Pulsed and continuous radiofrequency current adjacent to the cervical dorsal root ganglion of the rat induces late cellular activity in the dorsal horn.
BACKGROUND
Pulsed radiofrequency treatment has recently been described as a non-neurodestructive or minimally neurodestructive alternative to radiofrequency heat lesions. In clinical practice long-lasting results of pulsed radiofrequency treatment adjacent to the cervical dorsal root ganglion for the management of chronic radicular spinal pain have been reported without neurologic complications. However, the mode of action is unclear. An early (3 h) effect of pulsed radiofrequency as measured by an increase of c-Fos in the pain-processing neurons of the dorsal horn of rats has been described in the literature. This effect was not mediated by tissue heating. The authors investigated a possible late or long-term effect of three different radiofrequency modalities.


METHODS
Cervical laminectomy was performed in 19 male Wistar rats. The cervical dorsal root ganglion was randomly exposed to one of the four interventions: sham, continuous radiofrequency current at 67 centigrades, or pulsed radiofrequency current for 120 s or 8 min. The animals were sacrificed and the spinal cord was prepared for c-Fos labeling 7 days after the intervention.


RESULTS
The number of c-Fos immunoreactive cells in the dorsal horn was significantly increased in the three different radiofrequency modalities as compared with sham. No significant difference was demonstrated between the three active intervention groups.


CONCLUSIONS
The authors demonstrated a late neuronal activity in the dorsal horn after exposure of the cervical dorsal root ganglion to different radiofrequency modalities, which was not temperature dependent.
Van Zundert
Jan
J
Department of Anesthesiology and Pain Management, University Hospital Maastricht, The Netherlands. janvanzundert@pandora.be
de Louw
Anton J A
AJ
Joosten
Elbert A J
EA
Kessels
Alfons G H
AG
Honig
Wiel
W
Dederen
Pieter J W C
PJ
Veening
Jan G
JG
Vles
Johan S H
JS
van Kleef
Maarten
M
D000818:Animals; D005727:Ganglia, Spinal / Q000166:cytology / Q000502:physiology / Q000528:radiation effects*; D015870:Gene Expression / Q000502:physiology; D016762:Genes, fos; D007150:Immunohistochemistry; D007796:Laminectomy; D008297:Male; D010146:Pain / Q000503:physiopathology; D020671:Posterior Horn Cells / Q000502:physiology / Q000528:radiation effects*; D011846:Radio Waves; D051381:Rats; D017208:Rats, Wistar; D013696:Temperature