Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “SACRAL PLEXUS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 703 records · Page 39Linked to original sources
PubMed1984

Long term results of superselective sacral nerve resection for motor urge incontinence.

Eight female patients suffering from severe urge incontinence not manageable by conservative treatment were subjected to superselective sacral nerve resection in the period 1974-1977. The aim of the resection was a complete parasympathetic decentralization of the bladder. The resection was carried out according to the results of pre-operative sacral nerve blockade and per-operative electrical nerve stimulation. Post-operatively all cystometrograms were shifted to the right and four patients had bladder areflexia. At six months follow-up, three patients were continent, four were improved and one patient had an indwelling catheter for persistent retention. However, incontinence and detrusor instability returned in all the patients within one year. After seven to eight years follow-up one patient had died, two patients had had a urinary diversion operation and three had an indwelling urethral catheter. Only two patients were permanently improved. The surgical procedure was complicated by wound necrosis in one patient, by persistent dysesthesia in two and hypesthesia in three.

Adult↗
PubMed2002

Mictunrition and the sacral reflex arc: lessons from electrophysiological techniques.

Electrophysiological techniques applied either for diagnostic or therapeutic reasons have contributed to elucidation of the neurocontrol of micturition. But the ability of electrophysiological diagnostic tests to reveal neurogenic involvement in patients suffering from lower urinary tract dysfunction is limited, and has been overestimated. Furthermore, the correlation between a proven neurogenic deficit and the consecutive dysfunction is complex. The electrophysiological tests, however, may also be applied for testing the central nervous system integrative function, such as in testing reflex thresholds, excitability levels of motor nuclei, etc. The use of electrical stimulation for therapeutic purposes has instigated much physiological research. Insights related to micturition neurocontrol, as for instance that afferent inputs from lumbosacral and vesical sensory fibres modulate the micturition threshold, are being therapeutically exploited. It is expected that further use of electrophysiological techniques, being complementary to functional neuroimaging, will clarify particularly the temporal aspects of neurocontrol mechanisms involved in micturition.

Electric Stimulation↗
PubMed1998

Sacral reflexes: physiology and clinical application.

Sacral reflexes consist of motor responses in the pelvic floor and sphincter muscles evoked by stimulation of sensory receptors in pelvic skin, anus, rectum, or pelvic viscera. These responses may be elicited by physical or electrical stimuli. They have been used in research studies of the pathophysiology of pelvic floor and anorectal disorders and many have been recommended for diagnostic use. These reflexes are described and discussed in this review. More rigorous evaluation of their value in the clinical assessment and care of patients with pelvic floor and sphincter disorders is required. Currently direct comparisons of the value of particular responses are generally not available, and few of these reflexes have proven validity for use in clinical diagnosis.

Anal Canal↗
PubMed1999

Sacral spinal cord neurons responsive to bladder pelvic and perineal inputs in cats.

In chloralose-anesthetized or decerebrate male cats, 70% of 73 sacral spinal cord neurons activated from the bladder branch of the pelvic nerve also received excitatory inputs from urethra and/or perineal cutaneous nerves (sensory pudendal in 55% and superficial perineal in 84% of neurons). Only 29% of these neurons were excited by the hindlimb skin and muscle nerves tested. The pelvic nerve-responsive neurons received monosynaptic urethral/perineal input in 25% of cases and required temporal summation of this input in 47% of cases. Of 211 neurons responding to superficial perineal nerve stimulation, 101 were not excited by the other nerves tested. Neurons activated by superficial perineal nerve stimulation were found predominantly in S2. It is likely that the superficial perineal nerve represents an important pathway whereby perineal stimulation influences bladder function.

Animals↗
PubMed2002

Electrophysiological recordings during the peripheral nerve evaluation (PNE) test in complete spinal cord injury patients.

