Effect of local glucocorticoid injection on masseter muscle level of serotonin in patients with chronic myalgia.
The aim of this study was to compare the effects on the level of serotonin (5-HT) in the masseter muscle by intramuscular glucocorticoid (GC) administration in patients with fibromyalgia (FM) and localized myalgia (LM), as well as to determine associated changes in pain, tenderness, and microcirculation. The study comprised 22 patients with pain and tenderness in the masseter muscle region. Ten patients (all women) had FNI, and 12 (1 man and 11 women) had LM involving the temporomandibular system. The patients were examined clinically and by microdialysis at 2 visits 2-3 weeks apart and received local glucocorticoid treatment at the first visit. The ratio (S1/S2) between the initial level of 5-HT (S1) and steady state level (S2) was used as a relative measure of the intramuscular release of 5-HT. This ratio decreased significantly after treatment in the FM group. In the FM group there was also a negative correlation regarding changes between visits of 5-HT and changes of intramuscular temperature. In the LM group there was a negative correlation regarding changes between visits of 5-HT and changes of pressure pain threshold and pressure pain tolerance level. This study indicates that there is a reduction of the ratio between initial 5-HT and steady state level in the painful masseter muscle after intramuscular GC administration to FM patients, a reduction not present in the LM patients. In addition, 5-HT seems to be involved in the modulation of local muscle microcirculation in FM patients and in hyperalgesia in LM patients.
Department of Clinical Oral Physiology, Faculty of Odontology, Karolinska Institute, Huddinge, Sweden.
M
M
Ernberg
B
B
Hedenberg-Magnusson
P
P
Alstergren
S
S
Kopp
D000328:Adult; D000368:Aged; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D001831:Body Temperature / Q000187:drug effects; D005157:Facial Pain / Q000188:drug therapy / Q000378:metabolism; D005260:Female; D005356:Fibromyalgia / Q000188:drug therapy / Q000378:metabolism* / Q000503:physiopathology; D005938:Glucocorticoids / Q000008:administration & dosage / Q000627:therapeutic use*; D006801:Humans; D006930:Hyperalgesia / Q000188:drug therapy / Q000378:metabolism / Q000503:physiopathology; D007273:Injections, Intramuscular; D008297:Male; D008406:Masseter Muscle / Q000098:blood supply / Q000737:chemistry / Q000187:drug effects* / Q000503:physiopathology; D008775:Methylprednisolone / Q000008:administration & dosage / Q000627:therapeutic use*; D008833:Microcirculation / Q000187:drug effects; D017551:Microdialysis; D008875:Middle Aged; D017288:Pain Threshold / Q000187:drug effects / Q000502:physiology; D011312:Pressure; D012701:Serotonin / Q000032:analysis*; D013706:Temporomandibular Joint Dysfunction Syndrome / Q000188:drug therapy / Q000378:metabolism* / Q000503:physiopathology
D000893:Anti-Inflammatory Agents; D005938:Glucocorticoids; D012701:Serotonin; D008775:Methylprednisolone