Urodynamic effect of acute transcutaneous posterior tibial nerve stimulation in overactive bladder

PURPOSE

Of the various treatments proposed for urge incontinence, frequency and urgency electrostimulation has been widely tested. Different techniques have been used with the necessity of surgical implantation (S3 neuromodulation or sacral root stimulation) or without requiring surgery (perineal transcutaneous electrostimulation). Recently peripheral electrical stimulation of the posterior tibial nerve was proposed for irritative symptoms in first intention or for intractable incontinence. Clinical studies have demonstrated good results and urodynamic parameters were improved after chronic treatment. However, to our knowledge no data concerning acute stimulation and immediate cystometry modifications have been reported. We verified urodynamic changes during acute posterior tibial nerve stimulation.

MATERIALS AND METHODS

A total of 44 consecutive patients with urge incontinence, frequency and urgency secondary to overactive bladder were studied. There were 29 women and 15 men with a mean age +/-SD of 53.3 +/- 18.2 years. Of the patients 37 had detrusor hyperreflexia due to multiple sclerosis (13), spinal cord injury (15) or Parkinson's disease (9), and 7 had idiopathic detrusor instability. Routine cystometry at 50 ml. per minute was done to select the patients with involuntary detrusor contractions appearing before 400 ml. maximum filling volume. Repeat cystometry was performed immediately after the first study during left posterior tibial nerve stimulation using a surface self-adhesive electrode on the ankle skin behind the internal malleolus with shocks in continuous mode at 10 Hz. frequency and 200 milliseconds wide. Volume comparison was done at the first involuntary detrusor contraction and at maximum cystometric capacity. The test was considered positive if volume at the first involuntary detrusor contraction and/or at maximum cystometric capacity increased 100 ml. or 50% during stimulation in compared with standard cystometry volumes.

RESULTS

Mean first involuntary detrusor contraction volume on standard cystometry was 162.9 +/- 96.4 ml. and it was 232.1 +/- 115.3 ml. during posterior tibial nerve stimulation. Mean maximum cystometric capacity on standard cystometry was 221 +/- 129.5 ml. and it was 277.4 +/- 117.9 ml. during stimulation. Posterior tibial nerve stimulation was associated with significant improvement in first involuntary detrusor contraction volume (p <0.0001) and significant improvement in maximum cystometric capacity (p <0.0001). The test was considered positive in 22 of the 44 patients.

CONCLUSIONS

These results suggest an objective acute effect of posterior tibial nerve stimulation on urodynamic parameters. Improved bladder overactivity is an encouraging argument to propose posterior tibial nerve stimulation as a noninvasive treatment modality in clinical practice.

Steroid injection for heel pain: evidence of short-term effectiveness. A randomized controlled trial

OBJECTIVES

To compare the effectiveness of a steroid injection (25 mg/ml prednisolone acetate) with a local anaesthetic control in the treatment of heel pain and to determine any advantage for patients' comfort of using a posterior tibial nerve block to anesthetize the heel prior to infiltration.

METHODS

A double-blind randomized controlled trial using a 2 x 2 design in a hospital-based rheumatology clinic. Subjects comprised 106 patients with heel pain referred by general practitioners and other rheumatologists working in Camden and Islington Health Authority.

MAIN OUTCOME MEASURES

heel pain reduction at 1, 3 and 6 months, and patient comfort at the time of injection. All outcomes were measured using a 10 cm visual analogue scale.

RESULTS

A statistically significant reduction in pain was detected at 1 month (P=0.02) in favour of steroid injection, but thereafter no differences could be detected. Patient comfort was not significantly affected by anaesthesia of the heel (P=0.5).

CONCLUSIONS

A steroid injection can provide relief from heel pain in the short term. There appears to be no increase in patient comfort from anaesthetizing the heel prior to infiltration.

