1. SPPA 6400 Voice Disorders Tasko
Spasmodic Dysphonia
SPPA 6400 Voice Disorders Tasko

2. SPPA 6400 Voice Disorders Tasko
Spasmodic Dysphonia is primarily characterized by frequent voice breaks and significant vocal effort
SPPA 6400 Voice Disorders Tasko

3. Spasmodic Dysphonia (SD)
Controversial etiology
Psychologic vs. neurologic
SD is generally considered an
adult onset action induced focal dystonia
SPPA 6400 Voice Disorders Tasko

4. What is a focal dystonia?
Uncontrolled spasmodic muscle contractions
Often begin in adulthood
May be
restricted to a few muscles (focal)
Segmental (group of muscles)
General (large areas of the body)
Problems typically occur during task execution and appear normal at rest
SPPA 6400 Voice Disorders Tasko

5. Other Examples of Focal Dystonia?
Blepharospasm
Writer’s cramp
Torticollis (cervical dystonia)
SPPA 6400 Voice Disorders Tasko

6. Evidence for a neurogenic etiology for SD
Pts often exhibit other movement related problems (limb, orofacial)
Non-medical treatment meets only limited success
Limited evidence for neurologic differences between SD and normal population
Variety of neural loci implicated
basal ganglia, SMA
SPPA 6400 Voice Disorders Tasko

7. Potential Neural Mechanisms
Reduced neural inhibition
Increased neural plasticity
Abnormal sensory gating
SPPA 6400 Voice Disorders Tasko

8. Spasmodic Dysphonia: Other Observations
Symptoms may increase during stress
More likely to have had childhood measles/mumps
No more likely to have other neurological conditions
No obvious environmental patterns
More common for those with European ancestry
10 % report a family history
SPPA 6400 Voice Disorders Tasko

9. Spasmodic dysphonia: Types
Adductor SD (ADDSD)
Intermittent voice breaks in the middle of vowels
Strained-strangled, effortful voice quality
Spasmodic hyperadduction of TVFs
Abductor SD (ABDSD)
Abduction of true vocal folds (devoicing gesture)
Prolonged voiceless consonants & difficulty with voice onset following voiceless sounds
May have breathy voice quality
SPPA 6400 Voice Disorders Tasko

10. SPPA 6400 Voice Disorders Tasko
Vocal Tremor
voice breaks, frequency modulation or amplitude modulation at regular intervals (5 Hz)
Best observed during a sustained vowel task
Tremor is a common neurologic sign
Tremor therefore is highly suggestive of neural involvement
May be associated with known neurological disease
May be familial
Can occur as an isolated condition
Often co-occurs with SD (~ ¼ of SD have tremor)
SPPA 6400 Voice Disorders Tasko

11. SPPA 6400 Voice Disorders Tasko

12. Spasmodic Dysphonia & Related Disorders: Epidemiology
Prevalence of focal dystonia: 295 per million
Prevalence of SD: 1 per 100,000
Prevalence ranking for focal dystonia
Torticollis
Blepharospam SD
Females > Males
ranges from 1.4:1 – 7:1
ABSD less common
~ % of SD
SPPA 6400 Voice Disorders Tasko

13. Spasmodic Dysphonia: diagnostic tasks
Connected speech-will exhibit difficulties
Sustained vowel
Reduction/resolution of symptoms
less severe than connected speech
May have tremor ~ 5 Hz
Falsetto (count to 10) - Asymptomatic
Whisper (count to 10) - Asymptomatic
Singing (‘Happy Birthday’) – Improvement
Pitch glide - ↓ symptoms at highest pitches
Loud speech - ↓ symptoms for shouting
SPPA 6400 Voice Disorders Tasko

14. Adductor SD: diagnostic tasks
Sentences – all voiced
↑ difficulty
Sentences – high frequency voiceless
↓ difficulty
Eighty series (e.g. count 80, 81, 82…)
Sixty series (e.g. count 60, 61, 62)
repetitions of ‘we’ vs. ‘pea’, ‘tea’, ‘key’, ‘see’
‘we’ = ↑ difficulty
SPPA 6400 Voice Disorders Tasko

15. Abductor SD: diagnostic tasks
Sentences – all voiced
↓ difficulty
Sentences – high frequency voiceless
↑ difficulty
Eighty series (e.g. count 80, 81, 82…)
Sixty series (e.g. count 60, 61, 62)
repetitions of ‘we’ vs. ‘pea’, ‘tea’, ‘key’, ‘see’
voiceless = ↑ difficulty
SPPA 6400 Voice Disorders Tasko

16. ADSD vs. ABSD: Sentence Stimuli
All voiced segments…elicits ADSD symptoms
Early one morning a man and a woman were ambling along a one-mile lane running near rainy Island Avenue
Albert eats eggs every Easter early in the a.m.
SPPA 6400 Voice Disorders Tasko

17. ADSD vs. ABSD: Sentence Stimuli
Voiceless segments…elicits ABDSD symptoms
He saw half a shape mystically cross fifty or sixty steps in front of his sister Kathy’s house.
She sells seashells by the seashore.
SPPA 6400 Voice Disorders Tasko

18. ADSD: Other diagnostic tasks
Ingressive reading of all voiced segments
Unilateral RLN Block (lidocaine)
Will eliminate ADDSD within several minutes of ipsilateral paresis/paralysis
lasts about minutes
Should confirm paralysis endoscopically
Return of pre-block symptoms after nerve block effects abate
Recent evidence suggests this does not differentiate ADSD from MTD (Roy, et al. 2007)
SPPA 6400 Voice Disorders Tasko

