Gastric involvement in progressive systemic sclerosis: electrogastrographic and sonographic findings

Current status of multichannel electrogastrography and examples of its use

Electrogastrography (EGG) is a non-invasive diagnostic motility for recording gastric myoelectrical activity. Gastric myoelectrical activity was first recorded in 1922. Advances in recording equipment enabled widespread use of cutaneous EGG after 1985. Later, introduction of multichannel EGG (M-EGG) enabled measurement of electrical activity transmission. At present, M-EGG findings are used as objective indicators of gastric motility disorders caused by various diseases. EGG measures two categories of gastric electrical activity: electrical response activity, or spike potentials; and electrical control activity, or slow waves. The appearance of abnormal rhythmic electrical activity is indicative of abnormalities in gastric motility. The normal frequency range of gastric electrical activity (normogastria) is around 3 cycles per min. Multiple EGG parameters assist in the assessment of gastric myoelectrical activity, and significant correlations between EGG and other gastric motility tests have been demonstrated in many studies. In Japan, however, EGG remains in the exploratory stage, and its clinical use is limited. There are large variations in procedures and systems used in previous studies, thus there is a need for standardization of EGG procedures and technical terminology. Here, we outline the current status of EGG and report the M-EGG procedures used in our department in addition to our M-EGG findings.

The abstract of this manuscript was presented during an educational seminar titled "Current status of gastrointestinal motility tests and keys for immediate implementation" at the 54th Annual Meeting of the Japan Society of Smooth Muscle Research

Clinical effects of ghrelin on gastrointestinal involvement in patients with systemic sclerosis

The majority of patients with systemic sclerosis (SSc) have gastrointestinal (GI) tract involvement, but therapies using prokinetic agents are usually unsatisfactory. Ghrelin stimulates gastric motility in healthy human volunteers. In this study, we investigated whether ghrelin could improve gastric emptying in patients with gastrointestinal symptoms due to SSc. The study was performed in a randomized, double-blind, placebo-controlled crossover fashion on two occasions. Ten SSc patients with GI tract involvement received an infusion of either ghrelin (5.0 μg/kg) or saline, and gastric emptying rate was evaluated by ¹³C-acetic acid breath test. Gastric emptying was significantly accelerated by ghrelin infusion in patients with SSc (ghrelin vs. saline: 43.3 ± 11.4 min vs. 53.4 ± 5.4 min, P=0.03). No serious adverse effects were observed. Our results suggest that ghrelin might represent a new therapeutic approach for GI tract involvement in patients with SSc.

Gastrointestinal motility disorder assessment in systemic sclerosis

OBJECTIVES

SSc is a clinically heterogeneous and generalized disease, characterized by thickness of the connective tissue of the skin and internal organs, such as the digestive tract, impairing gastrointestinal (GI) motility. Our aim is to evaluate retrospectively abnormalities of oesophageal motility, gastric emptying, oro-cecal transit time (OCTT) and small intestine bacterial overgrowth (SIBO) in a large cohort of SSc patients.

METHODS

Ninety-nine SSc patients were included in the study. Forty-two patients underwent oesophageal conventional manometry, 45 performed a [(13)C]octanoic acid breath test to measure gastric emptying time and all 99 patients performed a lactulose breath test in order to evaluate OCTT and SIBO. Data were compared with healthy controls.

RESULTS

In SSc patients, median lower oesophageal sphincter (LOS) pressure [14 mmHg (25th-75th; 8-19) vs 24 mmHg (19-28); P < 0.01] and median wave amplitude [30 mmHg (16-70) vs 72 mmHg (48-96); P < 0.01] were lower than in controls. Oesophageal involvement, defined as reduced LOS pressure and ineffective oesophageal motility pattern, was encountered in 70% of SSc patients. A delayed gastric emptying time was present in 38% of SSc patients: mean t½ was 141 ± 79 min vs 90 ± 40 min of controls (P < 0.01). Also, OCTT was significantly delayed in SSc: median OCTT was 160 min (25th-75th; 135-180) vs 105 min (25th-75th; 90-135) of controls (P < 0.01). SIBO was observed in 46% of SSc compared with 5% of controls (P < 0.01).

