Colonic transit time and rectoanal videomanometry in Parkinson's disease

BACKGROUND: Constipation is a prominent lower gastrointestinal tract dysfunction that occurs frequently in Parkinson's disease (PD). OBJECTIVE: To investigate colonic transport and dynamic rectoanal behaviour during filling and defecation in patients with PD. METHODS: Colonic transit time (CTT) and rectoanal videomanometry analyses were performed in 12 patients with PD (10 men and 2 women; mean age, 68 years, mean duration of disease, five years; mean Hoehn and Yahr grade, 3; decreased stool frequency (<3 times a week) in six, difficulty in stool expulsion in eight) and 10 age matched normal control subjects (7 men and 3 women; mean age, 62 years; decreased stool frequency in two, difficulty in stool expulsion in two). RESULTS: In the PD patients, CTT was significantly prolonged in the rectosigmoid segment (p<0.05) and total colon (p<0.01) compared with the control subjects. At the resting state, anal closure and squeeze pressures of PD patients were lower than those in control subjects, though not statistically significant. However, the PD patients showed a smaller increase in abdominal pressure on coughing (p<0.01) and straining (p<0.01). The sphincter motor unit potentials of the patients were normal. During filling, PD patients showed normal rectal volumes at first sensation and maximum desire to defecate, and normal rectal compliance. However, they showed smaller amplitude in phasic rectal contraction (p<0.05), which was accompanied by an increase in anal pressure that normally decreased, together with leaking in two patients. During defecation, most PD patients could not defecate completely with larger post-defecation residuals (p<0.01). PD patients had weak abdominal strain and smaller rectal contraction on defecation than those in control subjects, though these differences were not statistically significant. However, the PD patients had larger anal contraction on defecation (p<0.05), evidence of paradoxical sphincter contraction on defecation (PSD). CONCLUSIONS: Slow colonic transit, decreased phasic rectal contraction, weak abdominal strain, and PSD were all features in our PD patients with frequent constipation.     

Anorectal function in multiple system atrophy and Parkinson's disease.

This study was designed to investigate anorectal function in Parkinson's disease and multiple system atrophy (MSA). After a standardized interview, 17 patients with Parkinson's disease (PD) and 16 patients with multiple system atrophy (MSA) underwent anorectal manometry with a continuously perfused multi-lumen catheter, located to record pressures from the anal canal, and a balloon for rectal distension. Data were analyzed by observers blind to the neurologic diagnosis. Disease duration was shorter in the MSA than in the PD group (6+/-4 versus 10+/-5 yrs, p<0.05). Most patients reported a bowel frequency of less than three evacuations per week and some patients had fecal incontinence. Most manometric recordings disclosed an abnormal pattern during straining (a paradoxic contraction or lack of inhibition) in 13 patients with MSA and 11 patients with PD. Mean anal pressures and rectal sensitivity threshold were not significantly higher in the MSA group, whereas the inhibitory anal reflex and rectal compliance thresholds were within the normal range in both groups. Manometric patterns did not differentiate patients with MSA from patients with PD. Most patients in both groups showed an abnormal straining pattern, decreased anal tone, or both dysfunctions. In conclusion, our findings suggest that although bowel and anorectal dysfunctions do not differentiate MSA from PD, both abnormalities occur earlier and develop faster in MSA than in PD.     

Mosapride citrate, a novel 5-HT4 agonist and partial 5-HT3 antagonist, ameliorates constipation in parkinsonian patients.

