Dry needling for headaches presenting active trigger points

Definition of dry needling

Therapeutic management of headaches mainly includes pharmacological and physical therapy approaches [1–3]. In the last decade, there has been an increasing interest in the use of dry needling (DN) for the treatment of headache as well as for neck and shoulder pain syndromes [4]. The American Physical Therapy Association (APTA) defined DN as a ‘skilled intervention using a thin filiform needle to penetrate the skin and stimulate trigger points (TrPs), muscles, and connective tissue for the treatment of musculoskeletal disorders’ [5]. Although acupuncture and DN share many similarities [6], they differ in many aspects, particularly the fact that DN inserts the needle into the muscle and not in standardized acupuncture points [7].

The most commonly accepted DN approach is the ‘fast-in and fast-out’ technique described by Hong [8]. This technique consists of the insertion of the needle penetrating the skin into a TrP until a local twitch response is obtained. The local twitch response is a sudden contraction of muscle fibers in a taut band [7]. Hong advocated that local twitch responses should be elicited during DN for a successful technique [8]. Once the first local twitch response is obtained, the needle is moved up and down, usually 3–5 mm, in vertical motions with no rotations at approximately 1 Hz. The time of application will depend on the irritability of the TrP [7]. This assumption is supported by one study observing an immediate drop in the concentrations of some neurotransmitters, including calcitonin gene-related peptide and substance P and several cytokines and interleukins in the extracellular fluid of the local TrP milieu after the insertion of a needle [9].

Scientific evidence for dry needling

Recent meta-analyses have found that trigger point dry needling (TrP-DN) may be effective for the treatment of upper quarter pain syndromes. In their meta-analysis, Kietrys et al. concluded that TrP-DN can be recommended (Grade A), compared to sham or placebo needling for decreasing pain at short term in patients suffering from upper quarter myofascial pain immediately after and at a 4-week follow-up [10]. However, the heterogeneity of the studies was high (I² = 86%) and the majority of the studies included in the meta-analysis had relatively small sample sizes. Although the overall effect size was large (standardized mean difference, SMD: 1.06), the 95% confidence interval was wide (95% CI 0.05–2.06) suggesting imprecision of the results [10]. A recent meta-analysis conducted by Liu et al. also found that TrP-DN was effective immediately after (SMD: 1.91; 95% CI 0.073–3.10) and at medium term (SMD: 1.07, 95% CI 0.27–1.87) compared with control or sham needling for the management of TrPs associated with neck and shoulder pain [11].

In their systematic review, France et al. found some evidence to support the use of DN in treating cervicogenic and tension-type headache [12]. This review included one clinical study on tension-type headache, one including a miscellaneous of patients presenting with myofascial head pain and a third case report centered in cervicogenic headache [12]. Interestingly, the results of this last study suggested that the addition of DN to conventional physiotherapy approaches rather than DN alone was a useful therapeutic strategy. Nevertheless, the inconsistency of the interventions between the studies, the points receiving the needling intervention, the heterogeneity of the samples, and the lack of appropriate control groups limited the conclusions. As a result, the review concluded that further research with stronger methodological design was clearly required.

Dry needling in headaches: clinical reasoning/research directions

The rationale for applying DN in headaches relates to the etiologic role of TrPs in these pain conditions. TrPs are defined as hypersensitive tender spots located in a taut band of skeletal muscles that are painful on mechanical stimulation and give rise to a referred pain [13]. Several muscles, e.g. upper trapezius, sternocleidomastoid, splenius capitis, or suboccipital muscles of the cervical spine can refer pain to the head mimicking headache. Active TrPs provoke spontaneous pain and are responsible for some of the patient’s symptoms, while latent TrPs do not cause spontaneous pain. There is clear scientific evidence supporting the role of active TrPs in tension-type, migraine, and cervicogenic headache [14]; although their relevance is slightly different depending on the headache disorder. For instance, TrPs are seemingly more related to tension-type headache than migraine [15].

The exact mechanism by which TrP-DN exerts its therapeutic effects remains to be elucidated, and both mechanical and neurophysiological mechanisms have been proposed [16]. Essentially, the application of TrP-DN on individuals with headaches may reduce both peripheral and central sensitization by removing a prolonged source of peripheral nociceptive inputs, by modulating spinal efficacy in the dorsal horn and by activating central inhibitory pain pathways [17]. All these effects are apparently initiated when active TrPs receive the needling intervention. Therefore, an accurate diagnosis of active TrPs should be conducted during clinical examination of patients with headache with the aim that the needling is introduced in the proper therapeutic target [18]. In fact, a recent study found that local lidocaine injections applied into TrPs in the peri-cranial muscles could be considered as an effective alternative treatment for individuals with episodic tension-type headache [19].

There is a need for further studies investigating the effectiveness of DN in patients with headaches. In order to be valid and clinically significant, future studies should contemplate the following recommendations: (1) an accurate identification of active TrPs is required; (2) the needling must be placed into active TrPs; (3) DN should be applied within a multimodal approach in conjunction with other therapies; (4) both active and placebo interventions mimicking DN must be compared with the aim of eliminating any placebo effect [20].

Financial and competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Additional information

Notes on contributors

César Fernández-De-Las-Peñas

María L. Cuadrado