- Email: [email protected]
Functional cerebral changes during rectal stimulation: A functional magnetic resonance imaging (fMRI) study in healthy humans
April 1998
Motility and Nerve-Gut Interactions A735
from the UES to a moderate-amplitude pressure trough 1.1 +- 0.7 cm into the esophagus (12.5 +- 0.7 cm above the LES) in all 7 animals. The remainder of the esophagus to the LES was divided into 2 regions by a conspicuous pressure trough of 84 +- 23 mm Hg at 6.9 +- 0.8 cm above the LES (49.6% of cephalocaudad esophageal length) in all animals (Figure). A third pressure trough separating distal body and LES aftercontraction was also noted in 6 animals. The 2nd trough separating the distal esophagus into 2 segments was the most consistent and dominant trough in the opossum. CONCLUSIONS: Topographic methods demonstrate sequential contraction segments to esophageal peristalsis in the opossum as in t h e human. The region corresponding to the smooth-muscle esophagus is comprised of 2 dominant, overlapping contraction segments, their separating trough identified 6.9 cm above the LES, a location similar to the described transition from cholinergicto noncholinergic-dominant control. These findings further suggest that topographically defined pressure segments represent different underlying neuromuscular control mechanisms
1,4 ......
~vi
0~ 4
8
|2
16
., -J, 20
• G3034 FUNCTIONAL CEREBRAL CHANGES DURING RECTAL STIMULATION: A FUNCTIONAL MAGNETIC RESONANCE IMAGING (fMRI) STUDY IN HEALTHY HUMANS. B, Cgffi!~l, D. Bouhassira2, J.M. Sabat~ 1, D. Souli6~, Y.S. Cordoliani 3, R. Jian I. 1) INSERM U 290 and H6pital Saint-Louis 2) INSERM U-161 3) D~partement de Neuroradiologie, HIA du Val-de-Gr~ce, Paris, France, In human, cerebral functional imaging (positron emission tomography and fMRI) demonstrated modifications of cerebral activity during somatic stimulation. However, changes in cerebral activity during visceral stimulation remained poorly investigated. The aims of this study were to analyze modifications of cerebral activity induced during rectal distensions by fMRI, a technique that allows a better spatial resolution than other functional imaging techniques. Methods: 12 right-handed healthy subjects were included. Functional images were acquired with a 1,5 T scanner using a gradient-echo echoplanar sequence (10 slices per sequence, 50 images per slice, slice thickness 5 ram). Each sequence involved 5 alternating 50s periods of rest (R) and rectal distensions (D) according to the distending protocol : R-D-R-D-R. Isobaric distensions were performed by a rectal balloon connected to an electronic barostat. For each subject, 3 successive sequences were performed during 3 levels of distensions which elicited 3 graded sensations : sensation of gas (grade 1), discomfort (grade 2) and moderate pain (grade 3). Signal changes between rest and stimulation periods were assessed with pixel-by-pixel t-test and correlation analysis of signal intensity. Re~ult~ : in 3 subjects data could not be interpreted due to movements artifacts. Grade 1 sensation induced a significant modification of the signal in only 3 subjects. Grades 2 and 3 sensations induced significant modifications of the signal which localization and amplitudes were very close in the 9 subjects. Increases in intensity were localized in the right cerebral cortex and mainly located in 4 regions : dorsomedian thalamic nucleus, insular cortex, cingulate cortex and orbital regions. No significant modifications of the somesthesic cortex activities were observed. Conclusion : cerebral "representation" of rectal sensitivity to distension appears to be lateralised on the right side. Rectal distensions seem to preferentially stimulate cortical areas associated with the limbic system which is involved in emotional control.
