Recurrent abdominal pain in children and the endogenous opiates: a brief hypothesis

The aetiology of recurrent abdominal pain in children (RAP) remains unclear. Some features of this syndrome suggest that an opiate-like mechanism may be involved. The evidence for this is reviewed, and it is hypothesised that RAP may result from a differential gastrointestinal response to stress mediated by the endogenous opiate system.     

Cortical correlates of an attentional bias to painful and innocuous somatic stimuli in children with recurrent abdominal pain

Recurrent abdominal pain (RAP) is a common gastrointestinal problem during childhood. It is not only a pediatric health problem, but may represent a risk factor for chronic pain, psychosomatic symptoms, and psychopathological problems later in life. Alterations in central pain processing and an attentional bias to potentially aversive somatic sensations could contribute to the unfavorable outcome of RAP during childhood. Fourteen children with RAP and 15 control children (age: 10-15 year) participated in an attentional task. Children had to respond to rare targets (tones) and ignore frequent either painful (pain threshold) or non-painful mechanical stimuli delivered at the hand. Event-related cortical potentials in response to the somatic stimuli and the tones were measured and stimulus intensity ratings, reaction time and number of errors were obtained. Painful as compared to non-painful stimuli elicited significantly larger N1, P2 and P3 components of the somatosensory-evoked potential (SEP) in all children. The RAP children responded with a significantly larger P3 to both painful and non-painful stimuli. No group differences were found for the auditory-evoked potentials. Perceived stimulus and pain intensity, reaction time and number of errors did not differ between groups. Similar to findings in adults with functional gastrointestinal disorders (FGIDs), children with RAP did not show somatic hyperalgesia as revealed by unaltered pain thresholds and middle latency pain-evoked SEPs. However, they displayed an attentional bias to painful and non-painful (innocuous) somatic stimuli as indicated by an enhanced P3. This may represent an important mechanism not only for the maintenance of RAP, but also for the development of psychosomatic symptoms.     

儿童再发性腹痛与幽门螺杆菌感染的关系及三联疗法的临床意义

目的探讨儿童再发性腹痛(recurrent abdominal pain,RAP)与幽门螺杆菌(Hp)感染的关系及三联疗法的临床意义。方法选择RAP患儿122例(RAP组),同期健康体检儿童62例(健康对照组),分别行13C-尿素呼气试验检测Hp,并对Hp阳性者予抗Hp三联根治性治疗。对两组Hp阳性率及清除率进行统计学分析。观察RAP组的疗效及不良反应。结果治疗前RAP组Hp阳性率高于健康对照组,差异有统计学意义(P<0.05)。治疗后两组Hp根除率比较差异无统计学意义(P>0.05)。治疗后RAP组中90例Hp阳性的患儿有效率为88.9%,不良反应发生率为30.3%。结论儿童RAP与Hp现症感染密切相关,三联疗法根除Hp临床效果好。     

Effects of stress on pain threshold and tolerance in children with recurrent abdominal pain

Models of stress-induced hyperalgesia state that exposure to stress can exaggerate subsequent pain experiences. Studies using both animal and human subjects have shown evidence for hyperalgesia as a function of stress [e.g., Jorum E. Analgesia or hyperalgesia following stress correlates with emotional behavior in rats. Pain 1988;32:341-48; Peckerman A, Hurwitz BE, Saab PG, Llabre MM, McCabe PM, Schneiderman N. Stimulus dimensions of the cold pressor test and the associated patterns of cardiovascular response. Psychophysiology 1994;31:282-90; Gameiro et al. Nociception and anxiety-like behavior in rats submitted to different periods of restraint stress. Physiol. Behav. 2006;87:643-49; Lucas et al. Visceral pain and public speaking stress: neuroendocrine and immune cell responses in healthy subjects. Brain Behav. Immun. 2006;20:49-56]. However, the role of stress in pediatric pain is not well understood. This study examined stress reactivity and pain tolerance and sensitivity in a population of children with Recurrent abdominal pain (RAP). Forty-nine children meeting criteria for RAP (28 female; mean age 13years; range 9-17years) were randomly assigned to either a condition in which they completed an experimental stressor paradigm (stress interview, serial subtraction task) followed by a pain task (cold pressor) or a condition in which they received the pain task prior to the stress tasks. Children who underwent the stress tasks before the pain task exhibited lower levels of pain tolerance than those who received the pain task first (p<.01); no differences were found between the two groups in pain threshold or pain intensity ratings. Further, pain tolerance was not related to individual differences in physiological reactivity (heart rate change) to the stressor. The present research demonstrates the first evidence of the occurrence of stress-induced hyperalgesia in a pediatric pain population.     

