When are peripheral nerve blocks useful for neuropathic pain?
In patients with focal peripheral neuropathic pain, diagnostic nerve blocks may be used to determine if a particular nerve is involved in a patient’s symptoms. The response to injection can help determine candidacy for therapeutic blocks (with steroids or a series of injections), neuroablative techniques, or surgical therapy. Currently, there are no clear standard recommendations for injectate (medication and volume) or treatment pathways. However, some studies do show perineural steroids as being useful in treatment in neuropathic pain secondary to trauma or compression, presumably due to the antiinflammatory effect and immunosuppression action on injured nerves.
On a related subject, limited data suggest that using regional anesthesia in patients with preamputation limb pain may help prevent phantom limb pain. There is not a clear role for this treatment after development of chronic phantom pain.