• G3035 SMALL BOWEL MOTILITY AND NATURAL HISTORY OF CHRONIC INTESTINAL PSEUDO-OBSTRUCTION. R.Cogfiandro, V.Stanghellini, L.Cogliandro, R.DcGiorgio, G.Barbara, B.Salvioli, R.Corinaldesi. Department of Internal Medicine and Gastroenterology; University of Bologna, Italy. Chronic intestinal pseudo-obstruction (CIP) is a syndrome characterized by impairment of gastrointestinal (GI) propulsion and recurrent episodes of obstruction in the absence of any lesion altering the intestinal transit. Few data are available on the natural course of CIP in adults. The aim of this study was to evaluate intestinal motility and long-term follow-up of CIP patients. Fifty-seven consecutive pts (22 M, 35 F) with clinical and radiological features of CIP, referred between 1985-1996, were investigated. Their median age was 20.5 yrs (range 0-74 yrs) at GI symptom onset, 34.5 yrs (0-74) at CIP onset, and 42 yrs (7-74) at CIP diagnosis. The mean time interval from CIP onset to diagnosis was 87.7 months (range 1-564). At presentation, subocclusive episodes were the only clinical manifestation in 24% of pts, while major symptoms were suggestive of bowel disorders (abdominal distension, pain, constipation, diarrhoea) (44%), dyspepsia (11%), or both (21%). In addition, extradigestive symptoms due to urological or gynecologic abnormalities were present in 12% of pts. Each patient underwent at least one manometric study of the small bowel by a stationary perfused technique (>6 hrs during fasting in all patients and >1 hr after feeding). Previously defined (Gut 1987; 28: 5-12) motor abnormalities were detected in all patients: abormal activity fronts (49%), bursts (60%), sustained uncoordinated contractions (14%), abnormal motor response to feeding (40%), hypocontractility (11%). Of the 57 pts, 2 were lost at follow up, and 55 were followed up (median duration 66 mos, range 12-132) using a structured questionnaire including 160 items; of these 3 died (2 M, 1F; 2 neoplasms, 1 surgical complication). Follow up yrs n o pts n° CIP episodes/pffyr n ° surgical pmcedures/pt/yr % pts with BMI < 20
1-4 55-46 7.5
5-8 46-42 5.4
9-12 42-26 4.6
13-16 26-15 4.3
17-20 15-8 3.9
21-24 8-6 3.6
> 24 6-1 3
0.25
0.07
0.11
0.16
0.07
0
0
54.7
58.6
59.6
67.1
68.6
50.0
0
Conclusions: Small bowel motility is invariably abnormal in CIP patients.
Despite an apparent steady decrease in the frequency of pseudo-obstructive episodes, the disease mantains its severity and induces a progressive increse in the percentage of patients with malnutrition over the first 20 years. • G3036 A NOVEL SUB-CLASSIFICATION OF IRRITABLE BOWEL SYNDROME VALIDATED BY DIFFERENCES IN POST-PRANDIAL COLONIC M O T O R ACTIVITY. SJ.Cole, H.D.Duncan, T.E.Bowling, A.H.Ralmundo, J.Rogers, D.B.A.Silk Department of Gastroenterology and Nutrition, Central Middlesex Hospital NHS Trust, London NW 17 7NS. New treatment strategies in Irritable Bowel Syndrome (IBS) involve central and end-organ targeting of pharmacotherapies at pathophysiological mechanisms thought to cause or aggravate symptoms. With the aim of optimising treatment targeting we have developed a new system of categorizing IBS patients according to clinical features into four groups, Spastic colon syndrome (A), functional diarrhoea (B), diarrhoea-predominant spastic colon syndrome (C) and midgut dysmotility (D). Towards determining whether there is a physiological basis to our system of categorization, studies have been carried out to characterise fasting and post-prandial colonic motor activity in groups of these patients. Methods A symptom questionnaire was completed on 32 patients and stored for later analysis by one investigator (DBAS) blinded to the motility data obtained ((A) n=12, (B) n=7,(C) n=7, (D) n=7). After an overnight fast, intubation of the unprepared distal colon was performed without sedation and with minimal air insufflation. 3 h recordings were then made from 4 channels (15 to 50 cm from the anus), with a standard meal being given after 0.5 h. The intubated colon was treated as a study segment (sum of all four channels) and the recordings analysed for Study Segment Activity Index, SSAI (mmHg.min) in 10 minute epochs. Results There are no significant differences in mean fasting SSAI between the groups ((A) 1609±SEM 205; (B) 1399+- 149, (C)1083 + 171, (D) 1446+-153) For 2.5h, the mean postprandial SSAI values were (A) 1842 +- 116; (B) 1280 +- 54; (C) 1282 +- 102; (D) 1490 +- 80. Significant differences (p<0.05, MANOVA) were found for comparison between all the groups except for (B) vs. (C) and (C) vs. (D). Conclusion Differences exist in post-prandial colonic motor activity responses between these groups of IBS patients which suggests there is a physiological basis to our proposed classification system.