CONCLUSION

GI involvement is very frequent in SSc patients. Oesophagus and small bowel are more frequently impaired, whereas delayed gastric emptying is less common.

Gastric dysmotility after liquid bolus ingestion in systemic sclerosis: an ultrasonographic study

Gastric involvement appears quite commonly in systemic sclerosis (SSc). The aim of this study was to evaluate gastric wall motility using ultrasonography, a noninvasive method able to track both filling and emptying of fundus and antrum. The study was performed in 20 SSc patients and 20 healthy control subjects. Gastric filling and emptying were evaluated by transabdominal ultrasonography, measuring changes in fundus and antral areas over a 1-h period after ingestion of a liquid bolus (500 ml of mineral water). Areas of both gastric fundus and antrum at basal evaluation were found to be smaller in SSc patients than in healthy controls. Gastric filling was significantly reduced after ingestion of liquid bolus. Gastric emptying was delayed both in fundus and antrum. No significant differences of gastric wall motility have been observed in different subsets of SSc patients. Our findings show that gastric dysmotility is frequent and severe in SSc patients, contributing to the gastrointestinal disturbances which are very common in this disease.

Gastrointestinal manifestation of systemic sclerosis--thickening of the upper gastrointestinal wall detected by endoscopic ultrasound is a valid sign

OBJECTIVE

Gastrointestinal (GI) tract involvement has been observed in the majority of patients with SSc. This has been attributed to an accumulation of extracellular matrix within the GI walls. We visualized the walls of the oesophagus, stomach and duodenum with its layers and measured the thickness in SSc patients and control patients utilizing endoscopic ultrasound (EUS).

METHODS

Twenty-five SSc patients and 25 controls were evaluated. In addition to analysis of clinical symptoms, endoscopy and EUS (20-MHz miniprobe) were performed. The thickness of the complete wall was measured, and the mucosa, submucosa and muscularis were evaluated separately.

RESULTS

Clinical symptoms of SSc patients were dysphagia (14/25) and heartburn (19/25). Endoscopic findings were hiatal hernia (16/25), oesophagitis (6/25), amotility (19/25) and a dehiscent pylorus (15/25). In comparison with controls, SSc patients had significantly thicker oesophageal [SSc 1.619 (0.454) mm, control 1.392 (0.333) mm; P = 0.025], antral [SSc 1.876 (0.635) mm, control 1.599 (0.291) mm; P = 0.029] and duodenal [SSc 1.730 (0.522) mm, control 1.525 (0.222) mm; P = 0.039] walls. Predominantly, submucosa and muscularis were significantly thicker in SSc patients. The presence of dysphagia or amotility was significantly associated with the thickening of the GI walls.

CONCLUSIONS

The EUS revealed a significant thickening of the walls of the upper GI tract in SSc patients. Predominantly, the submucosa and muscularis are enlarged. These results strengthen the hypothesis that increased matrix deposition is an important aspect in the pathogenesis of GI involvement in SSc.

Gastric slow waves, gastrointestinal symptoms and peptides in systemic sclerosis patients

Impaired gastric slow waves, frequent gastrointestinal (GI) symptoms and altered GI peptides have been reported in Scleroderma (SSc) patients. The aim of this study was to investigate the associations among these three important components in GI dysmotility. Seventeen fasted SSc patients underwent four channel surface electrogastrography, measuring % of normal gastric slow waves or dysrhythmia. Patients completed a questionnaire designed by us to assess demographics, upper and lower GI symptoms (symptom presence, frequency and impact on quality of life, QOL), by YES/NO, Likert Scales and Visual Analogue Scales 1-100 mm (called GI Dysmotility Questionnaire, GIDQ) and health-related QOL by SF-36. Fasting plasma vasoactive intestinal peptide (VIP) and motilin levels were measured by peptide immunoassays. There were significant correlations between percentages of gastric dysrhythmias (bradygastria or arrhythmia) and a number of major GI symptoms such as nausea, abdominal bloating and pain. The plasma level of VIP was correlated positively with % dysrhythmia but negatively with % normal slow waves. Motilin was positively correlated with slow wave coupling (coordination). No major differences were noted in the measured peptides or gastric slow waves between limited SSc and diffuse SSc. Correlations were noted between SF-36 domain scores and our GIDQ scores. In SSc patients, gastric dysrhythmias are correlated with certain GI symptoms. Correlations are also noted between plasma VIP/Motilin levels and gastric slow waves. Thus in SSc, gastric dysrhythmias may be predictive of development of certain dyspeptic symptoms. Plasma VIP may be involved in the development of dysrhythmias.

