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Abstract

Background:

There is good evidence in the literature supporting physiotherapy in the management of some forms of headache. Dry needling of myofascial trigger points is becoming an increasingly common approach despite a paucity of research evidence supporting its use. The purpose of this review was to determine the evidence supporting the use of dry needling in addition to conventional physiotherapy in the management of tension-type and cervicogenic headache.

Methods:

Ten databases were searched for evidence of the effect of dry needling on the severity and frequency of tension and cervicogenic headache based ICHD classifications.

Results:

Three relevant studies were identified and all three showed statistically significant improvements following dry needling, but no significant differences between groups. Only one study reported on headache frequency or intensity, reporting a 45 mm improvement in VAS score following the addition of dry needling to conventional physiotherapy. Two studies showed significant improvements with dry needling over 4–5 weeks of treatment. No adverse events were reported.

Conclusions:

The literature suggests that while there is insufficient evidence to strongly advocate for the use of dry needling, it may be a useful addition to conventional physiotherapy in headache management. Further research with a stronger methodological design is required.

Keywords

Dry needling headache physiotherapy

Introduction

Headache is one of the most commonly presenting health conditions (1), and accounts for an estimated 40% of neurological consults annually (2). Recent population studies have indicated that tension-type headache is the most common primary headache (1,3), with a global lifetime prevalence ranging from 30% to 78% (4). Tension-type headaches are characterised by a bilateral pressing or tightening quality, mild to moderate intensity, and pain that is not aggravated by physical routine, in the absence of vomiting and, in most instances, nausea, photophobia and phonophobia (4). Similar characteristics exist for cervicogenic headache (pain in the head or face) (4), making the two types difficult to distinguish clinically.

The precise mechanisms of tension-type and cervicogenic headaches are largely unknown; however, it is believed that peripheral pain mechanisms play a role (4) as well as genetic characteristics (5,6), and environmental, psychological and central factors (7). Much of the existing literature surrounding the management of headache has focussed on pharmacology, with a smaller emphasis on the role of allied health, such as physiotherapy. A systematic review investigating general physiotherapy management of headache reported that the current body of evidence was ‘insufficient to support or refute’ the efficacy of a range of physiotherapy techniques in the long-term management of tension-type headache (8). There is no comparable study investigating the effect of physiotherapy interventions on cervicogenic headache.

Dry needling is becoming increasingly popular among physiotherapists for the management of myofascial pain. Dry needling involves the insertion of a small gauge needle into identified trigger points (defined as ‘hyperirritable spots within a skeletal muscle or in the muscle fascia that are associated with a hypersensitive palpable nodule’) (9 –11). Current understanding of the physiological mechanism of dry needling suggests a combination of peripheral effects (including spinal and supraspinal mechanisms), as well as cortical effects (such as psychological or placebo mechanisms) (12).

There is some evidence (albeit of poor methodological quality) to suggest that dry needling can permanently deactivate myofascial trigger points (13). The addition of dry needling to conventional physiotherapy management of tension or cervicogenic headache such as massage, spinal mobilisations, myofascial release, strengthening and stretching exercises (14), therefore seems a logical step, and one that has been taken by physiotherapists internationally (15).

Because of the clinical similarities between tension-type and cervicogenic headaches, both were included in this review. The aim of this review was to find the evidence to support this combination of treatment modalities – specifically whether the addition of dry needling to conventional physiotherapy management reduces the severity and frequency of chronic (present for more than 14 days per month for more than 3 months (4)) tension-type and cervicogenic headache compared with conventional physiotherapy alone.

Methods

Study criteria and search terms

Studies of all research designs investigating the effect of dry needling on tension-type or cervicogenic headache severity and frequency were included (Table 1). A specific definition of tension-type or cervicogenic headache, which matched the ICHD classifications (4) had to be explicitly stated, and studies where participants were migraineurs were excluded.

Table 1.

Inclusion and exclusion criteria.

