Spasmodic Dysphonia
Diagnosis and Neurological Basis
of Spasmodic Dysphonia
Christy L. Ludlow, Ph.D.
Clinical Neurosciences Program
NINDS, National Institutes of Health
Bethesda, MD, USA
Adductor Spasmodic Dysphonia
• Intermittent spasms in the
thyroarytenoid & lateral cricoarytenoid
during vowels
Lateral
squeeze
Anterior-posterior
shortening
Abductor Spasmodic Dysphonia
Less common
Difficulty initiating vowel after voiceless
sound, prolonged h. p, t, k, s f,
Intermittent breathiness
Increased Abduction
may be on one side only during speech
Posterior
Cricoarytenoid
• Rare, 1-2/100,000
• Onset in middle life, idiopathic (weak genetic
predisposition), doesn’t respond to voice therapy
• 70-80% women
• Only affects speech,
• Whisper, crying and laughter all normal
• Gradual increase in voice breaks
• Chronic life long disorder
• 3 Types-adductor (vowel breaks)
• Abductor (prolonged voiceless consonants)
• Voice tremor in 60%
Adductor Sentences
(words beginning with vowels)
1. Tom wants to be in the army.
2. We eat eels every day.
4. I hurt my arm on the iron bar.
5. Are the olives large?
6. John argued ardently about honesty.
7. We mow our lawn all year..
Abductor Sentences
voiceless consonants h, s, p, t, k
1. He is hiding behind the house.
2. Patty helped Kathy carve the turkey.
3. A mahogany highboy isn't heavy
4. Boys were singing songs outside of our house.
5. The puppy bit the tape
6. Sally fell asleep in the soft chair.
7. The policy was suggested in an essay on peace
1
• Continuous harshness alone– Muscular
Tension Dysphonia-use voice therapy
– No intermittent voice breaks
• Continuous breathiness alone– paresis or
psychogenic
– No increased difficulty on voiceless consonants
• Other diagnoses to be excluded ,
– peripheral neuropathy,-breathy voice
– Parkinson disease,-breathy voice
– multiple sclerosis, -spastic voice
– cerebellar ataxia-spastic voice
-- myasthenia gravis-breathy voice
Possible Spasmodic
Dysphonia
Screening questions to patient
1. Is it a lot of work for you to talk?
(yes for SD)
2. Does your speech change?
(good and bad periods, never normal)
3. How long has it been an effort for you to talk ?
(more than 3 months)
4. Can you laugh, cry, shout , whisper, and yawn
normally?
(yes, for SD)
Nasoendoscopy for Definite Diagnosis of
Spasmodic Dysphonia
Only use decongestant no anesthesia which can reduce
symptoms
1. No anatomical defects of the larynx
(laryngeal structure is normal SD)
2. Normal vocal fold movement during respiration and nonvoice tasks e.g. whistling and coughing
(Sometimes see vocal fold asymmetry during speech
but not non-speech)
3. Examine for tremor during the prolonged vowels /i/ and /u/
(more than 1/3 of SD patients also have tremor)
4. Intermittent adductor or abductor vocal fold spasms during
either adductor or abductor sentences.
Diagnostic Criteria for
Spasmodic Dysphonia
• Workshop on spasmodic dysphonia June 2005,
developed consensus definition
• Ludlow, et al. Research priorities in spasmodic
dysphonia. Otolaryngol Head Neck Surg 2008;139:495505.
• Decided on three levels of diagnosis
– Possible, based on patient’s report
– Probable, based on clinical exam of voice symptoms
– Definitive, based on NIH nasolaryngoscopy during speech and
other movement tasks
Probable Diagnosis of Spasmodic
Dysphonia –Speech Analysis
1 . Count number of breaks in sentences
(at least 1 break in 3 sentences)
2. Rate the degree of strained choked voice
(Usually intermittent except in very severe
cases)
3. Listen for voice tremor in a prolonged
vowel
(usually around 5 oscillations per second)
4. The patient should laugh, cry, shout ,
whisper, or yawn normally
Pilot Study results 97% accuracy
conducted 2007
Canonical Scores Plot
9
7
FACTOR(2)
When is it not spasmodic
dysphonia?
