Using a comprehensive approach of clinico-behavioral testing and neuroimaging, the researchers will examine the clinical effects of the extended-release formulation of sodium oxybate on voice symptoms in spasmodic dysphonia in an open-label, proof-of-concept, dose-finding study.

Spasmodic dysphonia (SD), or laryngeal dystonia, is a chronic, debilitating condition that selectively affects speech production due to involuntary spasms in the laryngeal muscles. SD often extends beyond the impairment of vocal communication, causing significant occupational disability and life-long social isolation. Treatment of SD is limited to injections of botulinum toxin into the vocal cords, however, it is often only partially effective and can have side effects. More than half of the people with SD have some relief from drinking alcohol. The previous studies showed that immediate-release sodium oxybate (an oral drug that acts similarly to alcohol) significantly relieves voice symptoms in patients with alcohol-responsive SD. In this study, we will examine the efficacy and safety of extended-release sodium oxybate formulation (Lumryz) as a longer-acting oral agent for the treatment of patients with alcohol-responsive SD.

Inclusion Criteria:

1. Provision of signed and dated informed consent form
2. Stated willingness to comply with all study procedures and lifestyle considerations (see Lifestyle Considerations below) and availability for the duration of the study
3. Males and females
4. Age 21-80 years
5. Documented diagnosis of alcohol-responsive laryngeal dystonia
6. Documented positive response to immediate-release sodium oxybate (Xyrem) in prior studies
7. Willingness to adhere to the study intervention regimen

Exclusion Criteria:

1. The incapability of giving informed consent
2. Pregnancy or breastfeeding until a time when they are no longer pregnant or breastfeeding
3. Grade 2 or higher hepatic or renal dysfunction according to the NCI criteria
4. Moderate to severe congestive heart failure
5. Cognitive impairment (MoCA < 26)
6. Past or present suicidal ideations (according to C-SSRS)
7. Alcoholism or high risk for alcohol use disorder according to the NIAAA definition and DSM-5 criteria
8. Asymptomatic presentation due to botulinum toxin treatment until the time they are fully symptomatic and are at least 3 months after the last injection
9. Increased daytime sleepiness (Epworth Sleepiness Scale (ESS>10))
10. Past or present history of any neurological disorders (except for LD and co-occurring voice tremor), such as stroke, movement disorders, brain tumors, traumatic brain injury with loss of consciousness, ataxias, myopathies, myasthenia gravis, demyelinating diseases, alcoholism, drug dependence.
11. Past or present history of any psychiatric problems, such as schizophrenia, major and/or bipolar depression, or obsessive-compulsive disorder
12. Current use of medication(s) affecting the central nervous system
13. Past or present history of brain and/or laryngeal surgery
14. Presence of certain tattoos, ferromagnetic objects in their bodies (e.g., implanted stimulators, surgical clips, prosthesis, artificial heart valve, etc.) that are not MRI comparable and/or cannot be removed for the purpose of MRI study participation