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Spasmodic Dysphonia Workup

  • Author: Michael J Pitman, MD; Chief Editor: Arlen D Meyers, MD, MBA  more...
Updated: May 01, 2015

Laboratory Studies

Laboratory tests are generally unnecessary.


Imaging Studies

CT scanning with gadolinium or MRI: Reserve brain imaging for patients with focal findings upon neurologic examination that are beyond the distribution of spasmodic dysphonia (SD).


Other Tests

A study by Creighton et al indicated that the diagnosis of spasmodic dysphonia can be delayed by years owing to a lack of physician awareness of the condition and the need for well-defined diagnostic criteria. The study, in which 107 patients with spasmodic dysphonia answered questionnaires concerning diagnosis and treatment, found that diagnosis of the condition took an average of 4.43 years after patients first saw a physician for vocal symptoms. Patients also required visits to an average of 3.95 physicians before receiving the correct diagnosis.[16]

Neurologic examination

The occurrence of other neurologic signs not associated with other dystonias or tremor suggests that spasmodic dysphonia (SD) is secondary to another disease process. The neurologic examination may also reveal signs of other neurologic disorders that may be misconstrued as spasmodic dysphonia (SD).

Perceptual analysis

Grade, roughness, breathiness, atonicity, and strain (GRBAS) is the evaluation system currently used to evaluate perceptual judgment. GRBAS involves a scale of 0-3 (0 = normal or absence of deviance; 1 = slight deviance; 2 = moderate deviance; 3 = severe deviance).

Conversational speech or the reading of a passage is rated. The classic perceptual sign of spasmodic dysphonia (SD) is abnormal voice quality that is heard in contextual speech but not necessarily in singing, whispering, laughing, falsetto voice, or crying.

Sentences that elicit adductor breaks when spoken include the following:

  • "I eat apples and eggs."
  • "The dog dug a new bone."
  • "We mow our lawn all year."
  • "Early one morning, a man and a woman were ambling along a 1-mile lane, running near Rainy Island Avenue."

Sentences that elicit abductor breaks when spoken include the following:

  • "How high is Harry's hat?"
  • "Did he go to the right or to the left?"
  • "When he comes home, we'll feed him."
  • "He saw half a shape mystically cross a simple path, at least 50 or 60 steps in front of his sister Kathy's house."

Acoustic analysis

Acoustic measures reflect the status of vocal function. Standard deviation of the fundamental frequency or jitter (measured in ms) and amplitude modulation or shimmer are significantly higher in patients with spasmodic dysphonia (SD). The signal-to-noise ratio is generally lower in patients with spasmodic dysphonia (SD) than in healthy control subjects.

Aerodynamic analysis

Aerodynamic analysis of voice production includes the measurement of airflow and air pressure and their relationships during phonation.

In adductor spasmodic dysphonia (SD), mean airflow rates range from normal to extremely low.

In abductor spasmodic dysphonia (SD), mean phonatory airflow rate is generally above normal, with bursts of airflow occurring with the abductor spasm.

Subglottic pressure measures were estimated to be higher than normal in patients with adductor spasmodic dysphonia (SD).

Electromyographic analysis

In 2001, Hillel demonstrated that all the laryngeal muscles are involved in spasmodic dysphonia using examination with hooked wired electrodes.[17]

Either abductor or adductor muscle spasms are believed to predominate, resulting in the corresponding symptoms. EMG is generally not used in diagnosing spasmodic dysphonia (SD). In experienced hands, EMG guidance may not be necessary.[18]

Subjective evaluation by patient

The purpose of a subjective self-evaluation is to determine the deviance of voice quality and the severity of disability or handicap in daily professional and social life and to determine the possible emotional repercussions of the dysphonia.


Diagnostic Procedures


Videolaryngostroboscopy is the main clinical tool used in determining the origin of voice disorders. Abductor and adductor spasms can be visualized during voice breaks. This procedure can also be used to assess the quality of vocal fold vibration to evaluate treatment effectiveness.

