Effect of Vocal Exercise After Botulinum Toxin Injection for Spasmodic Dysphonia

SD is a rare voice disorder that usually starts when individuals are in early adulthood and
occurs in two common forms: adductor and abductor (Aronson, 1968, Brin et al., 1992,
Schweinfurth et al., 2002). Adductor is the more common form (Aronson, 1985, Blitzer et al.
1998). With adductor SD, patients have been described as "trying to talk whilst being
choked" (Critchley, 1939). The spasmodic hyperadduction of the vocal folds is associated
with strained-strangled, rough voice quality and sudden intermittent voice arrests (Aminoff,
Dedo, & Izdebski, 1978, Blitzer & Brin, 1992, Hillel, 2001, Izdebski 1992, Ludlow, Nauton, &
Bassich, 1984, Woodson, Zwirner, Murry, & Swenson, 1991). On the other hand, the
intermittent or continuous abduction of the vocal folds linked with abductor SD results in
breathy or whispered voice quality with sudden intermittent voice arrests (Aronson, 1985,
Hillel, 2001, and Zwitman, 1979).

Local injection of botulinum toxin is an effective treatment for spasmodic dysphonia and The
National Academies of Otolaryngology and Neurology has endorsed the toxin as the treatment
of choice for adductor spasmodic dysphonia. Consequently, this treatment is widely used. The
clinical benefit of the botulinum toxin is related to muscle weakness in the vocal folds and
the benefit lasts from 6 weeks to 6 months.

Studies have suggested that voluntary muscle exercise in the hand and face after botulinum
toxin injection may enhance the clinical effects of the toxin (Chen, Scott, & Smith, 2002;
Chen et al., 1999; Kim et. al 2003;. Exercise may speed up the absorption of the toxin by
the nerves and enhance the clinical response. You are invited to take part in a research
study to learn more about the effect of exercise on botulinum toxin injections for spasmodic
dysphonic. This project will examine whether or not exercise performed immediately following
botulinum toxin injection affects the clinical benefit received from the injection.

Inclusion Criteria:

1. diagnosis of adductor spasmodic dysphonia

2. receiving ongoing botulinum toxin injections for a minimum of 1 year

3. improvement in voice to at least 70% following each of the last three injections

Exclusion Criteria:

1. other neurological disorder

2. other dystonia

3. upper respiratory infection in the last two weeks

4. analgesia at time of injection

5. illiterate

6. under 18 years of age