Adductor Spasmodic Dysphonia (AD-SD)

A variant of spasmodic dysphonia in which the spasms push the vocal cords together, choking off or straining the voice. Adductor spasmodic dysphonia (AD-SD), also called strain-strangle phonation, is the most common variant of spasmodic dysphonia, comprising about 90% of the cases. It is to be distinguished from abductor spasmodic dysphonia (AB-SD), a variant in which the spasms pull the vocal cords apart.

In its classic variant, the adductory spasms of adductor spasmodic dysphonia are intermittent, each time clamping the vocal cords together momentarily, so that words or syllables in a person’s speech are intermittently choked out. In its tonic variant, the adductory spasms are more constant and sustained than intermittent, so that instead of interrupting the person’s speech, the spasms cause a constant strained or “tight” vocal quality.

Occasionally, a person has both abductory and adductory spasms; this is called mixed AB-AD spasmodic dysphonia.

Pure AD-SD tonic only, moderate severity

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AD-SD (1 of 2)

Sustained, clear phonation, standard light. Note vibratory blur of the vocal cord margins. The false vocal cords (lines) are in normal relation to the true vocal cords.

AD-SD (2 of 2)

Involuntary adductory spasm. Note that the false vocal cords suddenly over-close (arrows) as a result of the adductory spasm, and voice momentarily stops (along with vibratory blur).

Adductory spasm

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Adductory spasm (1 of 2)

Continuous phonation, standard light. Note the position of the false cords in relation to each other, and also the distance between the anterior face of the arytenoids and the petiole of the epiglottis.

Adductory spasm (2 of 2)

A moment later, an adductory spasm occurs. The spasm may momentarily stop the voice (phonatory arrest). Note the inward squeezing of the entire supraglottis (false cords, arytenoids, and petiole).

TA-only Paresis after Botox Injection for Spasmodic Dysphonia

This man with adductory spasmodic dysphonia, has had consistent results during 15 years of botulinum toxin injections, administered several times per year. After his most recent (routine, and unremarkable) injection with his longstanding dose, his initial weakness was exaggerated and is only beginning to subside after six weeks. This dramatic “outlier” result that cannot be attributed to botox targeting.  As seen in the photos below, the explanation is instead a right TA-only paresis.

The only reasonable interpretation is that the needle tip has “sheared” the branch of the recurrent laryngeal nerve supplying the thyroarytenoid muscle (leaving branches to the posterior cricoarytenoid and lateral cricoarytenoid muscles (PCA + LCA) undisturbed.

In a practice that supplies treatment to approximately 100 patients per month and ~1200 injections per year, this phenomenon occurs perhaps twice per year. The voice “always” recovers back to baseline SD symptomatology, but excessive breathiness starts to resolve only 6 weeks after the injection.

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Right Thyroarytenoid Atrophy (1 of 3)

At close range, notice the findings, from lateral to medial, of right (left of photo) thyroarytenoid atrophy: a) capacious ventricle; b) “spaghetti” compared to the left vocal cord’s “linguini” morphology; c) margin concavity; and D) flat conus contour. Notice that the cord is fully lateralized, due to intact PCA (posterior cricoarytenoid) function.

Sharp medial turning (2 of 3)

In a closer view, the right vocal cord begins to move to the midline. Notice the sharp medial turning of the vocal process, again validating that the LCA muscle is functioning.

Right vocal process overlaps left vocal process (3 of 3)

At the moment before voice begins, with the right cord at the midline, the margin bowing is again accentuated. Notice again the medially turned right vocal process also overlaps the left vocal process.
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Adductory Spasmodic Dysphonia – Tonic Variant

In this video are audio clips and footage of the vocal cords of a patient with Tonic AD-SD. Dr. Bastian also provides examples of 4 subtypes of AD-SD.

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Why Does Robert Kennedy Jr. Have a Hoarse Voice? The Answer Is SD…

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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.

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