title: Clinical indicators of paraplegia underplay universal spinal cord neuronal injury from transient aortic occlusion.
abstract: Paraplegia following complex aortic intervention relies on crude evaluation of lower extremity strength such as whether the patient can lift their legs or flex the ankle. Little attention has been given to the possible long-term neurologic sequelae following these procedures in patients appearing functionally normal. We hypothesize that mice subjected to minimal ischemic time will have functional and histological changes despite the gross appearance of normal function. Male mice underwent 3 min of aortic occlusion (n=14) or sham surgery (n=4) via a median sternotomy. Neurologic function was graded by Basso Motor Score (BMS) preoperatively and at 24h intervals after reperfusion. Mice appearing functionally normal and sham mice were placed on a walking beam and recorded on high-definition, for single-frame motion analysis. After 96 hrs, spinal cords were removed for histological analysis. Following 3 min of ischemia, functional outcomes were split evenly with either mice displaying almost normal function n=7 or near complete paraplegia n=7. Additionally, single-frame motion analysis revealed significant changes in gait. Histologically, there was a significant stepwise reduction of neuronal viability, with even the normal function ischemic group demonstrating significant loss of neurons. Despite the appearance of normal function, temporary ischemia induced marked cyto-architectural changes and neuronal degeneration. Furthermore high-definition gait analysis revealed significant changes in gait and activity following thoracic aortic occlusion. These data suggest that all patients undergoing procedures, even with short ischemic times, may have spinal cord injury that is not evident clinically.
authors.affiliation: Department of Surgery, University of Colorado, Denver, CO, USA. Electronic address: marshall.bell@ucdenver.edu.
authors.forename: Marshall T
authors.initials: MT
authors.lastname: Bell
authors.affiliation: Department of Anesthesiology, University of Colorado, Denver, CO, USA.
authors.forename: Ferenc
authors.initials: F
authors.lastname: Puskas
authors.affiliation: Department of Surgery, University of Colorado, Denver, CO, USA.
authors.forename: Daine T
authors.initials: DT
authors.lastname: Bennett
authors.affiliation: Department of Surgery, University of Colorado, Denver, CO, USA.
authors.forename: Joseph C
authors.initials: JC
authors.lastname: Cleveland
authors.affiliation: Department of Anesthesiology, University of Colorado, Denver, CO, USA.
authors.forename: Paco S
authors.initials: PS
authors.lastname: Herson
authors.affiliation: Department of Surgery, University of Colorado, Denver, CO, USA.
authors.forename: Joshua M
authors.initials: JM
authors.lastname: Mares
authors.affiliation: Department of Surgery, University of Colorado, Denver, CO, USA; Department of Anesthesiology, University of Colorado, Denver, CO, USA.
authors.forename: Xainzhong
authors.initials: X
authors.lastname: Meng
authors.affiliation: Department of Surgery, University of Colorado, Denver, CO, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Weyant
authors.affiliation: Department of Surgery, University of Colorado, Denver, CO, USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Fullerton
authors.affiliation: Department of Surgery, University of Colorado, Denver, CO, USA.
authors.forename: T
authors.initials: T
authors.lastname: Brett Reece
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001018:Aortic Diseases / Q000150:complications*; D006614:Hindlimb / Q000503:physiopathology; D008124:Locomotion / Q000502:physiology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009460:Neurologic Examination; D010264:Paraplegia / Q000209:etiology*; D015427:Reperfusion Injury / Q000150:complications*; D013119:Spinal Cord Injuries / Q000150:complications* / Q000209:etiology*; D013997:Time Factors
keywords: Aorta; Neurologic injury; Paraplegia; Spinal cord; Spinal cord ischemia–reperfusion