Model 3873

The temporary implantation of the spinal cord stimulator was performed under fluoroscopic guidance with local anesthesia (Dong et al., 2017 ). The targeted spinal level of implantation was evaluated preoperatively according to the dermatomes of the HZ lesion. The patient was placed prone, and the paramedial approach was used to insert the Tuohy needle into the epidural space (Dong et al., 2017 ). The needle stylet was removed, and an eight-contact stimulation lead (model 3873; Medtronic, Minneapolis, MN, United States) was inserted through the Tuohy needle and advanced toward the targeted spinal segment under fluoroscopic imaging (Figures 1B,C). A test of the stimulation was required during implantation to ensure optimal coverage of the painful dermatomes. We only enrolled patients in the study who had only one electrode implanted. To avoid the potential migration of electrodes, patients were required to stay in bed for 48 h after surgery.

A detailed description of the PNS procedure has been described by Lerman et al. (2015) (link). Briefly, patients were placed supine with the head turned to the contralateral side of the surgical approach. Local anesthesia was induced with 1% lidocaine in a total volume of 10 mL by infiltration 2 cm lateral to the orbit at the level of the supraorbital ridge and superficial temporal fascia. A 14-G Tuohy needle was inserted 2 cm posterolateral to the junction of the frontal and zygomatic portion of the orbital rim. The Tuohy needle was advanced through the tissue and aimed at a supra-periosteal tissue plane over the eyebrow in a semilunar path, cephalad to the orbicularis oculi, terminating slightly in the cranial midline. A test stimulation lead with eight electrodes (Model 3873; Medtronic, Minneapolis, MN, United States) was inserted through the Tuohy needle. Fluoroscopic imaging was used to identify the eight-contact lead overlying the supraorbital ridge (Figure 1), and the guiding needle was removed after the lead had been placed in the desired location. The distal ends of the inserted electrodes were connected to an extension multi-lead cable (Model: 355531; Medtronic). To program the implantable electrodes, the external cable was plugged into a neurostimulator (Model 37022; Medtronic).