Role of pudendal nerve terminal motor latency assessment in constipated patients

The importance of pudendal nerve terminal motor latency assessment for the evaluation of incontinence is well established. However, its role in constipated patients remains unclear. PURPOSE: The purpose of the present study was to assess the incidence of pudendal neuropathy in constipated patients and its correlation with others variables including age, sex, anal pressures, and anal electromyography. RESULTS: From 1988 to 1993, 161 patients with chronic constipation underwent pudendal nerve terminal motor latency assessment, anal electromyography, and anal manometry. The overall incidence of pudendal neuropathy was 23.6 percent; females and males had a similar incidence (24 percent vs. 23 percent, respectively; P > 0.05). Patients over 70 years old had a significantly higher incidence of pudendal neuropathy than did patients under 70 years (37 percent vs. 12 percent, respectively; P < 0.01). Patients with paradoxical puborectalis contraction on anal electromyographic assessment had a higher incidence of bilateral neuropathy, paradoxical puborectalis contraction (+)23 percent vs. paradoxical puborectalis contraction (-)8 percent, P < 0.05. Patients with pudendal neuropathy also had a higher incidence of decreased motor units potential recruitment than did patients without pudendal neuropathy (31.5 percent vs. 17 percent, respectively; P > 0.05). CONCLUSIONS: Pudendal nerve terminal motor latency assessment was able to detect unsuspected pudendal neuropathy in 24 percent of patients. This finding correlated with age and with the presence of paradoxical puborectalis contraction but not with manometric anal pressures, motor unit potentials recruitment, or the presence of polyphasia. However, the often espoused relationship between pudendal latency and external sphincter function could not be demonstrated.     

A constipation scoring system to simplify evaluation and management of constipated patients

PURPOSE: Constipation is a common complaint; however, clinical presentation varies with each individual. The aim of this study was to assess a standard scoring system for evaluation of constipated patients. MATERIALS AND METHODS: All consecutive patients with idiopathic constipation who were referred for anorectal physiologic testing were assessed. A subjective constipation score was calculated based on a detailed questionnaire that included over 100 constipation-related symptoms. Based on the questionnaire, scores ranged from 0 to 30, with 0 indicating normal and 30 indicating severe constipation. The constipation score was then compared with the objective findings of the physiology tests, which include colonic transit time (CTT), anal manometry (AM), cinedefecography (CD), and electromyography (EMG). Colonic inertia was defined as diffuse marker delay on CTT without evidence of paradoxical contraction on AM, CD, or EMG. Pelvic outlet obstruction was defined as paradoxical puborectalis contraction, rectal prolapse or rectoanal intussusception, rectocele, or sigmoidocele. RESULTS: A total of 232 patients (185 females and 47 males) of a mean age of 64.9 (range, 14-92) years were evaluated. All patients had a score of more than 15; on evaluation of the significance of different symptoms in the constipation score with the Pearson's linear correlation test, 8 of 18 factors were identified as significant (P < 0.05). These factors included frequency of bowel movements, painful evacuation, incomplete evacuation, abdominal pain, length of time per attempt, assistance for evacuation, unsuccessful attempts for evacuation per 24 hours, and duration of constipation. All 232 patients had objective obstruction attributable to one or more of the following causes: paradoxical puborectalis contraction (81), significant rectocele or sigmoidocele (48), rectoanal intussusception (64), and rectal prolapse (9). CONCLUSION: The proposed constipation scoring system correlated well with objective physiologic findings in constipated patients to allow uniformity in assessment of the severity of constipation.     