Studies	Participants	Interventions	Comparisons	Outcomes
Inclusion criteria
All primary empirical study designs All years Peer reviewed	Adults ≥18 years old, chronic headache >3 months since time of onset Cervicogenic, tension, posture/postural headaches as defined by the International Classification of Headache Disorders (ICHD).	Dry needling, dry needling ‘plus’	Any physiotherapy technique used to reduce pain, frequency or severity of headache (i.e. massage, mobilisation, manipulation, electrotherapies, traction, heat/cold therapy, exercise, education, stretching) No comparator	Headache frequency (i.e. headache diary) or Headache pain severity – self reported or validated questionnaire (i.e. VAS-pain, NRS)
Exclusion criteria
Languages other than English, animal studies Narrative reviews, editorials, letters to the editor Secondary studies Not peer-reviewed	Primary headaches other than cervical, tension or postural (ICHD) Acute headache (<3 months since onset) Secondary headache (i.e. caused by trauma, medical conditions (i.e. SOL such as tumour) or medications) Children/adolescents patients<18 years old	Intramuscular stimulation, sham acupuncture/needling, moxibustion, acupuncture, Chinese medicine, wet needling, pharmacological management (or any combination of these and dry needling)	Placebo headache medication during intervention period, pharmacology studies	Studies which do not contain outcomes related to headache pain frequency or severity

VAS-pain: visual analogue scale for pain; NRS: numerical rating scale; SOL: space occupying lesions.

Prior to finalising search terms, two authors (SF and SR) ran initial screenings to ensure chosen terms were relevant to the question. These practice searches included the use of MESH and explode/implode functions in each database (Table 2). An academic librarian was consulted (4 September 2012) to ensure appropriateness and scope of the search strategies. Based on this advice, MESH and ‘explode/implode’ functions were excluded from the systematic search because of lack of specificity to the research question.

Table 2.

Search terms.

Search terms
E-databases^a	P	I	C	O	Limits
Medline Embase Cochrane CINAHL Web of knowledge PEDro Hooked on Evidence Allied and contemporary medicine (AMED) Scopus	Chronic headache^b OR Cervicogenic headache^b OR Tension headache^b	Dry needl^b OR Acupuncture OR Acupressure OR Trigger point injection^b OR Traditional Chinese medicine	Physiotherap^b OR Manual therap^b OR Massag^b OR Mobilis^b OR TENS OR Physical Therap^b OR Exercis^b OR Rehab^b OR manipulat^b	Pain OR Reduce^b pain OR Sever^b OR Frequen^b	English only

Each of the PICO columns is linked with the Boolean ‘AND’.

^aDatabases chosen on the basis of medical, allied health or contemporary medicine backgrounds to ensure both dry needling and acupuncture articles were thoroughly researched.

^bTruncation symbol.

Because of the potential interchangeable use of terms ‘dry needling’ and ‘acupuncture’ in the literature, both search terms were used. To be eligible for the review, an explicit explanation of the dry needling intervention was required and needed to involve the insertion of needles precisely into identified myofascial trigger points with the aim of influencing tension-type or cervicogenic headache intensity or frequency (12,16). Articles relating to acupuncture or acupressure were excluded at the point of study screening, rather than risking missing appropriate studies during the search.

Search strategy

The initial database searches were conducted on 13 September 2012. Table 3 outlines the search strategy applied to the Medline database. Two authors (SF and SR) applied the exclusion and inclusion criteria to the title and abstract of all database results. The full text articles included based on title and abstract were then reviewed independently by three authors (JB, MM and MN). This process yielded three relevant studies as determined by the inclusion and exclusion criteria. The full texts of two studies were accessible, but the remaining article was only available by abstract. The author of that study was contacted to obtain a full text publication; however, they did not respond, so the article was excluded from this review.

Table 3.

Medline search strategy.

