Percutaneous Nerve Stimulation Research Articles

Peripheral neurostimulation in primary headaches.

Peripheral neurostimulation techniques have emerged as promising treatments for patients with medically intractable, highly disabling chronic daily headaches including chronic migraine (CM) and chronic cluster headache (CCH) besides other less common headache syndromes. Encouraging controlled and open label data in medically intractable CM and trigeminal autonomic cephalalgias (TACs) have suggested a meaningful therapeutic role for occipital nerve stimulation (ONS). In view of the frequent occurrence of pain in the first branch of trigeminal nerve, percutaneous supraorbital nerve stimulation alone or in combination with ONS has been used successfully in open label series of CM and CCH patients. In view of its connections with the trigeminovascular system, the stimulation of the sphenopalatine ganglion has been used as a therapeutic target for the treatment of acute cluster headache attacks, with promising results. Preliminary data in patients with epilepsy and migraine have suggested a potential efficacy of vagus nerve stimulation in the treatment of primary headaches. Non-invasive devices targeting peripheral nerves have been developed and initial experience is emerging for the acute and preventive treatments of primary headache disorders. This review analyses the available evidence on the efficacy and safety of the different peripheral neurostimulation techniques.

Urologic Agents for Treatment of Bladder Dysfunction in Neurologic Disease

Bladder dysfunction, which is commonly associated with neurologic disorders, can present in myriad ways, from complete retention of urine to total urinary incontinence. The multiple options for treating neurogenic bladder dysfunction range from minimally invasive lifestyle changes to major surgical interventions. Interventions may be driven by patient-reported nuisance or by medical necessity, as in the case of impaired compliance with associated upper urinary tract compromise. Pharmacologic treatment has long been the mainstay in the management of bladder dysfunction, particularly for overactive bladder symptoms [1]. While there are many different medications for overactive bladder dysfunction, most are in the category of antimuscarinics. Each medication has a slightly different side effect profile, which may be important in the drug selection process [2]. When these are not tolerated or are ineffective, beta agonists, phosphodiesterase inhibitors, tricyclic antidepressants, and the gamma aminobutyric acid (GABA)-B agonist baclofen can be added or substituted. For difficulty emptying, alpha adrenergic antagonists can be used [3]. Intravesical options are also available for overactive bladder (OAB) symptoms. The most common is botulinum toxin, which works by decreasing the activity of the detrusor smooth muscle, thereby decreasing OAB symptoms [4]. Percutaneous nerve stimulation may also be used [5•].

This Month in Adult Urology

No AccessJournal of UrologyThis Month in Adult Urology1 Mar 2014This Month in Adult Urology William D. Steers William D. SteersWilliam D. Steers More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2013.12.016AboutFull TextPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail "This Month in Adult Urology." The Journal of Urology, 191(3), pp. 571–572 References 1 : The impact of repeat biopsies on infectious complications in men with prostate cancer on active surveillance. J Urol2014; 191: 660. Link, Google Scholar 2 : Efficacy and safety of the coadministration of tadalafil once daily with finasteride for 6 months in men with lower urinary tract symptoms and prostatic enlargement secondary to benign prostatic hyperplasia. J Urol2014; 191: 727. Link, Google Scholar 3 : Inflammatory and tissue remodeling urinary biomarkers before and after mid urethral sling surgery for stress urinary incontinence. J Urol2014; 191: 703. Link, Google Scholar 4 : Effect of repeated prostate biopsies on erectile function in men on active surveillance for prostate cancer. J Urol2014; 191: 744. Link, Google Scholar 5 : Prediction of early and late complications after oral mucosal graft harvesting: multivariable analysis from a cohort of 553 consecutive patients. J Urol2014; 191: 688. Link, Google Scholar 6 : Maintenance percutaneous posterior nerve stimulation for refractory lower urinary tract symptoms in patients with multiple sclerosis: an open label, multicenter, prospective study. J Urol2014; 191: 697. Link, Google Scholar © 2014 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 191Issue 3March 2014Page: 571-572 Advertisement Copyright & Permissions© 2014 by American Urological Association Education and Research, Inc.MetricsAuthor Information William D. Steers More articles by this author Expand All Advertisement PDF DownloadLoading ...

