Selective neuromuscular blocks and chemoneurolysis in the localized treatment of spasticity.

Selective neuromuscular blocks and chemoneurolysis are currently the most widespread therapies for treating localized or locoregional spasticity. Both procedures present advantages and disadvantages. The main advantages of BTX-A are its relative ease of use, low incidence of side effects, reversibility and elevated efficacy. Its disadvantages are the limited maximum dose, which does not permit the treatment of many muscles simultaneously, especially if they are large, and its relatively high cost. Phenol neurolysis has a low cost, elevated efficacy in the control of pathologic muscle overactivity, and long duration of effect. Its disadvantages are the risk of injury to the vascular and sensory structures and the difficulty in performing the procedure. The risks associated with neurolysis have led to an increasing interest in and use of BTX-A, making it one of the most widely used therapies in treating localized spasticity. From the perspective of a balanced benefit-risk analysis, a viable option for some cases may be to combine phenol neurolysis for treating spasticity in large proximal muscles and BTX-A for treating hypertonia in small distal muscles.