Search	Terms	Hits
1	(chronic headache* or cervicogenic headache* or tension headache*).mp. [mp=title, abstract, original title, name of substance word, subject heading word, protocol supplementary concept, rare disease supplementary concept, unique identifier]	2311
2	dry needl* or acupuncture or acupressure or trigger point injection* or traditional chinese medicine).mp. [mp = title, abstract, original title, name of substance word, subject heading word, protocol supplementary concept, rare disease supplementary concept, unique identifier]	22,082
3	(physiotherap* or manual therap* or massag* or TENS or physical therap* or exercis* or rehab* or mobilis* or manipulat*).mp. [mp=title, abstract, original title, name of substance word, subject heading word, protocol supplementary concept, rare disease supplementary concept, unique identifier]	467,824
4	(pain or reduce* pain or sever* or frequen*).mp. [mp=title, abstract, original title, name of substance word, subject heading word, protocol supplementary concept, rare disease supplementary concept, unique identifier]	2,894,553
5	1 and 2 and 4	49
6	limit 5 to (english language and humans and “all adult (19 plus years)”)	17

Because of the lack of appropriate articles found in the initial database search, Scopus was searched (2 October 2012). From this search an additional dissertation study was identified from title and abstract. Full text examination indicated that the study was not peer reviewed and therefore did not match the inclusion criteria and was excluded. After the additional search was completed, eligibility was determined using the inclusion and exclusion criteria (Table 1) and the reference list of each article was pearled. One additional study was identified through this process.

Data analysis

The principal summary measure was pain severity. To ensure consistency, all stages of data analysis were completed by multiple reviewers. Three authors (JB, MM and MN) independently completed data extraction before collating the information to ensure all relevant data had been captured and interpreted in the same way. A meta-analysis was not conducted because of the inability to quantitatively compare study findings as a result of the variation in research designs. Study results were therefore compared descriptively. No additional analysis (such as subgroup analysis) was performed.

Critical appraisal of methodological bias

Studies were rated on the NHMRC hierarchy of evidence. Five authors independently allocated a level of evidence to the three studies and discussed discrepancies before reaching consensus. Following allocation to the hierarchy of evidence, each study was assessed for methodological bias using The Modified McMaster Critical Appraisal Tool for Quantitative Studies (CASP). The guidelines of the tool were examined prior to appraisal to ensure uniform application between authors. Following individual critical appraisal, disagreements between authors were discussed until consensus was reached.

Results

The search strategy produced 1296 possible studies, 76 of which remained after removal of duplicates and title and abstract screening. Seventy-two studies were excluded following full text review, one was irretrievable and three (17 –19) met the inclusion criteria for the review. Repeated attempts to contact the author of the irretrievable study were unsuccessful, and it was excluded, leaving three studies (17 –19), which met the inclusion criteria (Figure 1).

Figure 1.

PRISMA flowchart of search strategy.

Strength of evidence

Two included studies (17,18) were randomised controlled trials, level II on the NHMRC hierarchy of evidence, while the third (19) was a single case report (level IV). All three studies displayed inherent risk of bias for their design, scoring five (18), three (17) and five (19) of seven (Table 4).

Table 4.

Appraisal of bias.

Modified McMaster for quantitative studies	Karakurum et al. 2001 (17)	Venancio, Alencar and Zamperini 2008 (18)	Sillevis 2011 (19)
Study purpose
1. Was the purpose of the study stated clearly?	0	1	1
Sample size
2. Was the sample described in detail?	1	1	1
3. Was the sample size justified?	0	0	0
Outcome measures
4. Were the outcomes measures reliable?	0	1	1
5. Were the outcome measures valid?	0	1	1
Results
6. Were the analysis method(s) appropriate?	1	1	0
Conclusion
7. Conclusions were appropriate given study methods and results?	1	0	1
Total / 7	3	5	5

Although all studies reported the sample size appropriately, none provided justification for the selection. One RCT (18) selected outcome measures without established reliability or validity (Table 5), and although the symptom severity index has shown high internal consistency (α ≥ 0.92) and excellent test-retest reliability (ICC=0.97, 95% CI 0.96–0.99) in individuals with temporo-mandibular pain (20), the same strength has not yet been established for a headache population. The RCTs did, however, display precision in the statistical analysis approach selected, compared with Sillevis (19), which reported only a change in VAS (mm) and NDI (%) without analysis of statistical significance.

