This will be the first post in a 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, 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'd want it to be properly diagnosed and be pointed towards something that could actually help instead of frustrate. So here goes my first post...
Here are five forms of SD:
- 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... where symptoms of both AdSD and AbSD are present.
- SD with tremor... where there is also a tremor in the voice. In this case, the SD problem is compounded and accompanied by a separate disorder... 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).
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 is limited in effectiveness. There is something wrong in the wiring of the brain itself... which manifests in the end-organ, in this case, the larynx.
Posts to come: What Causes SD? How is SD Diagnosed? What are the treatments for SD? What can a vocal coach do to help?