title: Referred pain from trapezius muscle trigger points shares similar characteristics with chronic tension type headache.
abstract: Referred pain and pain characteristics evoked from the upper trapezius muscle was investigated in 20 patients with chronic tension-type headache (CTTH) and 20 age- and gender-matched controls. A headache diary was kept for 4 weeks in order to confirm the diagnosis and record the pain history. Both upper trapezius muscles were examined for the presence of myofascial trigger points (TrPs) in a blinded fashion. The local and referred pain intensities, referred pain pattern, and pressure pain threshold (PPT) were recorded. The results show that referred pain was evoked in 85% and 50% on the dominant and non-dominant sides in CTTH patients, much higher than 55% and 25% in controls (P<0.01). Referred pain spread to the posterior-lateral aspect of the neck ipsi-lateral to the stimulated muscle in both patients and controls, with additional referral to the temple in most patients, but none in controls. Nearly half of the CTTH patients (45%) recognized the referred pain as their usual headache sensation, i.e. active TrPs. CTTH patients with active TrPs in the right upper trapezius muscle showed greater headache intensity and frequency, and longer headache duration than those with latent TrPs. CTTH patients with bilateral TrPs reported significantly decreased PPT than those with unilateral TrP (P<0.01). Our results showed that manual exploration of TrPs in the upper trapezius muscle elicited referred pain patterns in both CTTH patients and healthy subjects. In CTTH patients, the evoked referred pain and its sensory characteristics shared similar patterns as their habitual headache pain, consistent with active TrPs. Our results suggest that spatial summation of perceived pain and mechanical pain sensitivity exists in CTTH patients.
authors.affiliation: Department of Physical Therapy, Occupational Therapy, Physical Medicine and Rehabilitation of Universidad Rey Juan Carlos, Alcorcón, Madrid, Spain. cesarfdlp@yahoo.es
authors.forename: César
authors.initials: C
authors.lastname: Fernández-de-Las-Peñas
authors.forename: Hong-You
authors.initials: HY
authors.lastname: Ge
authors.forename: Lars
authors.initials: L
authors.lastname: Arendt-Nielsen
authors.forename: Maria Luz
authors.initials: ML
authors.lastname: Cuadrado
authors.forename: Juan A
authors.initials: JA
authors.lastname: Pareja
mesh_terms: D000328:Adult; D002908:Chronic Disease; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000502:physiology*; D009209:Myofascial Pain Syndromes / Q000503:physiopathology*; D010147:Pain Measurement; D017288:Pain Threshold / Q000502:physiology; D053591:Referred Pain / Q000503:physiopathology*; D011312:Pressure; D018781:Tension-Type Headache / Q000503:physiopathology*