How Useful are Localization Techniques in Botulinum Toxin Injections for Dystonia and Spasticity Indications?

Abstract

There is irrefutable evidence for the effectiveness of botulinum toxin (BoNT) in the treatment of various disorders associated with excessive muscle contraction or autonomic dysfunction. One of the earliest indications as well as the most common BoNT treated movement disorder is dystonia, predominantly its focal forms, including blepharospasm, oromandibular, spasmodic, cervical and limb dystonia. Spastic disorders comprise another area where BoNT treatment has proved beneficial. Optimal therapeutic results, however, depend on several factors, including the BoNT serotype, dose, concentration, injected volume, frequency of application, as well as precise localization of the muscles producing the abnormal movement. The accuracy in targeting muscle localization is considered to be a key factor for determining the outcome of BoNT injections, even more important than dilution volume and dose. Various techniques to find the best injection site for the delivery of BoNT have been described in the literature. An attempt was made to summarize in one place the available evidence, and when possible to compare and point out the advantages and disadvantages of different techniques for localization of BoNT injections. The widely applied clinical indications for dystonia and spasticity have been specifically chosen as our focus in this present work.

Botulinum Neurotoxin Injections in Children with Self-Injurious Behaviors

“…These clinical assessments are critical to the appropriate selection of the target muscles. There are no well-designed, controlled, studies that have demonstrated superiority of electromyography guidance or electrical stimulation or ultrasound-guided injection over the use of anatomical landmarks [35,36]. Indeed, a recent study showed no difference between ultrasound and electrical stimulation in the outcomes of BoNT treatment of focal hand dystonia and upper limb spasticity [37].…”