Motility and Nerve-Gut Interactions A735
from the UES to a moderate-amplitude pressure trough 1.1 +- 0.7 cm into the esophagus (12.5 +- 0.7 cm above the LES) in all 7 animals. The remainder of the esophagus to the LES was divided into 2 regions by a conspicuous pressure trough of 84 +- 23 mm Hg at 6.9 +- 0.8 cm above the LES (49.6% of cephalocaudad esophageal length) in all animals (Figure). A third pressure trough separating distal body and LES aftercontraction was also noted in 6 animals. The 2nd trough separating the distal esophagus into 2 segments was the most consistent and dominant trough in the opossum. CONCLUSIONS: Topographic methods demonstrate sequential contraction segments to esophageal peristalsis in the opossum as in t h e human. The region corresponding to the smooth-muscle esophagus is comprised of 2 dominant, overlapping contraction segments, their separating trough identified 6.9 cm above the LES, a location similar to the described transition from cholinergicto noncholinergic-dominant control. These findings further suggest that topographically defined pressure segments represent different underlying neuromuscular control mechanisms
1,4 ......
~vi
0~ 4
8
|2
16
., -J, 20
• G3034 FUNCTIONAL CEREBRAL CHANGES DURING RECTAL STIMULATION: A FUNCTIONAL MAGNETIC RESONANCE IMAGING (fMRI) STUDY IN HEALTHY HUMANS. B, Cgffi!~l, D. Bouhassira2, J.M. Sabat~ 1, D. Souli6~, Y.S. Cordoliani 3, R. Jian I. 1) INSERM U 290 and H6pital Saint-Louis 2) INSERM U-161 3) D~partement de Neuroradiologie, HIA du Val-de-Gr~ce, Paris, France, In human, cerebral functional imaging (positron emission tomography and fMRI) demonstrated modifications of cerebral activity during somatic stimulation. However, changes in cerebral activity during visceral stimulation remained poorly investigated. The aims of this study were to analyze modifications of cerebral activity induced during rectal distensions by fMRI, a technique that allows a better spatial resolution than other functional imaging techniques. Methods: 12 right-handed healthy subjects were included. Functional images were acquired with a 1,5 T scanner using a gradient-echo echoplanar sequence (10 slices per sequence, 50 images per slice, slice thickness 5 ram). Each sequence involved 5 alternating 50s periods of rest (R) and rectal distensions (D) according to the distending protocol : R-D-R-D-R. Isobaric distensions were performed by a rectal balloon connected to an electronic barostat. For each subject, 3 successive sequences were performed during 3 levels of distensions which elicited 3 graded sensations : sensation of gas (grade 1), discomfort (grade 2) and moderate pain (grade 3). Signal changes between rest and stimulation periods were assessed with pixel-by-pixel t-test and correlation analysis of signal intensity. Re~ult~ : in 3 subjects data could not be interpreted due to movements artifacts. Grade 1 sensation induced a significant modification of the signal in only 3 subjects. Grades 2 and 3 sensations induced significant modifications of the signal which localization and amplitudes were very close in the 9 subjects. Increases in intensity were localized in the right cerebral cortex and mainly located in 4 regions : dorsomedian thalamic nucleus, insular cortex, cingulate cortex and orbital regions. No significant modifications of the somesthesic cortex activities were observed. Conclusion : cerebral "representation" of rectal sensitivity to distension appears to be lateralised on the right side. Rectal distensions seem to preferentially stimulate cortical areas associated with the limbic system which is involved in emotional control.
