title: Induction of prolonged tenderness in patients with tension-type headache by means of a new experimental model of myofascial pain.
abstract: Tenderness is the most prominent abnormal finding in patients with tension-type headache (TTH). Recently we developed a model of myofascial tenderness using intramuscular infusion of a combination of bradykinin, serotonin, histamine and prostaglandin E2. We aimed to examine tenderness after this combination in patients with episodic TTH (ETTH). Fifteen patients and 15 healthy controls completed the study. Participants received the combination into the non-dominant trapezius muscle in a randomized, double-blinded and placebo-controlled design. Local tenderness and stimulus-response functions, mechanical pain thresholds (PPDT) in the temporal region and on the finger, and total tenderness score (TTS) were recorded. A local, prolonged, and mild to moderate tenderness was reported both in patients (P = 0.001) and in controls (P = 0.001) after the combination compared with the placebo. The response to the combination tended to be increased in patients. The stimulus-response function was leftward shifted after the combination, compared with baseline in both groups. No changes in PPDT or TTS were found after the infusions, whereas baseline PPDTs were decreased in ETTH compared with controls (PPDTfinger: P = 0.033; PPDTtemporal: P = 0.015). Intramuscular infusion of a combination of endogenous substances induced prolonged tenderness in both patients with episodic TTH and healthy subjects. The present results suggest an increased excitability of peripheral muscle afferents in TTH.
authors.affiliation: Department of Neurology, Copenhagen Headache Center, University of Copenhagen, Glostrup Hospital, Glostrup, Copenhagen, Denmark. hjmoerk@dadlnet.dk
authors.forename: H
authors.initials: H
authors.lastname: Mørk
authors.forename: M
authors.initials: M
authors.lastname: Ashina
authors.forename: L
authors.initials: L
authors.lastname: Bendtsen
authors.forename: J
authors.initials: J
authors.lastname: Olesen
authors.forename: R
authors.initials: R
authors.lastname: Jensen
mesh_terms: D000328:Adult; D019540:Area Under Curve; D001920:Bradykinin / Q000627:therapeutic use; D016022:Case-Control Studies; D003027:Cluster Headache / Q000188:drug therapy* / Q000503:physiopathology; D015232:Dinoprostone / Q000627:therapeutic use; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D004558:Electric Stimulation; D005260:Female; D006632:Histamine / Q000627:therapeutic use; D006801:Humans; D007273:Injections, Intramuscular / Q000379:methods; D008297:Male; D009119:Muscle Contraction; D009132:Muscles / Q000294:innervation; D009209:Myofascial Pain Syndromes / Q000150:complications / Q000188:drug therapy; D010147:Pain Measurement; D017288:Pain Threshold; D010919:Placebos; D012701:Serotonin / Q000627:therapeutic use; D016896:Treatment Outcome
chemical_list: D010919:Placebos; D012701:Serotonin; D006632:Histamine; D015232:Dinoprostone; D001920:Bradykinin