Progression from symptom onset to the diagnosis of spasmodic dysphonia

People with SD initially notice either a gradual or sudden onset of difficulty in speaking. They may hear breaks in their voice during production of certain words or speech sounds, breathy-sounding pauses on certain words or sounds, or a tremulous shaking of the voice. They may feel that talking requires more effort than before. Often people say that their voice sounds as if they “have a cold or laryngitis.”

The symptoms of SD can vary from mild to severe. A person’s voice can sound strained, tight, strangled, breathy, or whispery. The spasms often interrupt the sound, squeezing the voice to nothing or dropping it to a whisper. Stress probably does not cause SD, but it can worsen the spasms.

Onset is usually gradual with no obvious explanation. Symptoms occur in the absence of any structural abnormality of the larynx, such as nodules, polyps, carcinogens, or inflammation. People have described their symptoms as worsening over an approximate 18-month period and then remaining stable in severity from that point onward. Some people have reported brief periods of remission, however this is very rare and the symptoms usually return.

Getting a proper diagnosis-where to start

Spasmodic dysphonia can be difficult to diagnose because the anatomy of the larynx is normal. SD has no objective pathology that is evident through x-rays or imaging studies like a CT or MRI scan, nor can a blood test reveal any particular fault. In addition, several other voice disorders may mimic or sound similar to it. The excessive strain and misuse of muscle tension dysphonia (MTD), the harsh strained voice of certain neurological conditions, the weak voice symptoms of Parkinson’s disease, certain psychogenic voice problems, acid reflux, or voice tremor are often confused with SD. Therefore, the best way to diagnose the problem is to find an experienced clinician with a good ear.

Getting a diagnosis can be a team effort. This is why it is important to prepare before you visit your physician and be prepared to communicate effectively. Don’t hesitate to ask any questions needed in order to fully understand your diagnosis. This applies to dealing with your initial diagnosis, the frustrations of treating your SD, and how to effectively cope.

What to expect during the exam

After taking the medical history, your medical professional will listen carefully to your speech to identify specific signs of SD, such as voice breaks. To help differentiate the condition and sub-type, they often ask the patient to read and speak specific phrases and sentences loaded with certain types of sounds. While additional evaluations may help to determine the diagnosis, often times, the experienced clinician expert’s perceptual analysis usually serves as the basis for making the SD diagnosis.

The physical examination continues by looking at the larynx in action. Even though the person with SD often has a normal anatomy, the physician should look at the larynx to rule out other common laryngeal disorders that can result in a hoarse voice. These include a wide variety of conditions that range from benign issues such as vocal cord nodules or polyps, to more concerning conditions such as vocal cord cancer.

Fiberoptic Laryngoscopy

One way to view the larynx is to insert a rigid endoscope, a straight, narrow metal rod containing a variety of lenses, through the mouth and toward the back of the throat while the person is saying “eeeee.” In this manner, the otolaryngologist obtains a close-up view of the structures of the larynx and the movement of the vocal folds.

Another common approach to viewing the vocal folds involves the use of a flexible endoscope. In this method, a very narrow, flexible tube with a lens is inserted through one nostril, around the back of the nose and down through the throat. This allows the doctor to evaluate the movements of the larynx while the person is speaking or singing.

Videostroboscopy

Usually these endoscopic examinations are performed with a specialized flickering light called a “stroboscope,” which allows the clinician to further evaluate the rapid fine movement of the vocal folds. These evaluations can be recorded for both the clinician and patient to review after the examination.

In addition to these tests, the otolaryngologist may recommend a laryngeal electromyography (EMG) test to obtain specific information about the specific muscles involved. The EMG test involves inserting a thin needle electrode through the neck into the muscles of the larynx and evaluating the electrical activity of the muscles at rest and during speaking. While some fine the EMG helpful, there are no specific types of signals that are diagnostic of only SD. With a confirmed diagnosis, the doctor can work with you to find the best course of treatment for your symptoms.

Electromyography

Once a diagnosis of SD is made, you should continue to take an active role in your health care. Ask questions, record the answers, get second opinions when necessary, and become fully educated about the condition and the treatment options.

Spasmodic dysphonia is estimated to affect approximately 50,000 people in North America, but this number may be inaccurate due to ongoing misdiagnosis or undiagnosed cases of the disorder. Although it can start at any time during life, SD seems to begin more often when people are middle-aged. The disorder affects women more often than men.

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