Long-term peripheral nerve stimulation for painful nerve injuries

BACKGROUND: Although peripheral nerve stimulation (PNS) has been used in the treatment of pain since 1965, only a few follow-up studies have been published. The aim of the present retrospective study was to carefully assess the long-term efficacy and safety of PNS in the treatment of painful nerve injuries. METHODS: Patients suffering from intractable pain due to peripheral nerve injuries underwent PNS after careful selection. Long-term results were evaluated based upon patients' reports of pain intensity on a visual analog scale (VAS) and their consumption of analgesics. Two categories of results were chosen: good, referring to 50% or more relief of pain with abstinence from analgesic medications; and poor, with less than 50% improvement. RESULTS: Of 154 referred patients, 46 (26 women and 20 men) were found suitable for PNS. Four etiologic factors were identified, the most common being nerve lesion following an operation in the region of the hip or knee. Other etiologies included entrapment neuropathy, pain following nerve graft, and painful neuropathy following a traumatic injection. The follow-up period was 3-16 years. Of the 46 patients who underwent surgery, the results were classified as good in 36 (78%) patients and as poor in 10 (22%) patients. Overall, pain intensity dropped from a VAS of 69 +/- 12 before surgery to 24 +/- 28 postoperatively (P < 0.001). CONCLUSIONS: PNS can produce good pain relief in the majority of carefully selected patients suffering from isolated painful neuropathies.