Sphincter Reflex Research Articles

Manometric studies in rectal prolapse.

Manometric studies of internal sphincter responses were carried out on 15 patients--14 with rectal prolapse and one with mucosal prolapse with proctitis cystica profunda. In all 12 patients studied preoperatively, the internal sphincter reflexes (inhibitory reflex) were absent or markedly obtunded. Anterior resection was performed on three of the patients in whom preoperative and postoperative manometric studies could be carried out. In one, the inhibitory reflex returned to normal after successful corrective surgery and in one, absence of the reflex persisted after anterior resection and this patient eventually had recurrent rectal prolapse.

DISORDERED ESOPHAGEAL, COLONIC, AND RECTAL MOTILITY IN INFANT BOTULISM

Impairment of both autonimic & voluntary neuromuscular transmission due to C. botulinum toxin in infants is recognized. Abnormalities of gastrointestinal motility in cases of infant botulism have been identified, but not fully defined. Four infants (ages: 5-9 mos.) with documented botulism (Type A:2, Type B:2) were evaluated for disordered esophageal, rectal, & colonic motility. Esophageal manometrics documented normal lower esophageal sphincter pressures (x:24 mm Hg; N:20-35) and relaxation. Distal (smooth muscle) peristalsis was normal, but proximal (striated muscle) peristalsis was absent in all patients. In addition, upper esophageal sphincter achalasia was documented in each. The resolution of the proximal esophageal dismotility was associated with overall clinical improvement and return of skeletal muscle strength. Rectal-colonic manometrics revealed low anal pressure profiles (x:45 mm Hg; N:80-120) with normal internal sphincter relaxation; 2/4 patients exhibited delayed return of resting pressures. Colonic EMG slow waves were observed with a frequency of 3-4 cycles/minute. Colonic spike bursts were observed, but not correlated with intraluminal pressure changes during the acute stage. Significant dismotility of the proximal esophagus is present during the acute phase of infant botulism and contributes to the dysphagia observed clinically. Disordered intraluminal colonic motility may account for the frequent observation of constipation, as rectal sphincter reflexes are preserved.

A lower esophageal sphincter reflex involving substance P.

The purpose of this study was to determine the mechanism by which distal esophageal acidification increases lower esophageal sphincter (LES) pressure in the anesthetized cat. Intraluminal pressures and myoelectric activity were recorded using fixed, localized manometric catheters and serosal bipolar silver-silver chloride electrodes. The increase in LES pressure (27.1 +/- 4.9 mmHg) and spike activity (133.8 +/- 22.6 spikes/min) following distal esophageal acidification were greater than after saline (P less than 0.001). These responses were abolished by either tetrodotoxin (intravenously) or intraluminal ethyl aminobenzoate. The responses were not antagonized by bilateral cervical vagotomy or by atropine, hexamethonium, phentolamine, propranolol, diphenhydramine, cimetidine, cinanserin, naloxone, haloperidol, or proglumide. Tachyphylaxis to substance P abolished the LES pressure and spike responses to exogenous substance P and to distal esophageal acidification but had no effect on the LES responses to phenylephrine (25.0 micrograms/kg iv) or pentagastrin (0.5 microgram/kg iv). The putative substance P antagonist [D-Pro2,D-Trp7,9]substance P was a partial antagonist and a weak agonist on the LES. Large doses of [D-Pro2,D-TRP7,9]substance P (200.0 micrograms/kg iv) gave a 61.3 +/- 19.3% inhibition of the LES pressure response to acid (P less than 0.05). Intravenous tetrodotoxin partially antagonized the LES response to substance P (10.0 micrograms/kg iv). These studies suggest that the increases in LES pressure and spike activity following distal esophageal acidification occur through a spike-associated enteric neural reflex that involves substance P as a neurotransmitter.

Evidence for an opiate-mediated pyloric sphincter reflex.

