SLAD-R (Selective laryngeal adductor denervation-reinnervation). This procedure was introduced by Dr. Gerald Berke of UCLA in the late 1990’s. It is a surgical option for adductory spasmodic dysphonia. The concept is to sever the anterior branch of the recurrent laryngeal nerve. This denervates the spasming laryngeal adductors (particularly thyroarytenoid and lateral cricoarytenoid muscles). The squeezed, strained quality and/ or “catching, cutting out, stopping” of the voice are replaced initially with an extremely breathy and weak voice. This initially weak voice is analogous to what one might sound like after a Botox injection that is far too high a dose. To return strength to the voice, a branch of the ansa cervicalis nerve that normally supplies some relatively “unimportant” neck muscles is anastomosed (connected) to the severed nerve. It takes 3 months to a year for tone to begin to return to the adductory muscles. Since the “unimportant” neck muscles were not affected by the dystonia, the hope is that the new nerve supply to the laryngeal muscles may not be affected by dystonia.
Six years post SLAD-R (1 of 4)
Six years after SLAD-R performed elsewhere. Note that re-innervation appears greater for left (right of photo) than right (left of photo) thyroarytenoid (TA) muscle. Signs of continuing atrophy of the TA muscle within the right cord (left of photo) include capacious ventricle ('V'); absence of “conus” ('C') bulk below the free margin (see contrast between /--/ on both sides); slight concavity or bowing of the free margin; and narrower band of the vocal cord itself that we sometimes refer to as the “spaghetti-linguini” larynx.
TA + LCA muscles (2 of 4)
While TA is more recovered on the left (right of photo) as seen in photo 1, here we see that the lateral cricoarytenoid (LCA) muscle has recovered more on the right (left of photo). At the prephonatory instant, the failure of the left (right of photo) vocal process to turn to the midline indicates continuing weakness of the LCA muscle.
Greater amplitude of right cord (3 of 4)
Under strobe illumination, open phase of vibration shows greater amplitude of right cord (left of photo), consistent with the atrophy of the permanently somewhat weak TA muscle seen in photo 1.
Patient has returned to Botox (4 of 4)
Closed phase of vibration. A few years after SLAD-R, this man’s spasms recurred sufficiently that he has resumed Botox injections.