Adductor Spasmodic Dysphonia (AD-SD)

Adductor spasmodic dysphonia (AD-SD) is a variant of spasmodic dysphonia in which the spasms push the vocal cords together, choking off or straining the voice. Also called strain-strangle phonation, AD-SD 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.

Classic AD-SD

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.

Tonic AD-SD

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

The false vocal cords are in normal relation to the true vocal cords — 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.

Adductory Spasm

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).

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 post SLAD-R Surgery — Angle of Abduction (1 of 5)

A year after SLAD-R, the angle of abduction (legs of the “V”) is the same bilaterally due to equal function of the PCA (posterior cricoarytenoid) muscle, not affected by the surgery. The margin of the folds (dotted lines) appear similar. But the bulk of the left thyroarytenoid muscle as manifested in the conus (bulge below the margin) appears to be less on the left (right of photo) than on the right (left of photo). The conus is also mildly flattened, as well. See the difference as marked by the bracketed lines.

Concave margin demonstrates TA muscle atrophy — Concave Margin (2 of 5)

As the cords approach approximation, the vocal processes are both beginning to point equally towards each other, suggesting that both LCA (lateral cricoarytenoid) muscles fully functional. However, the margin of the left cord appears to be subtly more concave than the right, suggesting mild TA (thyroarytenoid) muscle atrophy. (Compare dotted lines.)

Lateral buckling of left vocal cord — Lateral buckling (3 of 5)

During phonation under standard light, the cord margins are both blurred due to vibration, but the left side (right of photo) is buckling laterally, consistent with atrophy/flaccidity.

Mild bowing of the left vocal cord — Mild bowing (4 of 5)

Under strobe light, at maximally closed phase of vibration. This view again suggests mild bowing of the left cord (right of photo).

Greater amplitude due to atrophy and flaccidity — Greater amplitude (5 of 5)

The open phase of vibration shows much greater amplitude (lateral excursion) of left cord oscillation (lower right of photo) than on the right vocal cord (upper left of photo). Furthermore, the vibratory wave of the left cord is much greater, also consistent with atrophy/flaccidity.

Instruction Manual for SD Injections (AD & AB Variants)

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Post-Treatment for AD-SD

(the “strained-strangled” SD variant)

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Dropped syllables? Catches in Your Voice?

A strained voice, usually with “catches” or dropped syllables or words, may be the result of a rare neurological condition called adductory spasmodic dysphonia (AD-SD).

Abnormal muscular tone in vocal cords (laryngeal dystonia) results in abnormal vocal sound (spasmodic dysphonia). This video explains the disorder. Current standard of care is botox, which can dramatically diminish symptoms with 3 or 4 treatments per year.

AD-SD 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.

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

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.

Adductor Spasmodic Dysphonia (AD-SD)

Classic AD-SD

Tonic AD-SD

Pure AD-SD Tonic only, Moderate Severity

AD-SD (1 of 2)

AD-SD (2 of 2)

Adductory Spasm

Adductory spasm (1 of 2)

Adductory spasm (2 of 2)

SLAD-R Findings in Spasmodic Dysphonia

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)