The purpose of this study was to determine the mechanism by which the feline pylorus contracts in response to duodenal acidification. Simultaneous intraluminal pressures and serosal electrical activity were recorded from the antrum, pylorus, and duodenum of the anesthetized cat. The pylorus demonstrated a narrow zone of tonically increased pressure. Duodenal but not antral acidification increased the frequency and amplitude of phasic spike-associated pyloric contractions (P less than 0.001). This response was antagonized by tetrodotoxin, intraluminal (ethyl aminobenzoate), or naloxone. Bilateral cervical vagotomy, atropine, phentolamine, propranolol, cinanserine, diphenhydramine, or cimetidine had no effect on the pyloric response to duodenal acidification. Duodenal spike activity was also increased by duodenal acidification but was antagonized by atropine and not by naloxone. Leucine- or methionine-enkephalin intra-arterially produced dose-dependent increases in phasic pyloric contractions. The EDmax for leucin-enkephalin was 1.0 microgram/kg. The enkephalins inhibited duodenal spike activity in a dose-dependent fashion. These studies suggest that the pyloric spike-associated, high-amplitude phasic contractions in response to duodenal acidification involve local neural pathways that may be mediated through an opioid peptide. The pyloric response to duodenal acidification is distinguished from that of the duodenum, which is cholinergic.

Postoperative evaluation of fecal continence after sphincter-preserving operations for rectal cancer.

Seventy-eight sphincter-preserving operations for rectal cancer were evaluated from the viewpoint of postoperative fecal continence. Operative procedures consisted of 39 anterior resections and 39 pull-through operations and Maunsell-Weir's operation. Postoperative fecal continence was evaluated by questionnaires and anorectal examinations including (1) the distance from the anal verge to the anastomosis, (2) the length of sensation to light touch in the anal canal, (3) electromyography of the sphincter, (4) internal sphincter reflex (5) pressure profile of the anal canal, and (6) barium enema radiography. Patients' evaluations of their continence were good when the distance of the anastomosis was over 5 cm from the anal verge, and mostly poor under 3 cm. Good or fair evaluations were obtained when the internal sphincter reflex or high pressure zone of the anal canal were preserved. Size of the reservoir was measured using a planimeter on the lateral view of the barium enema up to 6 cm from the upper margin of the anal canal. Good or fair evaluations were obtained when size was 30 cm2.

Subclinical neurogenic bladder (author's transl)

There is a group of cases who show the clinical features of obstructive uropathy but neither anatomical obstruction nor neurological disorder. After introduction of urodynamic examinations to the lower urinary tract, this subclinical or occult neurogenic bladder dysfunction is frequently detected not only in the patients with severe obstructive lesions, but also in the patients with recurrent urinary tract infection and/or slight urination disorders.1. Consideration for possible neurological lesions:The age distribution chart of subclinical neurogenic bladder cases is very similar to that of neurogenically evident bladder dysfunction cases. The cases of neurogenic bladder clearly show the peculiar variety and incidence in each generation. Therefore, when the diagnosis of subclinical neurogenic bladder is made, it should be asked first of all whether the thorough neurological examinations have been made to find the causal diseases.2. Subdivision of vesico-urethral dysfunctions and the possible site of neurological lesions:Even in the same group of patients with the same neurological disease, such as meningomyelocele or cerebrovascular lesion, the urodynamic features are variable, and the nature of their vesico-urethral dysfunctions could be subdivided based on detrusor and sphincter reflex activities, detrusor-sphincter coordination, and voiding cystourethrographic pattern. However, these proceedings of classification do not necessarily simplify the complicated problem, “the decision of the site of neurological lesions”.3. Uninhibited bladder:The age distribution chart of all the cases with uninhibited bladder contraction shows the characteristic curve of parabola, in which the overwhelming majority of the cases are distributed in young children. Contrary to the high incidence of mechanical obstruction or organic disease in old patients, most of these children can not be proven to have any neurological defect, though organic urethral stenosis, including Lyon's Ring, is detectd in less than half of them.Even after excluding these mechanical obstruction or evident neurogenic bladder dysfunction, functional bladder neck obstruction or external sphincter spasm can be demonstrated in some of these uninhibited bladder cases, and all of them have positive urinary tract infection.4. The causal background of enuresis:Uninhibited bladder contraction can be detected in most of the enuretic children, but its incidence decreases rapidly after 10 years of age, and is replaced by other types of bladder dysfunction such as reflex bladder in elder children and adults.Anticholinergic drugs and/or Imipramine are used routinely in its treatment, but these drugs are not effective in the cases whose internal sphincter mechanism is weak. In these cases, combination of Imipramine or anticholinergic drugs with GOMT-inhibitor that elevates endogenous norepinephrine activities, thus increasing alpha-adrenergic response, are successful.5. Hypotonic or large bladder:If one excludes patients with obvious outflow obstruction, the detection rate of hypotonic or large bladder is high in patients with recurrent or persistent cystitis in females and chronic prostatitis in males.Although neurological lesions can not be detected by the usual neurological examination, spinal deformities on X-ray such as spina bifida occulta and spondylosis deformans are frequently visible both in children and adults. In middle aged people, the characteristic clinical histories, such as delivery in female, lumbar or ischiatric neuralgia, and perineal discomfort in both sexes are heard very often. In addition, disturbed detrusor and sphincter reflex activities, and abnormal decrease of UPP to alpha-blocker are constantly detected in these patients. These results are suggestive of the incomplete lesions of peripheral nerves concerned with micturition, probably at the level of the roots of the lumbar spinal nerves, cauda e

