Repetitive transcranial magnetic stimulation improves open field locomotor recovery after low but not high thoracic spinal cord compression-injury in adult rats

• Published in: Journal of neuroscience research Vol. 75; no. 2; pp. 253 - 261
• Main Authors: Poirrier, Anne-Lise, Nyssen, Yves, Scholtes, Felix, Multon, Sylvie, Rinkin, Charline, Weber, Géraldine, Bouhy, Delphine, Brook, Gary, Franzen, Rachelle, Schoenen, Jean
• Format: Journal Article Web Resource
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 15.01.2004; Wiley Liss, Inc
• Subjects: Animals; Axons - metabolism; Axons - radiation effects; Axons - ultrastructure; BBB score; central pattern generator; Efferent Pathways - cytology; Efferent Pathways - metabolism; Efferent Pathways - radiation effects; Electromagnetic Fields; Female; Immunohistochemistry; locomotion; Motor Activity - physiology; Motor Activity - radiation effects; Nerve Regeneration - physiology; Nerve Regeneration - radiation effects; Neurosciences & behavior; Neurosciences & comportement; Rats; Rats, Wistar; Recovery of Function - physiology; Recovery of Function - radiation effects; Sciences sociales & comportementales, psychologie; serotonin; Serotonin - metabolism; Serotonin - radiation effects; Social & behavioral sciences, psychology; Spinal Cord - cytology; Spinal Cord - growth & development; Spinal Cord - radiation effects; Spinal Cord Compression - therapy; spinal cord injury; Thoracic Vertebrae; Transcranial Magnetic Stimulation
• ISSN: 0360-4012; 1097-4547; 1097-4547
• DOI: 10.1002/jnr.10852

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. © 2003 Wiley‐Liss, Inc.