Absence of increasing cortical fMRI activity volume in response to increasing visceral stimulation in IBS patients

2004 ◽  
Vol 287 (2) ◽  
pp. G425-G435 ◽  
Author(s):  
Harjot Sidhu ◽  
Mark Kern ◽  
Reza Shaker
Keyword(s):  
Cognitive Processes ◽  
Cortical Activity ◽  
Neural Circuitry ◽  
Sensory Function ◽  
Visceral Sensation ◽  
Control Subjects ◽  
Healthy Female ◽  
Irritable Bowel ◽  
Brain Fmri ◽  
Stimulation Of

Cerebral cortical activity associated with perceived visceral sensation represents registration of afferent transduction and cognitive processes related to perception. Abnormalities of gut sensory function can involve either or both of these processes. Cortical registration of subliminal viscerosensory signals represents cerebral cortical activity induced by stimulation of intestinal sensory neurocircuitry without the influence of perception-related cortical activity, whereas those associated with perception represent both neural circuitry and cognitive processes. Our aims were to determine and compare quantitatively cerebral cortical functional magnetic resonance imaging (fMRI) activity in response to subliminal, liminal, and nonpainful supraliminal rectal distension between a group of irritable bowel syndrome (IBS) patients and age/gender-matched controls. Eight female IBS patients and eight age-matched healthy female control subjects were studied using brain fMRI techniques. Three barostat-controlled distension levels were tested: 1) 10 mmHg below perception (subliminal), 2) at perception (liminal), and 3) 10 mmHg above perception (supraliminal). In control subjects, there was a direct relationship between stimulus intensity and cortical activity volumes, ie., the volume of fMRI cortical activity in response to subliminal (3,226 ± 335 μl), liminal (5,751 ± 396 μl), and supraliminal nonpainful stimulation (8,246 ± 624 μl) were significantly different ( P < 0.05). In contrast, in IBS patients this relationship was absent and fMRI activity volumes for subliminal (2,985 ± 332 μl), liminal (2,457 ± 342 μl), and supraliminal nonpainful stimulation (2,493 ± 351 μl) were similar. Additional recruitment of cortical fMRI activity volume in response to increasing stimulation from subliminal to liminal and supraliminal domains is absent in IBS patients, suggesting a difference in the processing of perceived stimulation compared with controls.

scholarly journals Dimensions of Gut Dysfunction in Irritable Bowel Syndrome: Altered Sensory Function

1999 ◽  
Vol 13 (suppl a) ◽  
pp. 12A-14A ◽  
Author(s):  
Fernando Azpiroz
Keyword(s):  
Irritable Bowel Syndrome ◽  
Clinical Symptoms ◽  
Afferent Input ◽  
Sensory Function ◽  
Visceral Hyperalgesia ◽  
Gut Dysfunction ◽  
Irritable Bowel ◽  
Clinical Conditions ◽  
Normal Perception ◽  
Stimulation Of

Growing evidence suggests that symptoms in patients with irritable bowel syndrome (IBS) may be due to a visceral sensory dysfunction. Specifically, it has been shown that patients with IBS have hypersensitive responses to distension of the rectum, whereas their tolerance to somatic stimuli is normal or even increased. Furthermore, patients with IBS have hypersensitivity of the small bowel, which selectively affects mechanosensitive afferents, with normal perception of electrical stimulation of the gut. Sensory dysfunctions may also be associated with altered reflex activity, which may contribute to the clinical symptoms. Normally, a series of mechanisms at different strata of the nervous system modulate visceral afferent input and determine conscious perception. Conceivably, a dysfunction of these regulatory mechanisms may alter sensitivity in clinical conditions. To date, neither the origin nor the clinical significance of visceral hyperalgesia has been elucidated. However, it seems likely that the sensory and reflex dysfunctions of the gut in IBS may combine to different degrees, and their interaction may explain the clinical pleomorphism of the syndrome.

scholarly journals Sex differences in emotion-related cognitive processes in irritable bowel syndrome and healthy control subjects