Maintenance Percutaneous Posterior Nerve Stimulation for Refractory Lower Urinary Tract Symptoms in Patients with Multiple Sclerosis: An Open Label, Multicenter, Prospective Study

Percutaneous tibial nerve stimulation is an effective second line therapy for lower urinary tract symptoms. Data on percutaneous tibial nerve stimulation maintenance treatment are scarce. In this study we evaluate its effectiveness and propose an algorithm of percutaneous tibial nerve stimulation maintenance treatment in patients with multiple sclerosis. In this prospective, multicenter, open label trial consecutive patients with multiple sclerosis and lower urinary tract symptoms unresponsive to medical therapy were treated with 12 weekly sessions of percutaneous tibial nerve stimulation. Responder patients (50% or greater improvement of lower urinary tract symptoms as measured by the patient perception of bladder condition questionnaire) entered a maintenance phase with individualized treatment frequency based on patient response. Lower urinary tract symptoms were assessed using a 3-day frequency volume chart, urodynamics and patient perception of bladder condition questionnaire. Treatment satisfaction was evaluated using a global response assessment scale and a treatment satisfaction visual analog scale. A total of 83 patients were included in the study and 74 (89%) responded to initial treatment. Persistent efficacy occurred in all initial responders after a mean treatment of 24 months. The greatest frequency of maintenance percutaneous tibial nerve stimulation was every 2 weeks. Lower urinary tract symptoms and patient treatment satisfaction improved with time compared to initial treatment (p <0.05). Bladder diary parameters and voiding parameters improved compared to baseline (p <0.05). Prolonged percutaneous tibial nerve stimulation treatment leads to a persistent improvement of lower urinary tract symptoms in patients with multiple sclerosis.

Avaliação da adição do tramadol sobre o tempo de regressão do bloqueio motor induzido pela lidocaína: estudo experimental em ratos

JUSTIFICATIVA E OBJETIVOS: O tramadol bloqueia potenciais somatossensitivos in vitro e pode ser associado a anestésicos locais com o intuito de melhorar a qualidade da analgesia. O objetivo deste estudo foi avaliar se o tramadol altera o tempo de regressão do bloqueio motor da lidocaína em duas diferentes concentrações. MÉTODO: Ratos machos da linhagem Wistar, pesando de 250 a 300 g, foram submetidos a bloqueio de nervo ciático guiado por neuroestimulação percutânea. Os animais foram distribuídos em quatro grupos (n = 5 por grupo): lidocaína a 2% (GI), lidocaína a 0,5% (GII), lidocaína a 2% / tramadol 1,25 mg (GIII), e lidocaína a 0,5% / tramadol 1,25 mg (GIV). Foram avaliados tempo de regressão parcial e tempo de regressão completa do bloqueio motor. RESULTADOS: Todos os animais apresentavam bloqueio motor completo no momento do despertar da anestesia, que regrediu completamente durante o período de observação. O tempo de regressão completa do efeito da lidocaína a 2% foi 41 ± 1,71 minutos, lidocaína a 0,5% foi 25,26 ± 0,83 minutos, lidocaína a 2% / tramadol foi 46,06 ± 0,88 minutos e lidocaína a 0,5% / tramadol foi 36,15 ± 1,18 minutos. A associação da lidocaína a 0,5% ao tramadol 1,25 mg foi mais eficaz que lidocaína a 0,5% isoladamente. Os dados são apresentados como média ± erro padrão da média (epm). Considerou-se significativo p < 0,05 usando a ANOVA seguido do teste de Tukey. CONCLUSÃO: Tramadol possui efeitos semelhantes a anestésicos locais e, quando usado como adjuvante da lidocaína, prolonga a duração do bloqueio motor em ratos.

