The symptoms of SD depend on which form is present. The adductor type produces a strained or strangled voice quality. Abductor SD usually produces a breathy and effortful voice. Both types cause abrupt breaks in phonation and decreased intelligibility. Voice is often worse on the telephone or when the speaker is under stress.
Some voice production can be normal, such as laughing, coughing, and singing.
Botox treats the symptoms of SD, but it does not cure the disorder. The effects of Botox injections are usually apparent within 24 hours and last for four to six months. Risks and discomfort during the procedure are minimal. After an injection for adductor SD, patients may experience a weak, breathy voice and mild difficulty swallowing for one to two weeks. Voice therapy is used in conjunction with Botox injections to maximize voice capabilities during the breathy period, minimize the dysfunction as the spasms return, and lengthen the time between injections.