Huntoon, Elizabeth

Background and Objectives: Peripheral nerve stimulation (PNS) is analgesic for some lower extremity neuropathic pain syndromes. PNS currently involves open surgical placement of electrode(s). Increasingly, ultrasound guidance is used for perioperative neural block. Minimally invasive placement of PNS electrodes for lower extremity targets using ultrasound guidance has not been reported. We hypothesized that ultrasound-guided placement of PNS electrodes was feasible. Methods: Four cadaver mid-thigh transected fresh frozen specimens were studied. Specimens were scanned utilizing a 14 to 7 MHz linear probe and electrodes were placed proximal to the tibial, peroneal, and sciatic nerves at various locations. Anatomical dissection was performed to check placement accuracy and evaluate for grossly visible neural injuries. Results: Acceptable locations for ultrasound-guided electrode placement were: (1) tibial nerve, approximately 8 to 14 cm superior to the medial malleolus above the tarsal tunnel, or at the upper popliteal fossa; (2) peroneal nerve, approximately 2 to 4 cm inferior to the lateral fibular head or at the upper popliteal fossa; (3) sciatic nerve immediately superior to the bifurcation (high popliteal area); and (4) lateral sural nerve at the lower popliteal fossa. No grossly visible neural injuries were seen. Electrode placements appeared to be in satisfactory locations for stimulation. Conclusions: Ultrasound imaging to facilitate peripheral nerve electrode placement is feasible. This new minimally invasive approach to lead placement requires further study to determine trial implantation criteria, optimal locations, anchoring techniques, and best clinical practice.

Background and Objectives: Peripheral nerve stimulation (PNS) may provide analgesia for neuropathic pain syndromes in that nerve distribution. PNS electrode placement using ultrasound (US) guidance for upper extremity pain syndromes has not been reported. Existing anchoring technology may allow permanent implantation without significant migration. Methods: Three cadaver midhumeral fresh frozen upper extremity specimens were studied. US scanning was performed, targeting electrode placement at the radial, ulnar, and median nerves. Leads were anchored in the superficial fascia. The targeted nerves were exposed by careful dissection. Visual inspection for gross nerve damage, and electrode proximity to the nerve was performed. After confirmation of adequate lead placement, 2 extremities were sutured and placed in a continuous passive motion (CPM) machine for 21 hours to simulate activity. Each electrode was assessed for migration. Results: Acceptable locations for US-guided electrode placement were: radial nerve approximately 10-14 cm superior to the lateral epicondyle; median nerve approximately 6 cm below the antecubital fossa; and ulnar nerve approximately 9 to 13 cm above the medial epicondyle. One electrode was placed at each site without difficulty. After careful exposure, visual inspection showed no gross nerve damage. Each electrode had at least 2 electrical contacts within 2 mm of the nerve sheath. At CPM termination, only the median nerve electrode on 1 cadaver extremity had migrated significantly. Conclusions: This new minimally invasive approach to lead placement requires further study to determine implantation criteria, optimal locations, anchoring techniques, and electrode design to define best clinical practice.

Noncyclic breast pain is a common breast disorder prompting women to seek medical evaluation. We aimed to perform a pilot study on the relief of noncyclic breast pain using acupuncture. Thirty-seven women seen at a diagnostic breast clinic between April 2003 and January 2009 were enrolled. Treatment consisted of four acupuncture sessions over two weeks, with three months of follow-up. Response to treatment was measured with use of a breast pain questionnaire, a quality of life (QOL) questionnaire, and the Cleeland Brief Pain Inventory (BPI) assessed at baseline, end of treatment, and three months after treatment. Data were analyzed using standard descriptive statistics. Twenty-two patients completed four acupuncture sessions. Pain described as throbbing and heavy decreased significantly after acupuncture (p = 0.04 and p = 0.03, respectively). After treatment, pain scores (on the 10-point BPI scale) decreased by an average of 3.5 points for the worst pain during the previous month (p = 0.001), by 2.7 points for average pain (p < 0.001), and by 2.3 points for pain interference (p = 0.002). The percentage of patients reporting a clinically meaningful decrease of 2 points from baseline to the end of treatment included 67% (12/18) for the worst pain, 65% (11/17) for average pain, and 56% (10/18) for pain interference. QOL data showed no improvement in QOL measures (mental, physical, emotional, social, or spiritual well-being). The results of this preliminary study suggest that a randomized controlled trial may be warranted to evaluate the effect of acupuncture on noncyclic breast pain, as well as the optimal frequency of acupuncture treatments.