Up until now, the exact mechanism by which neuromodulation using sacral nerve stimulation works still remains unknown. Recent studies of pelvic floor contraction during peripheral nerve evaluation (PNE) have shown that several muscle responses are reflexly mediated. However, whether these reflexes originate from a segmental level within the sacral spinal cord or from supraspinal neuronal centers involving spino-bulbospinal pathways remains to be determined. Therefore, recordings of external anal sphincter reflexes during PNE in complete spinal cord injury (SCI) patients was performed. Three patients with complete SCI (two female and one male) suffering from neurogenic incontinence underwent the first stage of a stimulator implant (peripheral nerve evaluation). Stimulation was obtained through an electrode placed in the S3 foramen. Concomitantly, the latency of the response of the striated anal sphincter was measured using a concentric needle electrode placed in the striated part of the anal sphincter. Repeated measurements within an interval of 30 min were performed to confirm the reliability of the responses. In all subjects, reflex responses of early and late latencies could be recorded. The early response showed a mean latency of 41.2 ms (range 33.3-62 ms), which corresponds to a segmental reflex, similar to the pudendo-anal reflex. The late response appeared with a mean latency of 189.4 ms (range: 183.3-197.8 ms) and with high variability and fatigability, suggesting a reflex response organized at polysegmental spinal levels. Despite successful foramina lead placement, none of our complete SCI patients showed any improvement of neurogenic incontinence after 5 days of treatment by sacral nerve stimulation. The findings confirm that the anal contractions observed during peripheral nerve evaluation are reflex responses mediated by afferent pathways. Both the early and late reflex responses are of spinal origin, since they were obtained in complete SCI patients in whom all spino-bulbo spinal loops are supposed to be interrupted. The finding that neuromodulation is working in non-neurogenic patients but is less successful in complete SCI patients could give evidence that preserved spino-bulbo spinal loops contribute to the positive effects of neuromodulation. The role of an eventual spino-bulbo spinal loop acting during neuromodulation in non-neurogenic patients has to be assessed in further studies.

Adolescent↗
PubMed2002

Distribution, immunohistochemical characteristics and nerve pathways of primary sensory neurons supplying the porcine vas deferens.

The present study investigated: (1) the distribution and chemical coding of primary sensory neurons supplying the vas deferens in juvenile pigs by the use of retrograde tracing combined with double-labelling immunofluorescence, (2) nerve pathways from dorsal root ganglia (DRG) to the vas deferens by means of denervation procedures involving transection of the hypogastric or pelvic nerve combined with a retrograde tracing method, and (3) possible interactions of the substance P (SP)/calcitonin gene-related peptide (CGRP)-immunoreactive varicose nerve fibres on vas deferens projecting neurons (VDPN) in the anterior pelvic ganglion (APG). The vast majority of VDPN were found mainly in the lumbar L2, L3 and sacral S2, S3 pairs of DRG and showed a clear ipsilaterally organized projection pattern. Immunohistochemistry revealed that most of these neurons contained SP and/or CGRP, occasionally coexpressed with galanin. Interestingly, pronounced differences in the expression of SP and/or CGRP were observed between the lumbar and sacral VDPN in that most of the lumbar but less than half of the sacral neurons stained for these peptides. Denervation experiments showed that the neurons located within the lumbar DRG project through the ipsilateral hypogastric nerve, whereas those found within the sacral DRG send their processes through the ipsilateral and contralateral pelvic nerve. In the nerve-lesioned animals, especially in those with the hypogastric nerve cut, a dramatic reduction in the number of SP and/or CGRP-containing nerve terminals surrounding the efferent VDPN within the APG was observed. This study has disclosed the distribution and, for the first time, chemical coding and nerve pathways of vas deferens-projecting primary sensory neurons in a mammalian species, the pig. The results obtained also provide some novel information about the possible morphological and functional relationship between vas deferens-projecting primary sensory and pelvic efferent nerve cells.

Afferent Pathways↗
PubMed2003

The role of electrodiagnostic techniques in the reprogramming of patients with a delayed suboptimal response to sacral nerve stimulation.

