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

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

Individual prospective cohort study.

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.

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.

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.