SPASMODIC DYSPHONIA
 
SD is a focal dystonia characterized by involuntary spasms in the muscles for voicing (PSA, TA).

Facts:

• Cause is unknown

• Onset is usually gradual

• Average age of onset is between 30 and 50

• More common in females than in males

• Some cases are hereditary (gene on chromosome 9)

• Often diagnosed following respiratory tract infections, laryngeal damage due to injury, and vocal overuse

• Symptoms worsen under stressful conditions and while talking on the phone

Two main categorizations: Adductor, abductor

Adductor:

• Most common for

• Involuntary muscle spasms cause the vocal folds to slam togethe

• Stiffness of vocal folds

• Tight, strained, strangled or “over pressurized” voice (Stemple, 2000)

• Prolongation of vowel sounds

• Words are cut off or difficult to initiate due to spasms

• Stuttering like symptoms

• Most evident in vowels, liquids, glides

Abductor:

• Difficult to diagnose and to treat

• Involuntary muscle spasms in the PCA

• Abrupt, discontinuous escapes of air

• Inability of the TVF to close for voicing results in a whispered voice quality

• Voiceless consonants are prolonged

• /s/, /h/, /k/ before open vowel sound

• Pitch elevation on initiation of vowels

• Difficulty coordinating speaking and breathing

TX options:

• RLN resection

• Botox injections

• Pre and Post tx voice therapy

Successful Voice Therapy:

• Must introduce acquisition of new voicing skills and patterns not characterized by overpressure and interruptions

• Eliminate negative effects of surgery (paralysis) and Botox

• Produce phonation with higher pitch, increased breathiness, decreased intensity

• Intensive pre-TX therapy can greatly improve post-TX therapy outcomes

• Therapy goal: reduction of main components responsible for ADD/SD symptoms: TVF collision force, TVF contact area, and elevated subglottic air pressures (Ps)
  
   

http://www.voicedoctor.net/therapy/dystonia.htm http://www.nidcd.nih.gov/health/voice/spasdysp.asp
http://www.dysphonia.org/spasmodic/