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Spasmodic Dysphonia. Spasmodic Dysphonia is primarily characterized by frequent voice breaks and significant vocal effort. Spasmodic Dysphonia (SD). Controversial etiology Psychologic vs. neurologic SD is generally considered an adult onset action induced focal dystonia.
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Spasmodic Dysphonia SPPA 6400 Voice Disorders Tasko
Spasmodic Dysphonia is primarily characterized by frequent voice breaks and significant vocal effort SPPA 6400 Voice Disorders Tasko
Spasmodic Dysphonia (SD) • Controversial etiology • Psychologic vs. neurologic • SD is generally considered an adult onset action induced focal dystonia SPPA 6400 Voice Disorders Tasko
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
Other Examples of Focal Dystonia? • Blepharospasm • Writer’s cramp • Torticollis (cervical dystonia) SPPA 6400 Voice Disorders Tasko
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
Potential Neural Mechanisms • Reduced neural inhibition • Increased neural plasticity • Abnormal sensory gating SPPA 6400 Voice Disorders Tasko
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
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
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
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 • ~ 10-15 % of SD SPPA 6400 Voice Disorders Tasko
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
Adductor SD: diagnostic tasks • Sentences – all voiced • ↑ difficulty • Sentences – high frequency voiceless • ↓ difficulty • Eighty series (e.g. count 80, 81, 82…) • ↑ difficulty • Sixty series (e.g. count 60, 61, 62) • ↓ difficulty • repetitions of ‘we’ vs. ‘pea’, ‘tea’, ‘key’, ‘see’ • ‘we’ = ↑ difficulty SPPA 6400 Voice Disorders Tasko
Abductor SD: diagnostic tasks • Sentences – all voiced • ↓ difficulty • Sentences – high frequency voiceless • ↑ difficulty • Eighty series (e.g. count 80, 81, 82…) • ↓ difficulty • Sixty series (e.g. count 60, 61, 62) • ↑ difficulty • repetitions of ‘we’ vs. ‘pea’, ‘tea’, ‘key’, ‘see’ • voiceless = ↑ difficulty SPPA 6400 Voice Disorders Tasko
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
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
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 20-25 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
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
Distinguishing SD and MTD 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
Distinguishing SD and MTD MTD… • Is associated with reported pain, tenderness • Is not associated with tremor • Shows sustained improvement after manual circumlaryngeal therapy SPPA 6400 Voice Disorders Tasko
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
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
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
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
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
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
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
Botulinum Toxin (BOTOX) SPPA 6400 Voice Disorders Tasko
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
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
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
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 BOTOX Injection Sites SPPA 6400 Voice Disorders Tasko
BOTOX Injection Dosage Bilateral • 2.5 units per side Unilateral • 15 units • Unilateral considered superior, with longer lasting effects SPPA 6400 Voice Disorders Tasko
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
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
Selected CNS diseases • ALS • Parkinson’s Disease • Myasthenia gravis SPPA 6400 Voice Disorders Tasko