Mosapride citrate is a novel selective 5-HT4 receptor agonist. It facilitates acetylcholine release from the enteric cholinergic neurons. In contrast to cisapride, mosapride does not block K(+) channels or D2 dopaminergic receptors. The objective of this study is to perform an open study of mosapride citrate's effects on constipation, a prominent lower gastrointestinal tract disorder in parkinsonian patients. A total of 14 parkinsonian patients (7 with Parkinson's disease, 7 with multiple system atrophy; 10 men, 4 women; mean age, 67 years) with constipation (10 with bowel movement < 3 times/week; 14 with difficulty in defecation) were treated with 15 mg/day of mosapride citrate for 3 months. Pre- and posttreatment objective parameters in colonic transit time (CTT) and rectoanal videomanometry were obtained. Statistical analysis was made by Student's t test. Mosapride was well tolerated by all patients except for 1, who discontinued use of the drug because of epigastric discomfort. None had a worsening of parkinsonism or other adverse events. Thirteen patients reported subjective improvements in bowel frequency (>3 times/week, 13) and difficult defecation (13). Mosapride shortened CTT of the left colon (P < 0.01) and the total colon (P < 0.05). During rectal filling, mosapride lessened the first sensation (P < 0.05) and augmented the amplitude in phasic rectal contraction. During defecation, mosapride augmented the amplitude in rectal contraction (P < 0.05) and lessened the volume of postdefecation residuals. The present study showed for the first time that mosapride citrate augmented lower gastrointestinal tract motility, as shown in CTT and videomanometry, and thereby ameliorated constipation in parkinsonian patients without serious adverse effects.     

Rectal sensorimotor characteristics in female patients with idiopathic constipation with or without paradoxical sphincter contraction

Patients with chronic constipation fulfilling the Thompson criteria can show paradoxical sphincter contraction. Aim of this study was to evaluate rectal sensorimotor characteristics in patients with constipation with or without paradoxical sphincter contraction. Thirty female patients with chronic constipation and 22 female controls were investigated with anal manometry and rectal barostat. Paradoxical sphincter contraction was shown with manometry as a paradoxical increase of anal pressure during straining. Visceral sensitivity and compliance were tested by intermittent and continuous pressure-controlled distension. Patients were classified according to their sensations and compliance into normal, hypersensitive, reduced compliant, insensitive or excessive compliant rectum. Postprandial rectal response (PRR) and phasic volume events (PVEs) were registered for 1 h after a 600-kCal meal. Paradoxical sphincter contraction was found in 13 (43%) patients. In these patients, rectal sensitivity scores were higher (P = 0.045) than in patients without paradoxical contractions, but rectal compliance was not different. In 90% of patients an abnormal rectal sensitivity or compliance was found: excessively compliant in 35%, reduced compliant in 10%, hypersensitive in 27% and hyposensitive in 17%. Both patients with constipation (11%; P = 0.042) and controls (25%; P = 0.002) exhibited the presence of a postprandial rectal response. This response was not significantly different between idiopathic constipation, paradoxical sphincter contraction and controls. Patients with rectal hypersensitivity had lower response than other patients (P = 0.04). Patients with constipation had fewer basal PVEs compared controls (P = 0.03). Postprandial PVEs increased in both patients (P = 0.014) and controls (P < 0.001). Postprandial rectal response and PVE were not different in patients with or without paradoxical sphincter contraction. A total of 90% of female patients with idiopathic constipation show an abnormality in rectal sensation or compliance. The postprandial rectal response was comparable between patients with constipation and controls, however, PVEs were diminished. Patients with paradoxical sphincter contraction had higher rectal sensitivity but an unaltered compliance and postprandial rectal response. Future trials should investigate whether the classification of rectal abnormalities in patients with constipation has clinical importance.     

Levodopa ameliorated anorectal constipation in de novo Parkinson's disease: The QL-GAT study

Background

Gastrointestinal tract (GIT) dysfunction is common in Parkinson’s disease (PD) patients. However, it remains unclear whether levodopa affects GIT function in PD.

Objective

To perform an open study of levodopa’s effects on anorectal constipation in de novo PD patients by the quantitative lower-gastrointestinal autonomic test (QL-GAT).

Methods

Nineteen unselected de novo PD patients (10 men, 9 women; mean age, 66 years; mean duration of the disease, 2.2 years) were recruited for the study. Eighteen of the patients reported constipation. These patients were treated with 200/20 mg b.i.d. of levodopa/carbidopa for 3 months. Pre- and post-treatment, objective parameters in the QL-GAT that comprised the colonic transit time (CTT) and rectoanal videomanometry were obtained.

