Evidence of localized and widespread pressure pain hypersensitivity in patients with tension-type headache: A systematic review and meta-analysis

The relationship between myofascial trigger points sensitivity, cervical postural abnormality, and clinical tension-type headache parameters

BACKGROUND

Myofascial Trigger Points (MTrPs) play a significant role in the pathogenesis of Tension Type Headache (TTH). Abnormal cranio-cervical posture has been linked to various types of headaches. However, the correlation between MTrPs sensitivity, cervical postural alignment, and clinical measures of headache has not been extensively studied in patients with TTH.

OBJECTIVES

To investigate the relationship between MTrPs sensitivity in cervical and pericranial muscles, cervical postural abnormality, and clinical headache parameters in patients with TTH. Furthermore, to investigate the effect of sex on the examined variables and their association with headache type (episodic vs chronic TTH).

METHODS

A total of 72 patients with TTH of both sexes were enrolled in this study. Headache frequency and disability as clinical measures of headache, pressure pain threshold (PPT) of bilateral upper trapezius (UT) and suboccipital (SUB) muscles, cervical lordosis angle (CA), and anterior head translation (AHT) were measured.

RESULTS

Pericranial MTrPs sensitivity did not demonstrate any correlation with clinical headache parameters or cervical postural abnormality. However, there was a significant correlation between the frequency of headaches and the level of disability (r = 0.32, P < 0.05). In addition, episodic TTH was more prevalent in females who exhibited greater AHT and MTrPs sensitivity of both bilateral UT and right SUB muscles than males.

CONCLUSIONS

There was no correlation found between the frequency of headaches and the level of disability with measures of cervical posture alignment or MTrPs sensitivity in individuals with TTH.. Based on findings, Clinicians should consider sex differences when assessing patients with TTH.

Physical therapy in addition to occlusal splint in myogenic temporomandibular disorders: A randomised controlled trial

BACKGROUND

Myogenic temporomandibular disorders (M-TMD) commonly involve occlusal splint (OS) therapy and musculoskeletal physiotherapy (MPT).

OBJECTIVES

To compare the effects of combining OS with MPT and education (EG) against OS and education (CG), in chronic M-TMD patients.

METHODS

In this double-blind randomised controlled trial, 62 participants were assigned to either EG or CG. The primary outcomes, pain levels at rest (VAS rest), maximum oral opening (VAS open) and during chewing (VAS chew), were measured by Visual Analogue Scale (VAS) in cm. The secondary outcome was the range of motion (ROM) for maximum oral opening. Both interventions lasted 3 months, with outcomes assessed at baseline (T0), post-treatment (T1) and 3 months post-treatment (T2).

RESULTS

Intention-to-treat analysis revealed significant improvements favouring EG (VAS rest = -1.50 cm [CI95%: -2.67, -0.32], p = .04; VAS open = -2.00 cm [CI95%: -3.23, -0.75], p < .01; VAS chew = -1.71 cm [CI95%: -2.90, -0.52], p = .01; ROM = 4.61 [CI95%: 0.93, 8.30], p = .04). Additionally, VAS measures were influenced by follow-up times (VAS rest = -0.73 cm [CI95%: -1.30, -0.17], p = 0.03; VAS open = -0.97 cm [CI95%: -1.57, -0.37], p < .01; VAS chew = -1.15 cm [CI95%: -1.73, -0.58], p < .01). At T1, EG demonstrated higher number of responders compared to CG for VAS open (χ2(1) = 4.39, p = .04) and VAS chew (χ2(1) = 11.58, p < .01).

CONCLUSION

Adding MPT to education and OS yields better outcomes in terms of pain reduction and ROM improvement, in chronic M-TMD.

TRIAL REGISTRATION NUMBER

NCT03726060.

