Axonal degeneration and demyelination following traumatic spinal cord injury: A systematic review and meta-analysis

Zahra Hassannejad; Mahmoud Yousefifard; Yaser Azizi; Shayan Abdollah Zadegan; Kiavash Sajadi; Mahdi Sharif-Alhoseini; Aida Shakouri-Motlagh; Mona Mokhatab; Motahareh Rezvan; Farhad Shokraneh; Mostafa Hosseini; Alexander R Vaccaro; James S Harrop; Vafa Rahimi-Movaghar

doi:10.1016/j.jchemneu.2019.01.009

Axonal degeneration and demyelination following traumatic spinal cord injury: A systematic review and meta-analysis

J Chem Neuroanat. 2019 Apr:97:9-22. doi: 10.1016/j.jchemneu.2019.01.009. Epub 2019 Feb 3.

Authors

Affiliations

¹ Pediatric Urology and Regenerative Medicine Research Center, Children's Hospital Medical Center, Tehran University of Medical Sciences, Tehran, Iran; Sina Trauma and Surgery Research Center, Tehran University of Medical Sciences, Tehran, Iran.
² Physiology Research Center, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran.
³ Sina Trauma and Surgery Research Center, Tehran University of Medical Sciences, Tehran, Iran.
⁴ Department of Chemical and Biomolecular Engineering, University of Melbourne, Victoria 3010, Australia.
⁵ Cochrane Schizophrenia Group, Institute of Mental Health, University of Nottingham, Nottingham, UK.
⁶ Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
⁷ Department of Orthopedics and Neurosurgery, Rothman Institute, Thomas Jefferson University Philadelphia, USA.
⁸ Department of Neurosurgery, Thomas Jefferson University, Philadelphia, Pennsylvania, USA.
⁹ Sina Trauma and Surgery Research Center, Tehran University of Medical Sciences, Tehran, Iran; Department of Neurosurgery, Thomas Jefferson University, Philadelphia, Pennsylvania, USA; Brain and Spinal Injuries Research Center (BASIR), Neuroscience Institute, Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran. Electronic address: v_rahimi@sina.tums.ac.ir.

PMID: 30726717
DOI: 10.1016/j.jchemneu.2019.01.009

Abstract

The pathophysiology of spinal cord injury (SCI) related processes of axonal degeneration and demyelination are poorly understood. The present systematic review and meta-analysis were performed such to establish quantitative results of animal studies regarding the role of injury severity, SCI models and level of injury on the pathophysiology of axon and myelin sheath degeneration. 39 related articles were included in the analysis. The compiled data showed that the total number of axons, number of myelinated axons, myelin sheath thickness, axonal conduction velocity, and internode length steadily decreased as time elapsed from the injury (P_{for trend}<0.0001). The rate of axonal retrograde degeneration was affected by SCI model and severity of the injury. Axonal degeneration was higher in injuries of the thoracic region. The SCI model and the site of the injury also affected axonal retrograde degeneration. The number of myelinated axons in the caudal region of the injury was significantly higher than the lesion site and the rostral region. The findings of the present meta-analysis show that the pathophysiology of axons and myelin sheath differ in various phases of SCI and are affected by multiple factors related to the injury.

Keywords: Animal studies; Degeneration; Myelin sheath; Spinal cord injuries.

Publication types

Meta-Analysis
Research Support, Non-U.S. Gov't
Systematic Review

MeSH terms

Animals
Demyelinating Diseases / pathology
Demyelinating Diseases / physiopathology*
Nerve Degeneration / pathology
Nerve Degeneration / physiopathology*
Spinal Cord Injuries / pathology
Spinal Cord Injuries / physiopathology*