MANUAL THERAPY IN THE TREATMENT OF PRIMARY HEADACHES-a systematic review -

Introduction: Headache is listed as one of the most prevalent pain conditions, with signifi cant socioeconomic impact that affects the quality of life. Among these, we highlight the tension-type headache (TTH) and migraine. Treatment ranges from pharmacotherapy to physical therapy, emphasizing manual therapy. Objective: to highlight key fi ndings and results of manual therapy techniques in the treatment of primary headaches. Methods: A systematic literature review was conducted through research and original studies published in journals indexed in electronic databases PLoS, MEDLINE via PubMed, PEDro, Lilacs and SciELO, which contained analyzes related to the purpose of the study in question. To evaluate the methodological quality and statistical description, as well as the risk of bias of the selected physical therapy studies, the PEDro scale as well as the PRISMA checklist. Results: 1,205 articles were found, of which nine were selected. These, despite the variety of techniques and duration of the intervention, indicated a decrease in the frequency, intensity and use of analgesic medication, and elevation in pain threshold, endurance of fl exor muscles active cervical. A methodological analysis of trials was available for 55,5% of those and with scores ≥5 (PEDro scale). Conclusions: Manual therapy is show as an effective alternative in the treatment of primary headache.


INTRODUCTION
A systematic literature review was conducted through research and original studies published in journals indexed in electronic databases PLoS, MEDLINE via PubMed, PEDro, Lilacs and SciELO, which contained analyzes related to the purpose of the study in question.The descriptors used in the
Although there are multiple drugs used in the acute treatment and prophylaxis of primary headaches, still there is a large number of patients who remain without satisfactory results, be it for the ineffectiveness of drugs or due to intolerance to their adverse effects.Given this reality, there are important studies that contribute to the progress of knowledge on the treatment of primary headaches, as well as presenting alternative ways for the treatment, possibly resulting in minimization of the impact of this condition [31][32][33] .In this context, this study aims to highlight the main findings and results of manual therapy techniques in the treatment of primary headaches, migraine and CTT.electronic survey were defined after consultation of the Medical Subject Heading (MeSH), the portal of the NLM, and Health Sciences Descriptors (MeSH), through the portal of the Virtual Health Library (VHL).Therefore, the following descriptors were used: tension-type headache; migraine; physical therapy modalities and manual therapy, conjugate or not, in the period of 2004-2016.For contextualization and discussion of the topic, articles with a wider period of search were used, from 1975 to 2016.To ensure the quality of systematic revision was applied PRISMA checklist.The criteria for inclusion of articles were: sample of individuals with CTT and / or migraine, with diagnosis performed in accordance with the criteria of the International Headache Society (IHS); intervention group with the submission of individuals to any form of manual therapy as treatment of this particular clinical condition; outcome procedures in order to measure the effect of the therapy used on headacherelated variables.To evaluate the methodological quality and statistical description, as well as the risk of bias of the selected physical therapy studies, the PEDro scale [34][35][36] was consulted.
All stages (electronic search in the databases, selection and evaluation of potential articles, data extraction and quality analysis of the studies) were performed by two independent researchers.The results of each stage were compared by a third reviewer to check the correlation between the pairs.In case of disagreement, a third investigator was responsible for the final analysis.

RESULTS
In the search using the descriptors above, 1097 original articles were identified in the PLoS database, 77 in MEDLINE / PubMed, 19 in PEDro, 11 in LILACS and 1 in SciELO, totaling 1205 original articles.Of these, 1184 were excluded for one or more of the following reasons: repeated; review articles; issues not related, observed through analysis of the titles; language other than English; not available in full text.After that, the summaries of the 21 remaining articles were reviewed by two independent examiners.From this analysis 6 studies were excluded because they were found to be inadequate to the inclusion criteria of this review.Of the 15 remaining studies, analyzed in full, six were excluded for not presenting the issues related to the objective of the present study(see flow chart in figure 1).Thus, it was evident thatmost of the articles on this theme was identifiedin the MEDLINE/ PubMed database.The generalcharacteristics of the nine studies selected for this systematic review are summarized in table 1.