Results of biofeedback in constipated patients: a prospective study

PURPOSE: The aims of this study were to assess the results of biofeedback treatment in constipated patients and to identify variables that might be used to predict the outcome. METHOD: Twenty-eight patients (5 men; median age, 46 (range, 22-72) years) with any degree of paradoxical activation measured with thin hook needle electromyography in the external sphincter or puborectalis muscle were included. The symptom duration varied between 1 and 30 (median, 9) years. The patients had eight outpatient training sessions with electromyography-based audiovisual feedback. All patients were followed up prospectively with a validated bowel function questionnaire from which a symptom index was created. RESULTS: At three months, nine patients had no improvement and underwent other treatments. The remaining 19 patients were followed up for a median of 14 (range, 12-34) months. Twelve patients (43 percent) stated they had improved rectal emptying. A good result was associated with increased stool frequency (P < 0.05), improved symptom index (P < 0.01), and reduction of laxative use (P < 0.05). A long symptom duration, a high pretreatment symptom index, and laxative use were related to a poor result (P < 0.01-0.05). The improved group had less perineal descent (P < 0.05), and a prominent puborectalis impression on defecography tended to be more common (P = 0.06). CONCLUSION: With the use of wide inclusion criteria, biofeedback was successful in 43 percent of patients, with a treatment effect lasting at least one year. The results suggest that biofeedback should be used as the initial treatment of constipated patients with a paradoxical puborectalis contraction.     

Paradoxical sphincter reaction is influenced by rectal filling volume

PURPOSE: Paradoxical sphincter reaction is frequently found in constipated patients but sometimes also in incontinent patients and in asymptomatic subjects. Its significance in defecation disorders has, therefore, been debated. The aim of the present study was to investigate whether paradoxical sphincter reaction is influenced by rectal filling volume. PATIENTS AND METHODS: Eighteen patients with defecation disorders and paradoxical sphincter reaction shown by electromyography were reinvestigated with an extended electromyographic investigation while in the lying position and while in the sitting position, with 50-ml, 100-ml, and 150-ml water-filled rectal balloons. RESULTS: All 18 patients showing paradoxical sphincter reaction in the first investigation also showed the reaction at the second investigation in the lying position with a 0-ml volume of rectal contents. In the sitting position, with a volume of 150 ml of rectal contents, the increase in electromyographic activity disappeared in seven patients (39 percent) and no longer showed paradoxical sphincter reaction. Electromyography showed decreased activity in one patient and unchanged activity in six patients during straining. A closing reflex was seen after completed straining in all of these seven patients. CONCLUSIONS: The present study demonstrates that paradoxical sphincter reaction diagnosed by electromyography is influenced by the rectal filling volume and might diminish when the rectum is filled with contents. The conventional electrophysiologic technique in the diagnosis of paradoxical sphincter reaction might, therefore, overdiagnose this condition.     

Cinedefecography and electromyography in the diagnosis of nonrelaxing puborectalis syndrome

A prospective study was undertaken to assess the correlation between electromyography (EMG) and cinedefecography (CD) for the diagnosis of nonrelaxing puborectalis syndrome (NRPR). Clinical criteria for NRPR included straining, incomplete evacuation, tenesmus, and the need for enemas, suppositories, or digitation. EMG criteria included failure to achieve a significant decrease in electrical activity of the puborectalis (PR) during attempted evacuation. CD criteria included either paradoxical contraction or failure of relaxation of the PR along with incomplete evacuation. In addition, other etiologies for incomplete evacuation, such as rectoanal intussusception or nonemptying rectocele, were excluded by proctoscopy and defecography in all cases. One hundred twelve patients with constipation, 81 females and 31 males, with a mean age of 59 (range, 12-83) years were studied by routine office evaluation, CD, and EMG. Forty-two patients (37 percent) had evidence of NRPR on CD (rectal emptying: none, 24; incomplete, 18). Twenty-eight of these patients (67 percent) also had evidence of NRPR on EMG. EMG findings of NRPR were present in 12 of 70 patients (17 percent) with normal rectal emptying. Conversely, 14 of 72 patients (19 percent) with normal PR relaxation on EMG had an NRPR pattern on CD. The sensitivity and specificity for the EMG diagnosis of NRPR were 67 percent and 83 percent, and the positive and negative predictive values were 70 percent and 80 percent, respectively. Conversely, if EMG is considered as the ideal test for the diagnosis of NRPR, CD had a sensitivity of 70 percent, a specificity of 80 percent, and positive and negative predictive values of 66 percent and 82 percent, respectively. In summary, sensitivity, specificity, and predictive values of EMG and CD are suboptimal. Therefore, a combination of these two tests is suggested for the diagnosis of NRPR.     

