INTRODUCTION: To evaluate the safety and efficacy of incobotulinumtoxinA (IncoA) 
injection for treatment of essential hand tremor. In essential tremor and 
Parkinson's disease tremor, administration of onabotulinumtoxinA via a fixed 
injection approach improves the tremor but a high percentage of patients 
(30-70%) develop moderate to severe hand weakness which has limited its use in 
clinical practice.
METHODS: This study was performed from July 2013 to July 2016 on 33 subjects. 
This is a double-blind, placebo-controlled, crossover trial injecting 80-120 
units of IncoA into 8-14 hand and forearm muscles using a customized approach. 
The subjects were followed for 28 weeks. The treatment efficacy was evaluated by 
the Fahn Tolosa Marin tremor rating score and NIH genetic criteria for tremor 
severity at 4 and 8 weeks after each of the two sets of treatments. Hand 
strength was assessed by an ergometer.
RESULTS: There was statistically significant improvement in clinical rating 
score of tremor at 4 and 8 weeks following the IncoA injection.
CONCLUSION: In this study, injection of IncoA treatment via a customized 
approach improved essential tremor on the clinical scales and patient's 
perception with a low occurrence of significant hand weakness.