I had the pleasure of attending a conference on Spasmodic Dysphonia (known as SD) sponsored by the Vanderbilt Voice Center this week. Attendees included voice specialists and teachers as well as sufferers of SD who had traveled long distances to get fresh information about their mysterious and frustrating voice disorder. Instead of being a dry, boring medical recitation, it was fun, full of kindness and caring... and vitally illuminating. This will be the first post in a three-part series on this disorder with information gleaned from the doctors, speech pathologists and speakers with SD at this event. These experts included Charlie Womble, NSDA Board Director, Jennifer Muckala, M.A. CCC-SLP, C. Gailyn Garrett, M.D. (Medical director at Vanderbilt Voice Center), Fenna Phibbs, M.D., Amy Zeller, Ms. CCC-SLP, Brienne Ruel, Gwen Sims-Davis, Jill Van Vliet and several NSDA support group members who have SD. First, dear vocalists: before you self-diagnosis and scare yourself, let me state this firmly: In all probability, you don't have this! But if you did -- or knew someone who did you would want it to be properly diagnosed and to be pointed toward something that could actually help instead of frustrate. Secondly, dear fellow voice teachers and specialists here on TMV: If you have any information and/or experience with treating SD, please share by commenting. Ongoing research is desperately needed and has yet to yield a cure. What is Spasmodic Dysphonia (SD)? SD is a voice disorder that is part of a family of neurological disorders called dystonias. Dystonias cause muscles to contract and spasm involuntarily. There are five forms and combinations SD can take:
- Adductor spasmodic dysphonia (AdSD), which is by far the most common, is where the adductor vocal muscles (thyroarytenoid or TA muscles) are too active and spasm frequently on voiced speech sounds like vowels in the words "eat, back, in, I, olives, nest". The voice has a strained, strangled sound.
- Abductor spasmodic dysphonia (AbSD) occurs where the adductor vocal muscles (crycothyoid or CT muscles) are too active and spasm on voiceless speech sounds like "f, K, c, t, h, th." The voice is very breathy and the person feels short of breath when they talk. It is also often accompanied by chronic constriction: grabbing and holding of the vocal folds.
- Mixed spasmodic dysphonia presents both the symptoms of AdSD and AbSD.
- SD with tremor includes a tremor in the voice. In this case, the SD problem is compounded and accompanied by a separate disorder a tremor. The voice will have a rhythmic fluctuation, when sounding vowels, if a tremor is present.
- And lastly, SD may be mixed with -- or misdiagnosed as -- muscle tension dysphonia (MTD). This sometimes happens when a person with AdSD tries to control their vocal folds, holding them too tight and causing a chronic tension to occur. MTD, unlike SD, is functionally based and can be cured by modifying behavior (vocal re-training).
SD is maddenly consistently inconsistent, which means that it doesn't necessarily happen all the time, or happen in the same way. Sometimes you can fake it out for a while by speaking in a pitch or accent you don't normally use. One of the panel members with SD demonstrated in a hilarious Swiss accent that she could speak without spasm when she did this. A speech therapist expert in this field said that this would only be a temporary fix; if the person began speaking the new way all the time, the spasm would return. The speakers at this conference were unanimous in saying that SD is NOT a psychological disorder. It is a neurological one. What's the difference? A psychological disorder can be treated by learning different thought patterns. A neurological one is physiological: re-training treatment can mask symptoms, but is limited in what is possible. It's like an uncontrollable muscle twitch. There is something wrong in the wiring of the brain itself, which manifests in the end-organ, in this case, the larynx. It can, however, be exacerbated by stress, so there is a psychological component to it. Posts to come: What causes SD? How is SD diagnosed? What are the treatments for SD? What can a vocal coach do to help? This essay first published July 9, 2009 on The Modern Vocalist.com the Internet's #1 community for vocal professionals, voice health practitioners and pro-audio companies worldwide since November 2008.