Effectiveness of dry needling for improving pain and disability in adults with tension-type, cervicogenic, or migraine headaches: protocol for a systematic review

Headache is a major health concern as one of the most common type of all symptoms in the worldwide population [1, 2]. According to the 2016 Global Burden Disease study [3], “tension-type headache” and “migraine” which are described as primary headache syndromes have the third and sixth highest prevalence among 328 diseases and injuries in 195 countries from 1990 to 2016. Haldeman and Dagenais [4] reported that the prevalence of tension-type headaches, migraines, chronic daily headaches, and cervicogenic headaches in the general population is 38, 10, 3, and 0.4% to 2.5%.

Tension-type headache is identified by a bilateral pressing or tightening quality (non-pulsating quality), a mild to moderate intensity, and pain, which is not aggravated by routine physical activity, in the absence of vomiting, nausea, but may be accompanied by either photophobia or phonophobia [5‐8]. These symptoms, however, do not present simultaneously during the same episode [9]. This neurological disorder is more common among female patients (female-to-man ratio of 5:4). The peak prevalence occurs between the ages of 30 and 39 [10]. The International Headache Society [5] classifies tension-type headache into three subtypes according to headache frequency: infrequent episodic (< 1 day of headache per month), frequent episodic (1–14 days of headache per month), and chronic (≥15 days per month).

Despite extensive neurophysiological and clinical studies, the exact cause of tension-type headache remains unknown [6, 7], however, peripheral nociceptive mechanisms appear to be the main cause of episodic tension-type headache, while chronic tension-type headache may be caused by central sensitization, inadequate endogenous pain control, and peripheral myofascial mechanisms (myofascial nociception) [11‐15]. Previous experimental studies demonstrated that referred pain originating in myofascial TrPs within neck and shoulder muscles and surrounding soft tissues, such as fascia, tendons, and ligaments may reproduce headaches in patients with tension-type headache [16‐20]. TrPs can be defined as hyperirritable palpable spots of taut fibers located within a myofascial tissue, which have been known to cause non-dermatomal referral pain and discomfort [21]. Muscles which are commonly involved in tension-type headache include the sub-occipital, sternocleidomastoid, upper trapezius, levator scapula, splenius, temporalis, and masseter [14, 22, 23].

Cervicogenic headache is characterized by chronic pain that originates from bony structures or soft tissues of the neck and is referred to the head [24]. The pain of cervicogenic headache is usually unilateral with occipitofrontal distribution of spread [25]. The prevalence of cervicogenic headache has been estimated at 15–20% in patients with chronic headaches [26]. The most accepted mechanism of cervicogenic headache is convergence between the trigeminal nerve and C₁‐₃ nerves in the trigeminocervical nucleus [27]. The characteristics of tension-type headache and cervicogenic headache are similar, however, according to the Cervicogenic Headache International Study Group criteria [28] most cervicogenic headaches can be differentiated from tension-type headache and migraine with some overlap. In addition, according to Linde et al. [29], some patients may suffer from both types of headaches.

Migraine is defined as severe throbbing headache with nausea or vomiting associated with photophobia, that is aggravated by routine physical activity such as walking or climbing stairs [30, 31]. Migraine typically lasts between 4 and 72 h and has unilateral location [31]. Despite many migraine publications, the mechanism of migraine is not yet well understood [32]. The mechanism of migraine is believed to involve the trigeminal cervicogenic complex, which receives nociceptive information via afferent projections from the dura matter in large intracranial vessels [33]. A study conducted by Florencio et al. [34] indicated that patients with migraine exhibited active TrPs in their neck extensor muscles. According to the IHS, migraine is diagnosed if a person has at least 5 attacks fulfilling the abovementioned criteria [35].

Therapeutic management of headaches mainly comprises physical therapy and pharmacological approaches [36‐38]. In the last decade, there has been an increasing interest in the use of dry needling for the treatment of headache as well as for neck and shoulder pain syndromes [38]. Dry needling is a skilled intervention frequently performed by physical therapists, physicians, chiropractors, and acupuncturists for the relief of myofascial pain disorders [39, 40]. In this technique a fine sterile needle is utilized to penetrate the skin, subcutaneous tissues, fascia, and muscle, with the goal of deactivating TrPs without the use of an anesthetic [41]. Once a TrP is deactivated, the fine needle is removed [42]. It is an efficient, easy-to-learn-and-perform procedure with a low risk profile [43]. Hong [44] suggested that local twitch responses should be elicited during dry needling for a successful technique; however, recent studies have questioned this notion [45, 46]. The time of application will rely upon the irritability of the TrP [38]. Although dry needling might not change all central sensitization aspects, it is probable that local and referred pain will be reduced, muscle blood flow, oxygenation, patterns of muscle activation, and range of motion will be improved, and the biochemical environment of TrPs will be changed [47‐49]. Linde et al. [50] reported that the physiological mechanism of dry needling includes a combination of peripheral effects (such as spinal [i.e., gate control] and supraspinal [i.e., endogenous opioid system] mechanisms), as well as cortical effects (such as psychological or placebo mechanisms). It is hypothesized that dry needling may activate the serotonergic (5-HT) and noradrenergic descending inhibitory systems, which in turn may decrease pain [48]. Furthermore, Cagnie et al. [48] hypothesized that dry needling, via stimulation of the nociceptive fibers, may stimulate the enkephalinergic inhibitory dorsal horn interneurons. It is unclear whether the needle manipulation or the electrical stimulation is responsible for these results or both [48].

