Effects of DaxibotulinumtoxinA for Blepharospasm and Hemifacial Spasm

The goal of this clinical trial is to test the effects of DaxibotulinumtoxinA-Lanm (Daxxify) in patients with benign essential blepharospasms (BEB) and hemifacial spasms (HFS). The main questions to answer: 1. Is there clinically significant difference (measured by Jankovic Rating Scale (JRS) score from base to peak efficacy) for patients with BEB and HFS treated with Daxxify? 2. What percentage of patients achieve a clinical response? Participants historically treated with Botox for either BEB or HFS will be crossed over to Daxxify treatment in order to serve as their own control and examine the efficacy of Daxxify.

This will be a single-arm, crossover study, in which each patient is their own historical control using a 2:1 conversion ratio of Daxxify to Botox units. Study participants will be selected through the electronic medical records of ophthalmologists at Montefiore Medical Center. Medical documentation on each patient will include information on age, sex, race, Benign Essential Blepharospasm (BEB) diagnosis year and duration, Hemifacial Spasms (HFS) diagnosis year and duration, and past treatments. The immediate effects (desired or undesired) of Daxxify observed within 48-72 hours, will be defined as (1) complete relief of spasms (2) partial relief to a tolerable level (3) mild to moderate ocular irritation (4) ptosis. Overall efficacy will be evaluated using the base to peak efficacy (recorded in changes to Jankovic Rating Scale (JRS) scores) and be defined as (1) excellent (resolution of signs and symptoms, only requiring injections \> 5-6 months (2) moderate (improvement in signs and symptoms but requiring repeated injections within \< 5 months (3) poor (no improvement in signs and symptoms). Adverse side effects will be documented, and Daxxify will be discontinued in any patients who develop significant side effects that outweigh the benefits.

Inclusion Criteria: * Benign essential blepharospasm (BEB) or hemifacial spasm (HFS) as diagnosed by an ophthalmologist. * No known neurologic or neuromuscular systematic medications. * No history or surgical intervention for BEB or HFS. * Patients are required to have a minimum score of 4 out of 8 on the modified Jankovic Rating Scale for Severity/Frequency. Exclusion Criteria: * Patients will be excluded if age \< 18, are pregnant, are non-willing, or have contra-indications to botulinum toxin.