CHARACTERISTICS OF STUDIES
All nine studies analyzed used manual therapy techniques as treatment for primary headaches, combined or not with other interventions.The headache types investigated included CTT (chronic and / or episodic) and migraine, as the first being the most frequent in the included studies (n = 6).
As for the sample used, it can be found variability, considering between low to moderate in all studies (20-84 individuals included).The variables involved: frequency of headache; intensity of pain; medication for headache; headache-free days; index of headache; impact of headache on daily life; occupational impact of headache; pressure pain threshold (algometry); strength of the cervical flexor muscles; cervical range of motion (AM); quality of life; depressive symptoms; pain perception; and noticed overall improvement (see details in table 1).
The analysis of the methodological quality of the articles selected for this review, performed by consulting the PEDro scale, found that 55.5% (n = 5) were analyzed.Of the evaluated studies, all presented scores ≥5, thus being considered moderate to high the methodological quality, which suggests a high level of scientific evidence 46 .
The present study aims to highlight the key findings and results of manual therapy techniques in the treatment of primary headaches, migraine and CTT.Despite the variety of therapeutic approaches, generally speaking, it can be observed that the results were similar, showing a positive clinical evolution of participants subjected to manual therapy techniques.Studies of Castien 41 , Voigt 42 Ajimsha 43 , Arnadottir&Sigurdardottir 44 e Espí-López & Gómez-Conesa 45 used as intervention, isolated therapies (manual therapy) and the control groups (if there were any) received or not other kind of therapy (orientations, conventional physiotherapy, massage therapy and placebo therapy).In these studies, clinical improvement was observed, which could be related to the intervention.The remaining studies [37][38][39][40] applied combined therapies, in other words, besides manual therapy, the intervention groups were subjected to other techniques (standard physiotherapy, relaxation exercises, medication and multimodal behavioral therapy).As well as the studies with isolated therapy, positive patient clinical evolution was also observed.However, this therapy does not show which component of the therapeutic treatment was specific for the results obtained or if they are only observed due to their combination.
Frequency of episodes and intensity of pain are aspects usually investigated by researches who seek to evaluate treatments for headaches.In this review, it was observed that seven [37][38][39][40][41]43,45 and five 37,38,41,42,45 studies, respectively, measured these variables. With egard to frequency, 85.7% (n = 6) of the articles found statistically significant reduction of complaints after the intervention phase. As for intensi, 100% of analyzes showed improvement with statistical significance.To measure these variables, it has been reported frequently in the literature the use of "pain diaries" as a tool for tracking issues related to headache 18,[47][48][49][50][51] , as well as its subjective intensity on the analogue visual scale (AVS) 38 or by the McGill pain questionnaire 45,[52][53] .Primary headaches were also evaluated objectively using different physical variables (AM, algometry, resistance of deep cervical flexor muscles), showing improvement after the application of craniocervical manual therapy techniques 41,45 .
The pain medication has been widely used clinically as a prophylactic treatment for episodes of frequent or disabling headache 39 .However, excessive use of stimulant substances (caffeine, tobacco and alcohol) [54][55][56][57][58][59][60] , as well as excessive use of drugs may be risk factors for chronic headaches 17,41 .Non pharmacological therapies have shown good results in reducing drug use for the control of pain in these conditions 37,40 .In the study of Castien 41 , this variable did not significantly decrease in neither of the groups, which was probably due to the high number of patients not taking medication at the beginning of treatment (baseline condition).
The clinical condition of headache may be associated with considerable limitations in psychosocial ambit

FINAL CONSIDERATIONS
REFERENCES 61-64   .Thus, questionnaires about the impact or the inability due to headache are used to monitor progress in clinical and research environments 41,[65][66][67] .Among the instruments used in the included studies, HIT-6, HDI and MIDAS 68 are available, which considers different aspects related to the quality of life of patients with headache, including the psychosocial component 69,70 .All the studies reviewed, had a positive result in different aspects of life quality after the application of manual therapy techniques when comparing the pre-and posttreatment moments 37,40,42 .In the context of modern, online programs for different types of health care have been used, since many patients have difficulty in accessing specialized medical care, as in migraine [71][72][73][74][75] .In this sense, the study of Hedborg & Muhr 40 used multimodal behavioral therapy applied online in two treatment groups, one of them being combined with massage therapy sessions.The authors observed a significant improvement in both groups compared to pretreated moment (baseline) and control.However, the group combined with the massage therapy showed no significant effects.The authors correlated that this may have occurred due to the low frequency of sessions of manual therapy used after the beginning of treatment via internet.Of the eight studies included in this review, five 37- 39,41,42 were analyzed using the PEDro scale and classified as moderate to high the methodological quality.It is important to highlight, however, that some criteria of this scale are not always able to be fulfilled by certain studies, which can be applied in the articles included in this review, since any of them had maximum score.This probably occurred because the criteria that refer to the masking of therapists and participants were not followed by four articles 37,38,41,42 , due to the difficulty of masking in implementing technical manual therapy by a properly trained therapist.Finally, the studies investigated presented different limitations that should be considered such as: (1) the short time for intervention and period of treatment; (2) the sample size 38-42,44 ; (3) the inability to blind the applied techniques and (4) the no use of placebo 42 and control 44 may influence the results.Although cranial therapy technique manual76 and strengthening exercises of the cervical muscles (stabilization of the region) have presented evidence consideráveis 77 .Recently (2016) 78 , have be shown a low level of evidence/quality in work involving exercises nurses with primary headache.The authors suggest studies with methodologies and rigorous designs can provide helpful evidence strategies to treat primary headache 78 .
Despite the heterogeneity of the techniques used in the different studies reviewed (combined manual therapy technique or not), we observed a positive relationship between manual therapy and improvement in clinical and social aspects of primary headache.In this context, manual therapy presents itself as an important adjunct in clinical treatment of primary headache, since excessive use of drugs can also cause headaches and adverse effects.However, more research is needed to investigate the specific components of manual therapy acting on the algic condition of origin of primary headaches as well as the precise time of application for a safe recovery without relapse.

Figure 1 -
Figure 1 -Search flowchart in different databases

Table 1 -
General characteristics of the studies analyzed

Table 1 -
General characteristics of the studies analyzed