Peripheral nerve stimulator placement for neuropathic pain due to brachial plexus invasion by lung cancer: Case report.

Background: Chronic neuropathic pain has a prevalence between 7 and 11% of the population. Management typically involves pharmacologic agents, however, a high number needed to treat (NNT) and undesirable side effects limit their utility. Neuromodulation techniques, such as peripheral nerve (PNS) and spinal cord stimulators (SCS), have been utilized successfully in the treatment of chronic neuropathic pain syndromes. To date, there is limited evidence supporting use of PNS for cancer-related neuropathic pain. Case presentation: An 83 year old male presented to the outpatient pain clinic after experiencing worsening pain related to brachial plexus invasion from a left anterior chest wall metastatic lesion from a primary lung cancer. His treatment had included a left upper lobectomy followed by radiation and an initial round of chemotherapy. The chest wall metastatic lesion was unable to be resected. After subsequent tumor progression, the mass caused a worsening dull, achy pain in his left shoulder radiating down his left arm. A PNS system was implanted targeting the inferior trunk of the brachial plexus. The patient's pain score decreased after activation of the device and he was able to rely solely on the stimulator for pain management until his eventual death. Conclusions: This patient experienced a substantial reduction in pain and improvement in his quality of life through his eventual death suggesting PNS as a viable palliative pain option for neuropathic pain due to tumor invasion.