Heart rate changes as an autonomic component of the pain response

Autonomic variables have been recommended as measures of the affective-motivational component of the pain response in objective algesimetry. In the present study components of heart rate responses to painful heat stimuli and their relation to stimulus and sensation variables were analyzed. Twelve healthy subjects served. Sixty phasic stimuli of varying temperatures above and below pain threshold were delivered through a Marstock thermode in 1 session. Heart rate, respiration, and subjective stimulus ratings were recorded simultaneously. Phasic heat stimulation above and below pain threshold induced a tonic increase of the heart rate lasting up to more than 20 sec. High intensity stimulation generated steeper rises and greater mean increase than low intensity stimulation. In general, heart rate responses were more closely related to subjective sensation than to stimulus intensity. However, differential temporal analysis demonstrates that, until about 3 sec after stimulation, the autonomic response is determined solely by stimulus temperature, whereas, after approximately 6 sec, it is related only to subjective judgement. Accordingly, the heart rate responses reflect both a brief nocifensive reflex induced by the sensory component and, subsequently, a longer-lasting response which seems to be related to affective and/or cognitive evaluation. This separation of different stages of pain-processing by an autonomic indicator may be useful in clinical algesimetry.     

Brainstem involvement in the initial response to pain

The autonomic responses to acute pain exposure usually habituate rapidly while the subjective ratings of pain remain high for more extended periods of time. Thus, systems involved in the autonomic response to painful stimulation, for example the hypothalamus and the brainstem, would be expected to attenuate the response to pain during prolonged stimulation. This suggestion is in line with the hypothesis that the brainstem is specifically involved in the initial response to pain. To probe this hypothesis, we performed a positron emission tomography (PET) study where we scanned subjects during the first and second minute of a prolonged tonic painful cold stimulation (cold pressor test) and nonpainful cold stimulation. Galvanic skin response (GSR) was recorded during the PET scanning as an index of autonomic sympathetic response. In the main effect of pain, we observed increased activity in the thalamus bilaterally, in the contralateral insula and in the contralateral anterior cingulate cortex but no significant increases in activity in the primary or secondary somatosensory cortex. The autonomic response (GSR) decreased with stimulus duration. Concomitant with the autonomic response, increased activity was observed in brainstem and hypothalamus areas during the initial vs. the late stimulation. This effect was significantly stronger for the painful than for the cold stimulation. Activity in the brainstem showed pain-specific covariation with areas involved in pain processing, indicating an interaction between the brainstem and cortical pain networks. The findings indicate that areas in the brainstem are involved in the initial response to noxious stimulation, which is also characterized by an increased sympathetic response.     

Headache and recurrent abdominal pain: a controlled study by the means of the Child Behaviour Checklist (CBCL)

Headache and recurrent abdominal pain (RAP) are common disorders in children and adolescents, frequently referred to paediatricians. Both disorders show similarities in trigger and comorbid factors, their burden on family and individual life, and a paroxysmal trend with risks of chronicization over time. However, very few studies have compared directly headache and RAP. The main aim of this study was to compare the psychological profile of headache and RAP patients vs. healthy controls. A total of 210 children and adolescents [99 boys, 111 girls; age range 4-18 years; mean age (m.a.) = 11.04, SD 4.05] were assessed: 70 headache patients (m.a. 12.4 years; SD 2.9; F = 35, M = 35), 70 RAP patients (m.a. 9 years; SD 3.6; F = 30, M = 40) and 70 controls (m.a. 11.7 years; SD 4.6; F = 46, M = 24). The diagnoses had been made according to international systems of classification both for headache (ICHD-II criteria) and RAP (Rome II criteria). The psychological profile had been made according to the Child Behaviour Checklist 4-18 (CBCL). anova one-way analysis was used to compare CBCL scales and subscales between groups. Headache and RAP showed a very similar trend vs. control for the main scales of the CBCL, with a statistically significant tendency to show problems in the Internalizing scale (anxiety, mood and somatic complaints) and no problems in the Externalizing (behavioural) scale. Only for the Attention Problems subscale migraineurs showed a significant difference compared with RAP. In conclusion, headache and RAP show a very similar psychological profile that should be considered not only for diagnostic and therapeutic purposes, but also from the aetiological aspect.     

