Comparative effectiveness of propranolol and botulinum for the treatment of essential voice tremor.

[OBJECTIVES/HYPOTHESIS] To assess the comparative effectiveness of botulinum toxin and propranolol in patients with essential vocal tremor (EVT).

[STUDY DESIGN] Individual prospective cohort study.

[METHODS] Study patients were recruited at the Emory Voice Center from patients seeking treatment for EVT. Exclusion criteria included current β-blocker treatment, spasmodic dysphonia, or other disease that prevented the use of propranolol therapy. A 10-week washout period from prior botulinum toxin treatment occurred before enrollment. Patients were assessed via the Voice-Related Quality-Of-Life (VRQOL) questionnaire, Quality of life in Essential Tremor questionnaire, and blinded perceptual voice assessment. These assessments were made at baseline voice 2 weeks after propranolol therapy and 4 weeks after botulinum toxin injection.

[RESULTS] Eighteen patients were enrolled. After 2 to 4 weeks of propranolol therapy (with a maximum dosage of 60 mg to 90 mg per day), patients report an average ΔVRQOL of 9.31. Six patients report significant VRQOL improvement >10, with the rest reporting changes between -7.5 and 7.5. Fifteen patients were followed for at least 4 weeks after botulinum toxin injection, reporting an average improvement in scaled VRQOL of 22.00. Blinded perceptual voice assessment demonstrates an improvement in overall severity of tremor with botulinum toxin.

[CONCLUSIONS] In some patients with EVT, propranolol led to significant vocal improvement with no major side effects. Although botulinum toxin remains the gold-standard therapy for patients with EVT, propranolol represents a possible alternative or adjuvant therapy for certain patients.