Percutaneous Nerve Stimulation in Chronic Neuropathic Pain Patients due to Spinal Cord Injury: A Pilot Study

The long-term prognosis for neuropathic pain resolution following spinal cord injury (SCI) is often poor. In many SCI patients, neuropathic pain continues or even worsens over time. Thus, new treatment approaches are needed. We conducted a pilot study to evaluate the feasibility and effect of percutaneous (electrical) nerve stimulation (P(E)NS) in SCI patients with chronic neuropathic pain. In 18 weeks, 12 P(E)NS treatments were scheduled. Assessment with questionnaires was performed at baseline (T0), after 8 weeks (T8), 18 weeks (T18), and 12 weeks post-treatment (T30). From 26 screened patients, 17 were included. In total, 91.2% questionnaires were returned, 2 patients dropped out, and 4.2% of the patients reported minor side effects. Pain scores on the week pain diary measured with the numerical rating scale improved significantly at T8, from 6.5 at baseline to 5.4, and were still significantly improved at T18. Pain reduction of ≥ 30% directly after a session was reported in 64.6% sessions. In total, 6 patients experienced reduction in size of the pain areas at T18 and T30, with a mean reduction of 45.8% at T18 and 45.3% at T30. P(E)NS is feasible as an intervention in SCI patients and might have a positive effect on pain reduction in a part of this patient group.

Randomized controlled trial of percutaneous versus transcutaneous posterior tibial nerve stimulation in faecal incontinence

Percutaneous, transcutaneous and sham transcutaneous posterior tibial nerve stimulation was compared in a prospective blinded randomized placebo-controlled trial. Patients who had failed conservative treatment for faecal incontinence were randomized to one of three groups: group 1, percutaneous; group 2, transcutaneous; group 3, sham transcutaneous. Patients in groups 1 and 2 received 30-min sessions of posterior tibial nerve stimulation twice weekly for 6 weeks. In group 3, transcutaneous electrodes were placed in position but no stimulation was delivered. Symptoms were measured at baseline and after 6 weeks using a bowel habit diary and St Mark's continence score. Response to treatment was defined as a reduction of at least 50 per cent in weekly episodes of faecal incontinence compared with baseline. Thirty patients (28 women) were enrolled. Nine of 11 patients in group 1, five of 11 in group 2 and one of eight in group 3 had a reduction of at least 50 per cent in weekly episodes of faecal incontinence at the end of the 6-week study phase (P = 0·035). Patients undergoing percutaneous nerve stimulation had a greater reduction in the number of incontinence episodes and were able to defer defaecation for a longer interval than those undergoing transcutaneous and sham stimulation. These improvements were maintained over a 6-month follow-up period. Posterior tibial nerve stimulation has short-term benefits in treating faecal incontinence. Percutaneous therapy appears to have superior efficacy to stimulation applied by the transcutaneous route. NCT00530933 (http://www.clinicaltrials.gov).

Percutaneous Tibial Nerve Stimulation: A Clinically and Cost Effective Addition to the Overactive Bladder Algorithm of Care

Overactive bladder affects millions of adults, with profound personal and economic costs. Although antimuscarinic drugs can cause a reduction in voiding symptoms, the effect is modest, and many patients are intolerant of the side effects, or do not experience sufficient relief. For these patients, the modulation of bladder reflex pathways via percutaneous tibial nerve stimulation (PTNS) or via implanted sacral nerve stimulation (SNS) has been acknowledged as a logical next step in the algorithm of care. This review examines the mechanism of action, the relative benefits, adverse effects, and costs of percutaneous nerve stimulation compared to other treatment modalities.