Table 5.

Study results.

					Results
Study [Design] CAT score	Sample	Intervention(s)	Outcome Measure		Baseline [m (SD)]	Week 1 [m (SD)]	Week 4 [m (SD)]	Week 12 [m (SD)]	Change [%] (Baseline to final follow-up)
Venancio et al. 2008 (17) [RCT] – 3/8	N = 45 (40F, 5M) Moderate-severe headache ≥6-months (15% migraine, 25% TTH, 60% mixed) plus uni- or bilateral TrP in orofacial or cervical region Age: 18–65 years	1 episode of treatment G1 – DN G2 – Lidocaine (25% without vasoconstrictor) G3 – Lidocaine (25% without vasoconstrictor) + 0.2 ml corticoid	Modified Symptom Severity Index	G1	0.52 (0.09)	0.34 (0.08)	0.42 (0.08)	0.36 (0.17)	0.16 [30.7]**
				G2	0.60 (0.21)	0.40 (0.09)	0.46 (0.19)	0.46 (0.24)	0.14 [23.3]**
				G3	0.51 (0.10)	0.51 (0.20)	0.43 (0.11)	0.33 (0.12)	0.18 [35.3]**
Karakurum et al. 2001 (18) [RCT] – 4/8	N=30 (F) Intervention (I): 10 (67%) chronic TTH, 3 (20%) episodic TTH, 2 (13%) episodic TTH+ migraine Age: 28.4 ± 11.6 years Control (C): 10 (67%) chronic TTH, 5 (33%) episodic TTH Age: 27.9±10 years	Weekly treatment, 4 weeks [I: IDN; C: SDN] 0.3 gauge, 25 mm needles L+R splenius capitus L+R C5 splenius capitus & splenius cervicis L+R x 2 middle trapezius 30min per session			Baseline [m (SD)]		Week 4 [m (SD)]
			Headache index	I: DN	30.4 (16.4)		10.8 (5.9)		19.8 [65.1]*
				C: SDN	37.4 (16.4)		15.7(7.0)		21.7 [58.0]*
				I:C	NSD		NSD		–
			TrP tenderness	I: DN	1.67 (0.49)		0.60 (0.63)		1.07 [64.1]**
				C: SDN	1.67 (0.49)		1.47 (0.64)		0.2 [12.0]*
				I:C	NSD		**		–
			ROM (Limitation)	I: DN L	0.87 (0.74)		0.33 (0.49)		0.54 [62.1]*
				I: DN R	1.03 (0.85)		0.47 (0.83)		0.56 [54.3]*
				C: SDN L	0.80 (1.08)		0.80 (0.68)		0
				C: SDN R	0.87 (0.94)		1.07 (0.70)		−0.2 [23.0]
				I:C	NSD		NSD		–
Sillevis 2011 (19) [Case study] – 5/8	N=1 (F) 12-yr chronic CGH (suboccipital + supraorbital) Age: 34 years	9 treatments over 5 weeks (combined manual techniques) DN introduced at session 4 0.36 × 50 mm & 0.34 × 25 mm needles			Baseline	Visit 4	Visit 9 (week 5)		Change [%] (visit 4 to 9)
			VAS (mm)		69	55	10		45 [81.8]
			NDI (%)		78	68	12		56 [82.3]

Headache index = frequency x intensity.

TTH: tension-type headache; CGH: cervicogenic headache; IDN: intramuscular dry needling; DN: Dry needling (type not specified); SDN: subcutaneous dry needling; NDI: Neck disability index; ROM: Range of motion; I:C: between group significance; TrP: Trigger point; VAS: Visual analogue scale.

*p<0.05; **p<0.001.