Pupillary Reactivity in Children With Recurrent Abdominal Pain

Electronic pupillometry before and after phenylephrine instillation in the right eye was carried out in 18 children aged 10 to 16 years suffering from recurrent abdominal pain (RAP) and 15 age-matched controls. Before stimulation the pupillary diameter was almost equal in the two groups. After phenylephrine eye drops iris dilatation was greater in RAP patients than in controls, even though the difference was not statistically significant. These results seem to suggest children with RAP have a chronically disturbed receptor sensitivity in their iris neuromuscular junction caused by a sympathetic hypofunction, similar to that already reported in migrainous patients.     

Autonomic activation and pain in response to low-grade mental stress in fibromyalgia and shoulder/neck pain patients.

OBJECTIVE: Psychosocial stress is a risk factor for musculoskeletal pain, but how stress affects musculoskeletal pain is poorly understood. We wanted to examine the relationship between low-grade autonomic activation and stress-related pain in patients with fibromyalgia and localised chronic shoulder/neck pain. METHODS: Twenty-three female patients with fibromyalgia, 29 female patients with chronic shoulder-neck pain, and 35 healthy women performed a stressful task lasting 60min. With a blinded study design, we recorded continuous blood pressure, heart rate, finger skin blood flow and respiration frequency before (10min), during (60min) and after (30min) the stressful task. The physiological responses were compared with subjective reports of pain. RESULTS: The increase in diastolic blood pressure and heart rate in response to the stressful task were smaller in fibromyalgia patients compared with the healthy controls. Furthermore, fibromyalgia patients had reduced finger skin blood flow at the end of the stressful task compared to healthy controls. We also found an inverse relationship between the heart rate response and development and recovery of the stress-related pain in fibromyalgia patients. CONCLUSION: We found abnormal cardiovascular responses to a 60min long stressful task in fibromyalgia patients. Furthermore, we found a negative association between the heart rate response and the pain which developed during the stressful task in the fibromyalgia group, possibly a result of reduced stress-induced analgesia for fibromyalgia patients.     

Cme credit quiz

Abstract

Background: Attention-deficit/hyperactivity disorder (ADHD) in schoolchildren is often associated with troublesome relationships with family members and peers as well as difficulties in the classroom. The aims of this study were to assess the associations between attention-deficit/hyperactivity disorder (ADHD), recurrent subjective health complaints, and bullying in the peer group in schoolchildren. Method: Cohort study of 577 fourth graders (10-year-olds) in 1 municipality in Stockholm County, Sweden. All children were screened for attention and behavior problems through interviews with their parents and teachers. Children with high scores underwent further clinical and cognitive assessments. Information about health complaints and bullying was collected from the children themselves in a classroom questionnaire. The 516 children for whom there was information from all 3 data sources were included in the final study population. Results: Attention-deficit/hyperactivity disorder was associated with a 2-fold increased risk for recurrent abdominal pain (RAP), sleeping problems, and tiredness, while there was no association with headache. Bullying other students as well as being bullied were strongly associated with ADHD. There was a 2-fold increased risk for all kinds of health complaints among children being bullied, while bullies were more likely to report tiredness than other children. Conclusions: Evaluation and treatment strategies for ADHD need to include an effective evaluation and treatment of RAP, tiredness, and sleeping disturbances as well as assessment and effective interventions for bullying. Evaluation of ADHD should be considered in children with recurrent health complaints and in children involved in bullying. Antibullying interventions are important to prevent health problems in all children.     

磁控胶囊内镜在儿童再发性腹痛中的诊断价值

目的探讨磁控胶囊内镜在儿童再发性腹痛（RAP）中的应用价值。方法回顾性分析2021年1月-2021年6月上海交通大学医学院附属儿童医院内镜中心125例行磁控胶囊内镜检查的RAP患儿的临床资料,分析镜下病变检出情况和胶囊内镜在消化道各部位运行时间等。结果125例患者中,35例拟行全小肠检查（1例因吞服失败而未完成）,90例在磁控条件下行食管及胃部检查。磁控胶囊内镜在食管内的中位运行时间为8.5 (5.3,12.5) s,在胃内的中位运行时间为49.0 (17.7,94.0) min,行全小肠检查的患儿,胶囊内镜在小肠内的中位运行时间为252.0 (192.5,340.0) min,全小肠检查完成率为97.1%(34/35）,检查完成后所有胶囊内镜均顺利排出体外。上消化道病变检出率为71.8%(89/124）,小肠病变检出率为68.6%(24/35）。磁控胶囊内镜对儿童RAP的总体病变检出率为73.4%(91/124）。结论磁控胶囊内镜在RAP患儿胃肠道病变检查中有较高的病变检出率,且安全无痛苦,具有一定的临床应用价值。     

Recurrent Abdominal Pain in Children: Forerunner to Adult Irritable Bowel Syndrome?