Anismus: fact or fiction?

PURPOSE: Although anismus has been considered to be the principal cause of anorectal outlet obstruction, it is doubtful whether contraction of the puborectalis muscle during straining is paradoxical. The present study was conducted to answer this question. METHODS: During the first part of the study, we retrospectively reviewed 121 patients with constipation and/or obstructed defecation (male:female, 10/111; median age, 51 years). All of these patients underwent electromyography (EMG) of the pelvic floor and the balloon expulsion test (BET) in the left lateral position. Evacuation proctography was performed in all of these patients in the sitting position. Both the posterior anorectal angle and the central anorectal angle were measured. EMG and BET were also performed in ten controls (male:female, 4/6; median age, 47). In 147 patients with fecal incontinence (male:female, 24/123; median age, 58) only EMG activity was recorded. Criteria for anismus during straining were increase or insufficient (<20 percent) decrease of EMG activity, failure to expel an air-filled balloon on BET, and decrease or insufficient (<5 percent) increase of anorectal angle on evacuation proctography. Between June 1994 and March 1995, we conducted a second prospective study in a consecutive series of 49 patients with constipation and/or obstructed defecation and 28 patients with fecal incontinence. Both groups were compared with 19 control subjects. In this study, all three tests were performed. EMG and BET were performed both in the left lateral position and in the sitting position. RESULTS: The retrospective study was undertaken by comparing the constipated patients with the incontinent patients and the controls, and the anismus detected by EMG was found in, respectively, 60, 46, and 60 percent. Failure to expel the air-filled balloon was observed in 80 constipated patients (66 percent) and in 9 control subjects (90 percent). Based on posterior anorectal angle and central anorectal angle measurements, anismus was diagnosed in, respectively, 21 and 35 percent of constipated patients. In the prospective study, none of the tests showed significant differences regarding the prevalence of anismus between the two subgroups of patients and the control subjects. The prevalence of anismus only differed between constipated and incontinent patients when the diagnosis was based on BET in the sitting position (67 vs. 32 percent; P < 0.005). Our study shows that contraction of the puborectalis muscle during straining is not exclusively found in patients with constipation and/or obstructed defecation. The three tests most commonly used for the diagnosis of anismus showed an extremely poor agreement. CONCLUSION: Based on these findings, we doubt the clinical significance of anismus.     

Clinical and physiologic effects of biofeedback in outlet obstruction constipation

PURPOSE: We report the results of biofeedback (BF) on patients with outlet obstruction defecation (OOC), including those with and without measurable paradoxical puborectalis contractions (PP). Clinical and anorectal physiologic parameters (ARP) were assessed one week before and after a standardized course of BF. METHODS: Sixty-two consecutive patients (24 men, 38 women; mean age, 48 (standard error of the mean, 2.3) years) were recruited. All had persistent constipation despite six weeks of dietary fiber supplements. Colonic inertia was excluded by transit marker studies. Defecating proctography excluded anatomic abnormalities causing outlet obstruction. Patients underwent four outpatient sessions of biofeedback, each session lasting one hour. RESULTS: After BF, 56 patients (90.3 percent) were subjectively improved. Frequency of spontaneous bowel movements were significantly increased (P = 0.003). Frequency of laxative-induced (P = 0.004) and enema-induced (P = 0.005) stools were reduced. Anal resting (P = 0.04) and squeeze (P = 0.002) pressures were increased. Number of patients with PP was reduced from 40 to 31 (P = 0.004). Presence of PP did not affect response to BF. There were no differences in ARP between the 56 patients who improved and the 6 who did not. There were no side effects or clinical regressions after a mean follow-up of 14.9 (standard error of the means, 0.9) months. CONCLUSIONS: BF effectively treated OOC in 90.3 percent, regardless of PP. Anal pressures were increased, and PP was decreased.     