Somatosensory Profiling of Patients With Cluster Headache: A Systematic Review and Meta-analysis

The objectives were 1) to synthesize quantitative sensory testing results in cluster headache (CH) patients and to identify somatosensory differences from healthy subjects (HS), and 2) between symptomatic and asymptomatic sides in CH patients. Two independent reviewers conducted a literature search in MEDLINE, EMBASE, Web of Science, and CINAHL databases. Studies with observational designs were included. Methodological quality and risk of bias were assessed with the Newcastle Ottawa Scale. The selected studies underwent qualitative and quantitative analyses. The qualitative analysis showed inconsistent findings among multiple studies. Meta-analysis showed lower pressure pain thresholds (PPTs) on the symptomatic side of CH patients than HS in V2 (standardized mean difference [SMD] -1.01 [95% confidence interval (CI) -1.79, -.23], P = .01, I2 = 73%, n = 114), V3 (SMD -1 [95% CI -1.54, .45], P < .01, I2 = 82%, n = 354), and cervical region (SMD -1.25 [95% CI -2.07, -.44], P < .01, I2 = 84%, n = 194). Furthermore, lower PPTs than those detected in HS were found on the asymptomatic side in V3 (SMD -.77 [95% CI -1.27, -.27], P < .01, I2 = 79%, n = 354) and in the cervical region (SMD -1.13 [95% CI -1.97, -.3], P < .01, I2 = 85%, n = 194). However, no differences were found in V1 or the extratrigeminal points between these groups. No significant changes were found between symptomatic and asymptomatic sides in trigeminal and extratrigeminal regions. Mechanical hyperalgesia in the trigemino-cervical region of patients with CH could suggest the presence of central pain mechanisms. These results are of clinical relevance because their presence could be associated with a poorer prognosis, chronification, and treatment response. PERSPECTIVE: This study provides consistent findings on the somatosensory profile characterizing patients with CH. Clinicians should assess PPTs and other quantitative sensory testing variables in the trigeminal and extratrigeminal (cervical) regions.

Hyperalgesia, Increased Temporal Summation and Impaired Inhibitory Mechanisms in Episodic and Chronic Cluster Headache: An Observational Study

Cluster Headache (CH) is a primary headache that causes severe pain. Some evidence suggests that central mechanisms might be involved. The objective of this study was (1) to compare hyperalgesia signs, temporal summation and conditioned pain modulation among episodic (ECH) and chronic CH (CCH) patients and controls, (2) to compare these factors between sides in the patient groups and (3) to compare the psychophysical variables between the groups. This cross-sectional study included 71 subjects divided into three groups (ECH, CCH and controls). Pressure pain thresholds, temporal summation, conditioned pain modulation and other psychosocial variables were measured. The ANOVA showed differences for all physical outcome measures (p < 0.05). Bonferroni post hoc analyses showed differences when comparing the patient groups with the healthy subjects (p < 0.05), with large effect sizes (d > 0.8). No differences between the patient groups were found for almost all the variables (p > 0.05). Significant differences for all the variables were detected when comparing the symptomatic and non-symptomatic sides in both the ECH and CCH groups (p < 0.05). The ECH and CCH groups showed mechanical hyperalgesia, increased temporal summation and impaired inhibitory mechanisms compared to the controls. Side-to-side differences were also detected within the patient groups. Patients with CCH had poorer sleep quality and quality of life than the controls.

An Update on Temporomandibular Disorders (TMDs) and Headache

PURPOSE OF REVIEW

To provide an overview and highlight recent updates in temporomandibular disorders (TMDs) and their comorbidity with headache disorders regarding pathophysiology and management.

RECENT FINDINGS

In the last decade, there have been great advancements in the understanding of TMDs and their relationship with neurovascular pains such as headaches. Understanding of TMDs is necessary for the context of its comorbidity with primary headache disorders. The literature regarding management of these comorbidities is scarce but points to combination therapy including pharmacological and non-pharmacological approaches to optimize management. The use of CGRP receptor-targeted monoclonal antibodies or CGRP receptor antagonists should be explored for the management of chronic TMDs. It could also be used as a novel monotherapy or in combination with non-pharmacological approaches for TMDs' comorbidity with headache, particularly migraine. Research is needed to support evidence-based management protocols. A team involving neurology (headache medicine) and dentistry (orofacial pain) is critical for optimal management.