• G3035 SMALL BOWEL MOTILITY AND NATURAL HISTORY OF CHRONIC INTESTINAL PSEUDO-OBSTRUCTION. R.Cogfiandro, V.Stanghellini, L.Cogliandro, R.DcGiorgio, G.Barbara, B.Salvioli, R.Corinaldesi. Department of Internal Medicine and Gastroenterology; University of Bologna, Italy. Chronic intestinal pseudo-obstruction (CIP) is a syndrome characterized by impairment of gastrointestinal (GI) propulsion and recurrent episodes of obstruction in the absence of any lesion altering the intestinal transit. Few data are available on the natural course of CIP in adults. The aim of this study was to evaluate intestinal motility and long-term follow-up of CIP patients. Fifty-seven consecutive pts (22 M, 35 F) with clinical and radiological features of CIP, referred between 1985-1996, were investigated. Their median age was 20.5 yrs (range 0-74 yrs) at GI symptom onset, 34.5 yrs (0-74) at CIP onset, and 42 yrs (7-74) at CIP diagnosis. The mean time interval from CIP onset to diagnosis was 87.7 months (range 1-564). At presentation, subocclusive episodes were the only clinical manifestation in 24% of pts, while major symptoms were suggestive of bowel disorders (abdominal distension, pain, constipation, diarrhoea) (44%), dyspepsia (11%), or both (21%). In addition, extradigestive symptoms due to urological or gynecologic abnormalities were present in 12% of pts. Each patient underwent at least one manometric study of the small bowel by a stationary perfused technique (>6 hrs during fasting in all patients and >1 hr after feeding). Previously defined (Gut 1987; 28: 5-12) motor abnormalities were detected in all patients: abormal activity fronts (49%), bursts (60%), sustained uncoordinated contractions (14%), abnormal motor response to feeding (40%), hypocontractility (11%). Of the 57 pts, 2 were lost at follow up, and 55 were followed up (median duration 66 mos, range 12-132) using a structured questionnaire including 160 items; of these 3 died (2 M, 1F; 2 neoplasms, 1 surgical complication). Follow up yrs n o pts n° CIP episodes/pffyr n ° surgical pmcedures/pt/yr % pts with BMI < 20
1-4 55-46 7.5
5-8 46-42 5.4
9-12 42-26 4.6
13-16 26-15 4.3
17-20 15-8 3.9
21-24 8-6 3.6
> 24 6-1 3
0.25
0.07
0.11
0.16
0.07
0
0
54.7
58.6
59.6
67.1
68.6
50.0
0
Conclusions: Small bowel motility is invariably abnormal in CIP patients.
Despite an apparent steady decrease in the frequency of pseudo-obstructive episodes, the disease mantains its severity and induces a progressive increse in the percentage of patients with malnutrition over the first 20 years. • G3036 A NOVEL SUB-CLASSIFICATION OF IRRITABLE BOWEL SYNDROME VALIDATED BY DIFFERENCES IN POST-PRANDIAL COLONIC M O T O R ACTIVITY. SJ.Cole, H.D.Duncan, T.E.Bowling, A.H.Ralmundo, J.Rogers, D.B.A.Silk Department of Gastroenterology and Nutrition, Central Middlesex Hospital NHS Trust, London NW 17 7NS. New treatment strategies in Irritable Bowel Syndrome (IBS) involve central and end-organ targeting of pharmacotherapies at pathophysiological mechanisms thought to cause or aggravate symptoms. With the aim of optimising treatment targeting we have developed a new system of categorizing IBS patients according to clinical features into four groups, Spastic colon syndrome (A), functional diarrhoea (B), diarrhoea-predominant spastic colon syndrome (C) and midgut dysmotility (D). Towards determining whether there is a physiological basis to our system of categorization, studies have been carried out to characterise fasting and post-prandial colonic motor activity in groups of these patients. Methods A symptom questionnaire was completed on 32 patients and stored for later analysis by one investigator (DBAS) blinded to the motility data obtained ((A) n=12, (B) n=7,(C) n=7, (D) n=7). After an overnight fast, intubation of the unprepared distal colon was performed without sedation and with minimal air insufflation. 3 h recordings were then made from 4 channels (15 to 50 cm from the anus), with a standard meal being given after 0.5 h. The intubated colon was treated as a study segment (sum of all four channels) and the recordings analysed for Study Segment Activity Index, SSAI (mmHg.min) in 10 minute epochs. Results There are no significant differences in mean fasting SSAI between the groups ((A) 1609±SEM 205; (B) 1399+- 149, (C)1083 + 171, (D) 1446+-153) For 2.5h, the mean postprandial SSAI values were (A) 1842 +- 116; (B) 1280 +- 54; (C) 1282 +- 102; (D) 1490 +- 80. Significant differences (p<0.05, MANOVA) were found for comparison between all the groups except for (B) vs. (C) and (C) vs. (D). Conclusion Differences exist in post-prandial colonic motor activity responses between these groups of IBS patients which suggests there is a physiological basis to our proposed classification system.