Get access

Botulinum toxin: description of injection techniques and examination of controversies surrounding toxin diffusion


Erle Chuen-Hian Lim, Yong Loo Lin School of Medicine, National University of Singapore, c/o Division of Neurology, National University Hospital, 5 Lower Kent Ridge Road, Singapore 119074
Tel.: +65 67724353
Fax: +65 67794112


The benefits derived from botulinum toxin (BTX) injections may be negated by unintentional weakness of adjacent uninjected muscles. Such weakness may be the result of inaccurate targeting, or diffusion of BTX to surrounding muscles. Several techniques, using electromyographic, endoscopic or imaging guidance are purported to increase the accuracy of targeting. Diffusion of BTX is thought to be influenced by factors such as dose, concentration, injectate volume, number of injections, site and rate of injection, needle gauge, muscle size, muscular fascia, distance of needle tip from the neuromuscular junction, and protein content of the BTX formulation. This article describes techniques that aim to increase the accuracy of BTX injections and examines the controversies surrounding diffusion of BTX following injection.