Feasibility of Percutaneous Vagus Nerve Stimulation for the Treatment of Acute Asthma Exacerbations

This study assessed the feasibility of an investigational vagus nerve stimulation (VNS) device for treating acute asthma exacerbations in patients not responding to at least 1 hour of initial standard care therapy. This was a prospective, nonrandomized study of patients treated in the ED for moderate to severe acute asthma (forced expiratory volume in 1 second [FEV(1)] 25% to 70% of predicted). Treatment entailed percutaneous placement of an electrode near the right carotid sheath and 60 minutes of VNS and continued standard care. VNS voltage was adjusted to perceived improvement, muscle twitching, or adverse events (AEs). All AEs, vital signs, FEV(1), perceived work of breathing (WOB), and final disposition were recorded. Twenty-five subjects were enrolled. There were no serious AEs and no significant changes in vital signs. No subject required terminating VNS. One patient had minor bleeding from the procedure, and one had a hematoma and withdrew prior to VNS. AEs related to VNS were temporary and included cough (1 of 24), swallowing difficulty (2 of 24), voice change (2 of 24), and muscle twitching (14 of 24). These resolved when VNS ended. The FEV(1) improved at 15 minutes (median = 15.8%, 95% confidence interval [CI] = 9.3% to 22.4%), 30 minutes (median = 21.3%, 95% CI = 8.1% to 36.5%), and 60 minutes (median = 27.5%, 95% CI = 11.3% to 43.5%). WOB improved at 15 minutes (median = 53.9%, 95% CI = 33.7% to 73.9%), 30 minutes (median = 69.1%, 95% CI = 56.4% to 81.8%), and 60 minutes (median = 81.0%, 95% CI = 68.5% to 93.5%). Percutaneous VNS did not result in serious AEs and was associated with improvements in FEV(1) and perceived dyspnea. Percutaneous VNS appears to be feasible for use in the treatment of moderate to severe acute asthma in patients unresponsive to initial standard care treatment.

Tibial and Common Fibular Nerve Block in the Popliteal Fossa with Single Puncture Using Percutaneous Nerve Stimulator: Anatomical Considerations and Ultrasound Description

Techniques of peripheral nerve block have gained popularity over the last two decades becoming a growing anesthetic option for limb surgeries. This study proposes a technical approach of the tibial and common fibular nerves in the popliteal fossa with single puncture using percutaneous nerve stimulator, considering the correlation with an anatomical and ultrasound study. This prospective, observational, randomized study was performed with 28 patients scheduled for foot surgeries. After localizing the tibial and common fibular nerves through percutaneous stimulation, the puncture was performed at the point of tibial nerve stimulation with a 5-cm needle (B.Braun, Stimuplex 50), and 10 mL of levobupivacaine were injected. The needle was pulled back and redirected to the point of common fibular nerve stimulation looking for the corresponding motor response, and 10 mL of the local anesthetic were injected. Imaging study of the popliteal region was performed by ultrasound to correlate the anatomy with the technique used. Adequate anesthesia was obtained in all cases. The mean time to localize the tibial and common fibular nerves suing the percutaneous stimulator was 57.1 and 32.8 seconds, respectively, and with the nerve stimulator it was 2.22 and 1.79 minutes, respectively. The mean depth of the needle into the tibial nerve was 10.7 mm. The approach for tibial and common fibular nerves with single puncture in the popliteal fossa using peripheral nerve stimulator is a good option for anesthesia and analgesia for foot surgeries.

UP-03.192 Tibial Nerve Stimulation in Women with Non-Neurogenic Lower Urinary Tract Dysfunction

Non-neurogenic lower urinary tract dysfunction is a common urological problem. Electrical stimulation is a treatment approach for management of voiding dysfunction. In this prospective study, we evaluated efficacy and safety of percutaneous peripheric nerve stimulation (PPNS) for treatment of women with non-neurogenic bladder overactivity (BO) or chronic urinary retention (CUR).

