SPPA 6400 Voice Disorders Tasko Spasmodic Dysphonia

SPPA 6400 Voice Disorders Tasko

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


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


Other Examples of Focal Dystonia?

Blepharospasm Writer’s cramp Torticollis (cervical dystonia)


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


Potential Neural Mechanisms Reduced neural inhibition Increased neural plasticity Abnormal sensory gating


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


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


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)



Spasmodic Dysphonia & Related Disorders: Epidemiology Prevalence of focal dystonia: 295 per million Prevalence of SD: 1 per 100,000 Prevalence ranking for focal dystonia

1. Torticollis2. Blepharospam3. SD

Females > Males ranges from 1.4:1 – 7:1

ABSD less common ~ 10-15 % of SD


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


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


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


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.


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.


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)


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)


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



MTD… Is associated with reported pain, tenderness Is not associated with tremor Shows sustained improvement after manual

circumlaryngeal therapy



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


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


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


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.


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)


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


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


Botulinum Toxin (BOTOX)



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



Who benefits most? Moderate to severe ADDSD Vocal tremor ABSD ?

Patients who get questionable benefit Mild ADDSD Coexisting regional dystonia


BOTOX Injections: Procedures

Peroral Injection via oral cavity Uses less toxin No EMG verification

Percutaneous Through the neck tissue Uses EMG verification


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


BOTOX Injection Dosage

Bilateral 2.5 units per side

Unilateral 15 units Unilateral considered superior, with longer lasting

effects


Surgical Management:Recurrent Nerve Resection

Advantages Potential long term benefit (40%)Disadvantages Unpredictable side effects Symptom return (up to 60%) Permanent unilateral paralysis ControversialPatient types benefited Focal severe ADDSD


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


Selected CNS diseases ALS Parkinson’s Disease Myasthenia gravis

Documents

SPPA 6400 Voice Disorders Tasko Spasmodic Dysphonia