ISSUES AND PURPOSE Review the etiology and pathophysiology of recurrent abdominal pain (RAP) and its potential role as a precursor to irritable bowel syndrome (IBS) in adults. CONCLUSIONS Physiological mechanisms not easily identifiable as an organic cause may underlie symptoms in RAP patients. They may be triggered by psychosocial factors that result in greater functional disability, more clinic visits, and lower academic and social competence. Of these children, 25% will experience similar symptoms as adults; many will be diagnosed with IBS. PRACTICE IMPLICATIONS Nurses can provide early and efficient management of these children's care if they view the issues of abdominal pain/discomfort from a broader focus that includes the context of the child's experiences.     

Assessing recurrent abdominal pain in children

Recurrent abdominal pain is a frequent complaint of school-aged children. In 5-10 percent of the cases, RAP is the result of organic disease. Specific history and physical assessments are needed to detect organic disease. The assessment tool described in this article is a functional adjunct to a nurse practitioner's evaluation of RAP as well as of other recurrent pain. It provides additional information to identify less obvious organic causes and serves as a basis for involving the patient in development of a treatment plan.     

The role of the gut in migraine: the oral 51-Cr EDTA test in recurrent abdominal pain

Sixteen children with recurrent abdominal pain (or: "recurrent syndrome"), regarded as migraine equivalent in childhood, were submitted to the 51-Cr EDTA gut permeability test. The results were compared with those obtained in 10 healthy young adults and in 11 control children. The gut permeability in the recurrent syndrome was significantly higher than in healthy adults and control children (p less than 0.0006): The following results were obtained: 4.83 +/- 0.40 (mean +/- SEM) in the children with recurrent abdominal pain, and 2.35 +/- 0.24 2.51 +/- 0.21 in the healthy young adults and control children, respectively. The implications of these findings as far as migraine is concerned, are discussed.     

彩色多普勒超声对功能性再发性腹痛儿童肠系膜上动脉的血流动力学研究

目的通过研究功能性再发性腹痛（RAP）儿童肠系膜上动脉（SMA）血流动力学的变化,探讨功能性RAP与SMA血流动力学变化的相关性。方法超声测量40例功能性RAP儿童SMA的直径、血流量、收缩期峰值速度（PSV）、舒张末期速度（EDV）、搏动指数及阻力指数,并与45例健康儿童（对照组）比较。结果功能性RAP儿童组SMA的PSV、EDV、直径、血流量较对照组降低（P〈0．01）,搏动指数及阻力指数在两组间差异无统计学意义（P〉0．05）。结论功能性RAP儿童的SMA部分血流动力学指标降低,其变化对于功能性RAP的临床诊断具有参考价值。     

Differences in somatic perception in female patients with irritable bowel syndrome with and without fibromyalgia

BACKGROUND: Irritable bowel syndrome (IBS) and fibromyalgia (FM) are considered chronic syndromes of altered visceral and somatic perception, respectively. Because there is a significant overlap of IBS and FM, shared pathophysiological mechanisms have been suggested. Although visceral perception has been well studied in IBS, somatic perception has not. AIMS: To compare hypervigilance and altered sensory perception in response to somatic stimuli in patients with IBS, IBS+FM, and healthy controls. METHODS: Eleven IBS females (mean age 40), 11 IBS+FM females (mean age 46), and ten healthy female controls (mean age 39) rated pain perception in response to pressure stimuli administered to active somatic tender points, non-tender control points and the T-12 dermatome, delivered in a predictable ascending series, and delivered in an unpredictable randomized fashion (fixed stimulus). RESULTS: Although IBS patients had similar pain thresholds during the ascending series compared with controls, they were found to have somatic hypoalgesia with higher pain thresholds and lower pain frequency and severity during fixed stimulus series compared with IBS+FM patients and controls (P<0.05). Patients with IBS+FM were more bothered by the somatic stimuli and had somatic hyperalgesia with lower pain thresholds and higher pain frequency and severity. CONCLUSIONS: Both hypervigilance and somatic hypoalgesia contribute to the altered somatic perception in IBS patients. Co-morbidity with FM results in somatic hyperalgesia in IBS patients.     