Sacral neuromodulation is an approved therapy for frequency, urgency, urge incontinence and non-obstructive urinary retention. There are several recent reports on a subgroup of patients who are 'Iate failures' to therapy. This descriptive study aimed to determine whether the use of electrodiagnosis during reprogramming could provide objective data on device function in these patients and help direct therapy. We employed electrodiagnostic techniques to differentiate between those patients who could be reprogrammed in the office to a site of maximal response, those that required reoperation, and those in whom reoperation was unlikely to be successful. Our findings suggest that electrodiagnostic monitoring may help to direct future therapy in this group of patients who currently present a management challenge.

Action Potentials↗
PubMed2007

Sacral nerve stimulation induces pan-colonic propagating pressure waves and increases defecation frequency in patients with slow-transit constipation.

OBJECTIVE: Colonic propagating sequences are important for normal colonic transit and defecation. The frequency of these motor patterns is reduced in slow-transit constipation. Sacral nerve stimulation (SNS) is a useful treatment for fecal and urinary incontinence. A high proportion of these patients have also reported altered bowel function. The effects of SNS on colonic propagating sequences in constipation are unknown. Our aims were to evaluate the effect of SNS on colonic pressure patterns and evaluate its therapeutic potential in severe constipation. METHOD: In eight patients with scintigraphically confirmed slow-transit constipation, a manometry catheter (16 recording sites at 7.5 cm intervals) was positioned colonoscopically and the tip fixed in the caecum. Temporary electrodes (Medtronic) were implanted in the S2 and S3 sacral nerve foramina under general anaesthesia. In the fasted state, 14 Hz stimulation was administered and four sets of parameters (pulse width 300 or 400 micros; S2 and S3) were tested in four 2-h epochs, in random order, over 2 days. Patients were then discharged home with the sacral wires in situ and a 3-week trial stimulation commenced during which patients completed a daily stool diary. RESULTS: When compared with basal activity, electrical stimulation to S3 significantly increased pan-colonic antegrade propagating sequence (PS) frequency (5.4 +/- 4.2 vs 11.3 +/- 6.6 PS/h; P=0.01). Stimulation at S2 significantly increased retrograde PSs (basal 2.6 +/- 1.8 vs SNS 5.6 +/- 4.8 PS/h; P=0.03). During the subsequent three-week trial (continuous stimulation), six of eight reported increased bowel frequency with a reduction in laxative usage. CONCLUSION: These data demonstrate that SNS induces pan-colonic propagating pressure waves and therefore shows promise as a potential therapy for severe refractory constipation.

Adult↗
PubMedDate not supplied

[Temporary sacral neuromodulation in patients with urge incontinence].

We studied the effect of temporary sacral (S3) nerve stimulation in patients with urge incontinence (UI) who were subjected to percutaneous nerve evaluation of the S3 roots as a temporary screening test during 12 days to determine response to neuromodulation. All 18 patients (14 women and 4 men) underwent S3 neuromodulation. The response was assessed by a detailed voiding diary, symptom score and objective outcome was analyzed with urodynamic studies. We noticed a decrease of the average voiding frequency, the number of leakage episodes and pads use per 24 h in 10 days of S3 neuromodulation and returning to baseline symptoms in 20 days after completing S3 neuromodulation. Cystometrograms demonstrated increased cystometric capacity and decreased frequency and amplitude of unstable contractions. Correlation between symptomatic and urodynamic effects was incomplete. Temporary S3 neuromodulation relieved symptoms in UI patients.

Adult↗
PubMed2006

Spontaneous extrusion of sacral nerve implant secondary to massive weight loss.

