Idiopathic autonomic denervation in eight patients presenting with functional gastrointestinal disease. A causal association?

Comparisons between Manual Lymph Drainage, Abdominal Massage, and Electrical Stimulation on Functional Constipation Outcomes: A Randomized, Controlled Trial

BACKGROUND

Evidence supports abdominal massage (AM) or electrical stimulation (ES) as effective in treating functional constipation (FC). Manual lymph drainage (MLD) may also be beneficial, however, it was not previously investigated or compared to ES and AM.

METHODS

Sixteen college-aged males and 36 females were recruited. Participants were randomly assigned to MLD, AM or ES. Heart rate variability (HRV) measures for total power (TP), high frequency (HF), low frequency and LF/HF ratio assessed ANS outcomes. state-trait anxiety inventory (STAI) and stress response inventory (SRI) assessed psychological factors and bowel movement frequency (BMF) and duration (BMD) were recorded daily.

RESULTS

MLD significantly improved all ANS measures (p≤0.01); AM significantly improved LF, HF and LF/HF ratios (p = 0.04); and ES significantly improved LF (p = 0.1). STAI measures improved, but not significantly in all groups. SRI improved significantly from MLD (p < 0.01), AM (p = 0.04) and ES (p < 0.01), but changes were not significant between groups. BMD improved significantly in all groups (p≤ 0.02). BMF improved significantly only following MLD and AM (p < 0.1), but differences between groups were not significant (p = 0.39).

CONCLUSIONS

MLD significantly reduced FC symptoms and MLD had greater improvements than AM or ES.

Functional Disorders: Slow-Transit Constipation

Constipation is a very common complaint, with slow-transit constipation (STC) accounting for a significant proportion of cases. Old age, female gender, psychiatric illness, and history of sexual abuse are all associated with STC. The exact cause of STC remains elusive; however, multiple immune and cellular changes have been demonstrated. Diagnosis requires evidence of slowed colonic transit which may be achieved via numerous modalities. While a variety of medical therapies exist, these are often met with limited success and a minority of patients ultimately require operative intervention. When evaluating a patient with STC, it is important to determine the presence of concomitant obstructed defecation or other forms of enteric dysmotility, as this may affect treatment decisions. Although a variety of surgical procedures have been reported, subtotal colectomy with ileorectal anastomosis is the most commonly performed and well-studied procedure, with the best track record of success.

Gastric Enterovirus Infection: A Possible Causative Etiology of Gastroparesis

BACKGROUND

Gastroparesis (GP) is a disabling chronic gastroenterologic disorder with high morbidity that severely impacts patients' quality of life. GP can present acutely after a viral-like gastrointestinal illness resulting in speculation that in some patients, neurologic damage caused by the infection might underlie the pathogenesis of idiopathic gastroparesis (IGP).

AIMS

The aim of this study is to document case reports of Enterovirus (EV) infection as a possible cause of IGP.

METHODS

Eleven patients referred with a diagnosis of GP underwent workup to exclude known causes of GP. Those with a history of flu-like symptoms or gastroenteritis prior to onset of GP symptoms had gastric biopsies taken during upper endoscopy to assess for the presence of gastric mucosal EV infection. Data on presenting symptoms, extra-intestinal symptoms and conditions, prior nutritional support requirements, upper endoscopy findings, and response to therapy were cataloged.

RESULTS

Eleven patients were diagnosed as IGP. Nine had active EV infection on gastric biopsies and were included (7/9 female, mean age 43 years). Eight out of nine received EV treatment with antivirals and/or immune therapies, with a wide degree of variability in treatment regimens. Four out of eight who received EV treatment had symptomatic improvement. One patient had stable symptoms. Three patients are currently undergoing therapy.

CONCLUSIONS

Gastric EV infection was frequently detected (82 %) in patients undergoing investigation for IGP. Antiviral and/or immune therapies against EV seem to be favorable, as most of our patients had resolution of their GP symptoms after treatment. This is the first study to identify EV as a possible infectious etiology of IGP.

Sonographic evaluation of gallbladder motility in children with chronic functional constipation

Background/Aims

Studies in adults suggest that constipation may not be a purely colonic pathology and may be a component of a generalized gastrointestinal (GI) motor disorder in which proximal GI motility can be impaired. Pediatric data are scarce, and the natural history of the disorder remains undefined. We aimed to evaluate gallbladder motility in a subset of Asian children with chronic functional constipation.

Methods

Abdominal ultrasound was performed on 105 children, including 55 patients (aged 3 to 13 years) with chronic functional constipation who met the inclusion criteria and 50 age- and gender-matched controls. The gallbladder contractility index was calculated based on the preprandial and postprandial gallbladder areas. Preprandial and postprandial values for gallbladder volume and wall thickness were evaluated.

Results

The mean value of the contractility index for the patients (15.77±24.68) was significantly lower than the mean value for the controls (43.66±11.58) (p=0.001). The mean postprandial gallbladder volumes and areas were larger in children with gallbladder hypomotility (p<0.05). The mean duration of constipation (4.8 months) was significantly higher (p=0.004) in the children with gall-bladder hypomotility.

Conclusions

Gallbladder motility is significantly impaired in children with chronic functional constipation. This study contributes to the understanding of the underlying pathophysiology, which will enable advancement in and improved management of children with chronic constipation and associated gallbladder hypomotility.

The serotonin receptor mediates changes in autonomic neurotransmission and gastrointestinal transit induced by heat-killed Lactobacillus brevis SBC8803

Lactobacilli exhibit several health benefits in mammals, including humans. Our previous reports established that heat-killed Lactobacillus brevis SBC8803 (SBC8803) increased both efferent gastric vagal nerve activity and afferent intestinal vagal nerve activity in rats. We speculated that this strain could be useful for the treatment of gastrointestinal (GI) disorders. In this study, we examined the effects of SBC8803 on peristalsis and the activity of the efferent celiac vagal nerve innervating the intestine in rats. First, we examined the effects of intraduodenal (ID) administration of SBC8803 on efferent celiac vagal nerve activity (efferent CVNA) in urethane-anesthetised rats using electrophysiological studies. The effects of intravenous injection of the serotonin 5-HT3 receptor antagonist granisetron on changes in efferent CVNA due to ID administration of SBC8803 were also investigated. Finally, the effects of oral gavage of SBC8803 on GI transit were analysed using the charcoal propulsion method in conscious rats treated with or without granisetron. ID administration of SBC8803 increased efferent CVNA. Pretreatment with granisetron eliminated SBC8803-dependent changes in efferent CVNA. Furthermore, oral gavage of SBC8803 significantly accelerated GI transit, while pretreatment with granisetron inhibited GI transit. Our findings suggested that SBC8803 increased efferent CVNA and GI transit of charcoal meal via 5-HT3 receptors. Moreover, SBC8803 enhanced the activity of efferent vagal nerve innervating the intestine and promoted peristalsis via 5-HT3 receptors.

Adolescent fatigue, POTS, and recovery: a guide for clinicians

Many teenagers who struggle with chronic fatigue have symptoms suggestive of autonomic dysfunction that may include lightheadedness, headaches, palpitations, nausea, and abdominal pain. Inadequate sleep habits and psychological conditions can contribute to fatigue, as can concurrent medical conditions. One type of autonomic dysfunction, postural orthostatic tachycardia syndrome, is increasingly being identified in adolescents with its constellation of fatigue, orthostatic intolerance, and excessive postural tachycardia (more than 40 beats/min). A family-based approach to care with support from a multidisciplinary team can diagnose, treat, educate, and encourage patients. Full recovery is possible with multi-faceted treatment. The daily treatment plan should consist of increased fluid and salt intake, aerobic exercise, and regular sleep and meal schedules; some medications can be helpful. Psychological support is critical and often includes biobehavioral strategies and cognitive-behavioral therapy to help with symptom management. More intensive recovery plans can be implemented when necessary.

