Pathophysiological And Psychosocial Study Of Functional Vomiting

I Clinical Patterns and Psychosocial Aspects in Patients with Functional VomitingBackgroundAccording to the Rome Ⅲ criteria, functional vomiting (FV) is defined as recurrent, unexplained vomiting at least once per week that is not cyclical and lacks an organic basis. The clinical picture of FV remains incompletely studied, which needs to be further investigated. This study aims to explore clinical patterns, predisposing factors and psychosocial aspects in FV patients.Methods37consecutive patients who experienced chronic vomiting for at least1month were profiled by symptom questionnaires, including psychosocial influences (Zung self-rating anxiety and depression scale, SAS/SDS) and Eysenck personality questionnaire (EPQ). Exclusion criteria included organic disease to explain the recurrent vomiting, eating disorder, rumination, or major psychiatric disease according to DSM-IV.ResultsOverall,19of37patients met the Rome Ⅲ criteria of FV (4M,15F, age25.8±8.4, BMI18.7±3.3kg/m2),5of37patients were diagnosed as cyclic vomiting syndrome (CVS). All19patients had one or more episodes of vomiting per week and78.9%of them vomited every day. Postprandial vomiting occurred in94.7%of these patients (often10-30min after meals), lasting for several minutes and without self-induced maneuver. The vomitus consisted of food initially, sometimes changing to gastric juice and bile.52.6%had severe vomiting which compromised the quality of life. The most common accompanied symptoms were decreased calorie intake, postprandial fullness and anorexia. Predisposing factors included food, pressure and stress.57.9%of episodes were related to emotional changes.57.9%of FV patients had experienced negative events and10.5%had abuse history. Prevalence of abnormal psychological status in patients with FV was high and scores of SAS, SDS and EPQ-N were significantly higher than normal level. ConclusionsFV involved young female predominantly. Postprandial vomiting soon after meal without self-induced maneuver was the most common pattern of FV. Most patients were suffering from severe symptoms which impaired the quality of life. This study also indicated the association between FV and psychosocial factor and suggested its role in the pathogenesis of FV.Ⅱ Pathophysiological Mechanism of Functional VomitingBackgroundThe pathogenesis of functional vomiting (FV) remains unclear. These patients may have central, peripheral or mixed abnormalities. The objective of the study is to evaluate if there are gastric hypersensitivity and dysmotility in FV patients and to explore the possible pathogenesis of FV.Methods10healthy subjects (HS)(2M,8F, age30.2±7.7),19FV patients (4M,15F, age25.8±8.4),13functional dyspepsia (FD) patients with postprandial distress syndrome (7M,6F, age46.7±15.8) and14patients with belching disorders (BD)(3M,11F, age46.6±11.5) were enrolled in this study consecutively. GI symptoms and psychological states were evaluated by questionnaires. Cutaneous electrogastrography (EGG), gastric empting (GE) of radiopaque markers, liquid-nutrition load test (LNLT) and intragastric pressure (IGP) were performed in patients. LNLT was also performed in HS.ResultsEGG was performed on17of19FV patients. Fasting dominant frequency (DF) was almost within the normal range. However, there was a significant decrease of%N and postprandial DF.15FV patients received radiopaque marker measurements of gastric emptying and86.7%revealed delayed gastric emptying.13FV patients underwent LNLT. Compared to HS, IGP and the volume of liquid meal perfused (PV) at the maximum satiety were significantly lower in FV patients. There was no significant difference in EGG or GE among these groups. The severity of vomiting was correlated to postprandial N%and nausea was correlated to PR. There were significant correlations between postprandial DF, DP, PV and psychological states.ConclusionsPatients with FV had significant postprandial gastric dysrhythmia, delayed gastric emptying, impaired gastric accommodation and enhanced gastric sensitivity, which suggested that gastric dysmotility and hypersensitivity could play an important role in the pathogenesis of FV. There were significant differences of Gastric accommodation and sensitivity among the three groups. Gastric dysmotility was correlated to psychological states, which demonstrated its possible relationship with central abnormality.Ⅲ Psychological Influences and Central Mechanisms in Pathogenesis of FVBackgroundThe pathogenesis of functional vomiting (FV) remains unclear. These patients may have central, peripheral or mixed abnormalities. Limbic system, the central area involved in visceral sensorimotor function and mood regulation, could play a role in the pathogenesis of FV. The Purpose of this study is to explore the features of brain activity in FV patients by resting-state fMRI and to elucidate the possible central mechanisms.Methods8healthy subjects (HS)(F, age28.0±5.2) and8FV patients (F, age27.8±6.8) participated in this study. Psychological disorders were excluded by thorough clinical assessment. Both HS and FV patients completed questionnaires including SAS, SDS and EPQ. Using the regional homogeneity (ReHo) approach, we compare the brain activity between the two groups and examine the relationship between gastric function and brain activity in FV patients.ResultsFV patients had significant anxiety/depression states and neurotic personality. Compared with healthy controls, increased ReHo was found in FV patients in many limbic areas including the bilateral mid-cingulate cortex (MCC, BA24and32), left amygdala, right insular cortex, right thalamus, and other areas as left caudate nuclei, bilateral frontal sensory and motor areas (BA5and6). Decreased ReHo was found in the bilateral occipital lobe (BA18and19), bilateral orbital prefrontal cortex (BA11) and right middle temporal gyrus (BA39). Postprandial dominant frequency of electrogastrography was negatively correlated with ReHo in the bilateral MCC, left middle frontal gyrus, and was positively correlated with ReHo in the bilateral cuneus and right middle temporal gyrus.ConclusionsOur findings indicated that abnormal brain activity was distributed in limbic areas predominantly in FV patients during resting state. Some peripheral disturbance of gastric function might be related to specific abnormal patterns of brain activity. Abnormalities of cognition-emotion, visceral sensory and motor functions could contribute to the pathogenesis of FV together.