Leading the Way in Laryngeal Dystonia Treatment

Novel Unilateral Staged SLAD/R Surgery

Innovations in Ear, Nose & Throat | Summer 2025

University Hospitals Cleveland Medical Center is widely recognized for expert neurolaryngology care led by Nicole Maronian, MD, Chair of the Department of Otolaryngology – Head and Neck Surgery and Director of the University Hospitals Ear, Nose & Throat Institute. University Hospitals is a national leader in the management of neurogenic dysfunction of the larynx and pharynx.

N. Scott Howard, MD, MBA

“Dr. Maronian has been foundational in the treatment of spasmodic dysphonia, bringing minimally invasive techniques to Northeast Ohio that she developed during her fellowship with Dr. Al Hillel at the University of Washington Medical Center,” says N. Scott Howard, MD, MBA, Chief of the Laryngology Service and Director of the Voice, Airway and Swallowing Center at the UH Ear, Nose & Throat Institute.

Laryngeal Dystonia (LD), also known as Spasmodic Dysphonia (SD), is a rare neurological voice disorder marked by involuntary spasms of the muscles controlling the larynx. These spasms can cause the voice to sound strained, strangled or breathy. The resulting intermittent speech disruptions make communication difficult or even unintelligible. While the exact cause is not known, LD is thought to involve dysfunction in the central nervous system, particularly in the basal ganglia.

Subtypes of Laryngeal Dystonia

LD involves multiple laryngeal muscles and is classified into three main types based on which muscles are affected and the resulting voice quality:

• Adductor Laryngeal Dystonia (AdLD) is the most common form, accounting for approximately 80-90 percent of cases. It causes the vocal folds to spasm together, producing a strained, strangled and effortful voice. Speech may be choppy, with words cut off or difficult to initiate.
• Abductor Laryngeal Dystonia (AbLD) is less common. Spasms force the vocal folds apart during speech, leading to a breathy or whispery voice with frequent breaks, especially on voiceless consonants.
• Mixed Laryngeal Dystonia features both adductor and abductor types, with symptoms fluctuating between strained and breathy voice qualities. This type is often more challenging, favoring treatment of the dominant component.

Each of these subtypes can have a tremor component, which also impacts treatment decisions.

First-line Treatment

Despite extensive ongoing research, there is presently no cure for these forms of dystonia. Treatment focuses on managing symptoms and improving ease of communication. The standard first-line intervention is the injection of botulinum toxin (Botox®) into the affected laryngeal muscles, providing temporary relief. Patients typically require repeat injections every three to four months. Daxxify® is a newer formulation that may extend the duration of benefit for up to six months and is being explored as an investigational drug. Neither Botox nor Daxxify is FDA-approved specifically for use in LD, although Botox is considered standard of care. 

Dr. Maronian, Dr. Howard and Nina Zhao, MD, a third specialist within the division, all treat LD with Botox. “The injections are highly effective in reducing the spasms that occur during voicing,” Dr. Howard says. “However, patients typically need to return for treatment three to four times per year.”

Surgical Intervention

For individuals with the adductor subtype, surgical options are also available. Selective Laryngeal Adductor Denervation-Reinnervation (SLAD/R), which may provide a more permanent solution. SLAD/R interrupts and reinnervates the nerve supply to the larynx’s overactive adductor muscles. Developed by Dr. Gerald Berke at UCLA, with whom Dr. Howard trained, this approach aims to eliminate involuntary spasms and restore a more natural voice.

Notably, “Dilbert” comic strip creator Scott Adams underwent SLAD/R with Drs. Howard and Berke after years of struggling with this disorder and has openly discussed his experience. Adams reported significant improvement, regaining a functional voice and expressing satisfaction with the outcome — even describing his post-surgical voice as more effective than before his LD onset.

Novel Unilateral Staged Approach

In addition to his expertise with traditional bilateral SLAD/R surgery, Dr. Howard has developed a unilateral staged approach that minimizes patient side effects. Bilateral SLAD/R can result in several months of breathy voice, dysphagia and mild airway issues.

“Focusing on a unilateral approach has offered significant benefits to my patients — especially those unable to take extended time off work — because they typically experience excellent voice improvement right away without all of the downtime,” Dr. Howard says. “When we treat the first side, we disrupt the nerve signals to and from the larynx. Although surgery impacts just one side, the brain mysteriously sends a more normal signal to the unoperated side, allowing the patient to return to a more normal voice quality immediately. We do not yet fully understand the neuroplasticity following unilateral surgery, but we know that it works.”

Dr. Howard typically stages the second surgery nine months to a year after the initial side has fully recovered to avoid recurrence of symptoms.

Functional MRI Studies

Dr. Howard plans to study the brain’s response to this surgery using functional MRI, aiming to gain new insights into how a unilateral approach affects the brain. “We already know how our Botox treatments work, but this is a unique opportunity to study brain changes resulting from unilateral SLAD/R procedures,” he says. “We’re interested to see how the brain responds immediately after surgery to help us predict when the other side will restart spasms. This typically occurs about a year after the initial surgery. What is happening within the brain to allow this?”

Advocacy and Support: Dysphonia International

Laryngology experts at University Hospitals work with Dysphonia International (formerly the National Spasmodic Dysphonia Association), a leading nonprofit dedicated to supporting individuals affected by laryngeal dystonia/spasmodic dysphonia and related voice disorders. Meetups in the Cleveland area feature lectures and connect patients to others coping with these relatively rare conditions.

“When people have a voice disorder, it can shut them out of conversations and create significant social anxiety,” Dr. Howard says. “We have a number of patients who have greatly benefited from participating with the organization.” For more information, email area contact leader Eileen Meehan.

Improving Quality of Life

Communication struggles caused by LD can be detrimental to quality of life, and SLAD/R is only offered by a few surgeons nationwide. Patients frequently travel from out of state to seek treatment from Dr. Howard, and he also offers virtual consultation for both patients and providers.

“Dr. Maronian, Dr. Zhao and I are proud to work together to offer our patients the full spectrum of these treatment options to personalize their laryngeal dystonia care,” he says.

For more information or to refer a patient for treatment, call the UH Voice, Airway and Swallowing Center at 216-844-5055.

Contributing Expert:
N. Scott Howard, MD, MBA
Chief of Laryngology Service
Director, Voice, Airway and Swallowing Center
University Hospitals Ear, Nose & Throat Institute
University Hospitals Cleveland Medical Center
Associate Professor
Case Western Reserve University School of Medicine