gms | German Medical Science

57th Annual Meeting of the German Society of Neurosurgery
Joint Meeting with the Japanese Neurosurgical Society

German Society of Neurosurgery (DGNC)

11 - 14 May, Essen

Spinal cord injury pain – is the force defined contusion model of the rat an adequate “pain-model”?

Schmerzsyndrome nach spinaler Läsion – ist das kraft-definierte Kontusionsmodell in der Ratte ein adäquates "Schmerzmodell"?

Meeting Abstract

  • corresponding author F. Knerlich - Klinik für Neurochirurgie, UK S-H, Campus Kiel
  • M. Juraschek - Klinik für Neurochirurgie, UK S-H, Campus Kiel
  • U. Blömer - Klinik für Neurochirurgie, UK S-H, Campus Kiel
  • H.M. Mehdorn - Klinik für Neurochirurgie, UK S-H, Campus Kiel
  • J. Held-Feindt - Klinik für Neurochirurgie, UK S-H, Campus Kiel

Deutsche Gesellschaft für Neurochirurgie. Japanische Gesellschaft für Neurochirurgie. 57. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e.V. (DGNC), Joint Meeting mit der Japanischen Gesellschaft für Neurochirurgie. Essen, 11.-14.05.2006. Düsseldorf, Köln: German Medical Science; 2006. DocP 12.200

The electronic version of this article is the complete one and can be found online at:

Published: May 8, 2006

© 2006 Knerlich et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.



Objective: Spinal cord injury (SCI) often leads to variable chronic pain syndromes resistant to available modes of treatment. To provide the basis for future investigations towards amelioration of these pain syndromes, we established a force defined SCI model for rats, applying the commercially available Infinite Horizon (IH) Impactor device (PSI, Lexington, KY). We then investigated if this model was an appropriate “post contusion pain model” in behavioural tests performed 7d, 15d, and 6 weeks after inducing SCI of three different severity grades.

Methods: Male Long Evans rats (200-250g, n=72) were used. The individual and group preoperative baseline behaviours were obtained after mechanical and noxious radiant heat stimulation. Anesthetized rats received laminectomy on T8, were mounted in the IH-impactor device and a 1N, 1.5N, or 2N impact was applied. Controls received laminectomy without impact injury (n=8). On the 2nd postoperative day and following on one day per week, locomotor function was tested using Basso, Beattie and Bresnahan open field test. Animals able to support their weight were further tested for mechanical and thermal allodynia. Rats were sacrificed 72h (n=10), 7d (n=19), 15d (n=19), and 6 week (n=16) after SCI and transcardially perfused. Spinal cords and brains were removed for further investigations.

Results: Postoperatively the animals` locomotor ability correlated with the degree of injury, supporting reliability and consistency of the SCI model. The responses to mechanical stimulation significantly increased compared to intra-animal presurgical and sham control values. Additionally injured rats showed more supra spinal behaviours (e.g. vocalizing, foot licking). The development of mechanical allodynia was related to the degree of force. Effects on thermal sensitivity were less significant and more individually related.

Conclusions: To conclude, the force defined contusion model leads reproducibly to mechanical and thermal allodynia in rats and thus provides an adequate and reliable tool to investigate pain syndromes after SCI.