Urinary incontinence in women

Urinary incontinence affects women of all ages. History, physical examination, and certain tests can guide specialists in diagnosing stress urinary incontinence, urgency urinary incontinence, and mixed urinary incontinence. First line management includes lifestyle and behavior modification, as well as pelvic floor strength and bladder training. Drug therapy is helpful in the treatment of urgency incontinence that does not respond to conservative measures. In addition, sacral neuromodulation, intravesical onabotulinumtoxinA injections, and posterior tibial nerve stimulation can be used in select patient populations with drug refractory urgency incontinence. Midurethral synthetic slings, including retropubic and transobturator approaches, are safe and efficacious surgical options for stress urinary incontinence and have replaced more invasive bladder neck slings that use autologous or cadaveric fascia. Despite controversy surrounding vaginal mesh for prolapse, synthetic slings for the treatment of stress urinary incontinence are considered safe and minimally invasive.

Percutaneous tibial nerve stimulation in the treatment of refractory overactive bladder syndrome: is maintenance treatment necessary?

OBJECTIVE

To determine the effect of a pause in percutaneous tibial nerve stimulation (PTNS) in successfully treated patients with an overactive bladder (OAB), and the reproducibility of successful treatment when restored.

PATIENTS AND METHODS

Eleven patients (mean age 51 years) with refractory OAB (more than seven voids and/or three or more urge incontinence episodes per day) were successfully treated with PTNS, and then discontinued treatment. Patients completed bladder diaries and quality-of-life (QoL) questionnaires (Short Form-36 and I-QoL) before (T1) and after a 6-week pause (T2) of maintenance PTNS, and again after re-treatment (T3). The first objective was defined as a > or = 50% increase in the incontinence episodes and/or voiding frequency in the bladder diary after T2. The second objective was defined as > or = 50% fewer incontinence episodes and/or voiding frequency in bladder diary after T3.

RESULTS

At T2, seven of the 11 patients had a > or = 50% increase in incontinence episodes and/or voiding frequency in the bladder diary. The mean voided volume, nocturia, number of incontinence episodes and incontinence severity deteriorated significantly (P < 0.05). At T3, nine patients had > or = 50% fewer incontinence episodes and/or voiding frequency in the bladder diary. Nocturia, the number of incontinence episodes, incontinence severity, mean voided volume and quality of life improved significantly (P < 0.05).

CONCLUSIONS

Continuous therapy is necessary in patients with OAB treated successfully by PTNS. The efficacy of PTNS can be reproduced in patients formerly treated successfully.

Temporal summation--the key to motor evoked potential spinal cord monitoring in humans

Spinal motor evoked potentials (SMEP) were recorded from tibialis anterior muscle after epidural stimulation of the spinal cord at the low cervical or high thoracic level during scoliosis surgery. By using a double stimulus pulse to produce temporal summation within the spinal cord a maximal CMAP response was readily achieved despite good surgical anaesthesia.

Reversible spinal cord trauma in cats. Additive effects of direct pressure and ischemia

✓ In the barbiturate-anesthetized cat, spinal cord function was estimated using averaged cortical evoked potentials (CEP) elicited by stimulating the posterior tibial nerve. Although neither spinal cord compression nor an aortic blood pressure one-half the systemic pressure when applied individually blocked the CEP, these same factors when applied in combination produced reversible block of the CEP.

Percutaneous tibial nerve stimulation as neuromodulative treatment of chronic pelvic pain

PURPOSE

Neuromodulative therapies have been used with moderate success in patients with chronic pelvic pain. Intermittent Percutaneous Tibial Nerve Stimulation (PTNS) is a new, minimally invasive treatment option, which has shown to significantly decrease accompanying pain complaints in patients with lower urinary tract dysfunction, such as urge incontinence or urgency/frequency. In our study, we evaluate the objective results of PTNS in patients with chronic pelvic pain as their main complaint.

MATERIALS AND METHODS

In a prospective multicentre trial PTNS was evaluated in 33 patients with chronic pelvic pain. Effects were recorded by Visual Analogue Scale (VAS) for pain diaries, the McGill pain questionnaire and the SF-36 general quality of life questionnaire at baseline and after 12 weeks of treatment. Subjective (patients' request to continue chronic treatment to keep the obtained success) and objective responses (decrease in mean VAS >50% and VAS <3 after treatment) were evaluated.

RESULTS

A subjective response was seen in 42% of all patients. In seven patients (21%) mean VAS decreased >50%, in six cases (18%) the decrease was >25%. After 12 weeks of treatment, seven patients (21%) ended up with a mean VAS <3. In all patients quality of life (SF-36) significantly improved, as did the total pain rate intensity (McGill).

