Common practices in botulinum toxin injection for spasmodic dysphonia treatment: A national survey

Abstract

Objectives/Hypothesis: Although no clear guidelines exist, protocols in the treatment of spasmodic dysphonia (SD) vary among physicians. Previously published work comes from relatively few centers.Study Design: A descriptive survey among experts (laryngologists who practice Botulinum toxin injections for SD).Methods: An online 58-item survey was sent to all otolaryngologists who self-identify as laryngologists on the American Academy of Otolaryngology-Head and Neck Surgery website. Items surveyed included botulinum toxin injection technique, laterality, and dosage.Results: An 80% response rate was achieved (70 completed the survey). Participants collectively reported treating >4,000 SD patients in the past year (mean, 71 ± 68 patients/laryngologist). Eighty-seven percent perform injections exclusively in the office; the remainder both in the office and operating room. For adductor SD injections, 88% use electromyographic (EMG) guidance alone via cricothyroid approach. The remainder use anatomical landmarks alone (9%) or EMG with endoscopic guidance (3%). Sitting is the preferred patient position (70%; supine, 30%). A substantial majority (87%) begin with bilateral injections (starting dosage mode, 1.25 units/side). For abductor SD injections, 67% use EMG guidance alone and 31% use endoscopic guidance with or without EMG. Sitting is the preferred patient position (84%; supine, 16%). The preferred approach is anterior-translaryngeal (51%), followed by lateral-retrolaryngeal with rotation (34%). A considerable majority (79%) begin with unilateral injections (starting dosage mode, 5 units). When deciding on initial dosage, the most influential factor was balancing patients' desire/needs, followed by patients' frailty and risk of aspiration. The typical planned interval between injections is 3 to 4 months.Conclusions: Laryngologists follow fairly uniform protocols in the treatment of SD with some important and previously unpublished differences. This study documents areas of agreement and discordance among laryngologists in the United States for the treatment of SD.

Alternating Unilateral Versus Bilateral Injections of Botulinum Toxin for the Treatment of Adductor Spasmodic Dysphonia

“…Nevertheless, the majority of laryngologists prefer to start with bilateral injections, and an initial dosage of 1.25 IU/side, ranging from 0.25 to 5 IU, is preferred. 10 The typical planned interval between injections is 3 to 4 months, as the optimal effect of a BoNTA injection persists for almost 3 months. Unilateral injection can be performed on the same side until BoNTA becomes ineffective or alternatingly to each vocal fold at every visit.…”

“…However, clinical practices of BoNTA injection are not significantly different among laryngologists. 10,11…”

Impacto en la calidad de vida del tratamiento de disfonía espasmódica aductora con toxina botulínica A

“…De acuerdo con una encuesta reciente, respondida por laringólogos americanos, la elección de la dosis inicial está basada en el balance de deseo y necesidades de los pacientes y de la fragilidad y el riesgo de aspiración. La gran mayoría de los expertos inicia con inyección bilateral, con un rango de 0,25 a 5 unidades [21], de las cuales aplican 1,25 unidades por lado.…”

“…Se ha determinado que la dosis de toxina botulínica alcanzada en la titulación sería mayor en pacientes con mayor índice de masa corporal y con mejor salud global, sin diferencias significativas respecto a la edad ni al género[21,22]. El factor socioeconómico si bien podría afectar el número y frecuencia de las inyecciones, no tendría relación con la dosis requerida[22].…”

Quantitative laryngeal electromyography parameters may correlate with improved outcomes following botulinum toxin injection for spasmodic dysphonia

“…Botulinum toxin A (BoNT‐A) injection has emerged as the gold standard treatment 1,2 . BoNT‐A injection into the thyroarytenoid‐lateral cricoarytenoid (TA‐LCA) muscle complex is most commonly performed using qualitative electromyography (EMG) guidance 1‐4 . Needle localization is confirmed when motor units are recognized by the acoustic output during valsalva or vocalization, and BoNT‐A is subsequently injected.…”