Results

Levodopa was well tolerated by all patients. There was a trend toward subjective improvements in bowel frequency and difficulty defecating. Levodopa did not significantly change CTT of the total colon or any segment of the colon. During rectal filling, levodopa significantly lessened the first sensation (p < 0.05). It also tended to augment the amplitude of spontaneous phasic rectal contraction (not statistically significant). During defecation, levodopa significantly lessened the amplitude in paradoxical sphincter contraction upon defecation (PSD) (p < 0.01). It also tended to augment the amplitude of rectal contraction and lessen the amplitude of abdominal strain (not statistically significant). Overall, levodopa significantly lessened post-defecation residuals (p < 0.05).

Conclusions

The QL-GAT in the present study showed for the first time that levodopa augmented rectal contraction, lessened PSD, and thereby ameliorated anorectal constipation in de novo PD patients.     

Anourethral reflex. Description of a reflex and its clinical significance: preliminary study.

A new reflex which I call the 'ano-urethral reflex' is described and its clinical significance discussed. It was studied in 16 volunteers with normal vesical and rectal functions. A concentric needle electrode was introduced into the external and sphincter (stimulating), and another one into the external urethral sphincter (recording). The reflex response was recorded by EMG apparatus. The external urethral sphincter basal activity was increased with stimulation of the external anal sphincter. This reflex response was absent when the external and sphincter was anesthetised. The average latency of the reflex was 129.5 ms. Reflex urethral sphincter contraction at defecation guards against involuntary micturition which may result from rectal distension and levator contraction. The anourethral reflex can be a valuable diagnostic tool in routine investigations of patients with urological and proctological complaints.     

The effect of standard compared to enhanced instruction and verbal feedback on anorectal manometry measurements

Background Guidelines recommend instruction and motivation during anorectal manometry; however, its impact on findings has not been reported. This study assessed the effects of standard versus enhanced instruction and verbal feedback on the results of anorectal manometry. Methods High‐resolution manometry was performed by a solid‐state catheter with 10 circumferential sensors at 6 mm separation across the anal canal and two rectal sensors. Measurements were acquired first with standard instruction and then with enhanced instruction and verbal feedback. On both occasions, squeeze pressure and duration during three voluntary contractions and intra‐rectal pressure and recto‐anal pressure gradient (RAPG) during three attempts at simulated defecation were assessed. Key Results A total of 70 consecutive patients (54 female; age 25–82 years) referred for investigation of fecal incontinence (n = 31), constipation, and related disorders of defecation (n = 39) were studied. Enhanced instruction and verbal feedback increased maximum squeeze pressure (Δ10 ± 28.5 mmHg; P < 0.0038) and duration of contraction (Δ3 ± 4 s; P < 0.0001). During simulated defecation, it increased intra‐rectal pressure (Δ12 ± 14 mmHg; P < 0.003) and RAPG (Δ11 ± 20 mmHg; P < 0.0001). Using standard diagnostic criteria, the intervention changed manometric findings from locally validated ‘pathologic’ to ‘normal’ values in 14/31 patients with incontinence and 12/39 with disorders of defecation. Conclusions & Inferences Enhanced instruction and verbal feedback significantly improved voluntary anorectal functions and resulted in a clinically relevant change of manometric diagnosis in some patients. Effective explanation of procedures and motivation during manometry is required to ensure consistent results and to provide an accurate representation of patient ability to retain continence and evacuate stool.     

The external anal sphincter and the role of surface electromyography

Abstract  Assessment of the neuronal control of the external anal sphincter (EAS) has long been restricted to investigating patients with defecation disorders by invasive tools such as needle electromyography (EMG), while less invasive techniques have been regarded as non-suitable for diagnostic purposes. Multichannel surface EMG by means of electrode arrays applied to anal sphincter muscle records and identifies individual motor unit action potentials, their place of origin along the circumference, their repetitive firing frequency, and their progression along the muscle fibres at different levels within the anal canal. These data shed doubts on conventional knowledge about the anatomy of the EAS muscle, and confirms new concepts of anatomical differences between gender. This may eventually be transferred to a new understanding of the role of symmetry and asymmetry of pelvic floor innervation and its role in the pathogenesis of fecal incontinence.     