Pain sensitization and atrophy of deep cervical muscles in patients with chronic tension-type headache

OBJECTIVE

The aim of this study was to compare the pressure pain threshold and the thickness of the cervical muscles in patients with tension-type headache versus healthy participants.

METHODS

An observational, retrospective, cross-sectional study was conducted at the Universidad Europea de Madrid between May and June 2022. Adults aged 18-65 years with tension-type headache diagnosed for more than 6 months were compared to healthy controls. B-mode ultrasound imaging was employed to measure the thickness of the neck stabilizing muscles, longus colli, and multifidus at the C5 and C6 levels, respectively. pressure pain threshold measurements were assessed bilaterally in the following regions: upper trapezius, masseter, temporalis, anterior tibialis, and median nerve.

RESULTS

A total of 40 participants (90% females; 36.3±12.9 years, BMI 24.2±3.7 kg/m2) participated in the study. Compared with the control group (n=20), participants in the tension-type headache group (n=20) presented statistically significant lower values in all pressure pain threshold measures. Additionally, the tension-type headache group presented statistically significant lower values in the thickness of the following muscles: right multifidus at rest (1.0±0.2 cm versus 1.3±0.2 cm; p<0.001), left multifidus at rest (1.1±0.1 cm versus 1.3±0.1 cm; p<0.001) and during contraction (1.2±0.1 cm versus 1.5±0.2 cm; p<0.001), left longus colli at rest (1.0±0.2 cm versus 1.2±0.1 cm; p=0.01) and during contraction (1.2±0.2 cm versus 1.4±0.1 cm; p<0.001), and right longus colli during contraction (1.2±0.2 cm versus 1.4±0.2 cm; p=0.02).

CONCLUSION

This study concluded that patients with tension-type headache showed lower thickness and lower pressure pain threshold of cervical muscles compared to healthy controls.

The cervical spine in tension type headache

INTRODUCTION

The concept that headaches may originate in the cervical spine has been discussed over decades and is still a matter of debate. The cervical spine has been traditionally linked to cervicogenic headache; however, current evidence supports the presence of cervical musculoskeletal dysfunctions also in tension-type headache.

PURPOSE

This position paper discusses the most updated clinical and evidence-based data about the cervical spine in tension-type headache.

IMPLICATIONS

Subjects with tension-type headache exhibit concomitant neck pain, cervical spine sensitivity, forward head posture, limited cervical range of motion, positive flexion-rotation test and also cervical motor control disturbances. In addition, the referred pain elicited by manual examination of the upper cervical joints and muscle trigger points reproduces the pain pattern in tension-type headache. Current data supports that the cervical spine can be also involved in tension-type headache, and not just in cervicogenic headache. Several physical therapies including upper cervical spine mobilization or manipulation, soft tissue interventions (including dry needling) and exercises targeting the cervical spine are proposed for managing tension-type headache; however, the effectiveness of these interventions depends on a proper clinical reasoning since not all will be equally effective for all individuals with tension-type headache. Based on current evidence, we propose to use the terms cervical "component" and cervical "source" when discussing about headache. In such a scenario, in cervicogenic headache the neck can be the cause (source) of the headache whereas in tension-type headache the neck will have a component on the pain pattern, but it will be not the cause since it is a primary headache.

Cervicogenic headache

INTRODUCTION

Cervicogenic headache, first proposed as a distinct headache in 1983, is a secondary headache to a primary cervical musculoskeletal disorder. Research into physical impairments was integral to clinical diagnosis and to develop and test research informed conservative management as the first line approach.

PURPOSE

This narrative presents an overview of the body of cervicogenic headache research from our laboratory which was undertaken in the context of a broad program of research into neck pain disorders.