Sacral neuromodulation (Interstim, Medtronic, Minneapolis, Minnesota) is a recognized treatment for refractory urgency, frequency, and urge incontinence. Revision rates range from 10-33% mainly for pain over the implantable pulse generator site (IPG) or lead migration [Hassouna et al. J Urol 163:1849-1854, 2000; Schmidt et al. J Urol 162:352-357, 1999; Spinelli et al. J Urol 166:541-545, 2001; Swinn et al. Eur Urol 38:439-443, 2000; Weil et al. Eur Urol 37:161-171, 2000; Evaraert et al. Int Urogynecol J Pelvic Floor Dysfunct 11:231-236, 2000]. We report a case of spontaneous extrusion of the IPG through the subcutaneous fat and skin secondary to marked weight loss after gastric bypass surgery. Continued weight loss resulted in multiple surgical interventions and eventual removal of the device.

Aged↗
PubMed2005

Sacral nerve stimulation for faecal incontinence.

Faecal incontinence is a common problem. Conservative measures are effective in a significant proportion of patients. Failure of conservative management has until recently meant recourse to surgical intervention. Surgical treatment is often associated with disappointing results. Recently, sacral nerve stimulation (SNS) has been developed as a minimally invasive, effective technique for idiopathic and acquired faecal incontinence. The technique uses chronic low-level electrical stimulation of the sacral nerves, or neuromodulation, to produce a clinically beneficial effect on the distal colon and rectum, the pelvic floor and the anal sphincter complex. SNS is a 2-stage procedure: a diagnostic stage - temporary percutaneous nerve evaluation (PNE), and a therapeutic stage - permanent SNS. The predictive value of PNE is high, and the surgical trauma and morbidity of both procedures extremely low. The technique has been adapted from its original application in urinary dysfunction. It is almost impossible to produce level 1 evidence for this type of intervention; however, the results are superior to other interventions. Patient selection criteria are evolving, but there is a growing body of evidence that supports its use as first-line treatment for faecal incontinence in patients where conservative measures have failed.

Electric Stimulation Therapy↗
PubMed1998

Reduction of bladder outlet resistance by selective sacral root stimulation using high-frequency blockade in dogs: an acute study.

Detrusor-sphincter dyssynergia is a main problem in supra-sacral spinal cord injured patients. The problem of high pressure voiding is also encountered in most electrically induced micturition because of the mixed somatic and autonomic fiber components of the ventral sacral root. We studied the effect of selective high-frequency blockade at the sacral nerve root in an acute spinalized canine model to prevent the deleterious consequences associated with the elevated bladder outlet resistance. A new functional electrical stimulation system which can generate one signal composed of two independent adjustable current waveforms delivered via a single bipolar electrode was used in 11 dogs. The selectivity resulted from the inhibition of the sphincteric somatic innervation by a high frequency pulse while the low frequency stimuli activated the bladder autonomic fibers. Bladder and urethral pressure as well as electromyograms of external urethral sphincter were recorded to determine whether selective high-frequency blockade occurred. Our experiments showed that we were able to achieve selective blockade of the external urethral sphincter during the simultaneous detrusor stimulation, thus obtaining a more physiologic voiding.

Animals↗
PubMed1983

Pharmacological analysis of the responses of the feline urethra to autonomic nerve stimulation.

The effects of sympathetic and parasympathetic nerve stimulation on resistance to flow in the proximal urethra was examined in male, chloralose-anesthetized cats. Hypogastric (sympathetic) nerve stimulation increased urethral resistance, an effect that was blocked by the alpha-adrenergic antagonist prazosin (0.1 mg/kg), reduced 50% by ganglionic blockade with hexamethonium (0.4 to 0.6 mg/min) and potentiated by the beta-adrenergic antagonist sotalol (5 mg/kg). In the presence of phenylephrine-induced constrictions of the urethra, hypogastric nerve stimulation decreased resistance by a sotalol-sensitive, hexamethonium-resistant mechanism. The results imply that sympathetic stimulation can either raise or lower urethral resistance under different conditions, and that the organization of the nerves mediating the two types of response differs. Because pelvic nerve stimulation produced small and inconsistent responses, the parasympathetic input was instead activated by sacral ventral root stimulation. Sacral stimulation produced an atropine-sensitive constriction when basal urethral resistance was low, and dilatation when resistance was high. The latter response was reduced by atropine, but was resistant to sotalol. However, the decrease in resistance produced by acetylcholine in the presence of PE was not reduced by atropine, implying that acetylcholine-induced dilatation of the urethra is not due to activation of muscarinic receptors on smooth muscle. It is hypothesized that parasympathetic dilatation of the urethra may be mediated by a non-cholinergic, non-adrenergic inhibitory transmitter released from post-ganglionic neurons. A muscarinic mechanism may be involved in this response either to potentiate the action of the unknown transmitter or to facilitate the ganglionic excitation of these neurons. Parasympathetic constrictor responses can be attributed to activation of postganglionic cholinergic neurons.

