Essential Voice Tremor: A Study of Botulinum Toxin Treatment and Injection Augmentation

Essential Voice Tremor: An Unblinded Crossover Study of Botulinum Toxin Treatment and Injection Augmentation

Botulinum toxin is the common treatment of choice for patients with Essential Voice Tremor (EVT), but results are not universally beneficial to all patients. Inconsistent results are noted in the literature and are consistent with the PI's clinical experience. Injection augmentation, a well-established treatment for glottic insufficiency, which is a prominent factor in the clinical presentation of Essential Voice Tremor (EVT), has not been studied. By treating patients at separate times with botulinum toxin and injection augmentation in an unblinded prospective crossover treatment study, we can assess functional outcomes of these two treatments with the population of patients with Essential Voice Tremor (EVT).

The purpose of this study is to compare treatment with botulinum toxin to treatment with injection augmentation in patients diagnosed with essential voice tremor.

Botulinum toxin treatment is the injection of botulinum toxin into the muscles of the vocal cords through the skin of the neck. This is identical to the injections you may have received in the past for your disorder.

Injection augmentation is the injection of a filler material into the vocal cords through the skin of the neck, guided by the view from a flexible laryngoscope inserted through the nostril. The flexible laryngoscopy is identical to the procedure that the doctor has used to examine your vocal cords in the past. It is the routine diagnostic evaluation technique of voice disorders.

Periodic injections with botulinum toxin (Botox) is the current standard of care for patients diagnosed with essential voice tremor, but studies show only about 60% of patients benefit substantially enough to continue treatment. Poor vocal fold closure, a common characteristic of essential voice tremor, is treated in other situations (such as vocal fold paralysis or paresis) with injection augmentation; thus there is reason to think that it may be helpful to patients with essential voice tremor, perhaps even to a greater extent than botulinum toxin.

Inclusion Criteria:

• Male and female patients ages 18-100 who have been diagnosed with essential tremor of the voice (EVT) Diagnosis Code 478.75 Laryngeal Spasm.

Exclusion Criteria:

• WCMC subjects under age 18
• Pregnant patients
• Patients with laryngeal pathology besides tremor, including but not limited to polyps and other benign lesions, precancerous or cancerous changes, vocal fold paralysis, or other laryngeal disorders of mobility