & objective of this study was to see the outcomes of Botulinum Toxin injection in Adductor Spasmodic Dysphonia. This prospective, single arm, pre-port, interventional study was conducted in the Department of Otolaryngology-Head & Neck Surgery, Bangladesh Medical University (BMU), Dhaka, Bangladesh from January 2019 to June 2020 on 34 cases having Adductor Spasmodic Dysphonia. Cases were investigated by recording their Voice Handicap Index (VHI) scores at five time points: i) immediately prior to injection (baseline), ii) 1-3 days, iii) 2 weeks, iv) 8 weeks and (v) 12-week post-injection periods. In VHI, both individual (Functional, Physical and Emotional) subscale and total scores were considered. Comparison was done between pre-injection with post-injection VHI. All the information was recorded in a pre-tested questionnaire. In this study statistically significant improvement of VHI were found in 2-week post-injection time (Functional 13.74, Physical 20.03, Emotional 14.76, Total 48.53, p value <0.05) and 8-week post-injection time (Functional 8.24, Physical 12.47, Emotional 11.18, Total 31.89, p value <0.05). But no significant differences were found between pre injection VHI and VHI found in 1-3 days and 12-week post-injection period. Complications following this Botulinum Toxin injection were mild and subsided within 1-4 days. There was significant improvement of voice after Botulinum Toxin Injection in spasmodic dysphonia, although it needs repetition at about 12-week intervals.