Acetylcholine↗
PubMed1999

Effects of acute urinary bladder overdistension on bladder response during sacral neurostimulation.

OBJECTIVE: Urinary retention and micturition disorders after overdistension are clinically well-known complications of subvesical obstruction. We attempted to evaluate whether bladder overdistension influences bladder response and whether overdistension supports detrusor decompensation. METHODS: Following lumbal laminectomy in 9 male foxhounds, the sacral anterior roots S2 and S3 were placed into a modified Brindley electrode for reproducible and controlled detrusor activation. The bladder was filled in stages of 50 ml from 0 to 700 ml, corresponding to an overdistension. At each volume, the bladder response during sacral anterior root stimulation was registered. After overdistension, the bladder was refilled stepwise from 0 to 300 ml and stimulated. RESULTS: In all dogs, the bladder response was influenced by the intravesical volume. The maximum pressure (mean 69.1 cm H(2)O) was observed at mean volume of 100 ml. During overdistension, a significant reduction in bladder response of more than 80% was seen. After overdistension, a significant reduction in intravesical pressure of 19.0% was observed. In 2 cases, reduction in bladder response was more than 50% after a single overdistension. CONCLUSIONS: We conclude that motoric bladder function is influenced during and after overdistension. A single bladder overdistension can support acute and long-lasting detrusor decompensation. In order to protect motoric bladder function, bladder overdistension must be prevented.

Animals↗
PubMed2004

Extracellular voltage profile for reversing the recruitment order of peripheral nerve stimulation: a simulation study.

Electrical stimulation of peripheral nerve activates large-diameter fibers before small ones. A physiological recruitment order, from small to large-diameter axons, is desirable in many applications. Previous studies using computer simulations showed that selective activation of small fibers could be achieved by reshaping the extracellular voltage profile along the nerve using an array of nine electrodes. In this study, several electrode-array configurations were tested in order to minimize the number of contacts. Electrode arrays of 5, 7, 9, and 11 contacts with 0.75 mm contact separation were performed in computer simulations of dog sacral root (S2). Electrode arrays of 5 and 7 contacts recruited 40% of small axons (<10 microm) when recruiting only 10% of larger axons. Effectiveness of 9- and 11-contact arrays decreased with the presence of epineurium and perineurium. The effectiveness of electrode arrays was independent of stimulation pulsewidth. The biphasic-pulse stimulation with the amplitude of the second phase set as low as possible should be used to prevent the excitation of large axons during the second phase and to minimize the electrode corrosion. Arrays of 5 and 7 contacts also decreased the recruitment curve slope to 26% and 51% of the tripolar electrode, respectively. This modeling study predicts that reversing the recruitment order of peripheral nerve stimulation could be achieved by reshaping the extracellular voltage using electrode arrays of 5 or 7 contacts.

Action Potentials↗
PubMed2003

Risk of detrusor denervation in antireflux surgery demonstrated in a neurophysiological animal model.