Gastrointestinal symptoms and motility disorders in patients with systemic scleroderma

BACKGROUND

Studies on gastrointestinal symptoms, dysfunctions, and neurological disorders in systemic scleroderma are lacking so far.

METHODS

Thirty-eight scleroderma patients (34 limited, 4 diffuse), 60 healthy controls and 68 dyspeptic controls were scored for upper and lower gastrointestinal symptoms (dyspepsia, bowel habits), gastric and gallbladder emptying to liquid meal (functional ultrasonography) and small bowel transit (H2-breath test). Autonomic nerve function was assessed by cardiovascular tests.

RESULTS

The score for dyspepsia (mainly gastric fullness) was greater in scleroderma patients than healthy controls, but lower than dyspeptic controls who had multiple symptoms, instead. Scleroderma patients with dyspepsia had a longer disease duration. Fasting antral area and postprandial antral dilatation were smaller in scleroderma patients than dyspeptic and healthy controls. Gastric emptying was delayed in both scleroderma patients (particularly in those with abnormal dyspeptic score) and dyspeptic controls, who also showed a larger residual area. Despite gallbladder fasting and postprandial volumes were comparable across the three groups, gallbladder refilling appeared delayed in dyspeptic controls and mainly dependent on delayed gastric emptying in scleroderma. Small intestinal transit was also delayed in 74% of scleroderma and 66% of dyspeptic controls. Bowel habits were similar among the three groups. Autonomic neuropathy was not associated with dyspepsia, gastric and gallbladder motility and small intestinal transit.

CONCLUSION

In scleroderma patients dyspepsia (mainly gastric fullness), restricted distension of the gastric antrum and diffuse gastrointestinal dysmotility are frequent features. These defects are independent from the occurrence of autonomic neuropathy.

Gastric and enteric involvement in progressive systemic sclerosis

Progressive systemic sclerosis (PSS) is a chronic multisystem disease characterized by excess deposition of connective tissue in skin and internal organs, associated with microvasculature changes and immunologic abnormalities. Involvement of the gastrointestinal tract may occur in 2 stages, a neuropathic disorder followed by a myopathy. Gastric emptying is delayed in 10% to 75% of patients and correlates with symptoms of early satiety, bloating, and emesis. Compliance of the fundus is increased although perception of fullness is normal. Myoelectric abnormalities have been found in some studies. Treatments include metoclopramide, cisapride, and erythromycin. Bleeding from telangiectasias and watermelon stomach is treated endoscopically. Small bowel involvement in PSS occurs in 17% to 57% of patients. The migrating motor complexes are reduced or absent, predisposing to bacterial overgrowth. Malabsorption may also be due to pancreatic insufficiency. Barium enemas demonstrate pancolonic involvement in 10% to 50% of patients with PSS. Wide-mouthed diverticuli, involving all layers of the intestinal wall, are characteristic. Pseudoobstruction may respond to octreotide or prucalopride therapy. Complications include pneumatosis cystoides intestinalis, stercoral ulcerations, and perforation. Fecal incontinence may be due to dysfunction of the internal anal sphincter, a smooth muscle responsible for most of the resting anal sphincter pressure. Anal manometry may show a reduction or loss of the rectoanal inhibitory reflex. Treatments include biofeedback, sacral nerve stimulation, and surgery. PSS involves the gastrointestinal tract from the mouth to the anus. Studies are needed to define effective treatments in these diseases, which cause great morbidity.