Correlation between gastrointestinal hormones and anxiety-depressive states in irritable bowel syndrome

The aim of this study was to investigate the mechanism(s) of action of gastrointestinal hormones in the pathogenesis of irritable bowel syndrome (IBS), and the correlation between gastrointestinal hormones and psychological factors. Patients with IBS were divided into IBS with normal emotional state ratings and IBS in anxiety-depressive states groups. The two groups were then subdivided into IBS-constipation predominant (IBS-C) and IBS-diarrhea predominant (IBS-D) groups. Non-IBS patients with normal depression and anxiety ratings were recruited as controls. The serum concentrations of somatostatin (SS) and vasoactive intestinal peptide (VIP) were measured by radioimmunoassay, and the expression of SS and VIP in the colonic mucosa was detected by immunohistochemistry and radioimmunoassay. The anxiety-depression scores of patients with IBS were significantly different from those of the control group (P<0.05). The expression levels of SS and VIP in the serum and colonic mucosa of the patients with IBS were higher compared with those of the control group. Furthermore, the expression level of SS in the IBS-C group demonstrated a significantly larger increase than that in the IBS-D group (P<0.05); however, there was no significant difference in the expression of VIP between the IBS-C and IBS-D groups (P>0.05). In addition, the expression levels of SS and VIP in the IBS groups with normal emotional state ratings were notably different from those in the IBS groups in anxiety-depressive states (P<0.05). Anxiety-depressive states may lead to changes in the secretion of SS and VIP, and subsequently to changes in gastrointestinal motility and function.

Correlation between anxiety-depression status and cytokines in diarrhea-predominant irritable bowel syndrome

The aim of this study was to investigate the correlation between anxiety-depression status and cytokines in diarrhea-predominant irritable bowel syndrome (IBS-D). IBS-D patients were divided into an anxiety-depression IBS-D group and a non-anxiety-depression IBS-D group. Patients without IBS, anxiety or depression were selected as the control group. Scoring was performed using the self-rating anxiety scale (SAS) and self-rating depression scale (SDS). Levels of IL-1β and IL-10 in the blood and sigmoid colon mucosa were detected, and the proportions of IL-1β- and IL-10-positive cells in the sigmoid colon mucosa were determined. The results demonstrated that the SDS and SAS scores in the IBS-D group were significantly higher than those in the control group (P<0.05). The levels of IL-1β in the blood and sigmoid colon mucosa and the proportion of IL-1β-positive cells in the sigmoid colon mucosa in the IBS-D group were significantly higher than those in the control group (P<0.05). The levels of IL-10 in the blood and sigmoid colon mucosa and the proportion of IL-10-positive cells in the IBS-D group were significantly lower than those in the control group (P<0.05). The levels of IL-1β in the blood and sigmoid colon mucosa and the proportion of IL-1β-positive cells in the anxiety-depression IBS-D group were significantly higher than those in the non-anxiety-depression IBS-D group, and the levels of IL-10 and the proportion of IL-10-positive cells in the anxiety-depression IBS-D group were significantly lower than those in the non-anxiety-depression IBS-D group (P<0.05). Anxiety-depression status may cause the IL-1β and IL-10 levels in IBS patients to change and result in an imbalance of the proinflammatory and anti-inflammatory cytokines, leading to the occurrence or aggravation of IBS.

Autonomic nervous system activity in constipation-predominant irritable bowel syndrome patients

Background

The main mechanism underlying irritable bowel syndrome is currently believed to be a dysfunction of the brain-gut axis. Autonomic nervous system dysfunction can contribute to development of irritable bowel syndrome symptoms by disturbing visceral sensations.

Material/Methods

Thirty patients with a diagnosis of constipation-predominant irritable bowel syndrome and 30 healthy volunteers were included in the study. Resting and functional autonomic nervous system tests and percutaneous electrogastrography were performed. Plasma adrenalin, noradrenalin, insulin, ghrelin and cholecystokinin activity was analyzed.

Results

Increased sympathetic activation with disturbed parasympathetic function was demonstrated. Patients had substantially higher plasma catecholamine concentration, which confirms sympathetic overbalance. Hyperinsulinemia may explain sympathetic predominance followed by gastric and intestinal motility deceleration. Abnormal, reduced ghrelin and cholecystokinin titre may disturb brain-gut axis functioning and may be responsible for gastric motility deceleration. In electrogastrography, distinctly lower values of fasting normogastria percentage and dominant power were observed. Patients had substantially lower slow wave coupling percentage both in fasting and postprandial periods, which negatively correlated with plasma catecholamines level. Gastric myoelectrical activity disturbances may result from lack of sympatho-parasympathetic equilibrium.

Conclusions

Central sympathetic influence within the brain-gut axis is most probably responsible for myoelectrical activity disturbances in irritable bowel syndrome patients.

Heart rate variability in the irritable bowel syndrome: a review of the literature

BACKGROUND

Patients with irritable bowel syndrome (IBS) often present with disturbances of bowel habits (diarrhea, constipation) and abdominal pain/discomfort that are modulated by the autonomic nerve system (ANS). In this narrative review, we analyzed studies that measured ANS functioning in IBS by means of heart rate variability (HRV).

METHODS

The PUBMED was searched with the keywords 'irritable bowel syndrome' AND ('heart rate variability' OR 'autonomic function'). We included only papers that used 'traditional' HRV indices and diagnosed IBS based on Manning or Rome criteria. Studies were sub-grouped according to methodological features of HRV analysis (24-h monitoring, short-term laboratory records, records during sleep).

KEY RESULTS

Most studies reported no difference in HRV when the IBS population was compared to healthy controls. Dividing the IBS sample into subgroups--according to their predominant bowel symptoms, the severity of clinical course, the presence of depressive symptoms, or a history of abuse in the past--revealed changes in autonomic functioning.

CONCLUSIONS & INFERENCES

Patients with IBS appear to experience symptoms that may be the result of changes in ANS functioning. HRV measures in clinical routine may allow assessing these changes, but further studies performed in a standardized fashion should improve the validity of HRV measures for clinical research first.

Impaired gastric response to modified sham feeding in patients with postprandial distress syndrome

BACKGROUND

Impaired vagal function has been reported to be important in some patients with functional dyspepsia (FD). However, the pathophysiologic mechanisms influencing the cephalic phase of vagal activity in FD are incompletely understood. The aim of this study was to investigate the gastric response to modified sham feeding (MSF) on ultrasound and cardiovascular autonomic function in FD patients.

METHODS

Nineteen patients with postprandial distress syndrome (PDS, 11 men and eight women; mean age: 48.2 years) and 26 healthy subjects (HS, 13 men and 13 women; mean age: 45.0 years) were studied prospectively. Firstly, cardiovascular autonomic function was assessed by spectral analysis of RR interval variability. Antral contraction was then evaluated by ultrasonography after MSF was performed to stimulate the cephalic phase of vagal activity.

KEY RESULTS

Spectral analysis of RR interval variability showed that the high-frequency component was significantly smaller in the patients than in the HS (P<0.01). The frequency of antral contraction in response to MSF over 15 min was also significantly lower in the PDS patients than in the HS. The 15-min integrated antral contractile response (area under the contraction vs time curve) was significantly smaller in the PDS patients than in the HS (P<0.01). Univariate analysis revealed a modest correlation between the high-frequency component of RR interval variability and the area under the contraction vs time curve (n=46, r=0.49, P<0.01).

CONCLUSIONS & INFERENCES

Autonomic abnormalities affecting the cephalic phase of vagal activity may be important in the pathogenesis of FD.

The efficacy of treatment of patients with severe constipation or recurrent pseudo-obstruction with pyridostigmine

OBJECTIVE

Disorders of colonic motility, such as severe constipation and pseudo-obstruction, remain difficult to treat. The pathophysiology of these conditions is not completely understood, but previous studies suggest a deficiency of cholinergic innervation and an imbalance in autonomic regulation of colonic motor function as contributing factors. Therefore, increasing the availability of acetylcholine in the bowel wall with a cholinesterase inhibitor, such as pyridostigmine, may improve symptoms.