IMPLICATIONS

Early research validated manual examination of the upper cervical segments against anaesthetic nerve blocks, which was vital to clinical diagnosis of cervicogenic headache. Further studies identified reduced cervical motion, altered motor control of the neck flexors, reduced strength of flexor and extensor muscles, and occasional presentation of mechanosensitivity of the upper cervical dura. Single measures are variable and not reliable in diagnosis. We proved that a pattern of reduced motion, upper cervical joint signs and impaired deep neck flexor function accurately identified cervicogenic headache and differentiated it from migraine and tension-type headache. The pattern was validated against placebo controlled diagnostic nerve blocks. A large multicentre clinical trial determined that a combined program of manipulative therapy and motor control exercise is effective in the management of cervicogenic headache and outcomes are maintained in the long term. More specific research into cervical related sensorimotor controlled is warranted in cervicogenic headache. Further adequately powered clinical trials of current research informed multimodal programs are advocated to further strengthen the evidence base for conservative management of cervicogenic headache.

Debate: differences and similarities between tension-type headache and migraine

Tension-type headache (TTH) and migraine are two common primary headaches distinguished by clinical characteristics according to the 3^rd edition of the International Classification of Headache Disorders. Migraine is identified by specific features such as being more prevalent in females, being aggravated by physical activity, certain genetic factors, having photophobia, phonophobia, nausea, vomiting, or aura, and responding to specific drugs. Nonetheless, TTH and migraine share some common characteristics, such as onset occurring in the 20 s, and being triggered by psychological factors like stress, moderate pain severity, and mild nausea in chronic TTH. Both conditions involve the trigeminovascular system in their pathophysiology. However, distinguishing between TTH and migraine in clinical practice, research, and epidemiological studies can be challenging, as there is a lack of specific diagnostic tests and biomarkers. Moreover, both conditions may coexist, further complicating the diagnostic process. This review aims to explore the similarities and differences in the pathophysiology, epidemiology, burden and disability, comorbidities, and responses to pharmacological and non-pharmacological treatments of TTH and migraine. The review also discusses future research directions to address the diagnostic challenges and improve the understanding and management of these conditions.

Path Analysis Models Integrating Psychological, Psycho-physical and Clinical Variables in Individuals With Tension-Type Headache

Tension type headache (TTH) is a prevalent but poorly understood pain disease. Current understanding supports the presence of multiple associations underlying its pathogenesis. Our aim was to compare competing multivariate pathway models that explains the complexity of TTH. Headache features (intensity, frequency, or duration - headache diary), headache-related disability (Headache Disability Inventory-HDI), anxiety/depression (Hospital Anxiety and Depression Scale), sleep quality (Pittsburgh Sleep Quality Index), widespread pressure pain thresholds (PPTs) and trigger points (TrPs) were collected in 208 individuals with TTH. Four latent variables were formed from the observed variables - Distress (anxiety, depression), Disability (HDI subscales), Severity (headache features), and Sensitivity (all PPTs). Structural equation modelling (SEM) and Bayesian network (BN) analyses were used to build and compare a theoretical (model_theory) and a data-driven (model_BN) latent variable model. The model_BN (root mean square error of approximation [RMSEA] = 0.035) provided a better statistical fit than model_theory (RMSEA = 0.094). The only path common between model_bn and model_theory was the influence of years with pain on TrPs. The model_BN revealed that the largest coefficient magnitudes were between the latent variables of Distress and Disability (β=1.524, P = .006). Our theoretical model proposes a relationship whereby psycho-physical and psychological factors result in clinical features of headache and ultimately affect disability. Our data-driven model proposes a more complex relationship where poor sleep, psychological factors, and the number of years with pain takes more relevance at influencing disability. Our data-driven model could be leveraged in clinical trials investigating treatment approaches in TTH. PERSPECTIVE: A theoretical model proposes a relationship where psycho-physical and psychological factors result in clinical manifestations of headache and ultimately affect disability. A data-driven model proposes a more complex relationship where poor sleep, psychological factors, and number of years with pain takes more relevance at influencing disability.

Effects of diacutaneous fibrolysis in patients with tension-type headache: A randomized controlled trial

BACKGROUND

Manual therapy appears to be effective for the relief of tension-type headache (TTH), just as diacutaneous fibrolysis (DF) has shown to be a beneficial technique for the relief of symptoms in other dysfunctions. However, no studies have evaluated the potential beneficial effect of DF in TTH. The aim of this study is to analyze the effect of three sessions of DF in patients with TTH.