Wavelet analysis of scaling properties of gastric electrical activity

We present a novel approach to the analysis of fluctuations in human myoelectrical gastric activity measured noninvasively from the surface of the abdomen. The time intervals between successive maxima of the wavelet transformed quasi-periodic electrogastrographic waveform define the gastric rate variability (GRV) time series. By using the method of average wavelet coefficients, the statistical fluctuations in the GRV signal in healthy individuals are determined to scale in time. Such scaling was previously found in a variety of physiological phenomena, all of which support the hypothesis that physiological dynamics utilize fractal time series. We determine the scaling index in a cohort of 17 healthy individuals to be 0.80 ± 0.14, which compared with a set of surrogate data is found to be significant at the level P < 0.01. We also determined that the dynamical pattern, so evident in the spectrum of average wavelet coefficients of the GRV time series of healthy individuals, is significantly reduced in a cohort of systemic sclerosis patients having a scaling index 0.64 ± 0.17. These results imply that the long-term memory in GRV time series is significantly reduced from healthy individuals to those with systemic sclerosis. Consequently, this disease degrades the complexity of the underlying gastrointestinal control system and this degradation is manifest in the loss of scaling in the GRV time series.

Severe gastrointestinal involvement in systemic sclerosis: report of five cases and review of the literature

OBJECTIVE

To review current literature on the gastrointestinal tract (GIT) manifestations of systemic sclerosis (SSc) and to report on 5 patients with severe gastrointestinal SSc.

MATERIALS AND METHODS

The clinical course and histopathology of 5 patients are described. A review of the medical literature registered in MedLine and PreMedLine databases from 1996 through mid-2004 was performed using the keywords systemic sclerosis and scleroderma and combining them with text words such as gastric, gastrointestinal, anorectal, colonic, and hepatic.

RESULTS

All 5 patients had severe GIT involvement: 4 with diffuse cutaneous SSc (dcSSc) and 1 with limited cutaneous SSc (lcSSc). Autopsy results of 2 patients who died from severe malnutrition and aspiration pneumonia are presented. Literature review includes involvement from oral cavity to anus with varying degrees of severity. Most GIT manifestations result from dysmotility secondary to infiltration of the gastrointestinal wall with fibrous tissue and can cause life-threatening malabsorption and malnutrition. Diagnostic tests, pathology, and treatments of GIT SSc are reviewed.

CONCLUSIONS

GIT involvement in SSc can be severely debilitating and even life-threatening. Although morbidity is inevitable, appropriate supportive treatment can prolong survival.

RELEVANCE

GI complications of SSc cause significant morbidity and mortality.

Electrogastrography: basic knowledge, recording, processing and its clinical applications

The slow wave (SW) of the gastrointestinal (GI) tract mainly functions to trigger the onset of spike to elicit smooth muscle contraction, which provides the essential power of motility. Smooth muscle myogenic control activity or SW is believed to originate in the interstitial cells of Cajal (ICC). The electrical coupling promotes interaction between muscle cells, and ICC additionally contribute to SW rhythmicity. Stomach SW originates in the proximal body showing the continuous rhythmic change in the membrane potential and propagates normally to the distal antrum with a regular rhythm of approximately 3 c.p.m. A technique using electrodes positioned on the abdominal skin to pick up stomach rhythmic SW refers to electrogastrography (EGG). The stomach SW amplitude is very weak, while many visceral organs also produce rhythmic electricities, for example heartbeat, respiration, other organs of the GI tract and even body movements. Thus noise other than SW should be filtered out during the recording, while motion artifacts are visually examined and deleted. Finally, the best signal among all recordings is selected to compute EGG parameters based on spectral analysis. The latter is done not only to tranform frequency domain to time domain but also to provide information of time variability in frequency. Obtained EGG parameters include dominant frequency/power, % normal rhythm, % bradygastria, % tachygastria, instability coefficient and power ratio. Clinical experience in EGG has been markedly accumulated since its rapid evolution. In contrast, lack of standardized methodology in terms of electrode positions, recording periods, test meals, analytic software and normal reference values makes the significance of EGG recording controversial. Unlike imaging or manometrical studies, stomach motility disorders are not diagnosed based only on abnormal EGG parameters. Limitations of EGG recording, processing, computation, acceptable normal parameters, technique and reading should be known to conduct subjective assessments when EGG is used to resolve stomach dysfunction. Understanding basic SW physiology, recording methodology and indications may open EGG as a new domain to approach the stomach motor dysfunction.

