Thalamic Deep Brain Stimulation for Spasmodic Dysphonia- DEBUSSY Trial

Study Overview
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Brief Summary
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Laryngeal Dystonia (LD), also commonly referred to as spasmodic dysphonia, is a neurological voice disorder characterized by involuntary dystonic contractions of the laryngeal muscles. Current treatments such as botox and voice therapy only provide temporary relief and thus, the investigators are exploring new strategies to provide long-term, sustained improvement. Deep Brain Stimulation (DBS) is a neurosurgical procedure that involves the implantation of electrodes to deliver electrical stimuli to specific brain regions. It is the standard surgical treatment for many other movement disorders such as Parkinson's disease, essential tremor, and primary dystonia. This trial has been designed to test the hypothesis that DBS can improve the vocal dysfunction of LD.

Official Title
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Thalamic Deep Brain Stimulation for Spasmodic Dysphonia: A Prospective, Randomized, Double-Blinded, Sham-Controlled Trial

Conditions
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Spasmodic Dysphonia, Laryngeal Dystonia, Deep Brain Stimulation

Intervention / Treatment
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* Device: VIM Thalamic Deep Brain Stimulation ON
* Device: VIM Thalamic Deep Brain Stimulation OFF


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Clinically diagnosed isolated laryngeal dystonia (adductor spasmodic dysphonia) Able to give informed consent Patients who fall into the age range of 18-75 years old Patients with inadequate medical and BTX management of spasmodic dysphonia Exclusion Criteria: Dystonia present in other body parts (i.e- eyes, neck, limbs) in addition to larynx History of laryngeal denervation surgery for spasmodic dysphonia History of intracranial pathology (such as multiple sclerosis, tumors, or aneurysms) that may account for dystonia or essential tremor. History or evidence of ongoing psychiatric or neurodegenerative disorders (such as Parkinson's disease, Alzheimer's disease). Incompetent adults or those unable to communicate.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: DBS-on<br>Ventral intermediate Nucleus (VIM) Thalamic DBS on DBS system includes: Implantable Pulse Generator (IPG) DBS Lead DBS Lead Extension Kit | Device: VIM Thalamic Deep Brain Stimulation ON<br> <br> |
| Sham Comparator: DBS-off (sham-stimulation)<br>Ventral intermediate Nucleus (VIM) Thalamic DBS off DBS system includes: Implantable Pulse Generator (IPG) DBS Lead DBS Lead Extension Kit | Device: VIM Thalamic Deep Brain Stimulation OFF<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Unified Spasmodic Dysphonia Rating Scale (USDRS) | Assessments of spasmodic dysphonia using a standardized spasmodic dysphonia rating scale were done pre-operatively, blinded DBS ON, blinded DBS OFF, and open DBS ON. Voice recording taken of each patient reading standardized sentences were blinded and evaluated by two speech language pathologists. The scale ranges from 0-7, with lower scores being better and higher scores being worse. | After the first 6 months, the participants completed the USDRS twice (once per crossover). | 
| Voice-Related Quality of Life | Double-blinded assessments of voice-related quality of life with DBS ON/OFF were conducted using the V-RQoL for Spasmodic Dysphonia. The V-RQoL is a questionnaire that measures a patient's voice related quality of life. The scale ranges from 0-50, with higher scores representing a lower quality of life with respect to voice. | After the first 6 months, the participants completed the V-RQoL twice (once per crossover). | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Beck's Depression Inventory Scale | Beck's Depression Inventory Scale (BDI-II) was used in this study to evaluate the mood of the patients both pre-operatively and at the end of the one-year study. All 6 patients completed the BDI-II, which is a scale that identifies symptoms and attitudes associated with depression, and evaluates the presence and severity of depression. The BDI-II ranges from 0-63. Scores ranging from 0-10 are considered to be absent or minimal depression, 10-18 indicate mild to moderate depression, 19-29 indicate moderate depression, and 30-63 indicate severe depression. | All participants completed the BDI-II once pre-operatively and once 1 year post-operatively (after the 6-month open unblinded phase). | 
| Montreal Cognitive Assessment Scale (MoCA) | The MoCA was used to analyze the cognitive ability of the patients. It was first evaluated pre-operatively and again evaluated at the end of the one-year study. The MoCA scale ranges from 0-30 with higher scores indicating less cognitive impairment. Scores ranging from 18-25 indicate mild cognitive impairment, 10-17 indicate moderate cognitive impairment, and scores less than 10 indicate severe cognitive impairment. | All participants completed the MoCA once pre-operatively and once 1 year post-operatively (after the 6-month open unblinded phase). | 
| Voice-Handicap Index | The Voice-Handicap Index (VHI) is a questionnaire that measures the patients' perceived degree of handicap related to their voice. The VHI ranges from a scale of 0-100, with higher scores reflecting higher perceived degree of voice handicap and lower scores reflecting lower perceived degree of voice handicap. | All participants completed the VHI once pre-operatively and once 1 year post-operatively (after the 6-month open unblinded phase). |