Size of the effect

Two of the three included studies (17,18) investigated tension-type headache, whereas the third (19) reported on the effect of dry needling in a single case of clinically diagnosed cervicogenic headache, based on headache provocation during assessment. Using different measures of effect, all three studies reported significant improvements in tension-type (17,18) and cervicogenic (19) headache symptoms following a single (18) or multiple (17,19) treatments of dry needling (Table 5). The two RCTs investigating the effect of dry needling on chronic tension-type headache reported 30.7% (p<0.001) (18) and 65.1% (p<0.05) (17) reductions in headache symptoms following a single intervention and 4-weekly interventions respectively (one session per week for 4 weeks). Sillevis (19) reported a larger (85.5%) improvement in VAS-pain score (45 mm) following the use of dry needling on a single individual suffering from chronic cervicogenic-type headache, indicating clinical significance (21).

Results seem to indicate that multiple treatments may be more effective than a single intervention and that dry needling may produce clinically significant improvements in headache (cervicogenic and tension-type) symptoms. However, no study was able to demonstrate statistically greater outcomes following dry needling compared with lidocaine (without vasoconstrictor) injections, lidocaine (without vasoconstrictor) plus corticoid injections, or superficial dry needling.

Relevance of the evidence

The outcomes selected in each study prevented direct comparison of the results. The Modified Symptom Severity Index is designed to capture multiple dimensions of pain – temporal, sensory and affective (20), rather than pain severity in isolation, which may have been more appropriate given the aim of testing effectiveness of lidocaine injections (a local anaesthetic). Sillevis (19) used pain intensity measured by the VAS-pain scale as the primary outcome but failed to indicate whether it referred to headache pain or local neck pain (also part of the patients’ clinical presentation). The VAS-pain scale is a frequently applied subjective assessment tool in clinical practice and therefore an appropriate tool for the study design (retrospective case study). Karakurum et al. (17) opted for a composite measure of frequency and severity (headache index) as well as local tenderness on palpation and cervical range of motion; however, had a poorly defined research aim, making it difficult to assess appropriateness.

Discussion

Various aspects of the review findings have been scored from A (excellent) to D (poor) based on the NHMRC body of evidence matrix (Appendix).

Evidence base

The studies fitting the inclusion criteria of this review were level II (tension-type headache) and IV (cervicogenic headache) on the NHMRC hierarchy of evidence. All studies displayed vulnerability to bias regarding sample size justification, one RCT introduced bias by using outcome measures that lacked reliability and validity as well questionable appropriateness given the ambiguity surrounding the study aim (17). As a result, despite Venancio et al. (18) scoring 5/7 on critical appraisal, the combined evidence base (17,18) for dry needling for reducing the symptoms of tension-type headache is level C (satisfactory), and for cervicogenic headache, level D (poor), and should therefore be interpreted with caution.

Consistency

All three studies showed improvements in headache symptoms following dry needling treatment; however, they were not able to demonstrate greater effectiveness when compared with other techniques. One possible explanation for this is the choice of control treatment in the RCTs (17,18): dry needling being the control intervention of choice in (18), while (17) opted for superficial needling. Both approaches are likely to be problematic given the recent recognition of any needle penetrating the skin resulting in a physiological change (22,23). As such, neither approach produces a true ‘control’, which could account for the presence of a placebo response. The single participant in Sillevis (19) could be considered to have acted as her own control, given the addition of dry needling to her standard physiotherapy part-way through her course of treatment, thereby offering a direct comparison between conventional physiotherapy and dry needling. However, there is no way to account for latent effects of earlier treatment or practitioner skill in applying the interventions, so care needs to be taken in interpreting those findings.

The two studies using multiple intervention sessions (17,18), reported greater improvements in headache symptoms overall. This is likely to be more reflective of a clinical scenario and hence is an encouraging finding at face value. However, other factors such as the inconsistency of intervention application may confound the findings. For example, although both clearly outlined the location of the myofascial trigger points used, they were not the same in both studies and the duration of the intervention, the method of insertion and interval between treatments is unclear. Finally, the needle gauge and length was not the same in both studies, which could also influence study findings.