CONCLUSIONS

Despite very modest overall success rates and the need for placebo-controlled studies, PTNS may have a place in the treatment of patients with chronic pelvic pain who have already tried many other therapies and are left with no further option.

Preliminary results of peripheral transcutaneous neuromodulation in the treatment of idiopathic fecal incontinence

PURPOSE

Few therapeutic tools are available for treating idiopathic anal incontinence. Sacral neuromodulation appears to be effective in selected patients but requires surgical implantation of a permanent electrical stimulator. The aim of this work was to assess the efficiency of posterior tibial nerve (PTN) transcutaneous electrical nerve stimulation (TENS) in the treatment of anal idiopathic incontinence.

METHODS

Ten women were treated by PTN TENS, 20 min a day for 4 weeks. Functional results were evaluated by Wexner's incontinence score and anorectal manometry.

RESULTS

Eight of the ten patients showed a 60% mean improvement of their incontinence score after 4 weeks. This improvement remained stable over the 12-week follow-up period. Manometric parameters did not differ before and after stimulation.

CONCLUSION

PTN neuromodulation without surgically implanted electrode could represent a safe and low-cost alternative to permanent sacral neuromodulation for idiopathic anal incontinence.

Mechanisms of injury-induced calcium entry into peripheral nerve myelinated axons: role of reverse sodium-calcium exchange

To investigate the route of axonal Ca2+ entry during anoxia, electron probe x-ray microanalysis was used to measure elemental composition of anoxic tibial nerve myelinated axons after in vitro experimental procedures that modify transaxolemmal Na+ and Ca2+ movements. Perfusion of nerve segments with zero-Na+/Li(+)-substituted medium and Na+ channel blockade by tetrodotoxin (1 microM) prevented anoxia-induced increases in Na and Ca concentrations of axoplasm and mitochondria. Incubation with a zero-Ca2+/EGTA perfusate impeded axonal and mitochondrial Ca accumulation during anoxia but did not affect characteristic Na and K responses. Inhibition of Na(+)-Ca2+ exchange with bepridil (50 microM) reduced significantly the Ca content of anoxic axons although mitochondrial Ca remained at anoxic levels. Nifedipine (10 microM), an L-type Ca2+ channel blocker, did not alter anoxia-induced changes in axonal Na, Ca, and K. Exposure of normoxic control nerves to tetrodotoxin, bepridil, or nifedipine did not affect axonal elemental composition, whereas both zero-Ca2+ and zero-Na+ solutions altered normal elemental content characteristically and significantly. The findings of this study suggest that during anoxia, Na+ enters axons via voltage-gated Na+ channels and that subsequent increases in axoplasmic Na+ are coupled functionally to extraaxonal Ca2+ import. Intracellular Na(+)-dependent, extraaxonal Ca2+ entry is consistent with reverse operation of the axolemmal Na(+)-Ca2+ exchanger, and we suggest that this mode of Ca2+ influx plays a general role in peripheral nerve axon injury.

The effects of isoflurane and propofol on intraoperative neurophysiological monitoring during spinal surgery

OBJECTIVES

To compare the effects of isoflurane and propofol on intraoperative neurophysiological monitoring (IONM) during spinal surgery.

METHODS

Thirty-five patients were randomly assigned to receive isoflurane (n = 17) or propofol (n = 18) anesthesia. Somatosensory evoked potentials (SEPs) following posterior tibial nerve stimulation were recorded before induction as baselines. Isoflurane concentrations and propofol infusions were adjusted to obtain four pre-determined BIS ranges: 65-55, 55-45, 45-35 and 35-25. For each range, a stable state was maintained for at least 10 min to perform IONM. The SEP latency P40 and amplitude P40-N50, the onset latency and amplitude of transcranial motor evoked potentials (tcMEPs), and threshold intensity of triggered electromyographic activity (EMG) following pedicle screw stimulation were statistically analyzed.