Electromyography in near-total laryngectomy

OBJECTIVE: To investigate the dynamics of speech shunt muscle in patients with Pearson near-total laryngectomy by needle electromyography and correlation of ability to activate shunt muscle with speech production. DESIGN AND SETTINGS: Prospective study of patients with near-total laryngectomy at 2 hospital-based academic tertiary care centers. PARTICIPANTS AND INTERVENTION: Fourteen patients with near-total laryngectomy were subjected to percutaneous needle electromyographic study of the shunt muscle. MAIN OUTCOME MEASURES: Speech ability, electromyographic evidence of viable muscle in shunt wall, and ability to activate shunt muscle were recorded. RESULTS: Twelve of 14 patients had good speech; 11 had evidence of viable shunt muscle; and 9 were able to activate muscle by phonation, swallowing, or deep breathing, indicating preserved innervation. Six of the 12 patients with speech ability and 1 of the 2 patients without speech ability were able to recruit motor units during attempted phonation. CONCLUSIONS: Electromyography demonstrated viable muscle with retained innervation in 64% of the patients with near-total laryngectomy, proving its "dynamic" nature. However, the usefulness of shunt muscle activation in speech and prevention of aspiration needs further confirmation.     

Pudendal neuropathy is predictive of failure following anterior overlapping sphincteroplasty

PURPOSE: This study assessed the efficacy of anterior overlapping sphincteroplasty and parameters predictive of a successful outcome. METHODS: Clinical findings and physiologic investigations of female patients who underwent anterior overlapping sphincteroplasty for fecal incontinence between 1988 and 1996 were reviewed. The extent of sphincter damage was assessed at needle electromyography as the number of quadrants exhibiting decreased motor unit potentials. Prolonged pudendal nerve terminal motor latencies were those of greater than 2.2 ms. The size of the endoanal ultrasound defect was assessed as degrees circumference of the external sphincter in which viable muscle was absent. Patients were reviewed by telephone questionnaire and were asked to grade the outcome of their surgery as excellent or good (success) or fair or poor (failure). Incontinence was graded using a scoring system of 0 (perfect continence) to 20 (complete incontinence). RESULTS: There were 100 patients who had an overlapping sphincteroplasty; complete follow-tip information was obtained for 77 patients at a median of 24 (range, 2-96) months. The median age was 47 (range, 25-80) years and they had a median duration of incontinence of four (range, 0.1-39) years. Prior sphincteroplasty had been performed in 30 patients with a median of one (range, 1-7) operations. Investigations performed included electromyography (n = 49), pudendal nerve terminal motor latency (n = 71), endoanal ultrasound (n = 49), and manometry (n = 67). Sixty percent of patients had improved continence and 42 (55 percent) considered their surgery to have been successful as attested to by a significant decrease in their incontinence score (from 15.1 +/- 4.5 to 4.3 +/- 4.2; P < 0.0001). Neither patient age, parity, prior sphincteroplasty, cause or duration of incontinence, extent of electromyography damage, size of the endoanal ultrasound defect, nor any manometric parameter correlated with outcome. However, 62 percent of 59 patients with bilaterally normal pudendal nerve terminal motor latencies had a successful outcome compared with only 16.7 percent of 12 patients with unilateral or bilateral prolonged pudendal nerve terminal motor latencies (P < 0.01). CONCLUSION: Bilateral normal pudendal nerve terminal motor latencies are the only factors predictive of long-term success after overlapping sphincteroplasty.     