Of particular interest to this review is that rather than comparing the effect of dry needling against a control, Sillevis (19) added dry needling to an existing treatment plan, resulting in significant improvement in cervicogenic VAS-pain and neck disability score over subsequent treatment sessions. This may suggest that the addition of dry needling to conventional physiotherapy approaches rather than dry needling alone is a useful management strategy.

As a result of these issues, the consistency of the evidence for dry needling as a treatment for tension-type and cervicogenic headache is level C (satisfactory), indicating genuine uncertainty about the issue.

Clinical impact

Headache is the most prevalent pain disorder globally, affecting 66% of the population (24). This brings headache into the top ten most disabling disorders (25), causing 25 million working days lost yearly in the UK alone (3). The results of this study suggest that dry needling could significantly reduce the symptoms of tension-type headache (by 30–65%) (17,18) and cervicogenic headache (by up to 85.5%) (17,19). These results need to be viewed cautiously because of the risk of bias and methodological discrepancies in the studies; however, if further studies generate similar outcomes, given the prevalence of the conditions, dry needling has the potential to have a large clinical impact. As a result, the clinical impact of the findings is level B (good) based on the current evidence base.

Generalisability

Generalising the findings of the review needs to be done carefully because of the difficulty in clinically differentially diagnosing headache types. However, the two RCTs used IHC criteria (17,18) in determining their inclusion criteria, which suggests that their findings can confidently be generalised to other individuals with tension-type headache. The generalisability of the findings is therefore level A (excellent). Sillevis (19) used only headache reproduction on palpation in making the cervicogenic headache diagnosis and identified areas of myofascial pain, so the findings of this study must be more carefully generalised to the wider cervicogenic headache population (level B – good).

Conclusion

Overall, the evidence supports the use of dry needling in conjunction with other treatments for the management of tension-type and cervicogenic headache as defined by the ICHD. Although not conclusively stating that dry needling reduced the frequency and severity of headache symptoms (the focus of this review), each study reported improvements in their chosen outcomes. Furthermore, current understanding of how dry needling might work – insertion of a needle causing nerve fibre depolarisation, and in turn causing a contracted muscle to fasciculate and relax (17,18), and the similarities in tension-type headache, cervicogenic headache and myofascial trigger point symptoms (such as localised tenderness and referred pain), it seems plausible that management techniques that address myofascial trigger points, may also reduce tension-type and cervicogenic headache.

The study by Sillevis (19), while ranking lowest on the CEBM hierarchy of evidence, is perhaps the most consistent with clinical practice (multiple physiotherapy modalities over multiple treatment sessions), making its findings most relevant to the research question. Considering these findings in isolation, there is reason to suggest that in combination with other manual physiotherapy management approaches, dry needling is effective in reducing the frequency and severity of cervicogenic headache, findings which need to be verified by more methodologically sound research. Karakurum et al. (17) delivered dry needling to six pre-determined areas for 30 minutes per session over four sessions, and may also be reflective of clinical practice. Although this study found no significant difference between groups in terms of tension-type headache severity, the control group received superficial or minimal dry needling, which may have confounded the results (26), particularly in light of the inherent bias and the small sample size.

Current evidence for the benefit of dry needling in the treatment of tension or cervicogenic headache is ambiguous. Despite significant differences between the three studies making it difficult to compare results, none of the three reported any increase in headache symptoms or adverse events following the application of needling. All three reported a reduction in symptoms, but were unable to conclusively report that dry needling of myofascial trigger points alone was effective in reducing either the severity or frequency of tension-type (17,18) or cervicogenic headache (19). Future research of stronger methodological quality, lower risk of bias and greater homogeneity of the study population, is needed to verify the results of these studies. Until then, the use of dry needling in combination with conventional physiotherapy is an option in the management of individuals presenting with tension-type or cervicogenic headache.

Clinical implications

There is some evidence to support the use of dry needling in treating cervicogenic and tension-type headache.

Further research should be conducted to determine how beneficial dry needling is in the treatment of cervicogenic and tension-type headache.

Footnotes

Funding

This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.

Conflict of interest

None declared.

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