RESULTS

Compared with baseline values, P40 latency increased and P40-N50 amplitude decreased after anesthesia with isoflurane or propofol. Isoflurane caused a dose-dependent depression of SEPs, but propofol did not. TcMEPs were recordable and stable in all patients receiving propofol in each BIS range, but only recordable in 10 (58.8%) receiving isoflurane with BIS >55, and 3 (17.8%) with BIS <55. No difference was noted in triggered EMG.

CONCLUSIONS

Isoflurane inhibited IONM more than propofol. Propofol is recommended for critical spinal surgery, particularly when motor pathway function is monitored.

Progress of Flexible Electronics in Neural Interfacing - A Self-Adaptive Non-Invasive Neural Ribbon Electrode for Small Nerves Recording

A novel flexible neural ribbon electrode with a self-adaptive feature is successfully implemented for various small nerves recording. As a neural interface, the selective recording capability is characterized by having reliable signal acquisitions from the sciatic nerve and its branches such as the peroneal nerve, the tibial nerve, and the sural nerve.

Randomized trial of transcutaneous tibial nerve stimulation to treat urge urinary incontinence in older women

INTRODUCTION

The aim of this study was to examine the efficacy of transcutaneous electrical tibial nerve stimulation (TTNS) to treat urge urinary incontinence (UUI) in older women.

MATERIAL AND METHODS

The study design was a randomized clinical trial conducted on 51 elderly women (>60 years) with UUI. All were treated with 12 weeks of bladder retraining and pelvic floor muscle exercises, and 25 were randomly selected to receive TTNS in addition to the standard therapy. The cases were evaluated at the baseline and after the end of therapy by 3-day bladder diary, quality of life questionnaires (QoL), and subjective response.

RESULTS

Of the patients, 68.0% in TTNS group reported cure or improvement vs. 34.6% in the control group (P = 0.017). TTNS showed significant improvement in most areas of QoL and in UUI parameters when compared with the control group.

CONCLUSION

TTNS is efficacious to treat UUI in older women.

Schwannoma of the posterior tibial nerve: the problem of delay in diagnosis

Schwannomas are the most common tumours of the sheath of peripheral nerves. The clinical diagnosis is usually straightforward, but may be delayed for many years in a schwannoma of the posterior tibial nerve. The symptoms are often attributed to entrapment neuropathy or to lumbosacral radiculopathy. We describe 25 patients with a schwannoma of the posterior tibial nerve. Only three were diagnosed within a year of presentation. The mean time to diagnosis was 86.5 months with a median of 48 months (2 to 360). All the patients complained of pain, which was felt specifically in the sole of the foot in 18. A Tinel sign was detected in all 25 patients. MRI confirmed the diagnosis in all the cases in which it had been undertaken. Surgical resection of the lesion abolished the neuropathic pain. In patients with a long history of neuropathic pain in the lower limb in whom lumbar and pelvic lesions have been excluded, a benign tumour of the sheath of a peripheral nerve may explain the symptoms. Surgical resection of the tumour is safe and effective.

Ankle-foot orthoses: effect on gait abnormalities in tibial nerve paralysis

To study the biomechanical effects of gastrocnemius-soleus dysfunction and its potential remediation, the gait patterns of six able-bodied young adults were analyzed before and after induced temporary tibial nerve paralysis. Ambulation with the tibial nerve block was performed with and without the assistance of an ankle-foot orthosis (AFO) with a rigid anterior stop adjusted to either 5 degrees plantarflexion or 5 degrees dorsiflexion. The gait abnormalities resulting from tibial nerve paralysis include delayed advancement of the center of pressure, delayed ipsilateral heeloff and early contralateral heelstrike, decreased steplength, decreased ankle dorsiflexion moment, and increased knee flexion moment. This study provides quantitative information on the degree to which these abnormalities were corrected by appropriately adjusted AFOs. When using an AFO with an anterior stop, subjects with tibial nerve paralysis had improved advancement of the center of pressure (p less than 0.01). The body's ground reactive force line moved forward more normally, pivoting over the metatarsal head area and raising the heel earlier than observed with uncorrected tibial nerve paralysis, thus approximating the normal ankle dorsiflexion moment, normal timing of gait events, normal advancement of the hip, and normal steplength. The AFO with the anterior stop set at 5 degrees plantarflexion was more effective in restoring the values to normal than the AFO with the anterior stop set at 5 degrees dorsiflexion, but still did not consistently achieve the normal values. Only by using the AFO with the anterior stop set at 5 degrees plantarflexion was the increased knee flexion moment observed during the block reduced to normal levels (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Percutaneous Tibial Nerve Neuromodulation is Well Tolerated in Children and Effective for Treating Refractory Vesical Dysfunction