Results of Delorme's procedure for rectal prolapse

PURPOSE: This study was designed to examine the results of Delorme's procedure. METHODS: Thirty-two patients (24 males and 8 females, mean age, 70 years) underwent Delorme's procedure between 1978 and 1990 following symptoms lasting between two weeks and ten years. Thirteen patients had had 21 previous operations for prolapse. RESULTS: The mean operation time was 65 minutes. No blood transfusions were needed, there was no operative mortality, and only two patients had complications (one chest infection and one anastomotic dehiscence). No patients were lost to follow-up. Over a mean follow-up of 24 months (4 months to 4 years), 9 patients died of unrelated conditions. There were four recurrences (12.5 percent), two in patients who had each had two previous procedures. Incontinence improved in 46 percent. No patient became constipated and 50 percent of those constipated preoperatively improved. CONCLUSION: Although abdominal rectopexy is safe and has a low recurrence rate (< 5 percent), it involves the hazards of a laparotomy. In addition, up to 40 percent of patients become constipated after rectopexy which may be debilitating. Delorme's procedure has a low morbidity, results in good bowel function, and has a low recurrence rate. It can be performed on unfit patients with possible advantages over rectopexy and perhaps should be used more readily.     

Colectomy as treatment for constipation in selected patients

The aim of this study was to conduct a prospective assessment of the results of total abdominal colectomy and ileorectal anastomosis (TAC) in patients with colonic inertia. Overall, 416 patients were evaluated for chronic constipation. Of the patients 54 (13 per cent) had colonic inertia, defined as diffuse marker delay during transit study without paradoxical puborectalis contraction on cinedefaecography or electromyography. All 54 patients (42 women and 12 men), with a mean age of 49 (range 17-78) years, underwent TAC. Preoperative bowel frequency was a mean of one every 8 days, requiring large doses of laxatives, enemas or both. There was no major postoperative morbidity; five patients were readmitted due to bowel obstruction, three for successful conservative management while the other two required enterolysis. After a mean follow-up of 27 (range 2-51) months these 54 patients reported a mean frequency of spontaneous bowel movements of 3.7 (range 1-10) per day. 'Excellent' or 'good' outcome was reported by 51 patients (94 per cent). TAC can be performed with acceptable morbidity and 94 per cent of patients will have satisfactory improvement in bowel habit.     

Accuracy and reliability of transanal ultrasound for anterior anal sphincter injury

INTRODUCTION: Although transanal ultrasound has rapidly become the test of choice for the diagnosis of anal sphincter injury, the accuracy and reliability of this technique are unknown. This study evaluates the accuracy and reliability of transanal ultrasound for anterior (obstetric-related) anal sphincter injury. METHODS: Sixty-two women underwent transanal ultrasound with hard-copy images obtained at 0.5-cm intervals from the anal verge to 2.5 cm into the anal canal. All transanal ultrasound procedures were also recorded on videotape. Two experienced ultrasonographers blinded as to the patients' clinical history and examination independently reviewed the images and videotape recordings for the presence or absence of anal sphincter injury. RESULTS: The accuracy of transanal ultrasound in 22 incontinent women with known anal sphincter injury was 100 percent. The accuracy of transanal ultrasound in 20 nulliparous women with intact anal sphincters was only 35 percent but improved to 50 percent after the "real time" videotape was reviewed (P = 0.16) and further improved to 85 percent when interpretation was limited to the distal 1.5 cm of the anal canal (P = 0.004). In these nulliparous women, intact internal sphincters were more accurately predicted than intact external sphincters (95 vs. 85 percent; P = 0.24). Measurement agreement between the two ultrasonographers was 68 percent (fair; kappa, 0.26) but significantly improved to 78 percent (moderate; kappa, 0.48; P = 0.0001) when interpretation was limited to the distal 1.5 cm of the anal canal. Overall clinical agreement (final scan interpretation) was good (81 percent agreement; kappa, 0.61). Agreement was better for the internal sphincter (74 percent; fair; kappa, 0.36) than the external sphincter (61 percent; poor; kappa, 0.17; P = 0.0002). CONCLUSIONS: Although transanal ultrasound can accurately identify anterior anal sphincter injury when present, transanal ultrasound falsely identifies sphincter injury in at least 5 to 25 percent of normal anal sphincters. Only fair agreement in the interpretation of transanal ultrasound exists between experienced ultrasonographers. Both the accuracy and reliability of transanal ultrasound are significantly improved by limiting transanal ultrasound to the distal 1.5 cm of the anal canal.     

