What invasive procedures can be used for the treatment of PHN?
Over time, various invasive measures have been employed for PHN pain; however, none has proven to be beneficial. When one looks at the literature, the lack of ran-domized, controlled studies does not enable one to recom-mend one invasive procedure over another. Sympathetic blocks have been used for the treatment of pain from PHN; however, their efficacy has not been proven in large-scale studies. Simple infiltration of the painful area with local anesthetics and steroids has been employed by some prac-titioners as a way to provide immediate pain relief, and with the hope of benefiting the patient by the steroid’s peripheral action on nerve endings. Somatic nerve blocks, while providing transient pain relief, have never shown any long-lasting benefit. A recent study from Japan showed excellent, sustained pain relief with the use of intrathecal methylprednisolone and lidocaine; however, the results have been questioned and this therapy has not gained widespread acceptance. Other modalities such as spinal cord stimulation and dorsal root rhizotomies have also been described with varying results.