What is the optimum methodology for the clinical measurement of resting anal sphincter pressure?

There are conflicting recommendations from consensus groups with regard to the assessment of resting anal sphincter pressure. Our aims were to evaluate and compare the performance of three recognized techniques for the clinical measurement of resting anal sphincter pressure. METHODS: In each of 54 patients presenting for anorectal manometry, and suffering from constipation or fecal incontinence, three different techniques for assessment of resting anal pressure were undertaken, namely stationary, stationary pull-through and slow pull-through techniques. Resting anal sphincter pressures were compared between groups and between techniques. RESULTS: Mean resting anal sphincter pressure was lower with stationary, compared with stationary pull-through and slow pull-through, techniques (P < or = 0.002). Resting pressure was higher for constipation than incontinence regardless of technique used (P < 0.00001). The techniques were highly correlated with each other (P < 0.0001). The stationary pull-through technique conferred a minor advantage in the discrimination between constipation and incontinence. The stationary technique required significantly less time for completion (P < 0.0001). CONCLUSION: Resting anal sphincter pressure varies according to the specific technique employed, yet each technique is valid. The stationary pull-through technique confers a minor advantage in clinical discrimination of patients, but the stationary technique is more time-efficient. Standardized anal sphincter testing should be established to enable inter-laboratory comparisons.     

Stress induced urinary incontinence in patients with spinocerebellar degeneration

OBJECTIVES—To examine the pathophysiology of"stress induced urinary incontinence" (urinary incontinence evokedby abdominal straining) in patients with spinocerebellar degeneration.
METHODS—Micturitional symptoms of 184 patientswith spinocerebellar degeneration who were admitted to hospital werestudied repeatedly. Urodynamic studies were made in symptomaticpatients, and consisted of uroflowmetry, measurement of residual urine,urethral pressure profilometry, medium fill water cystometry, andexternal sphincter EMG
RESULTS—Twenty nine (15.8%) patients withspinocerebellar degeneration showed stress induced urinaryincontinence. Twenty of the 29patients had detrusor overactivity, lowcompliance detrusor, or residual urine, resembling urgency and overflowtypes of incontinence (complicated form). The other nine had none ofthese findings (pure form), but showed decreased maximum urethralclosure pressure in four, absence of bulbocavernosus reflex in two,absence of voluntary sphincter contraction in one, incompetent urinarystorage even at the first sensation in two, and high amplitude andpolyphasic neurogenic changes in three of five patients studied,indicative of neurogenic sphincter dysfunction.
CONCLUSIONS—Stress induced urinary incontinence inspinocerebellar degeneration had various underlying mechanisms. Some ofthe patients only showed evidence of pudendal denervation, which cancause external sphincter weakness and may reflect lesions of the sacral Onuf's nucleus and the pudendal nerve. Urodynamic studies are necessary to evaluate stress induced urinary incontinence in patients with spinocerebellar degeneration, to prescribe appropriate therapies.

     

Anorectal manometry in children with defecation disorders BSPGHAN Motility Working Group consensus statement

Defecatory disorders in children, including chronic constipation (CC) and fecal incontinence (FI), are common conditions worldwide and have a significant impact on children, their families, and the healthcare system. Anorectal manometry (ARM) and high‐resolution anorectal manometry (HRAM) are relatively novel tools for the assessment of anal sphincter function and rectal sensation and have contributed significantly to improving the understanding of the anorectum as a functional unit. ARM has been recognized as the investigation of choice for adults with symptoms of defecation disorders, including fecal incontinence (FI), evacuation difficulties, and constipation. Although it is the gold standard tool in adults, it has yet to be formally accepted as a standardized diagnostic tool in the pediatric age, with limited knowledge regarding indications, protocol, and normal values. ARM/HRAM is slowly becoming recognized among pediatricians, but given that there are currently no agreed guidelines there is a risk that will lead to diversity in practice. The British Society of Paediatric Gastroenterology, Hepatology and Nutrition (BSPGHAN)—Motility Working Group (MWG) therefore has taken the opportunity to provide guidance on the use of ARM/HRAM in children with CC and/or FI.     