Inter-observer reliability of the Spondylitis Functional Index Instrument for assessing spondylarthropathies

OBJECTIVE: To study the Spondylitis Functional Index (SFI) by having two physical therapists observe patients with spondylitis perform various tasks listed on the instrument. The physical therapists' observations were compared with each other and with the self-reported abilities of the patients. METHODS: Subjects (n = 30) were recruited from a cross-section of patients participating in a prospective randomized, multicenter, double-blind, parallel clinical trial of the efficacy of sulfasalazine on ankylosing spondylitis (n = 13), psoriatic arthritis (n = 13), and Reiter's syndrome (n = 4) conducted at the Veterans Affairs Medical Center in Salt Lake City. Percents of agreement and Cohen's kappa analysis were used to assess the reliability of the observations of the therapists and patients. RESULTS: The overall percent of agreement between the observers on the SFI was 93%. The overall percent of agreement between observer 1 and patients on the SFI was 66% and between observer 2 and patients was 67%. The overall inter-observer reliability measured by the Pearson coefficient was 0.91 and by Cohen's kappa was 0.86. Between observer 1 and the patients the Pearson was r = 0.53 and kappa = 0.39. For observer 2 the Pearson was r = 0.52 and kappa 0.39. CONCLUSIONS: We consider the agreement and reliability between observers to be high. The agreement and inter-observer reliability was poor between observers and patients. The SFI, as enhanced for use in this study to assess change in functional ability of patients with spondylitis, demonstrated high reliability when used by trained observers.     

The reproducibility of a method to identify the overuse and underuse of medical procedures

BACKGROUND: To assess the overuse and underuse of medical procedures, various methods have been developed, but their reproducibility has not been evaluated. This study estimates the reproducibility of one commonly used method. METHODS: We performed a parallel, three-way replication of the RAND-University of California at Los Angeles appropriateness method as applied to two medical procedures, coronary revascularization and hysterectomy. Three nine-member multidisciplinary panels of experts were composed for each procedure by stratified random sampling from a list of experts nominated by the relevant specialty societies. Each panel independently rated the same set of clinical scenarios in terms of the appropriateness of the relevant procedure on a risk-benefit scale ranging from 1 to 9. Final ratings were used to classify the procedure in each scenario as necessary or not necessary (to evaluate underuse) and inappropriate or not inappropriate (to evaluate overuse). Reproducibility was measured by overall agreement and by the kappa statistic. The criteria for underuse and overuse derived from these ratings were then applied to real populations of patients who had undergone coronary revascularization or hysterectomy. RESULTS: The rates of agreement among the three coronary-revascularization panels were 95, 94, and 96 percent for inappropriate-use scenarios and 93, 92, and 92 percent for necessary-use scenarios. Agreement among the three hysterectomy panels was 88, 70, and 74 percent for inappropriate-use scenarios. Scenarios involving necessary use of hysterectomy were not assessed. The three-way kappa statistic to detect overuse was 0.52 for coronary revascularization and 0.51 for hysterectomy. The three-way kappa statistic to detect underuse of coronary revascularization was 0.83. Application of individual panels' criteria to real populations of patients resulted in a 100 percent variation in the proportion of cases classified as inappropriate and a 20 percent variation in the proportion of cases classified as necessary. CONCLUSIONS: The appropriateness method is far from perfect. Appropriateness criteria may be useful in comparing levels of appropriate procedures among populations but should not by themselves be used to direct care for individual patients.     