METHOD

We studied thirteen patients with severe constipation (slow transit type) or recurrent pseudo-obstruction. The six patients with slow transit constipation had mechanical obstruction and pelvic floor dysfunction excluded, and normal calibre colon and slow transit confirmed. These patients were offered pyridostigmine in an attempt to avoid surgery. The seven patients with pseudo-obstruction had dilated bowel on imaging, and mechanical obstruction was excluded. These patients received pyridostigmine when symptoms recurred, despite previous treatments. Pyridostigmine was initiated at 10 mg b.i.d. and increased if required.

RESULTS

One of the six patients with slow transit constipation reported improvement of symptoms and had concurrently weaned anti-psychotic medications. Pyridostigmine was ceased in the remaining five patients due to lack of efficacy and/or side effects. Four patients proceeded to surgery for refractory symptoms. All seven patients with pseudo-obstruction had some improvement of symptoms with few side effects. Of these, two later had surgery for recurrent symptoms.

CONCLUSION

In patients with slow transit constipation, treatment with pyridostigmine does not improve symptoms. However, it does improve symptoms in patients with recurrent pseudo-obstruction with few side effects, offering an extra treatment option for these patients.

Slow transit constipation: a review of a colonic functional disorder

Constipation is a common gastrointestinal complaint that can cause significant physical and psychosocial problems. It has been categorized as slow transit constipation, normal transit constipation, and obstructed defecation. Both the definition and pathophysiology of constipation are unclear, but attempts to describe each of the three types have been made. Slow transit constipation, a functional colonic disorder represents approximately 15 to 30% of constipated patients. The theorized etiologies are disorders of the autonomic and enteric nervous system and/or a dysfunctional neuroendocrine system. Slow transit constipation can be diagnosed with a complete history, physical exam, and a battery of specific diagnostic studies. Once the diagnosis is affirmed and medical management has failed, there are several treatment options. Biofeedback, sacral nerve stimulation, segmental colectomy, and subtotal colectomy with various anastomoses have all been used. Of those treatment options, a subtotal colectomy with ileorectal anastomosis is the most efficacious with the data to support its use.

Expanding the phenotypes of the Pro56Ser VAPB mutation: proximal SMA with dysautonomia

The phenotype of 16 members of a family affected by a late-onset, dominant, progressive, motor and autonomic disorder is described. The VAPB (Pro56Ser) mutation was detected in Brazilian families with different phenotypes of motor neuron disorders. In this family, proximal and axial muscle weakness and atrophy, associated with abdominal protrusion, defined the motor phenotype. Death occurred in 10-15 years due to respiratory insufficiency. Tone and tendon reflexes were decreased and a distal tremor was common. Sensation was preserved. Autonomic abnormalities were also present, including choking, chronic intestinal constipation, sexual dysfunction, and sudomotor abnormalities, and on nerve morphology there was involvement of unmyelinated fibers. Electromyography disclosed ongoing denervation and reinnervation. Isolated dysfunction of motor and autonomic neurons is unusual among the spinal muscular atrophies. On this basis, this condition seems to represent a new category of disease.

Postinfectious gastroparesis related to autonomic failure: a case report

BACKGROUND AND AIM

Severe dysautonomia may be secondary to viral infections, resulting in impaired autoimmune, cardiovascular, urinary and digestive dysfunction. Herein, we present a case of a 31-year-old white female patient who had severe gastroparesis related to autonomic failure following an episode of acute gastroenteritis. This seems to be the first report providing thorough assessment of the enteric and autonomic nervous system by analysis of full-thickness small intestinal biopsies, cardiovagal testing and autopsy.

HOSPITAL COURSE

This patient affected by a severe gastroparesis was treated with antiemetics, prokinetics, analgesics and gastric electrical stimulation to control symptoms. Nutritional support was made using jejunal feeding tube and, in the final stage of disease, with total parenteral nutrition. Autonomic studies revealed minimal heart rate variability and a disordered Valsalva manoeuvre although the enteric nervous system and the smooth muscle layer showed a normal appearance. Hospital courses were complicated by episodes of bacteraemia and fungemia. Serum antiphospholipid antibodies were noted but despite anticoagulation, she developed a pulmonary embolism and shortly thereafter the patient died. Autopsy revealed acute haemorrhagic Candida pneumonia with left main pulmonary artery thrombus. Sympathetic chain analysis revealed decreased myelinated axons with vacuolar degeneration and patchy inflammation consistent with Guillain-Barre syndrome. The evaluation of the enteric nervous system in the stomach and small bowel revealed no evidence of enteric neuropathy or myopathy.

CONCLUSION

A Guillain-Barre-like disease with gastroparesis following acute gastroenteritis is supported by physiological and autonomic studies with histological findings.

The pathogenesis of gastrointestinal bacterial overgrowth

The normal indigenous intestinal microflora consists of about 10(15) bacteria that under physiological conditions reside mainly in the lower gastrointestinal tract. Bacterial overgrowth implies abnormal bacterial colonization of the upper gut, resulting from failure of specific defense mechanisms restricting colonization under physiological conditions. At present two types of bacterial overgrowth with defined pathogenesis can be distinguished: (1) gastric overgrowth with upper respiratory tract microflora resulting from selective failure of the gastric acid barrier, and (2) gastrointestinal overgrowth with Gram-negative bacilli (enteric bacteria) resulting from failure of intestinal clearance. Helicobacter pylori-induced gastritis of the oxyntic mucosa is the main cause of acquired failure of the gastric acid barrier, which is common among the healthy elderly. Intestinal clearance may fail as the result of impaired intestinal peristalsis or anatomical abnormalities that alter luminal flow. Impaired peristalsis is associated with conditions interfering with intestinal neuromuscular function including myopathic, neuropathic, autoimmune, infectious, inflammatory, metabolic, endocrine, and neoplastic diseases. Anatomical abnormalities are mainly the result of gastrointestinal surgery, intestinal diverticula or fistula. Combined failure of intestinal clearance and the gastric acid barrier results in more severe colonization with Gram-negative bacilli. Gram-negative bacilli are uncommon in the upper gut of otherwise healthy individuals with gastric hypochlorhydria, being acquired (H. pylori) or drug-induced. Significant bacterial overgrowth with Gram-negative bacilli is a rational in the search for an explanation to optimize clinical management. The clinical significance of colonization with upper respiratory tract microflora remains unclear. Translocation of live bacteria, their metabolic products, or antigens from a small bowel colonized by Gram-negative bacilli play a role in the pathogenesis of spontaneous bacterial peritonitis in hepatic disease and in certain types of sepsis, indicating that further studies can point to new patient populations with potential benefit from medical treatment.

Gallbladder and gastric motility in patients with idiopathic slow-transit constipation

OBJECTIVE

Idiopathic slow-transit constipation (STC) has been suggested to be a pangastrointestinal motility disorder. We investigated scintigraphically whether motility in the gallbladder and stomach was impaired in slow-transit constipation.

METHODS

Twenty-four patients with STC were studied. Colon transit time, gallbladder motility, and solid-phase gastric emptying were measured by scintigraphy.

RESULTS

Gallbladder dysmotility was observed in 8 of 18 (44.4%) patients. Mean gallbladder ejection fraction was 41.6 +/- 13.6% (range, 16.3-67.0%). Gastric emptying was delayed in 9 of 18 (50%) patients. Mean solid-phase gastric half-emptying time was 75 minutes. STC may be associated with impaired function of other gastrointestinal organs. Approximately half of patients with STC presented gallbladder or gastric dysmotility.

CONCLUSION

STC may not be a pure colonic abnormality; it may be a component of a pangastrointestinal tract motility disorder involving several organs.

Familial association of autonomic and gastrointestinal symptoms

Autonomic dysfunction occurs in the adult population with irritable bowel syndrome, but this association is not recognized in children. A mother and son with functional abdominal pain unresponsive to conventional treatment had complete resolution of symptoms with treatment directed at the autonomic dysfunction identified by testing. The authors recommend autonomic testing in patients with functional abdominal pain and suggest that autonomic dysfunction plays a direct and intrinsic role in the mechanism of these disorders and their symptoms.