Investigation of the utility of colorectal function tests and Rome II criteria in dyssynergic defecation (Anismus)

Although 30-50% of constipated patients exhibit dyssynergia, an optimal method of diagnosis is unclear. Recently, consensus criteria have been proposed but their utility is unknown. To examine the diagnostic yield of colorectal tests, reproducibility of manometry and utility of Rome II criteria. A total of 100 patients with difficult defecation were prospectively evaluated with anorectal manometry, balloon expulsion, colonic transit and defecography. Fifty-three patients had repeat manometry. During attempted defecation, 30 showed normal and 70 one of three abnormal manometric patterns. Forty-six patients fulfilled Rome criteria and showed paradoxical anal contraction (type I) or impaired anal relaxation (type III) with adequate propulsion. However, 24 (34%) showed impaired propulsion (type II). Forty-five (64%) had slow transit, 42 (60%) impaired balloon expulsion and 26 (37%) abnormal defecography. Defecography provided no additional discriminant utility. Evidence of dyssynergia was reproducible in 51 of 53 patients. Symptoms alone could not differentiate dyssynergic subtypes or patients. Dyssynergic patients exhibited three patterns that were reproducible: paradoxical contraction, impaired propulsion and impaired relaxation. Although useful, Rome II criteria may be insufficient to identify or subclassify dyssynergic defecation. Symptoms together with abnormal manometry, abnormal balloon expulsion or colonic marker retention are necessary to optimally identify patients with difficult defecation.     

Disturbances of ano-rectal function in multiple sclerosis

Thirty patients with multiple sclerosis (MS) [18 men and 12 women, mean age 40 years (range 22–50), disease duration 12 years (range 0.5–34), Kurtzke's Expanded Disability Status Score 6.0 (range 4.0–7.5)] were interviewed about bowel symptoms and studied using ano-rectal manometry. The results were compared with findings in healthy controls. Twenty-eight had bowel symptoms: 8 constipation, 10 constipation and infrequent faecal urgency, 4 infrequent faecal incontinence and 6 frequent faecal incontinence. Anal sphincter pressure at rest was significantly reduced in MS patients 69 (SD 17) cm H₂O, compared with 92 (SD 15) cm H₂O in controls, and the external sphincter contraction force was also significantly reduced. Rectal sensation and rectal compliance were reduced and the ano-rectal inhibition reflex (defaecation reflex) required a higher rectal pressure to be elicited in the patients. Upon rectal filling, an early external sphincter excitation was seen. The presence of faecal incontinence correlated strongly with reduced rectal sensation. The findings suggest that faecal incontinence can at least partly be explained by low anal sphincter pressure and poor rectal sensation. The findings of early sphincter excitation and increased threshold of ano-rectal inhibition reflex may be an important pathophysiological factor for constipation in MS patients.     

Anal sphincter dysfunction in Parkinson's disease

Striated anal sphincter function was studied electrophysiologically and radiologically in six patients with Parkinson's disease and chronic constipation. In five cases, there was paradoxic anal sphincter muscle contraction during simulated defecation straining resembling anismus-type pelvic outlet obstruction. Radiologic studies showed functional improvement of the defecatory mechanism following the administration of the dopamine receptor agonist apomorphine in four patients. Dysfunction of the striated anal sphincter musculature may be a significant cause of constipation in some parkinsonian patients, occurring as part of the generalized extrapyramidal motor disorder.     

Quantitative anal sphincter EMG in multisystem atrophy and 100 controls

OBJECTIVE: To evaluate data of quantitative anal sphincter EMG in normal controls and to compare them with patients with multiple system atrophy (MSA). METHODS: Quantitative anal sphincter EMG were performed on 100 normal controls and 11 patients with MSA to characterise EMG data in these two groups. RESULTS: In the normal controls, there was a trend for increased motor unit potential (MUP) amplitude, duration, area, and polyphasicity with advancing age. Patients with MSA exhibited similar MUP size and fibre density. Significant differences were found only in parameters of the recruitment pattern, which were reduced in MSA, with a diminution in the number of active MUPs during rest. CONCLUSIONS: These results may reflect either decreased number of motor cells in Onuf's nucleus without significant consequential reinnervation, or upper motor neuron involvement affecting the anal sphincter in MSA. They further underline the importance of comparative data for age matched controls.     