Metabolism of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in isolated rat lung and liver

PURPOSE: Assessment of sustained voluntary contraction of the external sphincter is helpful in evaluating the patient who has a defecation disorder on presentation. A new index of external sphincter function is described. METHOD: A prospective registry of patients referred for computerized anal manometry using standard protocols was reviewed. Patients were grouped by primary symptoms; those with overlapping complaints were excluded. The rate of fatigue, defined as the change in stationary squeeze over a 40-second period of voluntary contraction, was calculated by linear regression analysis. Fatigue rate index, a calculated measure of time necessary for the external sphincter to become completely fatigued, was determined to permit comparison of external sphincter fatigue in patients with different complaints. RESULTS: Twenty-six healthy volunteers (15 women; mean age, 45 years), 33 patients with a primary complaint of anal seepage (13 women; mean age, 53 years), 75 patients with gross incontinence (61 women; mean age, 53 years), and 49 patients with severe constipation (41 women; mean age, 45 years) were evaluated. Mean resting and squeeze pressures were 55 mmHg and 107 mmHg for volunteers, 37 mmHg and 97 mmHg for patients with seepage, 30 mmHg and 49 mmHg for incontinent patients, and 56 mmHg and 93 mmHg for constipated patients. Pudendal neuropathy, as evidenced by a prolonged pudendal nerve terminal motor latency (> 2.4 ms), was identified in 13 percent of volunteers, 32 percent of patients with seepage, 54 percent of incontinent patients, and 38 percent of constipated patients. Mean fatigue rate index was 3.3 minutes for volunteers, 2.3 minutes for seepage patients, 1.5 minutes for incontinent patients, and 2.8 minutes for constipated patients. Compared with volunteers and patients with seepage, the incontinent patients had a significantly shorter fatigue rate index (P < 0.05; Student's t-test), which was independent of the variations in resting pressure (P < 0.05; two-way analysis of variance). CONCLUSION: The external anal sphincter is normally subject to fatigue. Patients with worsening degrees of incontinence have a predictably lower fatigue rate index. Fatigue rate index is a simple measure of external sphincter integrity, which may be used in assessment of sphincter function and future treatment protocols.     

Clonazepam in the treatment of panic disorder: a double-blind, placebo-controlled trial investigating the correlation between clonazepam concentrations in plasma and clinical response

The aim of this study was to investigate the possibility of neuromuscular dysfunction in patients with faecal incontinence by measuring interference patterns in the external anal sphincter and puborectalis muscles with quantitative electromyography. The design was an open study including 20 patients with faecal incontinence; in 14 the aetiology was idiopathic and 6 had rupture of the external anal sphincter. Electromyographic interference patterns (turns/amplitude analysis) measured at rest and during maximum voluntary contraction in all patients were recorded together with fibre density measured by single fibre electromyography (n = 10) and anal pressure measured at rest and at maximum contraction (n = 17). A comparison was made with results of a previously published series of reference values taken from normal volunteers. The density of the interference pattern on maximum contraction of the puborectalis muscle was significantly lower among the patients with idiopathic faecal incontinence than among the reference group (137 compared with 241 turns/second, p < 0.01). There was also a significant difference on maximum contraction of the anal sphincter muscle among the group in whom it was ruptured compared with the reference group (76 compared with 165 turns/second, p < 0.05). Fibre density increased with age and was significantly higher among those with idiopathic incontinence (1.64 (0.2) compared with 1.33 (0.1) in the reference group, p < 0.01). There were no significant differences in anal manometry measurements between the groups. In conclusion, in patients with faecal incontinence the role of central activation of the perineal muscles is important, though other factors may play a part.     

Constipation assessed on the basis of colorectal physiology

BACKGROUND: Constipation is a collective term for symptoms of different aetiologies and pathophysiologies. Our aim was to determine the prevalence of colorectal pathophysiology findings in a prospective series of patients with chronic constipation. METHODS: A total of 155 consecutive patients with chronic constipation underwent anorectal manometry, electromyography (EMG), the balloon expulsion test, colonic transit-time study, and defecography. RESULTS: All investigations were completed by 134 patients (112 females) with a median age 52 (range, 17-79) years. Patients were categorized on the basis of transit time and pelvic-floor function as belonging to 1 of 4 groups: slow-transit constipation (STC) (delayed transit time but normal pelvic-floor function, n = 28), pelvic-floor dysfunction (PFD) (pelvic-floor dysfunction and normal transit time, n = 32), combined slow transit and pelvic-floor dysfunction (STC + PFD) (n = 27), and normal-transit constipation (NTC) (normal transit time and normal pelvic-floor function, n = 47). There was no difference between diagnostic groups in anal sphincter pressures. However, rectal sensitivity to balloon distension was lower (P < 0.05) in patients with delayed transit. Paradoxical puborectalis contraction (PPC) was found on EMG in 42 patients (31%). The prevalence of PPC was higher (P < 0.001) in patients with pelvic-floor dysfunction. Inability to evacuate the rectal balloon was reported by 37% of patients with pelvic-floor dysfunction and 12% of patients with normal pelvic-floor function (P < 0.001). Rectocele was the only anatomic abnormality at defecography which was associated with poor rectal emptying. CONCLUSIONS: About two-thirds of our patients with constipation had objective evidence of delayed transit or pelvic-floor dysfunction. No single test could reliably identify any of the pathophysiologic subgroups of constipation.     