Psychological and physiological responses to postprandial mental stress in women with the irritable bowel syndrome

OBJECTIVE

To investigate the psychological (affective and symptomatic) and physiological (autonomic and cortisol) responses to postprandial mental stress in women with irritable bowel syndrome (IBS). It was hypothesized that patients with IBS would show exaggerated autonomic and cortisol responses to the psychological stressor and that the stressor would enhance gastrointestinal symptoms.

METHOD

Twenty-four women with IBS and 20 healthy women participated in the two-day study protocol. Both days were identical, with the exception that on one day, a stressful mental task was completed after ingestion of a standard meal. Heart rate variability, cortisol, affective, and symptomatic responses were measured before and after application of the stressor.

RESULTS

Patients with IBS demonstrated increased negative affect at baseline and in response to the stressor. Gastrointestinal symptoms were not affected by the stressor. Appraisal of the stressor by patients with IBS was not different from that of controls. There were no group differences in the autonomic response to the stressor. There was no overall cortisol response to the stressor in either group.

CONCLUSIONS

Patients with IBS respond with greater negative affect to postprandial psychological stress as well as to food intake alone, and they can be distinguished from controls on the basis of self-report data. Patients with IBS cannot be differentiated from controls on the basis of the pattern of changes in sympathetic activation after the mental stressor. The stressor used in this study did not elicit a cortisol response in either group.

Role of autonomic dysfunction in patients with functional dyspepsia

BACKGROUND

The role of autonomic dysfunction in patients with functional dyspepsia is not completely understood.

AIMS

1. to prospectively assess abnormalities of autonomic function in patients with functional dyspepsia, 2. to assess whether autonomic dysfunction in these patients is associated with a. visceral hypersensitivity or b. delayed gastric emptying or c. severity of dyspeptic symptoms.

PATIENTS

A series of 28 patients with functional dyspepsia and 14 healthy volunteers without gastrointestinal symptoms were studied.

METHODS

All patients and controls were submitted to a battery of five standard cardiovascular autonomic reflex tests, dyspeptic questionnaire, gastric barostat tests and gastric emptying tests.

RESULTS

1. Autonomic function tests showed that both sympathetic and parasympathetic scores of dyspeptic patients were significantly higher than in controls; 2. visceral hypersensitivity was confirmed in dyspeptics in response to proximal gastric distension, demonstrating lower pain threshold; 3. delayed gastric emptying occurred more frequently in patients with functional dyspepsia than in controls; 4. epigastric pain and epigastric burning were significantly more prevalent in patients with definite evidence of autonomic dysfunction; 5. No significant association was found between presence of autonomic dysfunction and presence of visceral hypersensitivity or presence of delayed gastric emptying in patients with functional dyspepsia.

CONCLUSIONS

We concluded that a possible role of autonomic dysfunction in eliciting dyspeptic symptoms could not be determined from alterations in visceral hypersensitivity or delayed gastric emptying. Autonomic dysfunction might not be the major explanation for symptoms associated with functional dyspepsia.

Autonomic abnormalities in children with functional abdominal pain: coincidence or etiology?

BACKGROUND

There is increasing evidence that autonomic neuropathies may adversely affect gastrointestinal motility by involving the extrinsic nerves of the gut. The authors' hypothesize that functional abdominal pain in children is associated with generalized autonomic dysfunction.

METHODS

The authors performed detailed autonomic testing in eight patients with functional abdominal pain, including deep breathing, Valsalva, tilting (to assess parasympathetic and sympathetic adrenergic function), and axon-reflex function and thermoregulatory sweat testing to assess sympathetic cholinergic function. Patients also completed a questionnaire regarding other autonomic symptoms.

RESULTS

Results of autonomic testing were abnormal in seven patients. Parasympathetic function was normal in all, and the abnormalities were restricted to sympathetic cardiac, vasomotor, and sudomotor function. Abnormal results of axon-reflex testing in six were consistent with peripheral nervous system dysfunction. Five had decreased sweating over the abdomen, determined by thermoregulatory sweat testing. Five eight had nongastrointestinal autonomic symptoms, primarily palpitations and flushing.

CONCLUSIONS

Functional abdominal pain in the current patients is associated with generalized dysfunction of the autonomic nervous system. This dysfunction can be peripheral or central in different individuals but seems to be restricted to the sympathetic branch. The known function of the sympathetic nervous system as the motility "brake" suggests that pain could be a manifestation of unmodulated peristalsis, resulting in abdominal cramps.

Diarrhea- and constipation-predominant IBS patients differ in postprandial autonomic and cortisol responses

OBJECTIVE

As the primary link between brain and gut, autonomic and endocrine dysfunction may play a role in the pathophysiology of the irritable bowel syndrome (IBS). The aim of this study was to assess autonomic, endocrine, and symptomatic responses to food intake in diarrhea-predominant and constipation-predominant IBS patients, compared to normals.

METHODS

Twelve women with diarrhea-predominant or alternating IBS (IBS-D), 12 women with constipation predominant IBS (IBS-C), and 20 healthy women participated. GI symptoms, saliva cortisol concentration, heart rate, and heart rate variability were assessed at baseline and after a meal. Spectral analysis of heart rate variability was used as a measure of the sympathovagal regulation of the heart rate.

RESULTS

Both groups of IBS patients showed a significant postprandial increase in GI symptoms. IBS-D showed a significant increase in the low frequency/high frequency band ratio and a decrease in the high frequency band power during the first postmeal period, which was significantly different, not only from controls, but also from IBS-C. IBS-D also showed a significant postprandial increase in cortisol, which was not evident in controls or IBS-C. There was a significant correlation between the vagal response and the postprandial increase in GI symptoms in IBS-D (r = 0.6, p < 0.05).

CONCLUSIONS

These findings support the notion that the IBS symptom groups are characterized by different physiological responses to visceral stimuli, and point to a role of autonomic pathways in IBS symptomatology.

Comparison of autonomic nervous system indices based on abdominal pain reports in women with irritable bowel syndrome

Abdominal pain is an important symptom in irritable bowel syndrome (IBS), but patients report typical pain intensities ranging from mild to very severe. In a sample of women, the authors sought to determine whether measures of systemic autonomic activity are related to self-reported pain intensity and the occurrence of pain in the postprandial period. One hundred and six women with IBS and 41 controls completed bowel symptom and psychological distress questionnaires and wore 24-h Holter electrocardiogram monitors to estimate global heart rate variability measures of parasympathetic activity and sympathetic nervous system/parasympathetic nervous system balance. About one-third of the IBS sample reported severe or very severe abdominal pain (n = 34/106), and about one-half of the IBS sample reported postprandial pain (n = 52/106). Even after statistically controlling for age, body mass index, and psychological distress, vagal heart rate variability measures were markedly lower in women reporting high pain (P < 0.01) and markedly higher in women reporting postprandial pain (P < 0.02). The vagal component of heart rate variability appears to be reduced in women with severe abdominal pain, especially in those whose pain is not postprandial.

Autonomic regulation of cardiac function during sleep in patients with irritable bowel syndrome

OBJECTIVE

Several studies have provided evidence of abnormal autonomic activity in irritable bowel syndrome (IBS), suggesting that abnormal central nervous system-autonomic nervous system arousal mechanisms may be part of its pathophysiology. The goal was to investigate cardiac sympatho-vagal balance during waking and the different stages of sleep using heart rate variability analysis in IBS patients compared to healthy controls.

METHODS

A total of 15 IBS patients (13 female, two male, mean age 34.9 +/- 2.1 yr) and 15 controls (13 female, two male, mean age 36.2 +/- 2.3 yr) were studied during 1 h of pre-sleep quiet waking and during seven-hours of sleep. Polysomnography was used for the determination of state of consciousness. Electrocardiography provided the beat-to-beat intervals, which were then subjected to spectral analysis for determination of the percentage of energy in the low and high frequency bands, respectively. The low frequency/high frequency band ratio was also calculated. For each subject, heart rate variability analysis was performed using 15-min segments of waking, non-rapid eye movement sleep, and rapid eye movement sleep.

