Chemical denervation for the treatment of hypertonia and related motor disorders: Phenol and botulinum toxin

Chemical neurolysis with phenol and neuromuscular blockade with botulinum toxin (Btx) are two commonly used approaches to chemical denervation (CD) for the treatment of hypertonia and related motor disorders. Physiologic and therapeutic effects, technique, safety and toxicology, and side effects and complications are discussed for each. The patient can be approached by first considering whether CD is indicated in the context of other available options. A kinesiologic and functional evaluation is used to determine the target goals according to impairment and disability. If CD is indicated, the clinician must decide whether neuromuscular blockade with Btx or chemical neurolysis with phenol is a better choice by considering the advantages and disadvantages of each for a given situation. If chemical neurolysis with phenol is indicated, then one must consider whether motor branch or mixed sensorimotor block is more worthwhile.