19. Other signs/symptoms of ADDSD
Minimal signs of ↑ musculoskeletal tension
Minimal pain, tenderness, hypertonicity
Laryngeal elevation is in synchrony with adductor spasms
No sustained response to manual circumlaryngeal techniques (behavioral treatment)
Some transient improvement with laryngeal stabilization maneuvers (behavioral treatment)
SPPA 6400 Voice Disorders Tasko

20. Distinguishing SD and MTD
Severity of sustained vowel often commensurate with connected speech
No obvious differences between voiced and voiceless contexts (all contexts difficult)
Is usually continuous and rarely intermittent (no islands of normal speech)
Shows no improvement with falsetto or singing
SPPA 6400 Voice Disorders Tasko

21. Distinguishing SD and MTD
Is associated with reported pain, tenderness
Is not associated with tremor
Shows sustained improvement after manual circumlaryngeal therapy
SPPA 6400 Voice Disorders Tasko

22. Distinguishing SD and MTD
Studies of psychologic factors and dysphonia
MTD
tendency toward introversion and neuroticism SD
No evidence for psychological/personality factors
There is evidence pre-post differences that may be related to a reaction to the problem
SPPA 6400 Voice Disorders Tasko

23. SPPA 6400 Voice Disorders Tasko
Recent evidence
If there is not a voiced-voiceless difference in severity, it does not necessarily exclude ADSD from the Dx (1/2 ADSD did not show task specificity in recent study)
If there is a voiced-voiceless difference in severity, the likelihood of ADSD is increased
SPPA 6400 Voice Disorders Tasko

24. Spasmodic Dysphonia: Management
No known cure
Treatment aim is to control/relieve symptoms
Patient should be educated regarding management options
Advantages/disadvantages with all treatments
SPPA 6400 Voice Disorders Tasko

25. Spasmodic Dysphonia: Treatment options
Behavioral
Voice Therapy (limited benefit for moderate to severe ADDSD or tremor)
Medical
Botulinum Toxin injections (BOTOX)
Neuropharmacological Intervention
Surgical
Recurrent Laryngeal Nerve Section
Thyroplasty, myotomy etc.
SPPA 6400 Voice Disorders Tasko

26. When/Who to offer voice therapy?
During differential diagnosis (diagnostic therapy)
Coexisting muscle tension dysphonia
May extend the effect of BOTOX in ADDSD
ABSD pts who exhibit little response to BOTOX
Pts with mild/inconsistent symptoms of ADDSD
BOTOX may provide too great an effect
Trial therapy should be short term (< 5 sessions)
SPPA 6400 Voice Disorders Tasko

27. Possible Voice Therapy Techniques
Manual circumlaryngeal therapy
Breathy voice attack
Pitch elevation
Loudness reduction
Techniques for hyperfunctional voice disorders
resonant voice, yawn sigh, relaxation
Inhalation voice therapy
SPPA 6400 Voice Disorders Tasko

28. Medical Management: BOTOX Injections
Inject intrinsic muscles with BOTOX
BOTOX – neurotoxin that produces chemical denervation at neuromuscular junction
Advantages
Temporary
no (known) permanent injury
Side effects are temporary
SPPA 6400 Voice Disorders Tasko

29. Botulinum Toxin (BOTOX)
SPPA 6400 Voice Disorders Tasko

30. Medical Management: BOTOX Injections
Disadvantages
Temporary
Costly – re-injection every 4 mos.
Breathiness (7-20 days)
Swallowing side effects (3-5 days)
Poor predictability of patient response
Possible buildup of resistance to injections
SPPA 6400 Voice Disorders Tasko

31. Medical Management: BOTOX Injections
Who benefits most?
Moderate to severe ADDSD
Vocal tremor
ABSD ?
Patients who get questionable benefit
Mild ADDSD
Coexisting regional dystonia
SPPA 6400 Voice Disorders Tasko

32. BOTOX Injections: Procedures
Peroral
Injection via oral cavity
Uses less toxin
No EMG verification
Percutaneous
Through the neck tissue
Uses EMG verification
SPPA 6400 Voice Disorders Tasko

33. SPPA 6400 Voice Disorders Tasko
BOTOX Injection Sites
ADDSD
TA (most frequent)
LCA
Both
ABSD
PCA
must be percutaneous
technically demanding
Maybe CT
Vocal tremor
TA, sternohyoid and thyrohyoid
injections more likely bilateral
SPPA 6400 Voice Disorders Tasko

34. BOTOX Injection Dosage
Bilateral
2.5 units per side
Unilateral
15 units
Unilateral considered superior, with longer lasting effects
SPPA 6400 Voice Disorders Tasko

35. Surgical Management: Recurrent Nerve Resection
Advantages
Potential long term benefit (40%)
Disadvantages
Unpredictable side effects
Symptom return (up to 60%)
Permanent unilateral paralysis
Controversial
Patient types benefited
Focal severe ADDSD
SPPA 6400 Voice Disorders Tasko

36. Other Neurpharmacological Intervention
Propanolol (Inderal) for voice tremor
Artane (anticholinergic) for ABSD
Baclofen – muscle relaxant for ADDSD
Disadvantages
Limited voice change
Adjunct role at best
No controlled studies to demonstrate effectiveness
SPPA 6400 Voice Disorders Tasko

37. SPPA 6400 Voice Disorders Tasko
Selected CNS diseases
ALS
Parkinson’s Disease
Myasthenia gravis
SPPA 6400 Voice Disorders Tasko