RESULTS

The low frequency band power was significantly greater in IBS patients during waking. No group differences were found in high frequency band power during any state. The low frequency to high frequency band ratio was significantly greater in IBS patients during rapid eye movement sleep.

CONCLUSIONS

IBS patients have greater sympathetic activity during waking and greater overall sympathetic dominance during rapid eye movement sleep. These results support the presence of autonomic abnormalities in patients with IBS. The possibility is discussed that sympathetic dominance during rapid eye movement sleep may play a role in sensitizing the gut to waking stimulation.

Autoantibodies to ganglionic acetylcholine receptors in autoimmune autonomic neuropathies

BACKGROUND

Idiopathic autonomic neuropathy is a severe, subacute disorder with a presumed autoimmune basis. It is indistinguishable from the subacute autonomic neuropathy that may accompany lung cancer or other tumors. Autoantibodies specific for nicotinic acetylcholine receptors in the autonomic ganglia are potentially pathogenic and may serve as serologic markers of various forms of autoimmune autonomic neuropathy.

METHODS

We tested serum from 157 patients with a variety of types of dysautonomia. Immunoprecipitation assays with iodine-125-labeled epibatidine and solubilized human neuroblastoma acetylcholine receptors were used to detect autoantibodies that bound to or blocked ganglionic receptors.

RESULTS

Ganglionic-receptor-binding antibodies were found in 19 of 46 patients with idiopathic or paraneoplastic autonomic neuropathy (41 percent), in 6 of 67 patients with postural tachycardia syndrome, idiopathic gastrointestinal dysmotility, or diabetic autonomic neuropathy (9 percent), and in none of 44 patients with other autonomic disorders. High levels of the binding antibodies correlated with more severe autonomic dysfunction (including the presence of tonic pupils). Levels of these antibodies decreased in patients who had clinical improvement. All seven patients with ganglionic-receptor-blocking antibodies had ganglionic-receptor-binding antibodies and had idiopathic or paraneoplastic autonomic neuropathy.

CONCLUSIONS

Seropositivity for antibodies that bind to or block ganglionic acetylcholine receptors identifies patients with various forms of autoimmune autonomic neuropathy and distinguishes these disorders from other types of dysautonomia. The positive correlation between high levels of ganglionic-receptor antibodies and the severity of autonomic dysfunction suggests that the antibodies have a pathogenic role in these types of neuropathy.

Low-dose intravenous erythromycin: effects on postprandial and fasting motility of the small bowel

BACKGROUND

Erythromycin is a motilin agonist and its effects on gastrointestinal motility are dependent on both dose and whether it is administered during the postprandial or fasting state.

AIM

To study the motility response of the small bowel to a low dose of intravenous erythromycin after meal intake and during fasting.

METHODS

Eighteen healthy subjects with mean age of 25 years were studied by small bowel manometry. Erythromycin was administered intravenously (0.75 mg per kg body weight) during 20 min in the postprandial (n=9) and the fasting state (n=9), and the motility response was recorded.

RESULTS

Erythromycin significantly reduced the frequency of propagated contractions (P < 0.001) and the amplitude of contractions (P < 0.02) in the small bowel during established postprandial motility. During the fasting state, erythromycin invariably initiated a phase III-like activity, which was similar to the spontaneous nocturnal phase III and migrated significantly more slowly than the diurnal phase III (P < 0.01).

CONCLUSIONS

A low dose of erythromycin administered intravenously during the postprandial state significantly inhibits small bowel motility, whereas administration during the fasting state initiates a phase III resembling the nocturnal rather than the diurnal phase III. These effects of erythromycin may indicate interference with vagal pathways. Due to its inhibitory effects, the clinical use of erythromycin in patients with hypomotility should be reconsidered, and the potential usefulness of these effects in patients with exaggerated intestinal motility deserves further attention.

Symptom differences in moderate to severe IBS patients based on predominant bowel habit

OBJECTIVE

We sought to determine if irritable bowel syndrome (IBS) patients with different bowel habit predominance differ in self-reported viscerosensory symptoms related to the upper and lower gastrointestinal (GI) tract, somatosensory symptoms, and constitutional functions.

METHODS

Six hundred and twenty-five Rome criteria-positive IBS patients completed a bowel symptom questionnaire (BSQ), psychological symptom checklist (SCL-90), and health status (SF-36). Bowel habit predominance for IBS patients was determined using the Rome criteria for functional constipation (IBS-C; n = 140) and functional diarrhea (IBS-D; n = 216). The BSQ included questions about viscerosensory symptoms of the upper (chest pressure, bloating, fullness, early satiety, nausea) and lower GI tract (bloating, pain, incomplete evacuation), somatosensory symptoms related to the musculoskeletal system (pain in neck/shoulders, lower back/hip, muscles/joints), and constitutional functions (sleep, appetite, libido). Analysis was further conducted between the IBS-C and IBS-D patients, controlling for gender and quality of sleep, and using the Bonferroni correction to control for multiple comparisons.

RESULTS

Female gender was more prevalent among IBS-C than IBS-D (77% vs 56.1%, p < 0.01), whereas age did not differ (40.2 +/- 1.2 yr vs 39.5 +/- 1.0 yr). Symptoms referred to the upper GI were more prevalent in IBS-C than IBS-D: early satiety (56.7% vs 33.9%, p < 0.004), fullness (63.2% vs 38.5%, p < 0.05), and a trend for upper bloating (80.3 vs 62.6%). IBS-C patients reported higher severity ratings for lower GI bloating (p < 0.001). IBS-C more commonly reported musculoskeletal symptoms (92.2% vs 75.4%, p < 0.001), as well as impairment in sleep (31.3 vs 17.5%, p < 0.009), appetite (35.0% vs 18.4%, p < 0.015) and sexual function (45.2% vs 33.1%, p < 0.0021). There were no differences in SCL-90 and SF-36 scores.

CONCLUSIONS

Compared with the IBS-D group, the IBS-C patients show greater prevalence of a wide range of symptoms referred to the upper and lower abdomen, musculoskeletal, and constitutional functions. These findings may be related to differences in autonomic or perceptual responses to visceral and somatic stimuli, and are likely to have implications for treatment responses in the two subgroups.

The patterns of small bowel motility: physiology and implications in organic disease and functional disorders

The physiology and pathophysiology of small bowel motility are reviewed with particular focus on the motility patterns and periods that are detected by intraluminal manometry. Motility patterns are groups of phasic pressure waves resulting from contractions of the circular muscle layer of the small bowel that are organized by the enteric nervous system. Phase III of the migrating motor complex, the hallmark of the fasting motility period, thus reflects enteric neuromuscular function. Response to meal challenge also involves the CNS, reflexes beyond the gut and endocrine responses. Although specific disease diagnosis cannot be made by motility studies of the small bowel, the functional integrity is revealed. The normal occurrence of the essential patterns and periods of motility and the absence of distinctly abnormal patterns evidence preserved function, whereas the opposite indicates clinically significant dysmotility. Certain motility patterns are occasionally seen both in health and disease, and increased prevalence indicates a moderate dysfunction of yet unclear significance. Bacterial overgrowth with Gram-negative bacilli is the consequence of severe small bowel dysmotility, and a diagnosis that can be predicted by a motility study. Testing can be useful in the clinical management of paediatric and adult patients also by predicting the prognosis and response to enteral nutrition and medical therapy. Further studies are, however, needed to take full advantage of motility testing in clinical practise.