&lt;em&gt;In Vivo&lt;/em&gt; Canine Muscle Function Assay

We describe a minimally-invasive and reproducible method to measure canine pelvic limb muscle strength and muscle response to repeated eccentric contractions. The pelvic limb of an anesthetized dog is immobilized in a stereotactic frame to align the tibia at a right angle to the femur. Adhesive wrap affixes the paw to a pedal mounted on the shaft of a servomotor to measure torque. Percutaneous nerve stimulation activates pelvic limb muscles of the paw to either push (extend) or pull (flex) against the pedal to generate isometric torque. Percutaneous tibial nerve stimulation activates tibiotarsal extensor muscles. Repeated eccentric (lengthening) contractions are induced in the tibiotarsal flexor muscles by percutaneous peroneal nerve stimulation. The eccentric protocol consists of an initial isometric contraction followed by a forced stretch imposed by the servomotor. The rotation effectively lengthens the muscle while it contracts, e.g., an eccentric contraction. During stimulation flexor muscles are subjected to an 800 msec isometric and 200 msec eccentric contraction. This procedure is repeated every 5 sec. To avoid fatigue, 4 min rest follows every 10 contractions with a total of 30 contractions performed.

&lt;em&gt;In Vivo&lt;/em&gt; Canine Muscle Function Assay

We describe a minimally-invasive and reproducible method to measure canine pelvic limb muscle strength and muscle response to repeated eccentric contractions. The pelvic limb of an anesthetized dog is immobilized in a stereotactic frame to align the tibia at a right angle to the femur. Adhesive wrap affixes the paw to a pedal mounted on the shaft of a servomotor to measure torque. Percutaneous nerve stimulation activates pelvic limb muscles of the paw to either push (extend) or pull (flex) against the pedal to generate isometric torque. Percutaneous tibial nerve stimulation activates tibiotarsal extensor muscles. Repeated eccentric (lengthening) contractions are induced in the tibiotarsal flexor muscles by percutaneous peroneal nerve stimulation. The eccentric protocol consists of an initial isometric contraction followed by a forced stretch imposed by the servomotor. The rotation effectively lengthens the muscle while it contracts, e.g., an eccentric contraction. During stimulation flexor muscles are subjected to an 800 msec isometric and 200 msec eccentric contraction. This procedure is repeated every 5 sec. To avoid fatigue, 4 min rest follows every 10 contractions with a total of 30 contractions performed.

Acute effects of whole‐body vibration on peak isometric torque, muscle twitch torque and voluntary muscle activation of the knee extensors

The purpose of this investigation was to compare the acute effects of whole-body vibration (WBV) with a static squat on resting muscle twitch torque, peak isometric torque and voluntary muscle activation of the knee extensors during an isometric maximal voluntary contraction (MVC). Twenty-four healthy, strength-trained males were recruited for this randomized, cross-over design investigation. The WBV treatment consisted of three sets of 60 s of vibration (30 Hz, +/-4 mm) while standing in a semi-squat position. Voluntary muscle activation, peak isometric torque during MVC and resting muscle twitch torque (RTT) through percutaneous femoral nerve stimulation were obtained before and following the treatment. Change in peak isometric torque, voluntary muscle activation and the RTT were calculated as the difference between pre- and post-treatment values. There was no observable post-activation potentiation of muscle twitch torque or enhancement in voluntary muscle activation or peak isometric torque. However, decreases in the peak isometric torque (P=0.0094) and voluntary muscle activation (P=0.0252) were significantly smaller post WBV interventions compared with the control treatment. Based on the current data, it is unclear whether or not this was attributable to the effects of WBV but further research into this possibility is warranted.