Idiopathic abdominal pain in children: results,deficits and perspectives of empirical research

Recurrent abdominal pain (RAP) is one of the most common pain syndromes in childhood, with prevalence rates ranging from 10 to 20% in all school-age children. In nearly 50% the complaints persist over many years of their life-span to adolescence or adulthood. Although the empirical findings have increased in the last decade, our knowledge about the etiology, pathogenesis, and pathophysiology is still very limited. Current approaches suggest that we understand recurrent pain syndromes as a complex and multidimensional disturbance (biopsychosocial paradigm). In this respect there is strong evidence for the major importance of psychosocial causes (daily hassles, specific life events), psychopathological factors (anxiety, depression, somatization disorder), and social environmental influences (mother's psychopathology, social modelling, reinforcement) in the pathogenesis of functional abdominal pain. The noticeable correlation with other pain syndromes and functional disturbances indicates that recurrent pain may possibly be a manifestation of a basic somatization disorder. The unfavourable long-term prognosis supports the need for early and specific interventions. Psychological treatment requires a medical examination to exclude organic origins. Some of these invasive diagnostic procedures can be very difficult, expensive and distressing for the child. Behavioural medicine is based upon having an extensive family history and symptom analysis. The psychological interventions applied in clinical practice include prophylaxis, reduction of pain symptoms and environmental modification. In recent years there has been an increasing trend to create more complex and multidimensional behavioural treatment programs for children. Although preliminary data on the use of these behavioural medicine programs have shown some promise, further investigations are needed to examine the applicability and effectiveness of specific interventions in the treatment of abdominal pain symptoms.     

The Public Speaks on Primary Care

Abstract

Focusing on behavioral criteria for attention–deficit/hyperactivity disorder (ADHD) diagnosis leads to considerable neuropsychological profile heterogeneity among diagnosed children, as well as variable response to methylphenidate (MPH) treatment. Documenting “cold” executive working memory (EWM) or “hot” self–regulation (SR) neuropsychological impairments could aid in the differential diagnosis of ADHD subtypes and may help to determine the optimal MPH treatment dose. In this study, children with ADHD inattentive type (n = 19), combined type (n = 33), and hyperactive–impulse type (n = 4) underwent randomized controlled MPH trials; neuropsychological, behavioral, and observational data were collected to evaluate the children's responses. Those with moderate or significant baseline EWM/SR impairment showed robust MPH response, whereas response for those with lower baseline impairment was equivocal. Implications for medication use and titration, academic achievement, and long–term treatment efficacy are examined.     

Repeatability of autonomic responses to pain anticipation and pain stimulation.

In this study we address the problem of the repeatability of autonomic responses in the experimental setting. In healthy volunteers, we measured the heart rate (HR) response to pain anticipation and to pain elicited with galvanic stimulation. After evaluation of pain threshold (T), all subjects underwent the same experimental protocol, whereby a painful stimulus at 1.5T was delivered on the forehead following a warning, while the ECG was continuously recorded. The procedure was repeated three times across a three-week period. The parameters recorded included pain threshold, pain rating, HR response to pain anticipation and HR response to pain. We found a high correlation among the three sessions for all parameters, indicating that, as occurs for pain threshold and pain rating, individual differences in autonomic responses can be reliably reproduced as well, even though significant habituation develops.     

Psychophysiologic responses to a realistic laboratory abdominal pain stimulus

Small doses of the carbohydrate lactulose are widely used in the clinical setting to assess small bowel transit time because lactulose is not absorbed by the small intestine and its arrival in the intestine can be detected non-invasively by breath hydrogen testing. In this study, doses of this safe, widely used substance higher than those typically administered for transit tests were given to 12 healthy young adult men to produce symptoms of gas and intestinal distention similar to those commonly experienced by patients with irritable bowel syndrome and recurrent abdominal pain. Comparison of subjective and physiological responses to the administration of 0 and 30 g of lactulose in a double-blind placebo-controlled trial demonstrated that the 30 g lactulose dose produced significant increases in a number of measures reflecting the intra-intestinal pain stimulus. The results of the present study indicate that lactulose is a realistic and ethically acceptable stimulus for the production of transient mild abdominal pain in the laboratory.