Percutaneous Peripheral Nerve Stimulation Research Articles

Repositioning of Supraorbital Nerve Stimulation Electrode Using Retrograde Needle Insertion: A Technical Note

With growing interest and acceptance of peripheral nerve stimulation (PNS) approach, there is now an increasing need in developing clear procedural details to resolve frequent complications and minimize associated tissue injury. Migration and suboptimal positioning of PNS electrodes are one of the most commonly observed complications of PNS approach. We present a simple technique for repositioning a supraorbital electrode using retrograde insertion of introducer needle that allows one to place percutaneous (cylindrical) PNS electrode into appropriate anatomical location with minimal additional injury to surrounding tissues. This approach has been successfully used in multiple cases. An illustrative case of electrode revision with proposed technique is described in detail. This technically simple approach to repositioning of cylindrical supraorbital electrodes using retrograde needle insertion eliminates the need for a more elaborate and invasive procedure. The technique can be used for electrode repositioning in most PNS applications.

Ultrasound-Guided, Percutaneous Peripheral Nerve Stimulation

Peripheral nerve stimulation is a form of neuromodulation that applies electric current to peripheral nerves to induce stimulation paresthesias within the painful areas. To report a method of ultrasound-guided, percutaneous peripheral nerve stimulation. This technique utilizes real-time imaging to avoid injury to adjacent vascular structures during minimally invasive placement of peripheral nerve stimulator electrodes. We describe a patient that presented with chronic, bilateral foot pain following multiple foot surgeries, for whom a comprehensive, pain management treatment strategy had failed. We utilized ultrasound-guided, percutaneous tibial nerve stimulation at a thigh level to provide durable pain relief on the right side, and open peripheral nerve stimulation on the left. The patient experienced appropriate stimulation paresthesias and excellent pain relief on the plantar aspect of the right foot with the percutaneous electrode. On the left side, we were unable to direct the stimulation paresthesias to the sole of the foot, despite multiple electrode repositionings. A subsequent, open placement of a left tibial nerve stimulator was performed. This revealed that the correct electrode position against the tibial nerve was immediately adjacent to the popliteal artery, and was thus not appropriate for percutaneous placement. We describe a method of ultrasound-guided peripheral nerve stimulation that avoids the invasiveness of electrode placement via an open procedure while providing excellent pain relief. We further describe limitations of the percutaneous approach when navigating close to large blood vessels, a situation more appropriately managed with open peripheral nerve stimulator placement. Ultrasound-guided placement may be considered for patients receiving peripheral nerve stimulators placed within the deep tissues, and not easily placed in a blind fashion.

Peripheral Subcutaneous Stimulation for the Treatment of Intractable Postherpetic Neuralgia: Two Case Reports and Literature Review

Postherpetic neuralgia (PHN) is a common cause of chronic pain in the elderly. Antidepressants, anticonvulsants, and opioids may reduce discomfort in many patients, while others have pain intractable to all forms of therapy. We present a novel treatment approach for intractable PHN utilizing percutaneous peripheral nerve stimulation. Two cases are described in which an 80-year-old man and a 67-year-old woman with intractable PHN, lasting 2 and 10 years, respectively, were effectively treated with implantation of two octapolar leads in the lateral thoracic region. These cases suggest that peripheral nerve stimulation may offer an alternative treatment option for intractable pain associated with PHN especially in the elderly where treatment options are limited because of existing comorbidities.

Peripheral Nerve Stimulation: A Percutaneous Minimally Invasive Approach

We report on the use of a new percutaneous technique for peripheral nerve stimulation (PNS) treatment of chronic pain. A 56-year-old woman was diagnosed with algodystrophic syndrome, now called Complex Regional Pain Syndrome, type 2 (CRPS2), due to a lesion of the right medial nerve despite surgical revascularization, angioplasty and stent insertion. After a successful 10-day trial of PNS via a percutaneous quadripolar lead in the interscaline space, an implantable pulse generator was implanted in the abdominal subcutaneous tissue and connected to the subcutaneous lead via an extension. After one year of follow-up, the patient was still experiencing good pain relief. We conclude that this novel percutaneous PNS technique offers the advantage of being a minimally invasive approach that can be easily adopted for the management of chronic pain.

