However, the evidence of benefits in selected cases where other treatments have failed is highly significant. At the moment, the available scientific evidence is limited, the techniques used are heterogeneous, and the indications are dissimilar among the different authors. Energy for the stimulation comes from wearable devices acting both as induction generator and stimulator controllers. The middle portion of the lead contains circuitry capable of changing the frequency, intensity, and timing of the electrical stimuli. Most recent PNS models consist of an implantable wire with stimulating contacts on one end, and an electromagnetic coil receiver on the other end. Disadvantages include a higher risk of migration, catheter fracture and specific, smaller areas of effect (dependent on the stimulated nerve(s)). The advantages of PNS, as compared to SCS, are the less invasive implantation procedure, direct access to the anatomical target, faster recovery from surgery, and surgery-related costs. After examining the two cases in this paper, we changed our practice and suggest the implantation of PNS for radial, median and/or ulnar nerve stimulation in the upper arm region, which has significant advantages over the forearm region.

Unfortunately, in this second case the migration of the catheter affected the effectiveness of the treatment. For this procedure, the PNS device was implanted in the forearm. The second case presented a patient affected by progressive CRPS type II in the sensory regions of the ulnar and median nerve in the hand, unresponsive to drug therapy.

The procedure had a favorable outcome in fact, after one month the pain symptoms were absent (VAS 0) and the pharmacological therapy was suspended. An upper arm region approach for the PNS was chosen.

The first case describes a neuropathic syndrome after the traumatic amputation of the distal phalanx of the fifth digit secondary to a work accident with lack of responsiveness to a triple conservative therapy. We discuss two approaches to PNS placement in the upper extremity. Peripheral neuro-stimulation (PNS) has been proved to be effective for the treatment of neuropathic pain as well as other painful conditions.

Nerve test on arm painful