Pain ◽  
2013 ◽  
Vol 154 (10) ◽  
pp. 2088-2099 ◽  
Author(s):  
Jennifer S. Labus ◽  
Arpana Gupta ◽  
Kristen Coveleskie ◽  
Kirsten Tillisch ◽  
Lisa Kilpatrick ◽  
...  
Keyword(s):  
Irritable Bowel Syndrome ◽  
Sex Differences ◽  
Cognitive Processes ◽  
Control Subjects ◽  
Healthy Control ◽  
Irritable Bowel

Motor and sensory function of the rectum in different types of irritable bowel syndrome

2001 ◽  
Vol 120 (5) ◽  
pp. A399-A399
Author(s):  
J STEENS ◽  
P SCHAAR ◽  
C LAMERS ◽  
A MASCLEE
Keyword(s):  
Irritable Bowel Syndrome ◽  
Sensory Function ◽  
Different Types ◽  
Irritable Bowel

scholarly journals Error analysis of classic colonic transit time estimates

2000 ◽  
Vol 279 (3) ◽  
pp. G520-G527 ◽  
Author(s):  
Michel Bouchoucha ◽  
S. Randall Thomas
Keyword(s):  
Colonic Transit ◽  
X Rays ◽  
Control Subjects ◽  
Time Estimates ◽  
Transit Times ◽  
Daily Ingestion ◽  
Kinetic Coefficients ◽  
Classic Approach ◽  
Healthy Control ◽  
Irritable Bowel

Estimates of colonic transit times (CTT) through the three colonic segments, right colon, left colon, and rectosigmoid, are commonly based on radiopaque markers. For a given segment, CTT is usually calculated from just the number of markers visible in that segment on abdominal X-rays. This procedure is only strictly valid for the theoretical, but unrealistic, case of continuous marker ingestion (i.e., not for a single or once-daily ingestion). CTT was analyzed using the usual estimate of the mean CTT of one marker and also using a new, more realistic estimate based on the kinetic coefficients of a three-compartment colonic model. We directly compared our compartmental approach to classic CTT estimates by double-marker studies in six patients. We also retrospectively studied CTT in 148 healthy control subjects (83 males, 65 females) and 1,309 subjects with functional bowel disorders (irritable bowel syndrome or constipation). Compared with the compartmental estimates, the classic approach systematically underestimates CTT in both populations, i.e., in patients and in healthy control subjects. The relative error could easily reach 100% independent of the site of colonic transit delay. The normal values of total CTT are then 44.3 ± 29.3 instead of 30.1 ± 23.6 h for males and 68.2 ± 54.4 instead of 47.1 ± 28.2 h for females.

EVALUATION OF PROPRANOLOL-GLUCAGON TEST

1977 ◽  
Vol 86 (2) ◽  
pp. 243-250 ◽  
Author(s):  
Y. Okada ◽  
K. Watanabe ◽  
T. Takeuchi ◽  
T. Hata ◽  
H. Mikam ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Body Weight ◽  
False Negative ◽  
Human Growth ◽  
Maximum Level ◽  
Normal Children ◽  
Provocative Test ◽  
Glucagon Test ◽  
Control Subjects ◽  
Stimulation Of

ABSTRACT A propranolol-glucagon test was evaluated in 24 control normal children, 21 pituitary dwarfs, 15 patients with constitutional short stature, 2 with chromosome aberration and 4 with miscellaneous diseases. The dose of glucagon enough for the stimulation of human growth hormone (HGH) secretion is more than 20 μg/kg of body weight. During the test in the control subjects the serum HGH level increased from 2.3 ± 1.2 ng/ml to a maximum level of 30.0 ± 15.1 ng/ml, when 10 mg propranolol, regardless of body weight and 30 μg glucagon per kg of body weight are given. The dose of propranolol administered ranged from 0.2 to 1.0 mg/kg of body weight in normal children studied. Serum 11-OHCS also increased significantly from 14.5 ± 11.2 μg/100 ml to 30.1 ± 15.5 μg/100 ml (P <0.01). There was no difference in the maximum level of urinary total catecholamines in propranolol-glucagon test between 7 pituitary dwarfs and 7 control subjects. The mechanism of HGH response to propranolol-glucagon administration is unknown, but propranolol-glucagon administration is a sensitive and reliable provocative test for HGH secretion, since false negative responses of HGH are not observed in patients with non-pituitary disease.

