title: High cervical midline punctate myelotomy in the management of visceral pain in the mouse.
abstract: Increasing evidence implies the existence of a visceral pain pathway in the dorsal column of the spinal cord. Limited midline myelotomy has been used to treat intractable pelvic cancer pain. However, no obvious evidence has been provided that high cervical punctate midline myelotomy (CPMM) relieves visceral pain originating from the abdomen. This study was designed to examine the pain relief effect of CPMM in a mouse model of visceral pain. Thirty-six Institute of Cancer Research (ICR) mice were divided into three groups: Group 1, healthy controls; Group 2, treated with CPMM at C1 and C2; and Group 3, a sham group that underwent laminectomy at C1 and C2 without CPMM. All animals were tested for antinociception in the writhing test 24 hours after surgery. Visceral pain-related behaviors were counted from 5-20 minutes after intraperitoneal injection of 0.6% acetic acid. Writhing test scores were not significantly different between Groups 1 (56.7 +/- 10.7) and 3 (50.7 +/- 17.4). However, Group 2 (30.0 +/- 14.3) showed more than 40% antinociception after treatment, and writhing test scores were significantly different from those of Groups 1 and 3 (p < 0.001). Our results confirm that midline punctate myelotomy can relieve visceral pain and imply that there is a pathway in the posterior funiculus that signals visceral pain. Punctate midline myelotomy at the cervical or high thoracic level may be an alternative strategy in the management of intractable visceral pain due to abdominal or pelvic cancers.
authors.affiliation: Division of Neurosurgery, Armed Forces Taichung General Hospital, Kaohsiung, Taiwan.
authors.forename: Dyi-Sheng
authors.initials: DS
authors.lastname: Chang
authors.forename: Chih-Lung
authors.initials: CL
authors.lastname: Lin
authors.forename: Ann-Shung
authors.initials: AS
authors.lastname: Lieu
authors.forename: Chi-Yun
authors.initials: CY
authors.lastname: Cheng
authors.forename: Shu-Chuan
authors.initials: SC
authors.lastname: Wu
authors.forename: Mei-Hsiang
authors.initials: MH
authors.lastname: Hung
authors.forename: Joon-Khim
authors.initials: JK
authors.lastname: Loh
authors.forename: Tai-Hong
authors.initials: TH
authors.lastname: Kuo
authors.forename: Shen-Long
authors.initials: SL
authors.lastname: Howng
authors.forename: Shiuh-Lin
authors.initials: SL
authors.lastname: Hwang
mesh_terms: D000818:Animals; D002574:Cervical Vertebrae; D002818:Cordotomy / Q000379:methods*; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D010148:Intractable Pain / Q000601:surgery*; D017699:Pelvic Pain / Q000601:surgery; D013116:Spinal Cord / Q000601:surgery*; D014781:Viscera / Q000503:physiopathology