To the best of our knowledge, a systematic review conducted by France et al. [6] has investigated the effectiveness of dry needling and conventional physiotherapy in the management of cervicogenic headache or tension-type headache. Ten electronic databases were searched up to October 2012 and three relevant studies (two clinical trials and one case report) were identified through searches. Two included clinical trials with tension-type headache participants (40 male and 35 female) demonstrated statistically significant improvements following dry needling, but no significant differences between groups [6]. Furthermore, one case report study with a cervicogenic headache female that was included in the systematic review showed significant improvement in pain and neck disability index after nine treatment sessions of dry needling combined with manual therapy [6]. A formal meta-analysis was not performed because the number of studies included was not enough [6]. Additionally, grey literature was not included in the former systematic review to assure the comprehensiveness of the search strategy [6]. Although no systematic review and meta-analysis studies have been conducted to evaluate the effectiveness of dry needling on headache, several Cochrane systematic review studies have looked at the effectiveness of acupuncture in headaches [29, 50, 51]. In 2016, Linde et al., [29] investigated whether acupuncture is more effective than routine care, than ‘sham’ acupuncture; and other interventions in reducing headache frequency in adults with episodic or chronic tension-type headache. Twelve randomized trials with 2349 participants (median 56, range 10 to 1265) were included in the present systematic review and the results indicated that acupuncture is effective for treating frequent episodic or chronic tension-type headaches, but further trials - particularly comparing acupuncture with other treatment options such as physical therapy, massage or exercise - are needed [29]. In another systematic review, Linde et al. [51] assessed the effectiveness of acupuncture in reducing headache frequency in patients with migraine. Twenty-two trials with 4419 participants (median 42, range 27 to 1715) were included and the results showed that there was consistent evidence that acupuncture provides additional benefit to treatment of acute migraine attacks only or to routine care. However, Linde et al. [51] found no evidence for an effect of ‘true’ acupuncture over ‘sham’/‘placebo’ acupuncture. Moreover, it has been suggested that acupuncture is at least as effective as, or possibly more effective than, prophylactic drug treatment, and has fewer adverse effects [51]. Finally, Linde et al. [51] concluded that acupuncture should be considered a treatment option for patients with migraine willing to undergo this treatment.

Despite the widespread use of dry needling in the treatment of headaches, its effectiveness is still controversial when compared with other techniques. Furthermore, because the previous published systematic review on this topic is out of date, a new systematic review of the literature is needed. Hence, the main objective of this systematic review and meta-analysis is to evaluate the effectiveness of dry needling in comparison to other interventions on pain and disability in patients with tension-type headache, cervicogenic headache, and migraine.

This systematic review will be performed in accordance with the PRISMA statement [52] and principles outlined in the Cochrane Handbook for Systematic Reviews of Interventions [53]. This protocol has been prepared with regard to the PRISMA-P 2015 guidelines [54] and was registered on PROSPERO (International Prospective Register of Systematic Reviews, http://​www.​crd.​york.​ac.​uk/​PROSPERO/​; #CRD42019124125) in 4 March 2019. Ethical approval and patient consent will not be required since this is a systematic review of previously published studies and no new data collection will be undertaken.

Headaches are one of the main reasons for absenteeism from works or avoid physical and social activities [81]. From 2007 to 2017, the number of all-age years lived with disabilities attributed to headaches increased by 15.4% (95% UI, 14.6–16.2) [2]. Tension-type headaches, cervicogenic headaches, and migraines are three common types of headache which can have a considerable impact on individuals’ quality of life. Physical therapy is a treatment option that consists of interventions such as manual therapy, electrotherapy, exercises, and various maneuvers in order to improve pain, disability, and quality of life in patients with headaches. Dry needling is a physical therapy modality that involves inserting a fine filiform needle into the TrPs of soft tissues. There are many theoretical models that have influenced physical therapists and clinicians practicing dry needling [82]. The ‘fast-in-and-fast-out’ technique described by Hong [44] is probably one of the most widely used for the managements of neuromusculoskeletal pain and dysfunction [82].

Despite an increasing number of studies evaluating the effectiveness of dry needling for musculoskeletal disorders, no systematic review with meta-analysis has been carried out to examine the effectiveness of dry needling in patients with headaches. It is hoped that this study will provide useful information for physical therapists and clinicians on the treatment of tension-type headache, cervicogenic headache, and migraine.