METHODS

Randomized controlled trial in 86 subjects (43 intervention/ 43 control group). The headache frequency, the headache intensity, the pressure pain thresholds (PPTs) at trapeziometacarpal joint, upper trapezius, suboccipital, frontal and temporal muscles, parietal sutures and the cervical mobility were measured at baseline, at the end of the third intervention and one-month after the last intervention.

RESULTS

Statistically significant differences with p values <0.05 were observed between groups in favor of the intervention group in the one-month follow-up in the following variables: headache frequency, headache intensity, flexion, extension, right and left side-bending, right and left rotation, PPTs in left trapeziometacarpal joint, right suboccipital muscle, right and left temporal muscle, left frontal muscle and right and left parietal.

CONCLUSIONS

DF provides a beneficial effect in reducing headache frequency, relieving pain, and improving cervical mobility in patients with TTH.

The Role of the Autonomic Nervous System in Headache: Biomarkers and Treatment

Purpose of Review

In this review, the role of the autonomic nervous system in tension-type headache and migraine is reviewed.

Recent Findings

A pathophysiological model for tension-type headache is proposed that is compatible with most physiological and behavioral literature.

Summary

A treatment protocol is described that follows from this model. For migraine, incorporating autonomic factors into the pathophysiology offers rationales for behavioral interventions that have been shown to be useful in migraine treatment and a biofeedback protocol is proposed.

Convergent Validity of the Central Sensitization Inventory in Women with Fibromyalgia: Association with Clinical, Psychological and Psychophysical Outcomes

BACKGROUND

To assess the relationship between demographic, clinical, psychological, and pressure pain sensitivity outcomes with the central sensitization inventory (CSI) in female with fibromyalgia (FMS).

METHODS

One hundred twenty-six (n=126) females with FMS completed demographic (age, body mass index, height, weight), clinical (pain history, pain intensity at rest and during daily living activities), psychological (depression/anxiety levels) outcomes and widespread pressure pain sensitivity as well as the central sensitization inventory (CSI). After conducting a multivariable correlation analysis to identify the association between variables, a multiple linear regression model was performed to identify CSI predictors.

RESULTS

The CSI was negatively associated with age (r=-0.262) and PPTs (r ranged from -0.221 to -0.372) and positively associated with anxiety (r=0.541), depression (r=0.415), mean intensity (r=0.305), worst pain (r=0.249), and pain during daily living activities (r= 0.398). The stepwise regression analysis revealed that 47.4% of CSI variance in this sample was explained by anxiety levels (27.8%), PPT at greater trochanter (10.5%), age (1.4%), years with pain (4.8%) and pain during daily living activities (2.9%).

CONCLUSION

The current study found that age, pain intensity at rest and pain during daily living activities, anxiety levels, and pressure pain sensitivity are associated with the CSI (associated sensitization symptoms) in women with FMS.

Sensory Thresholds and Peripheral Nerve Responses in Chronic Tension-Type Headache and Neuropsychological Correlation

Chronic tension-type headache (CTTH) is a common disease with no fully defined pathophysiological processes. We designed a study to value electrophysiological responses in these patients and their correlation with possible psychopathological manifestations in order to deepen understanding of central and peripheral mechanisms of CTTH. In 40 patients with CTTH and 40 healthy controls, we used electrical stimulation to determine sensory threshold (SPT) and pain perception threshold (PPT) and the characteristics of the electrophysiological sensory nerve action potential (SNAP): initial sensory response (ISR) and supramaximal response (SMR). We then calculated the intensity differences between thresholds (IDT), namely SPT-PPT, ISR-SMR and SMR-PPT, and correlated these IDTs with psychological characteristics: trait and state anxiety, depression, and emotional regulation. The SPT, together with the ISR and SMR thresholds, were higher (p < 0.01) in CTTH patients. The SMR-PPT IDT was smaller and correlated with significantly higher indicators of depression, state and trait anxiety, and poorer cognitive reappraisal. CTTH patients have less capacity to recognize non-nociceptive sensory stimuli, greater tendency toward pain facilitation, and a poor central pain control requiring higher stimulation intensity thresholds to reach the start and the peak amplitude of the SNAP. This is consistent with relative hypoexcitability of the Aβ nerve fibers in distant regions from the site of pain, and therefore, it could be considered a generalized dysfunction with a focal expression. Pain facilitation is directly associated with psychological comorbidity.