Electrophysiological observations on the human pudendo-anal reflex.

A reproducible electrophysiological technique is described to determine the latency of reflex contraction of the external anal sphincter in response to stimulation of the dorsal genital nerve: the pudendo-anal reflex. This was studied in 38 asymptomatic control subjects and 20 women with neurogenic faecal incontinence, supplemented by determination of the mean motor unit potential duration (MUPD) of the external anal sphincter and anorectal manometry. The reflex latency in the control group was 38.5 +/- 5.8 (SD) ms and appeared to be independent of age or sex. Three patients with faecal incontinence had absent reflexes; the remainder showed significant prolongation of latency (56 +/- 12.2 SD ms) and diminution of amplitude. MUPD was prolonged in incontinence and showed significant correlation with the corresponding reflex latency determination (tau = 0.56, p less than 0.001). The latency of this polysynaptic spinal reflex hence provides a reliable index of neuropathy of the external anal sphincter.     

Electrodiagnostic evaluation of fecal incontinence

The aim of this study was to assess the utility of electrodiagnostic testing (EDT) for the evaluation of fecal incontinence (FI). Over a 5-year period, 225 patients (174 females) with FI were prospectively studied with anal manometry, anal ultrasonography, anal electromyography (AEMG), and pudendal nerve terminal motor latency (PNTML) assessment. The mean age was 60 (range 12–94) years. Causes of FI identified by clinical evaluation were obstetric injuries (45), rectal prolapse (43), iatrogenic or other trauma (42), neurologic disease (23), and idiopathic (72). EDT revealed abnormalities in 76% of patients. The incidence of pudendal neuropathy (PN) was 36% (bilateral 21%, unilateral 15%). Patients with PN were older than were those with normal PNTML (mean 71 vs. 63 years; P < 0.002). No relationship between squeeze pressure and PN could be demonstrated (P = 0.9). Reduced motor unit potential (MUP) recruitment on AEMG was present in 60% and was associated with decreased squeeze pressure (P < 0.001) and increased MUP polyphasia (P < 0.001). Concurrence of AEMG and anal ultrasonographic findings was observed in 35 of 41 patients (84%). Defects were overlooked in one study but identified by the other on three occasions, each. Moreover, 8 of 22 patients with demonstrated sphincter defects had unsuspected PN or extensive sphincter injury on AEMG that precluded sphincter repair. In conclusion, EDT proved to be a valuable tool in the evaluation and subsequent treatment of patients with FI. © 1995 John Wiley & Sons, Inc.     

Sphincter EMG and differential diagnosis of multiple system atrophy.

Multiple system atrophy (MSA) is a degenerative disease manifesting a combination of parkinsonism, cerebellar, pyramidal, and autonomic (including urinary, sexual, and anorectal) dysfunction. It is pathomorphologically defined, but lacks a definitive clinical diagnostic test. Sphincter electromyography (EMG), reflecting Onuf's nucleus degeneration, has been proposed as a helpful test; its value has been reevaluated by a critical review of the literature. In patients with probable MSA, abnormal sphincter EMG, as compared to control subjects, has been found in the majority of patients in all the different forms of the disease in most studies, including patients who, as yet, have no urological or anorectal problems. The prevalence of abnormalities in the early stages of MSA is as yet unclear. Patients with Parkinson's disease (PD) as a rule do not show severe sphincter EMG abnormalities in the early stage of the disease. Anal sphincter EMG abnormalities (abnormal spontaneous activity or motor unit potential changes three standard deviations above valid control data) distinguish MSA from PD in the first 5 years after the onset of symptoms and signs, and from pure autonomic failure, as well as from cerebellar ataxias, if other causes for sphincter denervation have been ruled out. With such criteria, the sensitivity of the method is, however, low. EMG does not distinguish MSA from progressive supranuclear palsy. Future studies should use standardized anal sphincter EMG to better compare results from different centers and precisely define the sensitivity and specificity of the method.     