PERCUTANEOUS AFFERENT NEUROMODULATION FOR THE REFRACTORY OVERACTIVE BLADDER: RESULTS OF A MULTICENTER STUDY

More than 20 million Americans have an overactive bladder, the predominant symptoms being frequency, urgency, urge incontinence and pelvic pain. While the etiology is not completely understood, most investigators believe the causes to be many and the pelvic floor to be intimately related. Whatever the etiology, traditional therapies, including dietary manipulation, bladder drill, medications and physical therapy, are often poorly tolerated and/or ineffective. We report a prospective, multicenter clinical trial that was undertaken to determine the safety and efficacy of percutaneous peripheral afferent nerve stimulation for treatment of refractive overactive bladder and/or pelvic floor dysfunction. A total of 53 patients with overactive bladders, in whom all traditional therapy failed, were enrolled in 1 of 5 sites within the United States. Patients received weekly percutaneous electrical stimulations via a 34 gauge needle placed near the tibial nerve 3 finger breadths above the ankle. Urodynamic studies, detailed voiding diaries, quality of life surveys, and incontinence impact questionnaires were completed before, during and after the study. Of the patients with a mean age of 57.4 years 89% (47 of 53) completed the 12-week study. A total of 71% of patients were classified as treatment successes by the investigators and were started on long-term treatment. On average patients noticed a 25% reduction in mean daytime and 21% reduction in mean nighttime voiding frequencies (p <0.05). Urge incontinence was reduced by an average of 35% (p <0.05). Statistically significant improvements were noted in selective pain and quality of life indexes. No significant adverse events related to treatment were noted in any patients. Percutaneous peripheral afferent nerve stimulation offers a safe, minimally invasive and effective treatment for managing refractive overactive bladder and/or pelvic floor dysfunction.

Peripheral cutaneous nerve distribution to the fingers.

Both sensory distribution charts and the unaffected side, are used as reference points in the assessment of cutaneous innervation. Sensory nerve conduction studies, in particular, often use comparison between sides. However, remarkable differences can be found between various sensory innervation maps, and no evidence was found in the literature for the assumption that the pattern of cutaneous sensory distribution of the peripheral nerves between the left and right limbs is symmetrical. The purpose of this study was to investigate variations in the sensory innervation of the fingers by means of a neurophysiological method, and to compare the results for the left and right hands. The subjects of this study were 31 young women. Percutaneous peripheral nerve stimulation was performed on the four nerve branches providing sensory innervation to the fingers, and action potentials were sought from the fingers by use of annular surface electrodes. Variations in the cutaneous innervation of the fingers between individuals often occurred and were found more frequently on the dorsal than the palmar aspect. The distribution of sensory innervation may even differ markedly between hands in the same individual. The cutaneous innervation of all peripheral nerves supplying the fingers may differ from the innervation patterns described in the various distribution charts. Prudence is called for when applying sensory distribution charts as absolute references for the assessment of cutaneous sensation in patients. Caution should also be applied when comparing one hand with the other when assessing the cutaneous innervation of the fingers.

H reflex studies in cerebral palsy patients undergoing partial dorsal rhizotomy

H reflex studies were performed in ten spastic children with cerebral palsy who underwent partial dorsal rhizotomy (PDR). Under anesthesia prior to PDR, H reflex amplitude evoked by percutaneous peripheral nerve stimulation gradually declined in all patients and became unobtainable in five. Motor responses could still be evoked by apparent dorsal root stimulation in these five, but since it was shown that they were M responses and not reflexes, PDR was performed randomly. In the other five patients, in whom H reflexes were still evokable, dorsal root stimulation evoked motor responses which were true reflex responses, and PDR was performed "selectively." Compared to preoperative values, postoperative Hmax/Mmax ratios declined, but no more so in selective than in random PDR. We conclude that current intraoperative methods for selection of "abnormal" dorsal rootlets for section may be invalid and may have no bearing on successful outcome, since spasticity improves even with random PDR.