Spasmodic Dysphonia SPPA 6400 Voice Disorders Tasko

Spasmodic Dysphonia SPPA 6400 Voice Disorders Tasko

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

Spasmodic Dysphonia (SD) o o o 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? o o Uncontrolled spasmodic muscle contractions Often begin in adulthood May be n restricted to a few muscles (focal) n Segmental (group of muscles) n 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? o o o Blepharospasm Writer’s cramp Torticollis (cervical dystonia) SPPA 6400 Voice Disorders Tasko

Evidence for a neurogenic etiology for SD o o 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 n basal ganglia, SMA SPPA 6400 Voice Disorders Tasko

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

Spasmodic Dysphonia: Other Observations o o o 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 o Adductor SD (ADDSD) n n n o Intermittent voice breaks in the middle of vowels Strained-strangled, effortful voice quality Spasmodic hyperadduction of TVFs Abductor SD (ABDSD) n n n 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 o o o o 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

SPPA 6400 Voice Disorders Tasko

Spasmodic Dysphonia & Related Disorders: Epidemiology o o o Prevalence of focal dystonia: 295 per million Prevalence of SD: 1 per 100, 000 Prevalence ranking for focal dystonia 1. 2. 3. o Females > Males n o Torticollis Blepharospam SD ranges from 1. 4: 1 – 7: 1 ABSD less common n ~ 10 -15 % of SD SPPA 6400 Voice Disorders Tasko

Spasmodic Dysphonia: diagnostic tasks o o o o Connected speech-will exhibit difficulties Sustained vowel n Reduction/resolution of symptoms n less severe than connected speech n 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 o o o Sentences – all voiced n ↑ difficulty Sentences – high frequency voiceless n ↓ difficulty Eighty series (e. g. count 80, 81, 82…) n ↑ difficulty Sixty series (e. g. count 60, 61, 62) n ↓ difficulty repetitions of ‘we’ vs. ‘pea’, ‘tea’, ‘key’, ‘see’ n ‘we’ = ↑ difficulty SPPA 6400 Voice Disorders Tasko

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

ADSD vs. ABSD: Sentence Stimuli All voiced segments…elicits ADSD symptoms o Early one morning a man and a woman were ambling along a one-mile lane running near rainy Island Avenue o 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 o He saw half a shape mystically cross fifty or sixty steps in front of his sister Kathy’s house. o She sells seashells by the seashore. SPPA 6400 Voice Disorders Tasko

ADSD: Other diagnostic tasks o o Ingressive reading of all voiced segments Unilateral RLN Block (lidocaine) n Will eliminate ADDSD within several minutes of ipsilateral paresis/paralysis n lasts about 20 -25 minutes n Should confirm paralysis endoscopically n Return of pre-block symptoms after nerve block effects abate n Recent evidence suggests this does not differentiate ADSD from MTD (Roy, et al. 2007) SPPA 6400 Voice Disorders Tasko

Other signs/symptoms of ADDSD o o o 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… o Severity of sustained vowel often commensurate with connected speech o No obvious differences between voiced and voiceless contexts (all contexts difficult) o Is usually continuous and rarely intermittent (no islands of normal speech) o Shows no improvement with falsetto or singing SPPA 6400 Voice Disorders Tasko

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

Distinguishing SD and MTD Studies of psychologic factors and dysphonia o MTD n o tendency toward introversion and neuroticism SD n n 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 o o 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 o o 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 o Voice Therapy (limited benefit for moderate to severe ADDSD or tremor) Medical o Botulinum Toxin injections (BOTOX) o Neuropharmacological Intervention Surgical o Recurrent Laryngeal Nerve Section o Thyroplasty, myotomy etc. SPPA 6400 Voice Disorders Tasko

When/Who to offer voice therapy? o o o 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 n o BOTOX may provide too great an effect Trial therapy should be short term (< 5 sessions) SPPA 6400 Voice Disorders Tasko

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

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

Botulinum Toxin (BOTOX) SPPA 6400 Voice Disorders Tasko

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

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

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

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

BOTOX Injection Dosage Bilateral o 2. 5 units per side Unilateral o 15 units o Unilateral considered superior, with longer lasting effects SPPA 6400 Voice Disorders Tasko

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

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

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