Respective value of pudendal nerve terminal motor latency and anal sphincter electromyography in neurogenic fecal incontinence.

Fecal incontinence may be related to a neurogenic injury. Electrodiagnostic tests including pudendal nerve terminal motor latency (PNTML) and external anal sphincter electromyography (AEMG) have been proposed to reveal anal nerve damage. The aim of this study was to assess the respective value of PNTML and AEMG in the diagnosis of fecal incontinence. This study included 80 women (range 23-85 years) with fecal incontinence secondary to obstetrical and/or surgical trauma. They were evaluated by performing PNTML and AEMG. The electrophysiological results were compared and interpreted in the light of anorectal manometry (ARM) results. Electrodiagnostic test abnormalities were found in 64 of 80 patients (80%), including 28 patients with abnormal results for both tests and 36 patients with only one abnormal test. Overall, a neurogenic AEMG pattern was found in 64% of patients and a prolonged PNTML in 51%. No correlation was found between PNTML value and either AEMG grade or ARM parameters, while AEMG grade strongly correlated with squeeze pressure measured by ARM. This study showed that AEMG and PNTML did not give redundant information and allowed to explicit the mechanisms of neurogenic fecal incontinence. We found that AEMG was more sensitive and more closely related to the anal functional status (ARM parameters) than PNTML. These electrodiagnostic tests, particularly AEMG as performed in everyday practice, are useful in the assessment of neurogenic fecal incontinence.     

Videourodynamic and sphincter motor unit potential analyses in Parkinson's disease and multiple system atrophy

OBJECTIVES: Urinary dysfunction is a prominent autonomic feature in Parkinson's disease (PD) and multiple system atrophy (MSA), which is not only troublesome but also a cause of morbidity in these disorders. Recent advances in investigative uroneurology offer a better insight into the underlying pathophysiology and appropriate management for urinary dysfunction. METHODS: twenty one patients with PD (15 men, six women, mean age 64 (49-76), mean disease duration 4 years (1-8 years), median Hoehn and Yahr grade 3 (1-4), all taking 300 mg/day of levodopa (100-500 mg)) and 15 with MSA (eight men, seven women, mean age 59 (48-72), mean disease duration 3 years (0.5-6 years)) were recruited. Videourodynamic and sphincter motor unit potential analyses in the patients with PD and MSA were carried out, looking for distinguishing hallmarks that might be useful in the differential diagnosis of these two diseases. RESULTS: Urinary symptoms were found in 72% of patients with PD and in 100% with MSA. Filling phase abnormalities in the videourodynamic study included detrusor hyperreflexia in 81% of patients with PD and 56% with MSA, and uninhibited external sphincter relaxation in 33% of patients with PD and 33% of those with MSA. However, open bladder neck at the start of filling was not seen in patients with PD but was present in 53% of those with MSA, suggestive of internal sphincter denervation. Sphincter motor unit potential analysis showed neurogenic motor unit potentials in 5% of patients with PD and in 93% of those with MSA, suggestive of external sphincter denervation. On voiding, detrusor-external sphincter dyssynergia was not seen in patients with PD but was present in 47% of those with MSA. Pressure-flow analysis showed that the Abrams-Griffiths number, a grading of urethral obstruction (outflow obstruction >40), in PD (40 in women and 43 in men) was larger than that in MSA (12 in women and 28 in men). Weak detrusor in PD (66% of women and 40% of men) was less common than that in MSA (71% of women and 63% of men). Postmicturition residuals >100 ml were absent in patients with PD but were present in 47% of patients with MSA. CONCLUSION: Patients with PD had less severe urinary dysfunction with little evidence of internal or external sphincter denervation, by contrast with the common findings in MSA. The findings of postmicturition residuals >100 ml, detrusor-external sphincter dyssynergia, open bladder neck at the start of bladder filling, and neurogenic sphincter motor unit potentials are highly suggestive of MSA.