Localized and widespread pressure pain hypersensitivity in patients with episodic or chronic migraine: A systematic review and meta-analysis

OBJECTIVE

This meta-analysis compared pressure pain sensitivity in trigeminal, cervical spine and remote pain-free areas between migraine patients and headache-free controls considering diagnosis (episodic versus chronic) and sex.Databases and data treatment: Electronic databases were searched for cross-sectional or prospective case-control studies comparing pressure pain thresholds between migraine and headache-free controls. Data were extracted by two reviewers. The risk of bias and methodological quality was assessed by Newcastle-Ottawa Quality Assessment Scale. Meta-analyses of trigeminal, extra-trigeminal (cervical spine) and remote pain-free areas were compared. Frequency of migraine and sex were taken into account. Mean differences (MD) and random effects were calculated.

RESULTS

Eighteen studies were included. Patients with migraine showed lower pressure pain thresholds than headache-free controls: trigeminal (MD -71.33 kPa, 95%CI -92.14 to -50.53), cervical spine (MD -68.50 kPa, 95%CI -84.67 to -52.33), and remote pain-free (MD -62.49 kPa, 95%CI -99.52 to -25.45) areas. Differences were consistently significant for episodic migraine in all locations, but only significant in the trigeminal area for chronic migraine (MD -67.36 kOPa, 95%CI -101.31 to -33.42). Overall, women had lower pressure pain thresholds than men. The methodological quality of most studies (66.7%) was good. The results showed a high heterogeneity.

CONCLUSION

This meta-analysis found low to high quality evidence showing lower pressure pain thresholds in trigeminal, extra-trigeminal, and remote pain-free areas in migraine sufferers when compared with headache-free controls. Hypersensitivity to pressure pain locally and widespread was consistently observed in episodic migraine, but locally in chronic migraine as compared to headache-free controls. Women with migraine were more sensitive than men.Registration number: https://doi.org/10.17605/OSF.IO/YJTAK.

Understanding the interaction between clinical, emotional and psychophysical outcomes underlying tension-type headache: a network analysis approach

OBJECTIVE

Evidence supports that tension-type headache (TTH) involves complex underlying mechanisms. The current study aimed to quantify potential multivariate relationships between headache-related, psychophysical, psychological and health-related variables in patients with TTH using network analysis.

METHODS

Demographic (age, height, weight), headache-related (intensity, frequency, duration, and headache-related disability), psychological and emotional (Hospital Anxiety and Depression Scale, Pittsburgh Sleep Quality Index), psycho-physical (pressure pain thresholds [PPTs] and myofascial trigger points) and health-related variables (SF-36 questionnaire) were collected in 169 TTH patients. Network connectivity analysis was unsupervised conducted to quantify the adjusted correlations between the modelled variables and to assess their centrality indices (i.e., the connectivity with other symptoms in the network and the importance in the modelled network).

RESULTS

The connectivity network showed local associations between psychophysical and headache-related variables. Multiple significant local positive correlations between PPTs were observed, being the strongest weight between PPTs over the cervical spine and temporalis area ([Formula: see text]: 0.41). The node with the highest strength, closeness and betweenness centrality was depressive levels. Other nodes with high centrality were vitality and headache intensity.

DISCUSSION

This is the first study applying a network analysis to understand the connections between headache-related, psychophysical, psychological and health-related variables in TTH. Current findings support a model on how the variables are connected, albeit in separate clusters. The role of emotional aspects, such as depression, is supported by the network. Clinical implications of the findings, such as developing TTH treatments strategies targeting these most important variables, are discussed.

Psychophysical testing in chronic migraine and chronic tension type headache: An observational study

BACKGROUND

Clinical presentation is the key to the diagnosis of patients with migraine and tension-type headache, but features may overlap when both become chronic. Psychophysical parameters may distinguish both conditions. We aimed to compare psychophysical aspects of patients with chronic migraine, chronic tension-type headache and headache-free controls, and to determine whether these can predict headache frequency.

