title: Chronic pancreatitis pain pattern and severity are independent of abdominal imaging findings.
abstract: OBJECTIVE
  Chronic pancreatitis is characterized by inflammation, atrophy, fibrosis with progressive ductal changes, and functional changes that include variable exocrine and endocrine insufficiency and multiple patterns of pain. We investigated whether abdominal imaging features accurately predict patterns of pain.
  
  
  METHODS
  We collected data from participants in the North American Pancreatitis Study 2 Continuation and Validation, a prospective multicenter study of patients with chronic pancreatitis performed at 13 expert centers in the United States from July 2008 through March 2012. Chronic pancreatitis was defined based on the detection of characteristic changes by cross-sectional abdominal imaging, endoscopic retrograde cholangiopancreatography, endoscopic ultrasonography, or histology analyses. Patients were asked by a physician or trained clinical research coordinator if they had any abdominal pain during the year before enrollment, those who responded "yes" were asked to select from a list of 5 pain patterns. By using these patterns, we classified patients' pain based on timing and severity. Abnormal pancreatitis-associated features on abdominal imaging were recorded using standardized case report forms.
  
  
  RESULTS
  Data were collected from 518 patients (mean age, 52 ± 14.6 y; 55% male; and 87.6% white). The most common physician-identified etiologies were alcohol (45.8%) and idiopathic (24.3%); 15.6% of patients reported no abdominal pain in the year before enrollment. The most common individual pain pattern was described as constant mild pain with episodes of severe pain and was reported in 45% of patients. The most common imaging findings included pancreatic ductal dilatation (68%), atrophy (57%), and calcifications (55%). Imaging findings were categorized as obstructive for 20% and as inflammatory for 25% of cases. The distribution of individual imaging findings was similar among patients with different patterns of pain. The distribution of pain patterns did not differ among clinically relevant groups of imaging findings.
  
  
  CONCLUSIONS
  Mechanisms that determine patterns and severity of pain in patients with chronic pancreatitis are largely independent of structural variants observed by abdominal imaging techniques. Pancreas-relevant quantitative and qualitative pain measures should be included in the evaluation of patients with chronic pancreatitis to assess pain severity independently of imaging findings.
authors.affiliation: University of Alabama at Birmingham, Birmingham, Alabama. Electronic address: melw@uab.edu.
authors.forename: C Mel
authors.initials: CM
authors.lastname: Wilcox
authors.affiliation: University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania.
authors.forename: Dhiraj
authors.initials: D
authors.lastname: Yadav
authors.affiliation: Department of Epidemiology, University of Pittsburgh Graduate School of Public Health, Pittsburgh, Pennsylvania.
authors.forename: Tian
authors.initials: T
authors.lastname: Ye
authors.affiliation: Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire.
authors.forename: Timothy B
authors.initials: TB
authors.lastname: Gardner
authors.affiliation: University of Chicago School of Medicine, Chicago, Illinois.
authors.forename: Andres
authors.initials: A
authors.lastname: Gelrud
authors.affiliation: Virginia Commonwealth University School of Medicine, Richmond, Virginia.
authors.forename: Bimaljit S
authors.initials: BS
authors.lastname: Sandhu
authors.affiliation: Mayo Clinic, Jacksonville, Florida.
authors.forename: Michele D
authors.initials: MD
authors.lastname: Lewis
authors.affiliation: Saint Louis University School of Medicine, St. Louis, Missouri.
authors.forename: Samer
authors.initials: S
authors.lastname: Al-Kaade
authors.affiliation: Indiana University School of Medicine, Indianapolis, Indiana.
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Cote
authors.affiliation: University of Florida College of Medicine, Gainesville, Florida.
authors.forename: Christopher E
authors.initials: CE
authors.lastname: Forsmark
authors.affiliation: University of Wisconsin School of Medicine, Milwaukee, Wisconsin.
authors.forename: Nalini M
authors.initials: NM
authors.lastname: Guda
authors.affiliation: Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: Darwin L
authors.initials: DL
authors.lastname: Conwell
authors.affiliation: Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: Peter A
authors.initials: PA
authors.lastname: Banks
authors.affiliation: Griffin Hospital, Derby, Connecticut.
authors.forename: Thiruvengadam
authors.initials: T
authors.lastname: Muniraj
authors.affiliation: Medical University of South Carolina, Charleston, South Carolina.
authors.forename: Joseph
authors.initials: J
authors.lastname: Romagnuolo
authors.affiliation: University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania.
authors.forename: Randall E
authors.initials: RE
authors.lastname: Brand
authors.affiliation: University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania.
authors.forename: Adam
authors.initials: A
authors.lastname: Slivka
authors.affiliation: Indiana University School of Medicine, Indianapolis, Indiana.
authors.forename: Stuart
authors.initials: S
authors.lastname: Sherman
authors.affiliation: Department of Epidemiology, University of Pittsburgh Graduate School of Public Health, Pittsburgh, Pennsylvania.
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Wisniewski
authors.affiliation: University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania.
authors.forename: David C
authors.initials: DC
authors.lastname: Whitcomb
authors.affiliation: University of Michigan School of Medicine, Ann Arbor, Michigan.
authors.forename: Michelle A
authors.initials: MA
authors.lastname: Anderson
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010146:Pain; D010179:Pancreas / Q000000981:diagnostic imaging* / Q000473:pathology*; D050500:Pancreatitis, Chronic / Q000473:pathology*; D011446:Prospective Studies; D011860:Radiography, Abdominal; D014481:United States
keywords: Abdominal Imaging; Abdominal Pain; Chronic Pancreatitis; NAPS2-CV