I recently came across a nice piece of clinical research by Cescon et al., 2019 (1) who looked at the prevalence and characteristics of myofascial trigger points (MTrPs) in the head and neck, frequently found in people with tension-type headache (TTH).
Research and clinical experience suggest that MTrPs are implicated in the development of tension-type headache (2). The MTrPs may act as a muscular source of nociception (potentially pain-inducing stimuli) which in turn can, over time, trigger the central sensitisation phenomenon common in chronic headache sufferers.
Referred pain from MTrPs can occur spontaneously, often due to physical or emotional stress or be 'triggered' by manual palpation (pressing on tender 'knots' within the neck muscles). The referred pain is often felt some distance from where the MTrP is located and can contribute to the feeling of a TTH. A TTH is usually but not limited to a sense of pain, tightness or pressure about the sides and back of the head.
The study (1) showed that of the 113 people who took part, all of whom were TTH sufferers, the muscular prevalence of MTrPs was 31% for Masseter, 48% for Sternocleidomastoid, 50% for Suboccipitalis, 46% for Splenius Capitis, 77% for Temporalis, and 44% for Upper Trapezius.
It was also interesting to note that when the MTrPs were stimulated in the experiment, they brought on an average of 22% to 54% of the patient's reported head pain.
The generated pain frequency maps of the MTrP showed that each muscle tends to refer pain to the same area, and the pain was localised in specific areas of the neck and head region in people with TTH.
In summary: MTrPs are highly prevalent in those with TTH, and certain muscles are more likely to develop MTrP. When these MTrPs are stimulated, up to an average of 54% of a patients head pain can be reproduced. As each MTrP tends to refer to the same region of the head, it is possible to use pain maps to work our where the MTrPs are located, and then treat them.
At the clinic, supported by mechanisms based research (3), we have determined the best way to treat MTrP is by use of medical acupuncture, descriptively referred to as 'dry needling' when treating MTrP.
1. Cescon C, Barbero M, Zuin P, Falla D, Palacios-Ceña M, Arendt-Nielsen L, Fernández-de-las-Peñas C. Referred pain maps of myofascial trigger points in tension-type headache. In: WCPT2019 Proceedings World Confederation for Physical Therapy Congress, 2019, May 10th-13th, Geneva, Switzerland.
2. Palacios-Ceña M, Wang K, Castaldo M, Guillem-Mesado A, Ordás-Bandera C, Arendt-Nielsen L, Fernández-de-Las-Peñas C. Trigger points are associated with widespread pressure pain sensitivity in people with tension-type headache. Cephalalgia. 2018 Feb;38(2):237-45.
3. Fernández-de-Las-Peñas C, Nijs J. Trigger point dry needling for the treatment of myofascial pain syndrome: current perspectives within a pain neuroscience paradigm. Journal of pain research. 2019;12:1899.