Treatment of Chronic Neuropathic Pain in Arms and Legs

The purpose of this study is to evaluate three different injectable solutions used to block ankle nerves to manage ankle pain. The current standard of medical care is to inject a combination of local anesthetics and steroids around injured nerves. There is evidence that injection of local anesthetic (without the steroid) can calm the injured nerve and provide pain relief from a few days up to a few months. Injection of sterile salt water also has the potential to provide pain relief by breaking scar tissue around the nerve thereby relieving compression. Injections of local anesthetic and steroids around injured nerves have been used for many years to provide relief of pain but the specific reason is not well known for this benefit. There are three possibilities: 1) Steroids can reduce inflammation and calm the nerves, 2) local anesthetics can have similar actions but with shorter duration (few days), and 3) injection of any solution can break scarring around an injured/compressed nerve. The study will compare pain relief and possible adverse effects from these three different solutions. This study will help provide definitive answers regarding pain relief and possible adverse effects of the three solutions. This, in turn, will determine the best possible option for injection in patients with nerve-related injury pain.