Voice Matters! Q & A with Dr. Kristina Simonyan, Voice Researcher and NIDCD Grantee
Kristina Simonyan, M.D., Ph.D.
Credit: Kristina Simonyan,
Icahn School of Medicine at Mount Sinai
Kristina Simonyan, M.D., Ph.D., is an associate professor of neurology and otolaryngology at the Icahn School of Medicine at Mount Sinai in New York. She initially trained as a physician, obtaining her M.D. from Yerevan State Medical University in 1998, but changed course part way through her otolaryngology residency and entered the world of biomedical research. She obtained her Ph.D. in 2003 from the German Primate Center and TiHo University of Hannover, where she studied with Uwe Jurgens, world-renowned voice researcher.
She followed up with a fellowship at NIH's National Institute of Neurological Disorders and Stroke, and today leads a research team at Mount Sinai focused on the brain mechanisms that control voice. In particular, her group seeks to understand the neurological basis for spasmodic dysphonia, a condition that affects the laryngeal muscles—the muscles inside the vocal folds of the larynx (or voice box)—and hampers speaking ability. In spasmodic dysphonia, the muscles inside the vocal folds experience sudden involuntary movements (spasms) that interfere with the ability of the folds to vibrate and produce voice.
To help us mark World Voice Day on April 16, 2014, we asked Dr. Simonyan to tell us about spasmodic dysphonia and her research on the disorder.
Can you tell me a little bit about spasmodic dysphonia?
Spasmodic dysphonia is one of the disorders that come under the umbrella of primary dystonias. These are disorders that cause involuntary movements and twisting in various body parts, which are sometimes very painful and uncomfortable for people. In spasmodic dysphonia, the muscle spasms occur in the laryngeal muscles, the muscles in the voice box.
Illustration of the neurological connections
in the brain controlling speech production.
Credit: Stefan Fuertinger and Kristina Simonyan,
Icahn School of Medicine at Mount Sinai
What goes wrong in the vocal folds of people with spasmodic dysphonia?
The interesting thing is that there is nothing wrong with the larynx or the vocal folds. Anatomically there are no lesions and no damage, and the larynx functions normally when it is free of spasms. It's a neurological condition, so what's happening in the larynx is a reflection of what's happening in the brain.
How do people get spasmodic dysphonia?
We know that there are genetic factors that contribute to the development of certain kinds of dystonia. In spasmodic dysphonia, there are families that have passed this condition down for generations, but we don't know the genes involved yet. We also know that environmental factors may contribute, but again, we haven't specifically identified them. There is also a gender difference. Spasmodic dysphonia affects women more than men, with a ratio of four to one, but we still don't understand why. It is a disorder whose manifestations depend on several factors.
Can you describe the impact of the disorder on patients?
Spasmodic dysphonia is extremely difficult on patients. The symptoms usually start at around 40 to 45 years of age, when many people are at the peak of their careers. It's especially hard if your career depends on your voice, like a singer, but it's difficult for all patients because they can't communicate effectively, and they feel isolated. I have patients who can't even say their names without breaking on each syllable.
How is the disorder treated?
Injection of botulinum toxin, or Botox, into the laryngeal muscles is the gold standard treatment for spasmodic dysphonia, but there are side effects. For a few weeks following treatment, patients can experience difficulty breathing, swallowing, and speaking. Botox acts by paralyzing the laryngeal muscles, so it affects all functions of the larynx. After experiencing a few weeks of side effects, patients usually have a few weeks of improved voice. But then the effect of Botox wears off and symptoms reappear. Out of a cycle that lasts three or four months patients have only about one month of improved voice when they can communicate easily. This is one of the downsides of Botox.
There are no specific oral medications for treating spasmodic dysphonia, so the available treatments target the management of symptoms rather than treating the disorder itself.
What was known about spasmodic dysphonia when you first started working on it?
When I started working with patients with spasmodic dysphonia about 10 years ago we didn't know very much about the brain pathways and mechanisms involved in this disorder. We knew that it was a neurological condition and that it was part of a larger group of dystonias, but there were no apparent lesions like those you can see on an MRI following a stroke or when someone has a tumor. There were also no known genes for this condition, so it was very difficult to look into the causes of this disorder. It was like a black box.
What aspect of spasmodic dysphonia are you working on now?
Based on large clinical studies, 10 to 12 percent of people with spasmodic dysphonia have an affected family member, so we're looking at these patients to look for genes associated with the disorder and if there are any brain abnormalities linked to their genetic status that we can detect. We are interested in how genes influence abnormal brain patterns in these patients and how they may be passed down for generations.
We're also looking at people who have the sporadic form of the disorder—people who don't seem to have other affected family members. We'd like to know if there are any differences between sporadic and familial cases at multiple levels, such as behavioral, clinical, genetic, and brain structure and function, and whether we can predict the development of spasmodic dysphonia in other family members.
Another part of my research is directed at understanding the brain effects of a novel drug, sodium oxybate, or Xyrem, which we found to be effective in some patients with spasmodic dysphonia. [Xyrem is approved by the U.S. Food and Drug Administration for the treatment of narcolepsy, a sleep disorder.] We don't fully understand how it works to reduce the spasms, but it might be a promising medication for some patients.
If you succeed in identifying genes linked to spasmodic dysphonia, what will be the next step?
A question that I often get from patients is will my child or grandchild get spasmodic dysphonia, and I don't know the answer. That's why we're doing this genetic study. We're trying to see if there's something that can be predictive of the condition for subsequent generations. We hope that we will be able to identify specific gene mutations in these patients that we can use as markers for prediction of the disorder. Knowing the genes involved could also lead us to new strategies for treating the condition.
What are your hopes for World Voice Day?
Voice is something that is extremely important for us as a means of communication, but it's something that we take for granted. We can express our thoughts, our worries, our joys, our fears—everything, through our voices. World Voice Day is a wonderful opportunity to raise awareness about the importance of having a voice. It also helps raise awareness of disorders, such as spasmodic dysphonia, that affect voice and speech. Not very many people know about these disorders but they profoundly affect patients and the people who surround them.