RESPONSES TO INFUSED METHACHOLINE IN FAMILIAL DYSAUTONOMIA

PEDIATRICS ◽  
1965 ◽  
Vol 36 (2) ◽  
pp. 225-230
Author(s):  
Alfred A. Smith ◽  
Jacob I. Hirsch ◽  
Joseph Dancis
Keyword(s):  
Heart Rate ◽  
Familial Dysautonomia ◽  
Sensory Function ◽  
Control Group ◽  
Simple Hypothesis ◽  
Control Subjects ◽  
Blood Pressures ◽  
Parasympathetic Function

Methacholine was infused into six control subjects and into five patients with familial dysautonomia. In the control group blood pressures were well maintained and a tachycardia was observed. In contrast, the blood pressures among the dysautonomic subjects usually fell and the heart rate did not increase. Parasympathetic responses such as tearing and coughing were far more marked and occurred in the dysautonomic at dosages lower than in the normal. In two cases the knee jerks, characteristically missing in dysautonomia were temporarily restored. Increased pain and normal axon flares in response to intradermal histamine were observed in two other patients indicating an improvement in sensory function. The enhanced responses to infused methacholine in dysautonomia suggest an insufficiency of parasympathetic function with effector supersensitivity. The basis for the improvement in sensory function is unknown. The simplest explanation of the observations is a deficiency in neurohumoral transmission. However, an objection to the quick acceptance of this simple hypothesis is also presented.

scholarly journals Dehydroepiandrosterone sulfate improves visceral sensation and gut barrier in a rat model of irritable bowel syndrome

2019 ◽  
Vol 852 ◽  
pp. 198-206 ◽  
Author(s):  
Tsukasa Nozu ◽  
Saori Miyagishi ◽  
Rintaro Nozu ◽  
Kaoru Takakusaki ◽  
Toshikatsu Okumura
Keyword(s):  
Irritable Bowel Syndrome ◽  
Rat Model ◽  
Dehydroepiandrosterone Sulfate ◽  
Visceral Sensation ◽  
Gut Barrier ◽  
Irritable Bowel

Upper thoracic sympathetic neuron responses to input from urinary bladder afferents

1983 ◽  
Vol 245 (3) ◽  
pp. R311-R320 ◽  
Author(s):  
R. Schondorf ◽  
W. Laskey ◽  
C. Polosa
Keyword(s):  
Electrical Stimulation ◽  
Urinary Bladder ◽  
Sympathetic Neuron ◽  
Neural Circuitry ◽  
Pelvic Nerve ◽  
Hypogastric Nerve ◽  
Bladder Afferents ◽  
Cervical Sympathetic ◽  
Upper Thoracic ◽  
Stimulation Of

The aim of the present study was to evaluate the organization of neural circuitry responsible for the intersegmental transmission of input from urinary bladder afferents to sympathetic preganglionic neurons (SPNs). The electrical activity of SPNs was recorded from axons of the cervical sympathetic trunk in anesthetized central nervous system (CNS)-intact and in unanesthetized midcollicular-decerebrate or acute C1 spinal cats. In all three preparations, tonically active SPNs were excited or inhibited by 1) electrical stimulation of myelinated afferents of the pelvic or hypogastric nerve, both of which contain bladder afferents, and 2) spontaneous contraction or distension of the urinary bladder. The SPN responses to bladder distension were abolished by pelvic nerve section. A comparison of responses of SPNs in CNS-intact and acute spinal animals to electrical stimulation of pelvic nerve afferents suggests that both propriospinal and supraspinal circuits are involved in the intersegmental transmission of input from bladder afferents to SPNs.

Sign in / Sign up

Export Citation Format

Share Document