Interaction of psychological, physiological and neuronal processes in functional dyspepsia

Functional dyspepsia is characterized by postprandial fullness, early satiation, epigastric pain, bloating, and nausea symptoms in the absence of structural changes in the gastrointestinal tract. Numerous works have been performed to identify the peripheral characteristics of functional dyspepsia and its association with dyspeptic symptoms, including changes of gastric motility, visceral sensitivity, secretion of hormones, functions of immune system. However, the pathophysiological mechanisms involved and standard treatment strategies are still lacking. The role of the dysfunction of the brain-gut axis and the effect of the food ingestion in the gastrointestinal symptoms of functional dyspepsia patients have therefore been attracting more interest in recent years. How the food is processed differently in the peripheral and in the central nervous system in functional dyspepsia has, however, received little attention in comparison to other functional gastrointestinal disorders. In this thesis, we used various approaches to examine the physiological and neuronal mechanisms in functional dyspepsia patients. We commenced by summarizing previous functional neuroimaging studies to establish their limitations. To bridge the resulting research gap, we investigated physiological and attentional responses to visual food cues, and measured the altered brain activity before and after the food ingestion in functional dyspepsia patients. In the paper I, we reviewed the current status of brain research related to functional dyspepsia and were able to clearly show a knowledge gap regarding neural mechanisms of food-related factors in functional dyspepsia patients. In paper II, we introduced how to design the neuroimaging study and interpret the results of it to clinicians. In paper III, we report findings of an eyetracking and behavioral study on functional dyspepsia patients. The patients showed 1) greater dyspeptic symptoms even after ingestion of a lower calorie and food intake from standard breakfast; 2) decreased pleasantness ratings to food images; and 3) reduced visual attention to food images in comparison to healthy controls. In paper IV, we report findings of a functional magnetic resonance imaging study during meal ingestion (yoghurt with different fat content and label info) in functional dyspepsia patients. The patients showed 1) greater abdominal pain, burning, and discomfort after high fat labeled yogurt ingestion than after low fat labeled yogurt ingestion irrespective of fat content, 2) increased activity in occipital areas before and after ingestion irrespective of fat content and label and increased activity in the middle frontal gyrus before ingestion, 3) increased functional connectivity between the insula and the precuneus after ingestion of yogurt with low fat label, and 4) greater nausea-related increased functional connectivity between the insula and the occipital gyrus after ingestion of high fat yogurt than of low fat yogurt. Furthermore, bidirectional influences between quality of life and depression, as mediated by dyspeptic symptoms and the impact of food craving on the amplitude of brain activity in the middle frontal gyrus, as mediated by depression in functional dyspepsia patients were recorded. In conclusion, the abnormal dietary behavior, reduced positive emotional response and visual attention to food images, and the role of cognitive perception of fat on the aggravation of dyspeptic symptoms should be considered in clinics and in research for functional dyspepsia

Decreased Peripheral and Central Responses to Acupuncture Stimulation following Modification of Body Ownership

Acupuncture stimulation increases local blood flow around the site of stimulation and induces signal changes in brain regions related to the body matrix. The rubber hand illusion (RHI) is an experimental paradigm that manipulates important aspects of bodily self-awareness. The present study aimed to investigate how modifications of body ownership using the RHI affect local blood flow and cerebral responses during acupuncture needle stimulation. During the RHI, acupuncture needle stimulation was applied to the real left hand while measuring blood microcirculation with a LASER Doppler imager (Experiment 1, N = 28) and concurrent brain signal changes using functional magnetic resonance imaging (fMRI; Experiment 2, N = 17). When the body ownership of participants was altered by the RHI, acupuncture stimulation resulted in a significantly lower increase in local blood flow (Experiment 1), and significantly less brain activation was detected in the right insula (Experiment 2). This study found changes in both local blood flow and brain responses during acupuncture needle stimulation following modification of body ownership. These findings suggest that physiological responses during acupuncture stimulation can be influenced by the modification of body ownership

IKT az óvodában : kihívások és lehetőségek

We suggest a new placebo analgesia animal model and investigated the role of the dopamine and opioid systems in placebo analgesia. Before and after the conditioning, we conducted a conditioned place preference (CPP) test to measure preferences for the cues (Rooms 1 and 2), and a hot plate test (HPT) to measure the pain responses to high level-pain after the cues. In addition, we quantified the expression of tyrosine hydroxylase (TH) in the ventral tegmental area (VTA) and c-Fos in the anterior cingulate cortex (ACC) as a response to reward learning and pain response. We found an enhanced preference for the low level-pain paired cue and enhanced TH expression in the VTA of the Placebo and Placebo + Naloxone groups. Haloperidol, a dopamine antagonist, blocked these effects in the Placebo + Haloperidol group. An increased pain threshold to high-heat pain and reduced c-Fos expression in the ACC were observed in the Placebo group only. Haloperidol blocked the place preference effect, and naloxone and haloperidol blocked the placebo analgesia. Cue preference is mediated by reward learning via the dopamine system, whereas the expression of placebo analgesia is mediated by the dopamine and opioid systems.Funding Agencies|international cooperation program [2014K2A3A1000166]</p

Pure Sensory Deficit at the T4 Sensory Level as an Isolated Manifestation of Lateral Medullary Infarction

In rare cases restricted sensory deficits along the somatotopic topography of the spinothalamic tract can develop from a lateral medullary infarction. To our knowledge, isolated dermatomal sensory deficit as a single manifestation of a lateral medullary infarction has not been reported previously. A 58-year-old man presenting with sudden left-sided paresthesia complained of sensory deficit of pain and temperature below the left T4 sensory level without other neurologic deficits. Diffuse- and T2-weighted magnetic resonance imaging (MRI) of the brain showed high signal intensities in the right lower medulla oblongata, whereas thoracic-spine MRI and somatosensory evoked potentials produced normal findings

Cognitive and behavioral effects of lamotrigine and carbamazepine monotherapy in patients with newly diagnosed or untreated partial epilepsy

AbstractPurposeIn this prospective study, we compared the long-term cognitive and behavioral effects of lamotrigine (LTG) and carbamazepine (CBZ) in patients with newly diagnosed or untreated partial epilepsy.MethodsThis was a multicenter, open-label, randomized study that compared monotherapy with LTG and CBZ in newly diagnosed or untreated patients with partial epilepsy. We employed an 8-week titration period and a 40-week maintenance period. Neuropsychological tests, Symptom Check List-90, and QOLIE-31 were assessed at baseline, 16 weeks, and 48 weeks after drug treatment. A group-by-time interaction was the primary outcome measure and was analyzed by use of the linear mixed model.ResultsA total of 110 patients were eligible and 73 completed the 48-week study (LTG, n=39; CBZ, n=34). Among the cognitive tests, significant group-by-time interaction was identified only in phonemic fluency of Controlled Oral Word Association Task (p=0.0032) and Stroop Color–Word Interference (p=0.0283), with a significant better performance for LTG group. All other neuropsychological tests included did not show significant group-by-time interactions. Among the subscales of Symptom Check List-90, significant group-by-time interactions were identified in Obsessive-Compulsive (p=0.0005), Paranoid Ideation (p=0.0454), Global Severity Index (p=0.0194), and Positive Symptom Total (p=0.0197), with a significant improvement for CBZ group. QOLIE-31 did not show significant group-by-time interactions.ConclusionOur data suggest that epilepsy patients on LTG have better performance on phonemic fluency and the task of Stroop Color–Word Interference than do patients on CBZ, whereas patients on CBZ had more favorable behavioral effects on two subscales and two global scores of Symptom Check List-90 than did patients on LTG