Carbon Dioxide Urethral Pressure Profilometry Before and After External Sphincterotomy in Spinal Cord Injury Patients

Seven spinal cord injury patients were studied before and after transurethral external sphincterotomy with combined electromyographic and gas urethral pressure profilometry. The technique was simple, rapid, accurate and reproducible in evaluating the completeness of external sphincterotomy. A significant reduction in maximum urethral closure pressure, as well as in the residual urine volume, was a consistent finding after sphincterotomy. The electromyographic profile showed evidence of periurethral striated muscle activity preoperatively in 2 patients with lower motor neuron lesions in whom the bulbocavernosus reflex could not be elicited. Thus, absence of the bulbocavernosus reflex did not eliminate sphincter reflex activity.

Reflexogenic contraction of the ileo-cecal sphincter in the cat following small or large intestinal distension.

The effect of distension of a small or large intestinal loop on the ileo-cecal sphincter (ICS) in the cat was studied with a flow-recording technique. Distension of a small or large intestinal loop, isolated from the adjacent intestine, but with its mesenteric vascular and nervous supply intact, elicited a contraction of the ICS concomitant with an inhibition of the adjacent large and small intestinal motility. Vagal and pelvic nerve section did not affect the response to distension of the ICS nor exclusion of the adrenal glands from the circulation. The sphincter reflex could be entirely or almost entirely eliminated by cutting both the splanchnic and lumbar colonic nerves, but not one or the other. Spinal anesthesia bocked the reflex response indicating a spinal reflex arc. The reflex persisted after atropine and propranolol, while both guanethidine and phenoxybenzamine completely abolished the reflex contraction of the sphincter. The present results indicate that the excitatory intestino-ileo-cecal sphincteric reflex is a spinal reflex with the main afferent and/or efferent fibres located within the major splanchnic and lumbar colonic nerves. The excitatory motor response in the sphincter is adrenergic and mediated via alpha-receptors.

Internal Anal Sphincter Derangement with Anal Fissures

Rectosphincteric manometric studies in patients with anal fissures demonstrated an abnormal internal anal sphincter reflex in response to rectal distention. This abnormal reflex response, characterized by an overshoot contraction immediately after a normal relaxation, was present in all 7 patients with fissures, but not in 17 subjects without anal disease. In 3 patients studied after treatment, the response returned to normal. These studies suggest that reflexly stimulated internal sphincter spasm plays a role in the pathogenesis of anal fissures, and that surgical approaches should be directed to the internal, rather than the external anal sphincter.