Usefulness of electromyographic techniques of the bulbocavernosus muscle in the diagnosis of neurogenic impotence

OBJECTIVE: To analyze the utility of electromyographic study of the bulbocavernosus muscle. METHODS: 126 impotent patients were evaluated by physical examination and neuroandrologic profile. The physical examination consisted in an exploration of the anal tone and the bulbocavernosus reflex. The neuroandrologic profile consisted in selective electromyography of the bulbocavernosus muscle, the determination of the S2-S4 evoked potentials, somatosensory potential of the pudenal nerve, electromyography of cavernous smooth muscle (SPACE) sympathetic skin response and cystometry. RESULTS: The results of the bulbocavernosus electromyography and S2-S4 evoked potentials were different from the data obtained from the physical examination of the anal tone and the bulbocavernosus reflex. Selective bulbocavernosus electromyography showed a sensitivity of 57% and a specificity of 84%. The S2-S4 evoked potentials showed a sensitivity of 61% and a specificity of 100%. The diagnostic value of the S2-S4 evoked potentials increased at 39 msec cutoff (sensitivity = 66%; specificity = 95%). Exploration of the anal tone is very specific for neurologic lesion in impotence (93%), but has a low sensitivity (30%). The clinical bulbocavernosus reflex showed a good specificity (85%) and sensitivity (75%) in the diagnosis of pudendal efferent lesion, but is less useful in the diagnosis of neurogenic impotence. CONCLUSIONS: The highest diagnostic value was obtained with the S2-S4 evoked potentials. Selective electromyography of the bulbocavernosus muscle showed a moderate diagnostic value. Physical examination of peripheral pudendal innervation does not appear to be useful for screening for neurologic lesion in impotence because of its low sensitivity, which may be due to existing incomplete nervous lesions.     

Diagnosis and management of fecal incontinence in elderly patients

Fecal incontinence is a physically and psychologically disabling condition that affects millions of Americans, especially those over the age of 65 years. The pathophysiology is often multifactorial, with decreased anorectal sensation, reduced rectal compliance. anal sphincter dysfunction, altered stool consistency and immobility playing significant roles. A detailed history and a thorough physical examination are always necessary in patients with fecal incontinence and physiologic tests, including anorectal manometry, cinedefecography and electromyography, may be required for proper diagnosis and treatment. In most patients fecal incontinence is initially treated with conservative measures, such as biofeedback training or alteration of the stool consistency (if appropriate). If conservative management fails, surgical intervention, such as sphincteroplasty or gracilis muscle transposition, may be considered.     

Durability of monopolar Teflon-coated electromyographic needles

The results of a two-year study on durability and cause of failure of electromyographic monopolar electrodes are reported. The electrodes were obtained from the regular stock of three different manufacturing sources. Durability is defined on the basis of the number of patients that could be examined before failure. The range was 3 to 110 with the averages 19.7, 33.8, and 62.5 for the three different manufacturers. Common causes of electrode failure included: Teflon retraction, 40.6%; tip dullness or burrs, 34.8%; structural failure of wire or pin, 13.1%; electrical artifacts, 9.7%; and bending of needle shank, 5.7%. Variations in manufactures' tip contour and bevel correlated with tip durability.