METHODS

An examiner blinded to the diagnosis assessed 100 participants (chronic migraine (n = 38), chronic tension-type headache (n = 31) and controls (n = 31)). Assessed variables included painful area, pressure pain thresholds, temporal summation, cervical range of motion, neck posture, headache and neck impact, quality of life, and kinesiophobia. Comparison between groups was performed with one-way ANOVA and multiple linear regression was used to assess the headache frequency predictors.

RESULTS

We found differences of both headache groups compared to controls (p < 0.01), but not between headache groups. Neck disability was a significant predictor of headache frequency for chronic tension-type headache (adjusted R² = 0.14; β = 0.43; p = 0.03) and chronic migraine (adjusted R² = 0.18; β = 0.51; p < 0.01).

CONCLUSIONS

Chronic tension-type headache and chronic migraine showed similar psychophysical results, but were significantly worse when compared to controls. The psychophysical examination did not discriminate between headache types. The variable best explaining headache frequency for both headache types was neck disability.

Has the Phase of the Menstrual Cycle Been Considered in Studies Investigating Pressure Pain Sensitivity in Migraine and Tension-Type Headache: A Scoping Review

OBJECTIVE

The aim of this scoping review was to identify if the phase of the menstrual cycle was considered in observational studies comparing pressure pain sensitivity between women with migraine or tension-type headache (TTH) and headache-free women.

METHODS

A systematic electronic literature search in PubMed, Medline, Web of Science, Scopus, and CINAHL databases was conducted. Observational studies including one or more groups with TTH and/or migraine comparing pressure pain thresholds (PPTs) were included. The methodological quality (risk of bias) was assessed with the Newcastle-Ottawa Scale. Authors, objectives, inclusion/exclusion criteria, size sample, female sample, tool to assess PPTs, mean age, and the use of any medication were extracted and analyzed independently by two authors.

RESULTS

From a total of 1404 and 1832 identified articles for TTH and migraine, 30 and 18 studies satisfied the criteria and were included. Nineteen (63.4%) studies assessing TTH patients and eleven (61.1%) assessing migraine patients showed a high risk of bias. The most common flaws were attributed to improper selection of control and control over other additional factors. Based on the systematic review, just one study including TTH and one including migraine patients considered the menstrual cycle.

CONCLUSION

The results of this scoping review identified that the phase of the menstrual cycle has been rarely considered in studies investigating sensitivity to pressure pain in primary headaches, such as TTH or migraine, although there is evidence showing the relevance of the phase of the menstrual cycle in pain perception.

Evidence of Bilateral Localized, but Not Widespread, Pressure Pain Hypersensitivity in Patients With Upper Extremity Tendinopathy/Overuse Injury: A Systematic Review and Meta-Analysis

OBJECTIVE

The presence of altered nociceptive pain processing in patients with upper extremity tendinopathy/overuse injury is conflicting. Our aim was to compare pressure pain thresholds (PPTs) in symptomatic and distant pain-free areas between patients with upper extremity tendinopathy/overuse injury and controls.

METHODS

Five databases were searched from inception to October 15, 2020. The authors selected case-control studies comparing PPTs between individuals with upper extremity tendinopathy/overuse injury and pain-free controls. Data were extracted for population, diagnosis, sample size, outcome, and type of algometer. Results were extracted by 3 reviewers. The methodological quality/risk of bias (Newcastle-Ottawa Quality Assessment Scale) and evidence level (Grading of Recommendations Assessment, Development and Evaluation approach) were assessed. Meta-analyses of symptomatic, segment-related, and distant pain-free areas were compared.