PURPOSE

We evaluated pain tolerability and the preliminary results of percutaneous tibial nerve stimulation (PTNS) in children with unresponsive lower urinary tract symptoms (LUTS).

MATERIALS AND METHODS

A total of 23 children 4 to 17 years old with LUTS refractory to conventional treatment underwent PTNS at 12, 30-minute weekly sessions. Ten patients had idiopathic overactive bladder, 7 were in nonneurogenic urinary retention and 6 had neuropathic bladder. Ten children were carefully evaluated for pain during needle insertion and electrical stimulation using certain scoring systems, namely the faces pain rating scale, Children's Hospital of Eastern Ontario pain scale, visual analogue scale and Questionario Italiano del Dolore. Evaluation was done at the first, sixth and last sessions. An anxiety-depression test was administered. All 23 children underwent clinical and urodynamic evaluation before and after treatment.

RESULTS

All except 1 patient completed treatment. An anxious-depressive trait was found in 7 of 10 children/parents on anxiety-depression testing. Regarding pain, the faces pain rating scale never showed the severe pain face, the Children's Hospital of Eastern Ontario scale showed signs of pain at the beginning of each stimulation but not at the end, and the visual analog scale generally showed a low score with a further decrease during the first (p = 0.05), sixth (p = 0.03) and twelfth (p = 0.02) sessions. The Questionario Italiano del Dolore score was significantly related to the affective component of pain (p = 0.002) and it decreased between the first and last sessions. The 10 children with overactive bladder had symptom improvement in 80%, incontinence was cured in 5 of 9 and urodynamics showed normalization of cystometric bladder capacity in 62.5% with no more unstable contractions in those who became continent. Symptoms improved in 71% of the children in urinary retention. One of 3 and 4 of 7 patients had incontinence and post-void residual urine cured, respectively. Urodynamics showed an improved detrusor pressure at maximum flow (p = 0.009) and flow rate (p = 0.005). Symptoms and urodynamics did not significantly change in the neuropathic bladder group.

CONCLUSIONS

PTNS is safe, minimally painful and feasible in children. It seems helpful for treating refractive nonneurogenic LUTS.

Comparison of the parasacral approach and the posterior approach, with single- and double-injection techniques, to block the sciatic nerve

BACKGROUND

The purpose of this study was to compare parasacral and Winnie's single- or double-injection approaches for sciatic nerve block.

METHODS

One hundred fifty adults scheduled to undergo lower limb surgery were randomized to receive on the sciatic nerve 20 ml ropivacaine, 0.75%: single bolus for parasacral and Winnie's single injection. For Winnie's double injection, the peroneal and tibial nerves received separately 10 ml plus 10 ml. Blocks were performed with the use of nerve stimulator (intensity < 0.5 mA, 1 Hz). For the parasacral method, a line was drawn between the posterior superior iliac spine and the ischial tuberosity; needle entry was at 6 cm inferior to the posterior superior iliac spine.

RESULTS

The groups were similar. Time to perform the block was 2 (1-5) min for the parasacral method, with no difference from Winnie's single injection (3 [1-10] min), but was shorter with double injection (5.5 [2-15] min) (P = 0.0001). Onset of sensory block was similar in the parasacral (25 [7.5-50] min) and Winnie single-injection groups (25 [5-50] min) but significantly longer in the double-injection group (15 [5-50] min). Success rates for complete block were similar in the parasacral (66%) and Winnie's double-injection groups (68%) after 30 min but higher in the Winnie's single-injection group for tibial sensory and motor block (48%) (P < 0.017).

CONCLUSION

Time to perform a parasacral block was short, and the parasacral approach had a high success rate and a short onset time. Therefore, this block might be a useful alternative to Winnie's modification for sciatic nerve block.