Delayed gastric emptying in patients with diffuse versus limited systemic sclerosis, unrelated to gastrointestinal symptoms and myoelectric gastric activity

OBJECTIVE

To study the gastric function in patients with diffuse and limited systemic sclerosis (SSc) in relation to the degree of upper gastrointestinal symptoms.

METHODS

Scintigraphic gastric emptying and recording of the myoelectric signals of the stomach were examined in 15 patients with diffuse SSc (dSSc), 13 patients with limited SSc (lSSc) and 15 healthy controls. The frequency of upper gastrointestinal symptoms was determined using a questionnaire.

RESULTS

Patients with dSSc had slower gastric emptying (scintigraphic gastric half-emptying time median (Md) 103 min, range 75-447 min) than control subjects (Md 70 min, range 38-94) and patients with lSSc (Md 76 min, range 43-460). Electrogastrographic recordings did not differ between dSSc, lSSc or controls. Symptoms tended to be more abundant in dSSc patients than in lSSc patients, however, patients with a high frequency of symptoms did not differ from patients with low frequency of symptoms in gastric function, as measured with scintigraphic gastric emptying or electrogastrography (EGG). Neither EGG nor a thorough review of upper gastrointestinal symptoms could predict delayed gastric emptying.

CONCLUSION

The higher prevalence of delayed gastric emptying in patients with dSSc in this study indicates a more severe involvement of the gastrointestinal tract in dSSc than in lSSc, and stresses the importance of differentiating between the subtypes of SSc patients. Since EGG dysrythmia did not correlate with gastric emptying we concluded that factors other than defective myoelectric signals might contribute to a disturbed gastric function.

Gastric involvement in systemic sclerosis: a prospective study

OBJECTIVES

This study aims to assess the prevalence of gastric electrical activity dysfunction with cutaneous electrogastrography (EGG), disturbances of gastric emptying function using radiopaque pellets, and gastric endoscopic abnormalities in patients with systemic sclerosis (SSc). We also investigate for an association between EGG and gastric-emptying data with clinical manifestations and esophageal motor disturbances.

METHODS

Fasting and postprandial gastric electrical activity was studied in 22 consecutive patients with SSc (17 with and 5 without clinical gastric manifestations) and 22 age- and sex-matched healthy subjects. Gastric emptying of radiopaque pellets and gastroscopy were also performed in SSc patients.

RESULTS

The prevalence of EGG disturbances was as high as 81.82% in SSc patients. SSc patients exhibited, compared with controls, higher median percentage of dominant frequency in bradygastria during the fasting period and lower median values for postprandial electrical power and postprandial to fasting ratio for electrical power. Gastric emptying of radiopaque pellets was delayed in 11 SSc patients, and gastroscopy demonstrated "watermelon stomach" in 3 SSc patients. No correlation was found between the severity of gastric impairment and clinical presentation, SSc duration and subsets, and esophageal manometric impairment.

CONCLUSIONS

Our study underlines the high frequency of gastric dysfunction in SSc patients. It suggests the usefulness of EGG in SSc in noninvasively detecting disorders of gastric electrical activity at an early stage and symptomatic patients with gastroparesis (because there was a correlation between values of postprandial to fasting ratio for electrical power of < 1 on EGG and delayed gastric emptying). Gastric-emptying evaluation of radiopaque pellets may further be a helpful method to depict symptomatic SSc patients with gastroparesis. Finally, our series confirms that watermelon stomach diagnosis should be excluded in SSc patients presenting with gastrointestinal hemorrhage or with anemia related to iron deficiency.