PURPOSE: Earlier anatomical studies have shown a close connection between the ureterovesical junction and detrusor innervation. It prompted us to develop an animal model to demonstrate the risk of partial or complete impairment of this neuronal connection during antireflux surgery. MATERIALS AND METHODS: Six female Göttinger minipigs were anesthetized and laminectomized. After placement of the S3 sacral nerves into separate electrode compartments of a modified Brindley electrode the lower urinary tract was exposed by an abdominal midline incision. After bladder instillation with 150 ml NaCl 1 bilateral and 2 unilateral stimulations (left and right sides) were performed and intravesical pressure was recorded urodynamically. The left ureter was then prepared circularly in 3 steps 10, 5 and 1 cm, respectively, proximal to the ureterovesical junction. After each preparation step bilateral and unilateral stimulation was repeated. Results were recorded urodynamically and video documented. RESULTS: Bilateral stimulation before preparation of the left ureter led to a concentric detrusor contraction with an average maximum detrusor pressure of 51 cm H(2)O. Unilateral stimulation resulted in ipsilateralbound bladder tilting with an intravesical pressure of 18 and 19 cm H(2)O on the right and left sides, respectively. After preparation of the left ureter 10, 5 and 1 cm from the ureterovesical junction a maximum detrusor pressure of 17, 10 and 1 cm H(2)O was documented, respectively. While there was almost no stimulation response of the bladder after the last preparation step at 1 cm on the left ureter, the initial bladder pressure of 18 cm H(2)O could be reproduced under stimulation on the right side. CONCLUSIONS: Analogous to human cadaver studies, we were able to prove neurophysiologically strictly unilateral detrusor innervation, drawing from the pelvic plexus dorsomedial to the ureterovesical junction into the bladder. Preparation of this ureterovesical junction during antireflex surgery, coagulating measures in this area or the affixation of anchor sutures after a Vest suture involves the risk of unilateral or bilateral detrusor decentralization.

Animals↗
PubMed1989

Penile erection in the rat: stimulation of the hypogastric nerve elicits increases in penile pressure after chronic interruption of the sacral parasympathetic outflow.

Penile erection, a vascular event mediated by the autonomic nervous system, is often adversely affected by injury to the spinal cord. To further characterize the laboratory rat as an animal model of penile erection and to investigate erectile responses following neural injury, the present study has examined pressor penile responses in intact rats and in animals deprived of sacral parasympathetic outflow. Increases in penile pressure result from graded stimulation of postganglionic parasympathetic fibers. The vasodilator response is insensitive to blockade with atropine, a cholinergic antagonist. Penile tumescence also results from stimulation of the pelvic nerve, but not the hypogastric nerve. However, beginning 3 days after unilateral interruption of the pelvic nerve, stimulation of the ipsilateral hypogastric nerve results in an increase in penile pressure. This novel response, which is blocked by a ganglionic antagonist, is maximally developed at 1 week post-lesion, is stable for at least 3 months and remains confined to the side of the lesion. These results suggest that the rat, although relatively small, can be used to obtain quantitative data on penile erection. Moreover, the model may lend itself to an analysis of the mechanisms of altered control of visceral tissues following injury to the nervous system.

Animals↗
PubMed2004

Parameters of successful sacral root neuromodulation of the pelvic floor: a retrospective study.

INTRODUCTION/OBJECTIVE: Neuromodulation of the pelvic floor (InterStim) is a relatively new technique in the field of urology. We present our observations for effective neuromodulation on our patient population. MATERIALS AND METHODS: In a retrospective case review study, we studied the charts of 67 patients, who underwent InterStim operations between the years 1993 to 2002. All patients had a good response to InterStim. Patients with inefficient or inconclusive responses were not included in the study. All the relevant patient data was recorded from their charts. For each patient, the following was recorded; the amplitude in volts, the pulse width (in microseconds) and rate, the mode (cycling versus continuous), the electrodes and their position, the load impedance, and the change in amplitude over time. RESULTS: Amplitude over time showed an initial plateau, followed by a small increase that gets larger. CONCLUSIONS: Long-term management of InterStim recipients requires increasing amplitude following the implantation of the IntreStim to maintain the same satisfactory levels of urinary control.

Adult↗