Generally, an ENT (ear, nose, and throat) specialist, or otolaryngologist, and a speech language pathologist will perform a comprehensive exam, including a review of the patient’s medical history and symptoms and a visualization of vocal fold movement using a special camera called a flexible laryngoscope through the nose. The patient may be asked to read or repeat several phrases so the physician can assess different voice qualities (i.e., overall severity, breaks, roughness, strain, breathiness). SD is diagnosed by listening to the specific voice changes during these speech tasks and distinguishing it from other types of hoarseness, in addition to examining the larynx.
There is no cure for SD. Treatments are often focused on decreasing the spasms or by improving control of the associated symptoms. Specific treatment options depend on each patient but may include:
Botulinum toxin A injections—Botulinum toxin A (Btx A) is injected into the laryngeal muscles that control the opening (abduction) and closing (adduction) of the vocal cords. Btx A blocks nerve impulses at the muscle receptor site. This weakening of the injected muscle(s) is only temporary, varies from person to person, and is based on dosage, but the average duration of the effect is three to four months. Possible side effects are usually brief and include a breathy or whispery voice, difficulty swallowing, or pain/soreness at the site of injection. Commonly, Btx A injection to the vocal cords results in a period (approximately two months) of close-to-normal voice for many ADSD patients. Btx A is the most reliable and thoroughly evaluated treatment for SD.
Voice therapy—Voice therapy cannot cure SD, but with the help of a speech language pathologist patients may be able to learn how to readjust breathing patterns, phonation, resonance, and articulation to make their voice work more efficiently and to better manage symptoms, such as breaks, strain, roughness, and breathiness. Voice therapy should incorporate individual goals, such as strategies for speaking in groups, speaking on the phone, speaking with less effort, and managing quality of life issues associated with SD.
Surgical options—Several surgical options have been used to try to treat SD, yet surgery for SD remains a controversial topic. Most procedures are designed to treat ADSD. In Type II Thyroplasty surgery, the surgeon separates the vocal cords slightly to reduce the severity of spasms, which can result in a weaker or breathier voice. Another procedure, called Selective Laryngeal Adductor Denervation-Reinnervation (SLAD-R), involves cutting the nerves to the vocal cord muscles and reinnervating those muscles with a different nerve. Long-term studies have not been published on the results of these surgeries for SD.