Identification of human brain loci processing esophageal sensation using positron emission tomography.
OBJECTIVE
Brain loci that process human esophageal sensation remain unidentified. The aim of this study was to identify the brain loci that process nonpainful and painful human esophageal sensation.


METHODS
In 8 healthy subjects (7 men; age range, 24-47 years), distal esophageal stimulation was performed by repeatedly inflating a balloon at volumes that produced either no sensation, definite sensation, or pain. Two positron emission tomography scans were performed for each sensation using H2(15)O. Magnetic resonance brain scans were also performed in each subject, and the positron emission tomography data were coregistered with magnetic resonance scans. Analysis of covariance-corrected t images showing the contrasts definite sensation-baseline, pain-baseline, and pain-definite sensation were created.


RESULTS
Nonpainful stimulation elicited bilateral activations along the central sulcus, insular cortex, and frontal/parietal operculum (P < 0.01). Painful stimulation produced more intense activations of the same areas and additional activation of the right anterior insular cortex and the anterior cingulate gyrus. Multiple areas of decreased activation were also observed; prominent among these was the right prefrontal cortex, which was inhibited during both nonpainful and painful stimulation.


CONCLUSIONS
Esophageal sensation activates bilaterally the insula, primary somatosensory cortex, and operculum. The right anterior insular cortex and anterior cingulate gyrus process esophageal pain.
Aziz
Q
Q
Department of Medicine, University of Manchester, England.
Andersson
J L
JL
Valind
S
S
Sundin
A
A
Hamdy
S
S
Jones
A K
AK
Foster
E R
ER
Långström
B
B
Thompson
D G
DG
D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging / Q000502:physiology*; D002404:Catheterization; D002560:Cerebrovascular Circulation / Q000502:physiology; D004947:Esophagus / Q000294:innervation* / Q000502:physiology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010104:Oxygen Radioisotopes; D010146:Pain / Q000503:physiopathology*; D012677:Sensation / Q000502:physiology; D014055:Tomography, Emission-Computed; D014867:Water
D010104:Oxygen Radioisotopes; D014867:Water