RESULTS

The search identified 807 publications with 19 studies (6 shoulder, 13 elbow) eligible for inclusion. The methodological quality ranged from fair (48%) to good (37%). Patients exhibited lower bilateral PPTs than controls at the symptomatic area (affected side: MD = -175.89 kPa [95% CI = -220.30 to -131.48 kPa]; nonaffected side: MD = -104.50 kPa [95% CI = -142.72 to -66.28 kPa]) and the segment-related area (affected side: MD = -150.63 kPa [95% CI = -212.05 to -89.21 kPa]; nonaffected side: MD = -170.34 kPa [95% CI = - 248.43 to -92.25]) than controls. No significant differences in PPTs over distant pain-free areas were observed.

CONCLUSION

Low to moderate quality evidence suggests bilateral hypersensitivity to pressure pain at the symptomatic and contralateral/mirror areas in patients with upper extremity tendinopathies/overuse injury. Moderate quality of evidence supports bilateral pressure pain sensitivity in the segment-related area (neck) in lateral epicondylalgia, but not in subacromial impingement syndrome. No evidence of widespread pressure pain hyperalgesia was reported.

IMPACT

Early identification of people with altered pain modulation could guide clinicians in treatment strategies. This review shows that there is a complex interplay between peripheral and central pain mechanisms in upper extremity tendinopathies/overuse injuries and that there likely are different subgroups of patients with upper extremity conditions.

Patient Profiling Based on Spectral Clustering for an Enhanced Classification of Patients with Tension-Type Headache

Profiling groups of patients in clusters can provide meaningful insights into the features of the population, thus helping to identify people at risk of chronification and the development of specific therapeutic strategies. Our aim was to determine if spectral clustering is able to distinguish subgroups (clusters) of tension-type headache (TTH) patients, identify the profile of each group, and argue about potential different therapeutic interventions. A total of 208 patients (n = 208) with TTH participated. Headache intensity, frequency, and duration were collected with a 4-week diary. Anxiety and depressive levels, headache-related burden, sleep quality, health-related quality of life, pressure pain thresholds (PPTs), dynamic pressure thresholds (DPT) and evoked-pain, and the number of trigger points (TrPs) were evaluated. Spectral clustering was used to identify clusters of patients without any previous assumption. A total of three clusters of patients based on a main difference on headache frequency were identified: one cluster including patients with chronic TTH (cluster 2) and two clusters including patients with episodic TTH (clusters 0–1). Patients in cluster 2 showed worse scores in all outcomes than those in clusters 0–1. A subgroup of patients with episodic TTH exhibited pressure pain hypersensitivity (cluster 0) similarly to those with chronic TTH (cluster 2). Spectral clustering was able to confirm subgrouping of patients with TTH by headache frequency and to identify a group of patients with episodic TTH with higher sensitization, which may need particular attention and specific therapeutic programs for avoiding potential chronification.

Clinical Reasoning for the Examination and Physical Therapy Treatment of Temporomandibular Disorders (TMD): A Narrative Literature Review

The current narrative literature review aims to discuss clinical reasoning based on nociceptive pain mechanisms for determining the most appropriate assessment and therapeutic strategy and to identify/map the most updated scientific evidence in relation to physical therapy interventions for patients with temporomandibular disorders (TMDs). We will also propose an algorithm for clinical examination and treatment decisions and a pain model integrating current knowledge of pain neuroscience. The clinical examination of patients with TMDs should be based on nociceptive mechanisms and include the potential identification of the dominant, central, or peripheral sensitization driver. Additionally, the musculoskeletal drivers of these sensitization processes should be assessed with the aim of reproducing symptoms. Therapeutic strategies applied for managing TMDs can be grouped into tissue-based impairment treatments (bottom-up interventions) and strategies targeting the central nervous system (top-down interventions). Bottom-up strategies include joint-, soft tissue-, and nerve-targeting interventions, as well as needling therapies, whereas top-down strategies include exercises, grade motor imagery, and also pain neuroscience education. Evidence shows that the effectiveness of these interventions depends on the clinical reasoning applied, since not all strategies are equally effective for the different TMD subgroups. In fact, the presence or absence of a central sensitization driver could lead to different treatment outcomes. It seems that multimodal approaches are more effective and should be applied in patients with TMDs. The current paper also proposes a clinical decision algorithm integrating clinical diagnosis with nociceptive mechanisms for the application of the most appropriate treatment approach.