Contributor Information and Disclosures

Michael J Pitman, MD Assistant Professor of Otolaryngology, New York Medical College; Director, Division of Laryngology, Director, The Voice and Swallowing Institute, Department of Otolaryngology, The New York Eye and Ear Infirmary

Michael J Pitman, MD is a member of the following medical societies: Alpha Omega Alpha, Voice Foundation, American Academy of Otolaryngology-Head and Neck Surgery

Disclosure: Nothing to disclose.


Soly Baredes, MD Professor and Chairman, Department of Otolaryngology-Head and Neck Surgery, Rutgers New Jersey Medical School; Director of Otolaryngology-Head and Neck Surgery, University Hospital

Soly Baredes, MD is a member of the following medical societies: American Academy of Otolaryngology-Head and Neck Surgery, American College of Surgeons, American Head and Neck Society, American Laryngological Association, The Triological Society, American Medical Association, North American Skull Base Society, Society of University Otolaryngologists-Head and Neck Surgeons, Triological Society, New York Head and Neck Society, New York Laryngological Society, New Jersey Academy of Otolaryngology-Head and Neck Surgery, The New Jersey Academy of Facial Plastic Surgery, International Skull Base Society

Disclosure: Nothing to disclose.

Ameet R Kamat, MD Staff Physician, Department of Otolaryngology, New York Eye and Ear Infirmary

Ameet R Kamat, MD is a member of the following medical societies: Alpha Omega Alpha, Phi Beta Kappa

Disclosure: Nothing to disclose.

Specialty Editor Board

Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Received salary from Medscape for employment. for: Medscape.

Erik Kass, MD Chief, Department of Clinical Otolaryngology, Associates in Otolaryngology of Northern Virginia

Erik Kass, MD is a member of the following medical societies: American Academy of Otolaryngology-Head and Neck Surgery, American Medical Association, American Association for Cancer Research, American Rhinologic Society

Disclosure: Nothing to disclose.

Chief Editor

Arlen D Meyers, MD, MBA Professor of Otolaryngology, Dentistry, and Engineering, University of Colorado School of Medicine

Arlen D Meyers, MD, MBA is a member of the following medical societies: American Academy of Facial Plastic and Reconstructive Surgery, American Academy of Otolaryngology-Head and Neck Surgery, American Head and Neck Society

Disclosure: Serve(d) as a director, officer, partner, employee, advisor, consultant or trustee for: Cerescan;RxRevu;SymbiaAllergySolutions<br/>Received income in an amount equal to or greater than $250 from: Symbia<br/>Received from Allergy Solutions, Inc for board membership; Received honoraria from RxRevu for chief medical editor; Received salary from Medvoy for founder and president; Received consulting fee from Corvectra for senior medical advisor; Received ownership interest from Cerescan for consulting; Received consulting fee from Essiahealth for advisor; Received consulting fee from Carespan for advisor; Received consulting fee from Covidien for consulting.

Additional Contributors

Anthony P Sclafani, MD Director of Facial Plastic Surgery and Surgeon Director, New York Eye and Ear Infirmary of Mt Sinai; Professor of Otolaryngology, Icahn School of Medicine at Mt Sinai

Anthony P Sclafani, MD is a member of the following medical societies: American Academy of Facial Plastic and Reconstructive Surgery, American Academy of Otolaryngology-Head and Neck Surgery, American College of Surgeons

Disclosure: Received salary from Aesthetic Factors, Inc. for consulting; Received consulting fee from Meditech Medical Enterprises for independent contractor; Received royalty from Thieme Medical Publishers for author; Received royalty from Jaypee Medical Publishers for author.


Darius Bliznikas, MD Staff Physician, Department of Otolaryngology, Wayne State University School of Medicine

Darius Bliznikas, MD is a member of the following medical societies: Sigma Xi

Disclosure: Nothing to disclose.

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Thyroarytenoid injection for adductor spasmodic dysphonia. Needle is advanced through the cricothyroid membrane.
Posterior cricoarytenoid (PCA) injection for abductor spasmodic dysphonia. Needle is advanced through the inferior constrictor muscle to the PCA muscle.
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