New Evidence for Trigger Point Involvement in Tension-Type Headaches

ABSTRACT

Objective: To review current evidence for trigger point [TrP] involvement in tension-type headache [TTH].

Findings: It seems that mechanical pain sensitivity is a consequence and not a causative factor for TTH. Recent evidence modifying previous knowledge about relationships between muscle tissues and chronic tension-type headache, suggests a potential role of myofascial TrPs in the genesis of the pain. In fact, active TrPs reproducing the headache attacks are present in both episodic and chronic TTH in a similar percentage, supporting an etiological role of active TrPs in TTH. Further, spatial and temporal summation of TrP activity is present in TTH. An updated pain model suggests that headache perception can be explained by referred pain from TrPs in the craniocervical muscles, mediated through the spinal cord and the trigeminal nucleus caudalis rather than tenderness of the muscles themselves. Different therapeutic strategies, i.e., pharmacological, physical therapy, psychological, and acupuncture, are generally used for the management of TTH. All these therapeutic interventions are also targeted to inactivating TrP activity.

Conclusions: Although there is an increasing comprehension of the role of active TrPs in TTH, future studies investigating the effectiveness of inactivation of TrPs into the evolution of TTH are urgently needed.

KEYWORDS. :

• Tension-type headache
• mechanical pain sensitivity
• muscle trigger points
• central sensitization
• peripheral sensitization