Randomized Trial of Percutaneous Tibial Nerve Stimulation Versus Sham Efficacy in the Treatment of Overactive Bladder Syndrome: Results From the SUmiT Trial

The Study of Urgent PC vs Sham Effectiveness in Treatment of Overactive Bladder Symptoms (SUmiT) was a multicenter, double-blind, randomized, controlled trial comparing the efficacy of percutaneous tibial nerve stimulation to sham through 12 weeks of therapy. The improvement in global response assessment, voiding diary parameters, and overactive bladder and quality of life questionnaires was evaluated. A total of 220 adults with overactive bladder symptoms were randomized 1:1 to 12 weeks of treatment with weekly percutaneous tibial nerve stimulation or sham therapy. Overactive bladder and quality of life questionnaires as well as 3-day voiding diaries were completed at baseline and at 13 weeks. Subject global response assessments were completed at week 13. The 13-week subject global response assessment for overall bladder symptoms demonstrated that percutaneous tibial nerve stimulation subjects achieved statistically significant improvement in bladder symptoms with 54.5% reporting moderately or markedly improved responses compared to 20.9% of sham subjects from baseline (p <0.001). All individual global response assessment subset symptom components demonstrated statistically significant improvement from baseline to 13 weeks for percutaneous tibial nerve stimulation compared to sham. Voiding diary parameters after 12 weeks of therapy showed percutaneous tibial nerve stimulation subjects had statistically significant improvements in frequency, nighttime voids, voids with moderate to severe urgency and urinary urge incontinence episodes compared to sham. No serious device related adverse events or malfunctions were reported. This pivotal multicenter, double-blind, randomized, sham controlled trial provides level I evidence that percutaneous tibial nerve stimulation therapy is safe and effective in treating overactive bladder symptoms. The compelling efficacy of percutaneous tibial nerve stimulation demonstrated in this trial is consistent with other recently published reports and supports the use of peripheral neuromodulation therapy for overactive bladder.

Randomized Trial of Percutaneous Tibial Nerve Stimulation Versus Extended-Release Tolterodine: Results From the Overactive Bladder Innovative Therapy Trial

The Overactive Bladder Innovative Therapy trial was a randomized, multicenter, controlled study that compared the effectiveness of percutaneous tibial nerve stimulation to extended-release tolterodine. The reduction in overactive bladder symptoms along with global response assessments was evaluated. A total of 100 adults with urinary frequency were randomized 1:1 to 12 weeks of treatment with weekly percutaneous tibial nerve stimulation or to 4 mg daily extended-release tolterodine. Voiding diaries and an overactive bladder questionnaire were completed at baseline and at the end of therapy to compare 24-hour voiding frequency, urinary urge incontinence episodes, voids causing waking, volume voided, urgency episodes and quality of life indices. Global response assessments were completed by subjects and investigators after 12 weeks of therapy. The global response assessment demonstrated that subject assessment of overactive bladder symptoms compared to baseline was statistically significant in the percutaneous tibial nerve stimulation arm with 79.5% reporting cure or improvement compared to 54.8% of subjects on tolterodine (p = 0.01). Assessments by investigators were similar but did not reach statistical significance (p = 0.05). After 12 weeks of therapy objective measures improved similarly in both groups for reductions in urinary frequency, urge urinary incontinence episodes, urge severity and nighttime voids, as well as for improvement in voided volume. There were no serious adverse events or device malfunctions. This multicenter, randomized trial demonstrates that percutaneous tibial nerve stimulation is safe with statistically significant improvements in patient assessment of overactive bladder symptoms, and with objective effectiveness comparable to that of pharmacotherapy. Percutaneous tibial nerve stimulation may be considered a clinically significant alternative therapy for overactive bladder.

Revision of a Superficially Migrated Percutaneous Occipital Nerve Stimulator Electrode Using a Minimally Invasive Technique

Objective. Percutaneous techniques for occipital nerve stimulation have been in the literature since 1999. Lead migration continues to be the most common complication to the technique. The authors would like to introduce a new technique for revision of a superficially migrated occipital nerve stimulator electrode. Materials and Methods. Technical report of initial case where revision was performed. Results. The patient had successful revision of his superficially migrated occipital nerve stimulator using a new percutaneous approach. He had no signs of infection and full return of prior function of the stimulator at two weeks and three-month follow-up visits. Conclusion. This case demonstrates a new safer technique for revision of a superficially migrated occipital nerve stimulator lead. The technique is a more direct and simple solution to a common problem in the percutaneous placement of occipital nerve stimulators.