Gene targeting reveals a critical role for neurturin in the development and maintenance of enteric, sensory, and parasympathetic neurons

Neurturin (NTN) is a neuronal survival factor that activates the Ret tyrosine kinase in the presence of a GPI-linked coreceptor (either GFR alpha1 or GFR alpha2). Neurturin-deficient (NTN-/-) mice generated by homologous recombination are viable and fertile but have defects in the enteric nervous system, including reduced myenteric plexus innervation density and reduced gastrointestinal motility. Parasympathetic innervation of the lacrimal and submandibular salivary gland is dramatically reduced in NTN-/- mice, indicating that Neurturin is a neurotrophic factor for parasympathetic neurons. GFR alpha2-expressing cells in the trigeminal and dorsal root ganglia are also depleted in NTN-/- mice. The loss of GFR alpha2-expressing neurons, in conjunction with earlier studies, provides strong support for GFR alpha2/Ret receptor complexes as the critical mediators of NTN function in vivo.

Slow-transit constipation: solitary symptom of a systemic gastrointestinal disease

INTRODUCTION

Autonomic neuropathy is thought to play a role in the pathogenesis of slow-transit constipation, but other gastrointestinal organs may also be involved, even if they are symptom-free. We investigated whether motility in gastrointestinal organs other than the colon was impaired in patients with slow-transit constipation and whether the autonomic nervous system was involved.

METHODS

Twenty-one consecutive patients (18 females; median age, 46 years) with severe chronic constipation (< or = 2 defecations/week and delayed colonic transit time) were studied. Autonomic neuropathy function was tested with esophageal manometry, gastric and gallbladder emptying (fasting and postprandial motility) by ultrasonography, orocecal transit time (H2-breath test), colonic transit time (radiopaque markers), and anorectal volumetric manometry. The integrity of the autonomic nervous system was assessed by a quantitative sweat-spot test for preganglionic and postganglionic fibers, tilt-table test, and Valsalva electrocardiogram R-R ratio.

RESULTS

Esophageal manometry showed gastroesophageal reflux or absence of peristalsis in five of the seven patients examined. Gallbladder dysmotility (i.e., increased fasting, postprandial residual volume, or both) was observed in 6 of 14 (43 percent) patients. Gastric emptying was decreased in 13 of 17 (76 percent) patients. Orocecal transit time was delayed in 18 of 20 (90 percent) patients; median transit time was 160 (range, 90-200) minutes. Median colonic transit time was 97 (range, 64-140) hours. Anorectal function showed abnormal rectoanal inhibitory reflex and decreased rectal sensitivity in 11 of 19 (58 percent) patients. Signs of autonomic neuropathy of the sympathetic cholinergic system were found in 14 of 18 (78 percent) patients. Only one of nine patients had vagal abnormalities detected with the Valsalva test and four of five patients with a history of orthostatic hypotension had a positive tilt-table test.

CONCLUSIONS

Slow-transit constipation may be associated with impaired function of other gastrointestinal organs. More than 70 percent of patients with slow-transit constipation present some degree of autonomic neuropathy. Severe constipation may be the main complaint in patients with a systemic disease involving several organs and possibly involving the autonomic nervous system. This should be considered in the management of such cases.

Sensory and autonomic neuropathy in patients with idiopathic slow-transit constipation

BACKGROUND

Slow-transit constipation (STC) is a severe disorder of unknown aetiology, which may result from an autonomic or sensory neuropathy. This study aimed to investigate patients with STC for the presence of neural dysfunction, and relate the findings to other factors, including any familial associations.

METHODS

Thirty-three patients with STC were studied using standard neurophysiological tests and a range of quantitative sensory and autonomic tests. The findings were compared with those of 20 matched control subjects and nine diabetic patients with gastrointestinal symptoms.

RESULTS

Twenty of the 33 patients with STC gave a family history of constipation, including an affected identical twin and Hirschsprung's disease (n = 3). None had abnormalities on neurological examination or nerve conduction studies. Fifteen of the 33 patients had abnormalities on quantitative tests, including all six who required a colectomy. Eleven patients with STC had reduced axon-reflex sweating in the presence of normal sweat gland responses (P < 0.001, all patients with STC versus controls). Twelve patients with STC had small sensory fibre dysfunction, with significantly increased thermal thresholds (cool, P < 0.05; warm, P < 0.01); these included six of nine patients with STC and rectal hyposensation. There were similar findings on quantitative testing in diabetic patients.

CONCLUSION

Quantitative tests in patients with STC provide evidence of a small fibre neuropathy. The high incidence of a positive family history, particularly a possible association with Hirschsprung's disease, suggests a genetic basis, which deserves further investigation.

Spectral analysis of heart rate variability in patients with irritable bowel syndrome

BACKGROUND

Autonomic dysfunction, both adrenergic and cholinergic, has been associated with the irritable bowel syndrome (IBS). The accuracy of the methods in use, however, has been limited by the need for active co-operation by the patients, with consequent difficulties in standardization. The aim of this study was to investigate the function of the autonomic nervous system in patients with IBS by using spectral analysis of the heart rate variability, an accurate method depending very little on patient cooperation.

METHODS

Eighteen patients with IBS were compared with 36 sex- and age-matched controls. Spectral analysis of heart rate variability was performed to quantify sympathetic and parasympathetic nerve activity.

RESULTS

The patients with IBS had significantly higher sympathetic activity than controls (P = 0.005). There was no significant (P = 0.308) increase in parasympathetic activity. There were no significant differences in heart rate or blood pressure between the patients and controls.

CONCLUSION

Spectral analysis of heart rate variability has been used to assess the function of the autonomic nervous system in patients with IBS. IBS patients have significantly increased symphathetic activity, whereas parasympathetic activity does not differ from that of controls.

Effect of mental stress and cisapride on autonomic nerve functions in functional dyspepsia

BACKGROUND

Disordered autonomic nerve function is frequently present in patients with functional dyspepsia (FD). In this study we investigated whether the prokinetic cisapride, which acts via acetylcholine receptors, and stress may modulate these abnormalities.

METHODS

Nineteen patients (6 men, 13 women) with FD and 10 healthy subjects (3 men, 7 women) were studied after 3 days' treatment with 10 mg cisapride three times daily and placebo in a crossover design. Mental stress was induced with a videogame. Sympathetic and vagal nerve functions were assessed noninvasively by skin conductance and respiratory sinus arrhythmia, respectively.

RESULTS

Vagal tone was significantly lower in FD patients than in controls both before and after mental stress (P < 0.001). Sympathetic tone was higher in patients with FD than in controls (P < 0.03). Generally, stress scores were increased by mental stress in both groups (P < 0.001). In FD patients, but not in controls, cisapride significantly increased the sympathetic tone both before (P < 0.05) and after stress (P < 0.05).

CONCLUSIONS

Patients with FD have lower vagal tone and higher sympathetic tone than healthy controls. Treatment with cisapride increased sympathetic tone in the patient group but had no effect on vagal tone.

Effect of perturbations and a meal on superior mesenteric artery flow in patients with orthostatic hypotension

Our aims were to evaluate to role of superior mesenteric blood flow in the pathophysiology of orthostatic hypotension in patients with generalized autonomic failure.

METHODS

Twelve patients with symptomatic neurogenic orthostatic hypotension and 12 healthy controls underwent superior mesenteric artery flow measurements using Doppler ultrasonography during head-up tilt and tilt plus meal ingestion. Autonomic failure was assessed using standard tests of the function of the sympathetic adrenergic, cardiovagal and postganglionic sympathetic sudomotor function.

RESULTS

Superior mesenteric flow volume and time-averaged velocity were similar in patients and controls at supine rest; however, responses to cold pressor test and upright tilt were attenuated (p < 0.05) in patients compared to controls. Head-up tilt after the meal evoked a profound fall of blood pressure and mesenteric blood flow in the patients; the reduction of mesenteric blood flow correlated (r = 0.89) with the fall of blood pressure in these patients, providing another manifestation of failed baroreflexes. We make the novel finding that the severity of postprandial orthostatic hypotension regressed negatively with the postprandial increase in mesenteric flow in patients with orthostatic hypotension.

CONCLUSION

Mesenteric flow is under baroreflex control, which when defective, results in, or worsens orthostatic hypotension. Its large size and baroreflexivity renders it quantitatively important in the maintenance of postural normotension. The effects of orthostatic stress can be significantly attenuated by reducing the splanchnic-mesenteric volume increase in response to food. Evaluation of mesenteric flow in response to eating and head-up tilt provide important information on intra-abdominal sympathetic adrenergic function, and the ability of the patient to cope with orthostatic stress.

