Study Purpose: This study is for people with spasmodic dysphonia (SD), a condition causing voice breaks. Botox injections into a voice muscle help treat SD but can cause temporary voice weakness and breathiness for 2-3 weeks. Researchers believe that taking amifampridine can reduce these symptoms.

Amifampridine: This medication helps improve communication between nerves and muscles, possibly making voice stronger after Botox treatment.

Participation Details:

• The study includes adults aged 18 and over who experience significant breathiness after Botox injections for SD.
• Participants must agree to use a reliable form of birth control during the study if they can have children.
• People with a history of seizures or certain medication use cannot join.

Note: Pregnant or breastfeeding women cannot participate. The study aims to find out if amifampridine can help with voice symptoms after Botox. This is a chance to contribute to important research and potentially find a new way to help people with SD.