Prevention and treatment of painful neuromas of the superficial radial nerve by the end-to-side nerve repair concept: an experimental study and preliminary clinical experience

This article studies the utilization of the end-to-side neurorrhaphy concept in the prevention and treatment of painful neuromas. A total of 20 rats were divided into 2 groups (10 rats per group). In group A, the tibial nerve was divided and left lying in the subcutaneous tissue. In group B, the cut ends of the tibial nerve were sutured to the adjacent peroneal nerve in an end-to-side fashion. Evaluation was performed 90 days after nerve injury. For group A, the proximal end of the tibial nerve formed a "classic" neuroma and the distal end showed a degenerated nerve. In group B, the proximal end of the tibial nerve formed a "non-classic" neuroma and the nerve healed into the peroneal nerve with continuity of the epineurium of the 2 nerves. The distal end of the tibial nerve in group B showed evidence of axonal regeneration. Preliminary clinical experience utilizing the same technique in the prevention and treatment of painful neuromas of the superficial radial nerve is presented and other techniques of nerve-to-nerve implantation are discussed.

Irritation induced bladder overactivity is suppressed by tibial nerve stimulation in cats

PURPOSE

We investigated the effects of tibial nerve stimulation on bladder overactivity induced by acetic acid irritation.

MATERIALS AND METHODS

Cystometry was performed in 10 α-chloralose anesthetized female cats by infusing saline or acetic acid through a urethral catheter that was secured by a ligature around the urethra. Intravesical infusion of 0.25% acetic acid was used to irritate the bladder and induce bladder overactivity. Multiple cystometrograms were done before, during and after tibial nerve stimulation to determine the inhibitory effect on the micturition reflex.

RESULTS

Infusion of 0.25% acetic acid irritated the bladder, induced bladder overactivity and significantly decreased bladder capacity to about 20% of control capacity measured during saline infusion. Tibial nerve stimulation at low (5 Hz) or high (30 Hz) frequency significantly increased bladder capacity to about 40% of saline control capacity when it was applied during acetic acid infusion cystometrogram. Bladder contraction amplitude was smaller during acetic acid irritation than during saline distention due to significantly smaller bladder capacity. Tibial nerve stimulation at 5 Hz increased bladder capacity and bladder contraction amplitude.

CONCLUSIONS

Activation of somatic afferents in the tibial nerve of cats can partially reverse the bladder overactivity induced by intravesical administration of a chemical irritant that activates C-fiber afferent nerves. These data are consistent with clinical studies showing that tibial nerve neuromodulation is effective treatment for overactive bladder symptoms.

Afferent volley patterns and the spinal release of immunoreactive substance P in the dorsal horn of the anaesthetized spinal cat

Microprobes bearing immobilized antibodies to the C-terminus of substance P were used to measure release of this neuropeptide in the spinal cord of the anaesthetized spinal cat in response to peripheral nerve stimulation. Release of substance P was just detectable in laminae I, II with 150 stimuli (0.5 Hz, 5 min) and was near maximal with 300 stimuli. Using two periods of stimulation of 10 min separated by 15 min, greater levels of substance P were detected during the second period. Fifteen to 25 min after two periods of peripheral nerve stimulation levels of substance P detected by microprobes were still elevated above those present prior to stimulation. Stimulation with bursts of three impulses when delivering a fixed number of stimuli resulted in detection of increased levels of substance P at sites adjacent to the areas of maximal release. The results suggest that maximal release of substance P from the central terminals of primary afferent fibres occurs with relatively few impulses and at low frequencies in agreement with what is known of release from the peripheral terminals of these fibres.

Posterior tibial nerve stimulation for overactive bladder-techniques and efficacy

The ideal treatment for overactive bladder is still elusive. In those where medication fails to improve symptoms options include invasive treatments such as botulinum toxin-A, sacral neural stimulation or posterior tibial nerve stimulation. Scientific professional society guidelines advise percutaneous posterior tibial nerve stimulation as a third line treatment option only after multi-disciplinary team review as well as failure of both conservative and pharmacological management. The aim of this article is to review all techniques for tibial nerve stimulation and their efficacy.