POD-11.01: Percutaneous pudendal nerve stimulation for the treatment of urge incontinence

POD-11.01: Percutaneous pudendal nerve stimulation for the treatment of urge incontinence

Early Excision of a Full-Thickness Burn Prevents Peripheral Nerve Conduction Deficits in Mice

A full-thickness 20 percent body surface area burn in mice produces a significant decrease in tibial motor nerve conduction velocity within 6 hours of the burn and in sensory conduction velocity within 7 days. This suggests that cutaneous burn injury produces a systemic response that affects peripheral motor and sensory nerve function at a distance from the burn site. The authors tested the hypothesis that burn wound excision either 30 minutes or 3 hours after burn would prevent neuropathy. A 20 percent body surface area third-degree burn was applied to the backs of anesthetized mice using procedures that followed National Institutes of Health guidelines. Motor nerve conduction velocity and sensory conduction velocity were determined in intact, anesthetized mice by percutaneous nerve stimulation. Burn wounds were excised and closed at 30 minutes or 3 hours after burn. Motor nerve conduction velocity and sensory conduction velocity were measured before burn and 1, 3, 7, 14, and 21 days after a burn or sham procedure. The number of circulating neutrophils and serum concentrations of tumor necrosis factor-alpha, nitrite, and electrolytes were also determined in each group. Motor nerve conduction velocity and sensory conduction velocity in the 30-minute excision (n = 10) and sham group (n = 5) were not significantly different. Motor nerve conduction velocity and sensory conduction velocity in the nonexcised group (n = 10) and 3-hour excision group (n = 10) were significantly decreased. Serum tumor necrosis factor-alpha concentration was elevated 6 hours after burn in nonexcised animals (n = 9) and in 3-hour excision mice (n = 8) but was not significantly different in the sham (n = 8) and the 30-minute excision group (n = 7). The authors conclude that burn wound excision at 30 minutes but not at 3 hours prevents the nerve conduction deficits measured in mice with 20 percent body surface area burns. The cellular basis of burn-induced neuropathy is unknown, but nitric oxide and tumor necrosis factor alpha-alpha appear to play a role.

Bacterial contamination of test stimulation leads during percutaneous nerve stimulation

Objectives To analyze the bacterial contamination of conventional percutaneous nerve stimulation (PNE) leads. Sacral neuromodulation has become an important tool for the treatment of urgency and chronic retention. Patients likely to benefit from this type of therapy are identified by PNE testing before implantation of the definitive system. Recently, a new system was introduced, using a self-blocking electrode that remains in place for both PNE testing and final implantation. PNE testing warrants an extracorporeal stimulator. Thus, using the same electrode for both external stimulation and definitive implantation may carry a significant risk of infection. Methods Bilateral PNE testing was performed in 11 consecutive patients (8 women and 3 men, mean age 41.6 years) for either urgency (n = 7) or chronic retention (n = 4). Electrodes were placed under aseptic conditions and stimulated for 3 days. At the end of each test, the electrodes were removed and evaluated microbiologically. Results In 5 of the 11 patients (9 of 22 leads), significant bacterial growth was detected: Staphylococcus epidermidis in 5, Escherichia coli in 3, and Enterococcus faecalis in 1. However, no patient showed signs of inflammation at the electrode insertion sites. Conclusions Bacterial growth was found in 45.5% of the patients after conventional PNE testing under aseptic conditions. Therefore, the new electrodes may well carry an elevated risk of infection. Infection of the implant can lead to major surgical revision or even explantation. Thus, additional studies of the infection risk of this new electrode are warranted before its general use can be recommended.