Repetitive transcranial magnetic stimulation improves open field locomotor recovery after low but not high thoracic spinal cord compression-injury in adult rats.
Electromagnetic fields are able to promote axonal regeneration in vitro and in vivo. Repetitive transcranial magnetic stimulation (rTMS) is used routinely in neuropsychiatric conditions and as an atraumatic method to activate descending motor pathways. After spinal cord injury, these pathways are disconnected from the spinal locomotor generator, resulting in most of the functional deficit. We have applied daily 10 Hz rTMS for 8 weeks immediately after an incomplete high (T4-5; n = 5) or low (T10-11; n = 6) thoracic closed spinal cord compression-injury in adult rats, using 6 high- and 6 low-lesioned non-stimulated animals as controls. Functional recovery of hindlimbs was assessed using the BBB locomotor rating scale. In the control group, the BBB score was significantly better from the 7th week post-injury in animals lesioned at T4-5 compared to those lesioned at T10-11. rTMS significantly improved locomotor recovery in T10-11-injured rats, but not in rats with a high thoracic injury. In rTMS-treated rats, there was significant positive correlation between final BBB score and grey matter density of serotonergic fibres in the spinal segment just caudal to the lesion. We propose that low thoracic lesions produce a greater functional deficit because they interfere with the locomotor centre and that rTMS is beneficial in such lesions because it activates this central pattern generator, presumably via descending serotonin pathways. The benefits of rTMS shown here suggest strongly that this non-invasive intervention strategy merits consideration for clinical trials in human paraplegics with low spinal cord lesions.
Poirrier
Anne-Lise
AL
Research Centre for Cellular and Molecular Neurobiology, Neuroanatomy Laboratory, University of Liege, Belgium.
Nyssen
Yves
Y
Research Centre for Cellular and Molecular Neurobiology, Neuroanatomy Laboratory, University of Liege, Belgium.
Scholtes
Felix
F
Research Centre for Cellular and Molecular Neurobiology, Neuroanatomy Laboratory, University of Liege, Belgium.
Multon
Sylvie
S
Research Centre for Cellular and Molecular Neurobiology, Neuroanatomy Laboratory, University of Liege, Belgium.
Rinkin
Charline
C
Research Centre for Cellular and Molecular Neurobiology, Neuroanatomy Laboratory, University of Liege, Belgium.
Weber
Géraldine
G
Research Centre for Cellular and Molecular Neurobiology, Neuroanatomy Laboratory, University of Liege, Belgium.
Bouhy
Delphine
D
Research Centre for Cellular and Molecular Neurobiology, Neuroanatomy Laboratory, University of Liege, Belgium.
Brook
Gary
G
Department of Neurology, Aachen University Medical School, Aachen, Germany.
Franzen
Rachelle
R
Research Centre for Cellular and Molecular Neurobiology, Neuroanatomy Laboratory, University of Liege, Belgium.
Schoenen
Jean
J
Research Centre for Cellular and Molecular Neurobiology, Neuroanatomy Laboratory, University of Liege, Belgium.
D000818:Animals; D001369:Axons / Q000378:metabolism / Q000528:radiation effects / Q000648:ultrastructure; D004525:Efferent Pathways / Q000166:cytology / Q000378:metabolism / Q000528:radiation effects; D004574:Electromagnetic Fields; D005260:Female; D007150:Immunohistochemistry; D009043:Motor Activity / Q000502:physiology / Q000528:radiation effects; D009416:Nerve Regeneration / Q000502:physiology / Q000528:radiation effects; D051381:Rats; D017208:Rats, Wistar; D020127:Recovery of Function / Q000502:physiology / Q000528:radiation effects*; D012701:Serotonin / Q000378:metabolism / Q000528:radiation effects; D013116:Spinal Cord / Q000166:cytology / Q000254:growth & development / Q000528:radiation effects*; D013117:Spinal Cord Compression / Q000628:therapy*; D013904:Thoracic Vertebrae; D050781:Transcranial Magnetic Stimulation
D012701:Serotonin