If these measures do not control symptoms, a mixture of an anesthetic and a corticosteroid (eg, 1.5 mL of a 4-mg / mL dexamethasone solution mixed with 1.5 mL of 1% lidocaine) may be injected into the carpal tunnel at a site just ulnar to the palmaris longus tendon and proximal to the distal crease at the wrist.