Selective autonomic and sensory deficits in slow transit constipation

Chronic idiopathic constipation is likely to be a heterogeneous condition. Our previous studies on the stimulated sweating response suggested that autonomic dysfunction may be a cause in a subset of patients. Our aims were to test selectively the neural and sweat gland components of the sweat response and to test unmyelinated sensory fibres so as to determine whether a small fibre neuropathy is present. Twelve female patients with proven slow transit constipation and nineteen age-matched healthy volunteers took part in the study. The sensory tests included thermal thresholds and axon reflex vasodilatation in response to intradermal capsaicin, measured with a laser Doppler. Direct and axon reflex sweating was induced with intradermal methacholine and nicotine, respectively, and measured with an evaporimeter. Non-parametric tests were used for statistical comparison with a group of seven control subjects. Results are expressed as medians and range. All four patients who reported constipation from childhood had a selective deficit of unmyelinated afferent fibre function in the feet, with markedly elevated thresholds to warm sensation (controls 5.2; 4.3-10.6, patients 13.8; 11.8-16.1 delta T (degree C), P < 0.02) and heat pain (controls 10.6; 8.2-14.7, patients 18.1; 13.9-22.6 delta T (degree C), P < 0.05) and a reduced response to capsaicin (controls 47.0; 24-117, patients 13.5; 12-30 delta Flux (V), P < 0.005). In contrast, patients with adult onset constipation (n = 7) had a selective neural sweating deficit (controls 49.8; 32.0-61.8; patients 27.7; 7.3-44.3 g/m2 h, P < 0.05), indicating dysfunction of post-ganglionic sympathetic cholinergic fibres. Patients from both groups were shown to have normally functioning sweat glands in direct response to methacholine. Our findings suggest that patients with severe chronic idiopathic constipation may have selective small fibre neuropathies, of which constipation is a manifestation.

Hyperventilation, central autonomic control, and colonic tone in humans

Symptoms attributable to hyperventilation are common among patients with the irritable bowel syndrome (IBS); indeed, some have suggested that hyperventilation may exacerbate the alimentary symptoms of IBS. Hyperventilation changes haemodynamic function through central and peripheral mechanisms; its effects on colonic motor function, however, are unknown. The aim of this study, therefore, was to assess the effects of hyperventilation on colonic tone and motility and on cardiovascular autonomic activity, and to discover if hypocapnia was critical to elicit the response. Phasic and tonic motility of the transverse and sigmoid colon, end tidal PCO2, pulse rate, and beat to beat pulse variability were assessed before, during, and after a five minute period of hypocapnic hyperventilation in 15 healthy volunteers; in seven other subjects, effects of both eucapnic and hypocapnic hyperventilation were evaluated. Hypocapnic but not eucapnic hyperventilation produced an increase in colonic tone and phasic contractility in the transverse and sigmoid regions and an increase in pulse rate and pulse interval variability. The findings are consistent with inhibition of sympathetic innervation to the colon or direct effects of hypocapnia on colonic smooth muscle, or both. These physiological gut responses suggest that some of the changes in colonic function are caused by altered brain or autonomic control mechanisms.

Gastroparesis of digestible and indigestible solids in patients with insulin-dependent diabetes mellitus or functional dyspepsia

Gastric emptying of a solid meal and of 10 indigestible radiopaque solids was measured with scintigraphic and radiological techniques in 50 healthy volunteers (controls), 41 patients with insulin-dependent diabetes mellitus, and 50 patients with functional dyspepsia. Gastroparesis was found in 51% of our diabetic patients and 74% of our patients with dyspepsia. The values of Tlag, T1/2 and the percentage of isotope remaining in the stomach at 105 min were 14.9 min, 59.4 min and 25.3% in control subjects; 21.4 min, 88.1 min, and 46.9% in diabetic patients (P < 0.05 vs the control group); and 23.2 min, 114.6 min, and 58.7% in dyspeptic patients (P < 0.05 vs the control group). Whereas all healthy volunteers emptied all 10 indigestible solids in less than 4 hr, only 51% and 32% of diabetics and dyspeptics, respectively, achieved this emptying time (P < 0.01). Their respective values of T1/2 were 81 min, 212 min, and 203 min (P < 0.01 for diabetics and dyspeptics vs controls). We found no correlation between the findings for gastric emptying of digestible and indigestible solids. We conclude that gastroparesis affecting digestive and interdigestive motility is present in a high percentage of diabetics and functional dyspeptics and that conscientious evaluation of gastroparesis in both groups requires studies designed specifically to characterize each type of motility.

Predominant symptoms in irritable bowel syndrome correlate with specific autonomic nervous system abnormalities

BACKGROUND/AIMS

Irritable bowel syndrome may be influenced by the autonomic nervous system. Abnormalities in autonomic function, colon transit time, and psychological profiles in 21 patients were assessed.

METHODS

Using modified Manning criteria for irritable bowel syndrome, patients were classified as constipation-predominant or diarrhea-predominant. Autonomic function was determined by one vagal cholinergic and two sympathetic adrenergic measures. Colon transit was assessed by radiopaque markers, and psychological profiles were determined by three inventories.

RESULTS

Autonomic function tests showed that diarrhea-predominant subgroup values for one sympathetic adrenergic measure (postural adjustment ratio) were significantly different from controls (P < 0.01). Constipation-predominant subgroup values were significantly lower for the vagal cholinergic measure R-R interval (P < 0.05). Colon transit measures differed by subgroup in left, right, rectosigmoid, and total colon transit times. Both subgroups differed significantly from controls on psychological measures; the constipation subgroup showed more psychological distress.

CONCLUSIONS

Irritable bowel syndrome specific-symptom subgroups had different patterns of autonomic functioning, colonic transit, and psychological measures. The constipation subgroup is associated with a cholinergic abnormality and the diarrhea-predominant subgroup with an adrenergic abnormality. These findings suggest specific associations between the autonomic nervous system, predominant physical symptoms, colon transit time, and psychological factors in patients with irritable bowel syndrome.

Diarrhea and autonomic dysfunction in a patient with hexosaminidase B deficiency (Sandhoff disease)

The causal factors and the physiopathology of motor diarrhea are still unclear. This case report describes a 60-year-old white man with severe diarrhea for more than 10 years and minor signs of autonomic dysfunction. Extensive investigation showed that small intestinal motility and absorption were normal but that accelerated colon transit precluded water and solute absorption from the large bowel. Orthostatic hypotension, sexual dysfunction, and loss of sweating suggested dysfunction of the autonomous nervous system, which was confirmed by reduced plasma concentrations of norepinephrine and dopamine. Rectal biopsy specimens showed enlarged enteric ganglion cells filled with lipidic material. Levels of total hexosaminidase and hexosaminidase B in plasma, white blood cells, and fibroblasts were decreased, as found in Sandhoff disease. The pedigree of the proband's family showed several affected and heterozygous individuals, detected by examination of total hexosaminidase and hexosaminidase B levels in plasma. Among the five homozygous subjects, three had a clinical picture of diarrhea and orthostatic hypotension since the age of 50. Therefore, hexosaminidase B deficiency should probably be regarded as a cause for dysautonomia; dysfunction of the gastrointestinal tract, manifested by motor diarrhea or esophageal dysmotility, could be the initial and prevalent presentation of dysautonomia.

