Selective Laryngeal Adductor Denervation-Reinnervation (SLAD-R)
Selective Laryngeal Adductor Denervation-Reinnervation (SLAD-R) is a newer surgical treatment for adductory spasmodic dysphonia, introduced by Dr. Gerald Berke of UCLA[1] in the late 1990s. During the procedure, the anterior branch of the recurrent laryngeal nerve, which supplies the thyroarytenoid (TA) and lateral cricoarytenoid (LCA) muscles—both essential for voice production—is severed. This eliminates the strained, squeezed quality of the voice, as well as the characteristic “catching” or “cutting out,” of speech. However, without additional intervention, the voice would remain permanently weak, or dystonic nerve impulses could reestablish unwanted connections.
To avoid this, SLAD-R includes a simultaneous reinnervation process. A branch of the ansa cervicalis nerve, which typically serves less critical neck muscles, is harvested and connected to the severed nerve. This helps restore function while preventing unwanted nerve regeneration. However, the reconnection process takes time, leaving patients with a breathy, whispery voice for three or more months before some muscle tone and vocal volume return.
While many patients experience long-term improvement, others may redevelop spasms and require additional treatments, such as Botox injections or vocal cord muscle debulking. The effectiveness of SLAD-R varies, and outcomes are difficult to predict for any individual. It would be helpful to have an online source of voice recordings of many patients at various times: before SLAD-R surgery, and also at 3 months, 6 months, 1 year, and 2 years after surgery.
How Effective Is SLAD-R in Treating AD-SD?
Consider this scenario: A 40-year-old man with Adductor SD is considering SLAD-R. He has responded well to Botox injections but desires a more consistently “perfect” result. The variability in his injection outcomes—particularly the initial breathiness and duration of effect—has been frustrating. Should he consider SLAD-R?
Different SD experts may have differing opinions on this, and what follows is just my perspective (Dr. Bastian’s).
I continue to believe that “high-quality Botox injections” remain the mainstay treatment for spasmodic dysphonia.
By “high quality,” I mean:
- Availability on demand rather than only occasionally.
- Skilled administration with minimal discomfort.
- Consistent results—ensuring the injections work every time while minimizing variability in breathiness and duration of benefit.
- Quality assurance—any rare “complete miss” injection should be repeated at no charge if the patient returns within a month.
Put simply, well-planned, consistent Botox injections—administered on a schedule or as needed—remain the best approach for most patients, provided they are performed optimally. That said, surgery is always an option, and interested patients should seek the opinion of Dr. Berke or one of his direct trainees.
Logistics
SLAD-R is a major surgery requiring patience and commitment. The procedure itself lasts several hours, followed by a prolonged postoperative voice recovery. Patients typically experience a very weak, breathy voice for 3 or more months before muscle tone begins to return; this is likened to receiving an extremely high-dose Botox injection. Some patients may also require additional vocal cord thinning procedures later on.
Some Factors to Consider
Outcomes vary. While some patients are highly satisfied, others do not find it life changing. If only we could predict individual results in advance, the decision would be much simpler.
Another factor to consider: Dystonia can evolve over time. I have seen cases where long-standing adductor SD later transitioned to abductor SD. Dystonia often seems to “fight back,” adapting to surgical interventions. In such cases, Botox may become needed post-surgery.
It would be invaluable for patients considering SLAD-R if there were a resource—perhaps a website—where individuals could listen to before and 2-year postoperative voice recordings of others who have undergone the procedure.
Ultimately, this is a deeply personal decision. If SLAD-R achieves the outcome he hopes for, the patient you mention will be very glad he pursued it. However, he must approach it with realistic expectations and a full understanding of the potential challenges.
Differential Re-Innervation after SLAD-R Surgery
Six years post SLAD-R (1 of 4)
TA + LCA muscles (2 of 4)
Greater amplitude of right cord (3 of 4)
Patient has returned to Botox (4 of 4)
SLAD-R Findings in Spasmodic Dysphonia
This man has had longstanding laryngeal dystonia causing adductory spasmodic dysphonia. More than a year before these photos, he underwent SLAD-R on the left side (right of photo). The left cord moves normally, and one can see full recovery of the LCA (lateral cricoarytenoid) muscle, but the TA (thyroarytenoid) muscle is atrophic and flaccid.
Angle of Abduction (1 of 5)
Concave Margin (2 of 5)
Lateral buckling (3 of 5)
Mild bowing (4 of 5)
Greater amplitude (5 of 5)
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One Man’s Experience Over Time with SLAD-R
SLAD-R is a surgical alternative to ongoing “botox” injections for treatment of adductory spasmodic dysphonia. The surgery involves intentionally cutting the nerves that close the vocal cords for voice and reconnecting a different nearby nerve supply (reinnervating the nerves).
This surgery requires the patient’s willingness to endure an extremely breathy voice for many months after the procedure, while awaiting reinnervation.
