title: Antinociceptive effect of linear polarized 0.6 to 1.6 microm irradiation of lumbar sympathetic ganglia in chronic constriction injury rats.
abstract: Linear polarized near-infrared light created with linear polarized near-infrared light therapy equipment (Super Lizer HA-550, Tokyo Iken Co, Ltd, Tokyo, Japan) has been used for the treatment of various painful disorders in Japan. Irradiation near the stellate ganglion with a Super Lizer (ISGL) is an especially notable therapeutic method used with stellate ganglion block (SGB) or substitutes for SGB. ISGL is a safe, simple, well-tolerated, and effective treatment. We examined the effects of irradiation with a Super Lizer applied to an area near the lumbar sympathetic ganglia on the ligated side in a chronic constriction injury (CCI) model, which is believed to be an animal model of complex regional pain syndrome (CRPS). Rats showing thermal hyperalgesia in a radiant heat test 1 wk postoperatively were used in Experiments 1 and 2: (1) Thermal hyperalgesia of irradiation group (n = 11) was less than that of the control or nonirradiation (n = 11) group at 1, 3, and 8 h after irradiation; however, the effect disappeared 12 h after irradiation. (2) Daily irradiation (n = 16) and 1 wk (n = 14) from 7 days after nerve ligation significantly shortened the interval from thermal hyperalgesia until recovery. Rats showing mechanical hyperalgesia in the von Frey hair test 1 wk postoperatively were used in Experiment 3: 1 wk irradiation beginning 7 days after nerve ligation (n = 9) did not promote the recovery from mechanical hyperalgesia. We speculate that repeated ISGL may be more effective than a single ISGL in alleviating pain in CRPS patients. We cannot explain the discrepancy between the results obtained in Experiments 2 and 3. We believe the results of this study are relevant to the effect of ISGL for patients with upper-limb CRPS: irradiation near the lumbar sympathetic ganglia of the rat is effective for thermal but not mechanical pain in CCI.
authors.affiliation: Department of Rehabilitation, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Muneshige
authors.forename: Katsuhiro
authors.initials: K
authors.lastname: Toda
authors.forename: Dianli
authors.initials: D
authors.lastname: Ma
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kimura
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Asou
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Ikuta
mesh_terms: D000818:Animals; D002908:Chronic Disease; D020918:Complex Regional Pain Syndromes / Q000532:radiotherapy*; D003251:Constriction, Pathologic / Q000532:radiotherapy; D007259:Infrared Rays / Q000627:therapeutic use*; D008297:Male; D009619:Nociceptors / Q000528:radiation effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013233:Stellate Ganglion / Q000528:radiation effects*