5
3
1
-1
Groups
MTD
SD
Tremor
-3
-5
-5
-3
-1
1
3
5
7
9
FACTOR(1)
Ludlow, et al. Otolaryngol Head Neck Surg 2008;139:495-505.
2
Neurological Control of the
Larynx for Voice Production
Motor Control for
Voice
Central Nervous System
Brain
Brain stem
Spinal Cord
Peripheral Nervous System
Motor Nerves
Sensory Neurons and Nerves
Motor Cortex
From Penfield &
Roberts, 1959
Electrical stimulation of motor cortex
Elicits Vocalization
Motor Control
for Voice
Disrupts Vocalization
Proposed Motor
Area for
Laryngeal
Muscles
Based on
Simonyan &
Jürgens, 2003
Penfield & Roberts, 1959
Motor Control Cortical
for Voice
Regions Active for Voice
During Speech in Humans
Brain control for voice for speech,
Loucks et al., NeuroImage, 2007
voiced
unvoiced
Laryngeal muscle
control
Huang et al, Human Brain
Mapping 2002;15:39-53.
Auditory
Laryngeal muscle
control
Thalamus
3
Central Nervous System- The Motor Pathway
The Cortico-Bulbar System rapidly conducts
to the Laryngeal Muscles in ~12 ms
V
Motor Contex
Corticobular pathway
Stimulate at cortex
Left SLN
Left RLN
Brain stem
NA
50
200 µV
S
10 ms
15 ms
Laryngeal Muscle Response
Basal Ganglia and Thalamus: Modulation of Motor and Sensory Control
cortex
D2
D1
excitatory
inhibitory
Deep brain stim
In dystonia
Regions of interest in SD
Simonyan et al., presented at the Society for
Neuroscience 2007, comparing ADSD and ABSD
ADSD vs controls during whimper
Cortical control of
the Laryngeal muscles
ABSD vs controls during whimper
Internal capsule
Pallidum
ADSD vs controls during breathing
ABSD vs controls during breathing
thalamus
4
Comparison of ADSD and ABSD
very similar pattern of brain function differences
Simonyan et al 2007, Brain
DTI Study showing white matter
abnormalities in ADSD
Diffusion tensor Imaging: measuring axon
alignment in white matter tracts
Axonal Thinning in the Genu of the Internal Capsule
Head and neck region of the internal capsule
Similar Findings of White Matter
abnormalities in other dystonias
• Carbon et al., 2004 in
persons carrying the
DYT1 mutation
Simonyan et al., also found Structural
Differences in the Thalamus and Cerebellum
in Spasmodic Dysphonia
Increased Mean > Diffusivity in Thalamus and cerebellum
5
Relationship of severity of SD and Increased
Diffusivity in the Thalamus
Increased diffusivity in the thalamus and
basal ganglia in cervical dystonia
Increased breaks in patients with increased diffusivity
Leonardo Bonilha et al., 2007 Structural white matter
abnormalities in cervical dystonia (torticollis)
Areas for Study in Post Mortem
brains
Studies of a post Mortem Brain of a
Patient with Adductor SD
Axonal Thinning in the Internal Capsule
Region in internal capsule
control
Patient with SD
Internal capsule
thalamus
Simonyan et al., Brain 2007
Axonal Thinning in the Genu of the Internal Capsule
High resolution studies in basal
Ganglia in SD brain
Internal capsule
Pallidum
thalamus
6
Deposits in Brain Tissue of SD
patient
Putamen
Pallidum
Internal Capsule
Some accumulation of mineral deposits in the brain of a SD patient in
Regions showing functional and structural abnormalities in SD
Research needs
•
•
•
•
To diagnose SD identify the brain abnormalities
Use 7Tesla to confirm abnormality in individuals
Find a biomarker for the disease
To prevent/cure SD—to stop the development of
spasmodic dysphonia we need to know what
causes abnormal deposits in the internal
capsule, basal ganglia and cerebellum
– Now need to know what has produced those deposits
– Can we reverse the process?
Simonyan et al., Brain 2007
7