Autonomic dysfunction in patients with chronic intestinal pseudo-obstruction

We prospectively evaluated autonomic function in 50 patients with clinical and manometric features of a neuropathic form of chronic intestinal pseudo-obstruction (CIP). In 26 patients, there were underlying disease processes that may have affected extrinsic neural control to viscera: diabetes mellitus (n = 16), previous gastric surgery (n = 5), and other neurologic disorders (n = 5). Our aim was to characterize autonomic function in these patients, and those 24 with CIP unassociated with a known underlying neurologic disorder (idiopathic group). We assessed vagal function and sympathetic cholinergic and adrenergic function by means of standardized autonomic tests and quantitated postprandial antral pressure activity. We also measured postprandial levels of pancreatic polypeptide and neurotensin as indicators of vagal function and of the delivery of nutrients to the distal small bowel. Among the idiopathic group (n = 24), two had evidence of a generalized sympathetic neuropathy and five abdominal vagal dysfunction (one had both). Among diabetic patients, three had sympathetic adrenergic failure, six had orthostasis with normal plasma noradrenaline, ten had signs of generalized sympathetic neuropathy and eight had abdominal vagal dysfunction. Vagal dysfunction was identified in all three patients who underwent vagotomy as part of their previous gastric surgery. In the other neurologic syndromes, vagal function was abnormal in three of the five patients. Thus, autonomic and, particularly, vagal dysfunction are confirmed in a majority of patients with CIP associated with known diabetes or neurologic disorders; however, a previously unrecognized autonomic (chiefly vagal) neuropathy of undetermined cause has been identified in five of the 24 'idiopathic' CIP patients.

Autonomic dysfunction in gastrointestinal motility disorders

The records of 113 consecutive patients with a suspected gastrointestinal motility disorder referred between January 1988 and July 1991 were retrospectively reviewed. The aims were to identify the prevalence of autonomic dysfunction in those with or without associated neurological disease and to determine the diagnostic value of testing for autonomic dysfunction. All patients had gastrointestinal manometry (3 hours fasting, 2 hours fed), 94 of 113 underwent testing of sympathetic adrenergic and cholinergic function and cardiovagal cholinergic function. All tests were scored in a standard manner. There was a significant (p < 0.05) but modest (r = 0.28) rank correlation between autonomic and motility scores. This correlation was stronger (r = 0.67, p = 0.01) in diabetic patients. The number of patients in each group with autonomic dysfunction was as follows: irritable bowel syndrome nine of 33, idiopathic upper gastrointestinal dysmotility six of 21, diabetes mellitus nine of 13, identified non-diabetic neurological syndromes six of nine, postvagotomy or abdominal surgery three of 11, and myopathic pseudo-obstruction two of seven. Autonomic testing is useful in the assessment of autonomic involvement outside the gastrointestinal tract. Logistic discriminant analysis showed that autonomic function testing did not add to the diagnostic value of motility tests in distinguishing between patients with and without irritable bowel syndrome, although a slight improvement was indicated for identifying neuropathic dysmotilities. Thus, the aetiological role of general autonomic dysfunction in irritable bowel syndrome and idiopathic and postvagotomy dysmotilities deserves further study. The addition of autonomic function tests does not add substantially to the diagnostic accuracy of clinical, radiological, endoscopic, and manometric techniques in most patients referred for evaluation of a suspected motility disorder.

Autonomic nervous system function in patients with functional abdominal pain. An experimental study

Functional abdominal pain--that is, pain without demonstrable organic abnormalities--has often been associated with psychologic stress. The aim of the present study was to investigate whether sympathetic nervous system response to laboratory stress and basal parasympathetic neural activity were disturbed in 22 patients with functional abdominal pain (functional group) as compared with 14 healthy controls (healthy group) and 26 patients with organic abdominal pain (organic group) due to duodenal ulcer (DU), gallstones, or urinary tract calculi. Plasma adrenocorticotrophic hormone (ACTH) and serum cortisol measurements were included, to assess the pituitary-adrenocortical axis. Heart rate, systolic blood pressure, and plasma adrenaline increased significantly in all groups in response to a stress test (mental arithmetic). Plasma noradrenaline increased in the DU patients only, and plasma ACTH and serum cortisol did not increase at all in any of the groups. As a measure of parasympathetic neural activity, independent of sympathetic neural activity, the beat-to-beat variation of the heart rate was calculated. The functional patients had a significantly higher beat-to-beat variation expressed as the mean square successive differences of the R-R intervals (MSSD), indicating a higher basal parasympathetic neural activity (mean MSSD +/- SEM = 64 +/- 6 msec in the functional group, 46 +/- 6 msec in the healthy group, and 49 +/- 6 msec in the organic group; P = 0.03). A reduced sympathetic neural response as indicated by a lesser stress-induced increment in heart rate, was seen in both patient groups (functional, 13 +/- 2 beats/min; organic, 10 +/- 2 beats/min) as compared with the healthy group (19 +/- 2 beats/min; P = 0.003).(ABSTRACT TRUNCATED AT 250 WORDS)

Detection of subclinical autonomic neuropathy in constipated patients using a sweat test

Chronic idiopathic constipation may be the result of an autonomic neuropathy. This hypothesis was tested in 23 constipated patients and 17 age matched controls, using the acetylcholine sweat spot test devised to test autonomic integrity in diabetes. Acetylcholine (0.01%) was injected in the dorsum of the foot painted with a mixture of starch and iodine. Active sweat glands appeared on the surface of the skin as small black dots which were photographed and counted, using a grid with 60 subareas. Two measurements were made: the number of dots per unit subarea (sweat spot test score) and the % number of abnormal subareas (with less than six spots). These two parameters were correlated. The median sweat spot test score was 9.53 in patients and 13.92 in controls (p = 0.0001), the receiver operating characteristic curve showing that a score of 12 delimited normal and abnormal subjects. Increasing age was correlated with a low score in patients, probably because of prolonged symptoms. Seventy per cent of patients and one control had a borderline or abnormal number of subareas. These results suggest that idiopathic constipation is associated with a degree of autonomic denervation. The sweat spot test is an easy, inexpensive method to test this hypothesis and deserves a place in the clinical assessment of slow transit constipated patients.

Effect of chemical sympathectomy on scintigraphic gastric and small bowel transit in the rat

Our aims were to measure gastric and small bowel transit of radiolabeled chow or liquids in rats and to assess the effect of pharmacologically induced chronic sympathectomy of at least 5 weeks duration. Three series of experiments were performed. In series I, four rats in each group underwent i.p. chloral hydrate anesthesia, tracheostomy with intubation and mechanical ventilation: they received by gavage 1.0 g rat chow dissolved in 1.5 ml saline labeled with 1.0 mCi 99mTc-DTPA In series II, four rats in each group were anesthetized with only i.p. chloral hydrate and received 1.5 ml labeled saline. Rats were placed on a gamma camera for dynamic acquisition of 1-min images for 7 h in series I, and 4 h in series II. Activity was quantitated in stomach and cecum; gastric emptying was analyzed by the power exponential model. In series III, four rats in each group were studied for 1 h on gamma camera and sacrificed after 5 h. At the end of each study, the stomach, small bowel, cecum and colon were removed and radioactivity counted in each organ in a dose calibrator. Quantitation of radioactivity by gamma camera was highly accurate: labeled chow in the stomach at 7 h was identical by external camera and counting of the excised organ (linear regression slope = 1.01, r = 0.97, P less than 0.0001). Similar precision was observed with labeled liquids (slope = 0.93, r = 0.93, P = 0.001). Chow emptied slower than liquid in both groups (P = 0.048). Ileocecal movement of isotope occurred by bolus transfers.(ABSTRACT TRUNCATED AT 250 WORDS)

Small intestinal motility and transit in disease

Disorders of small intestinal motility and transit are becoming increasingly recognized partly as a result of a greater awareness of their existence and partly because suitable diagnostic methods are more widely available. Usually, the neuropathic and myopathic forms can be separated, and gut disease secondary to a generalized neuromuscular disorder can be identified by the clinician. The availability of better non-invasive methods for the diagnosis of disorders of motility and transit would greatly facilitate their management. Treatment must include the restoration and maintenance of nutrition, attempts to improve intestinal motor function and resection of any segments of localized disease. Regrettably, all such measures are ineffective in the severest cases. In the future, a greater understanding of the enteric neural control of the smooth muscle and an ability to manipulate it with novel, specific drugs or peptidergic receptor agonists and antagonists, or electrical pacing, may lead to more effective therapies.