Uses and technique of ultrasound-guided botulinum toxin infiltration.

Botulinum toxin (BT) is a neurotoxin that causes flaccid paralysis by inhibiting the release of acetylcholine at the neuromuscular junction, and it may lead to long-term muscle atrophy. It is used to treat conditions associated with muscle hypertrophy or to enhance muscle flexibility, thereby facilitating surgical procedures. It has been shown that ultrasound-guided administration is superior to the anatomical landmarks technique as it reduces side effects and improves efficacy. Although some applications are not officially approved, evidence supports its efficacy and safety in the treatment of various conditions. Some of these more established conditions include anterior abdominal wall hernias, piriformis syndrome, thoracic outlet syndrome, bruxism, spasticity and cervical dystonia. The objective of this study is to review the uses of botulinum toxin in muscular and neuromuscular disorders, analysing its efficacy, safety and the importance of ultrasound guidance in its administration.