Laryngeal Dystonia (LD) - also called spasmodic dysphonia - is a voice disorder that leads to strained or choked speech. Current therapeutic options for treating LD are very limited. LD does not respond to conventional speech therapy and is treated primarily with Botulinum toxin injections to provide temporary symptom relief. There is no cure for LD.
Vibro-tactile stimulation to treat the voice symptoms of LD
Vibro-tactile stimulation (VTS) is a non-invasive neuromodulation technique that our laboratory developed for people with LD. In a first study, supported by the National Institutes of Health, our team documented that a one-time 30-minute application of VTS over the laryngeal area can result in measurable improvements in the voice quality of people with LD. The effects of VTS are very immediate, that is, can happen within minutes. We could show that LD is associated with atypical patterns of cortical activity during voice production: (1) a reduced movement-related desynchronization of motor cortical networks, (2) an excessively large synchronization between left somatosensory and premotor cortical areas. We could further demonstrate that VTS induced a significant suppression of theta band power over the left somatosensory-motor cortex and a significant rise of gamma rhythm over right somatosensory-motor cortex. That is, there is a fast neural response to VTS observable in brain areas involved in speech production. These results have been published in the journals Clinical Neurophysiology and Scientific Reports.
A clinical trial to assess the longitudinal effects of VTS
In a second research study also funded by the National Institutes of Health, we investigated systematically the possible longer-term benefits of this approach for improving the voice symptoms of people with LD. Study participants administered VTS at home for up to 8 weeks. In addition, researchers assessed their voice quality and monitored the corresponding neurophysiological changes in the brain using electroencephalography in the laboratory at the beginning, in the middle and at the end of the VTS in-home training. The main findings were that up to 57% of participants showed a meaningful improvement in an objective voice measure (Cepstral Peak Power) or a reduction in perceived voice effort. These results inform patients and clinicians about the possible impact of this therapeutic approach. It promotes the development of wearable VTS devices that would enlarge the available therapeutic arsenal for treating voice symptoms in LD. The first findings of this longitudinal study are published in the open-access journal Frontiers of Neurology.
This study has been registered at ClinicalTrials.gov ID: NCT03746509
Note: This clinical trial has stopped recruiting new participants.
Determining the usability of in-home application of laryngeal VTS
This study aimed to get insights in how people with laryngeal dystonia used our vibration device at home over a 2-month period. Participants follow a specific study protocol where they increased the weekly dosage of VTS over a period of 4 weeks. A total of 32 participants monitored the changes in their voice and recorded their user experience. One cohort of participants taped the vibrators to the skin, while the second cohort used a wearable collar with embedded vibrators to apply laryngeal VTS. Results from exit interviews showed that people much preferred the collar versus the taping the vibrators on the skin. Preliminary data analysis indicated that the effectiveness of receiving vibration via the collar is equally effective than direct skin vibration.
This study has been registered at ClinicalTrials.gov ID: NCT06111027.
Note: This clinical trial has stopped recruiting new participants.
Some testimonials from study participants
When I received the vibration I noticed that it elongated the effects of the Botox I received. I did not need to return as often to my otolaryngologist for injections.
I found the VTS to be beneficial in helping to alleviate some of my SD symptoms. Further funding is necessary to develop a practical device that can be of help to other SD patients and offer an alternative to the typical Botox injections. I will be first in line to test this new VTS collar.
I found over time that producing ordinary conversation was less effortful.
Less breathy and able to talk louder. When talking to a classroom, I was able to project, without having to repeat myself. I was/am able to speak better for a few days.
Yes, the more I have used the device, the more my voice has been toned and I have been able to master it. This is the first time I have such a good voice quality and I see it lasts even with a light Botox injection (1 unit) in only one vocal cord.
Contact us
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Team members
Members of our interdisciplinary research team include Dr. Peter Watson, a voice disorder specialist, and Dr. Yang Zhang, an expert in the analysis of cortical activity during speech. Both are faculty in the U of M Department of Speech, Language and Hearing Sciences. Dr. George Goding from Otolaryngology represents the clinical partner in the team. He is an expert in LD and treats these patients regularly in the U of M Lion’s Voice Clinic. Dr. Divya Bhaskaran, Dr. Naveen Elangovan, Shima Amini and Dr. Cagla Ozkul from HSCL complement the team.
Contact information
Dr. Jürgen Konczak, Ph.D. is the principal investigator of these studies. You can contact him at [email protected]. Ms. Shima Amini is the clinical research coordinator. She can be reached at [email protected].
Watch webinar from Dysphonia International