Self-Reported Facial Pain in UK Biobank Study: Prevalence and Associated Factors

Variability in the prevalence of depression among adults with chronic pain: UK Biobank analysis through clinical prediction models

BACKGROUND

The prevalence of depression among people with chronic pain remains unclear due to the heterogeneity of study samples and definitions of depression. We aimed to identify sources of variation in the prevalence of depression among people with chronic pain and generate clinical prediction models to estimate the probability of depression among individuals with chronic pain.

METHODS

Participants were from the UK Biobank. The primary outcome was a "lifetime" history of depression. The model's performance was evaluated using discrimination (optimism-corrected C statistic) and calibration (calibration plot).

RESULTS

Analyses included 24,405 patients with chronic pain (mean age 64.1 years). Among participants with chronic widespread pain, the prevalence of having a "lifetime" history of depression was 45.7% and varied (25.0-66.7%) depending on patient characteristics. The final clinical prediction model (optimism-corrected C statistic: 0.66; good calibration on the calibration plot) included age, BMI, smoking status, physical activity, socioeconomic status, gender, history of asthma, history of heart failure, and history of peripheral artery disease. Among participants with chronic regional pain, the prevalence of having a "lifetime" history of depression was 30.2% and varied (21.4-70.6%) depending on patient characteristics. The final clinical prediction model (optimism-corrected C statistic: 0.65; good calibration on the calibration plot) included age, gender, nature of pain, smoking status, regular opioid use, history of asthma, pain location that bothers you most, and BMI.

CONCLUSIONS

There was substantial variability in the prevalence of depression among patients with chronic pain. Clinically relevant factors were selected to develop prediction models. Clinicians can use these models to assess patients' treatment needs. These predictors are convenient to collect during daily practice, making it easy for busy clinicians to use them.

Educational attainment, family background and the emergence of pain gradients in adulthood

Current studies have indicated that the number of individuals living with pain has risen in recent years, with nearly half of all adults in some countries living with some form of pain. Such trends have prompted researchers to explore differences in pain across different sociodemographic groups, with a dominant focus on educational attainment. However, much of the studies fail to consider the confounding role of early life characteristics, such as family background. Using data on over 400,000 individuals from the UK Biobank, we look at how educational attainment is associated with nine different domains of pain (headache, facial, neck, back, hip, knee, stomach, all over, and no pain). Ultimately, we find that compared to those with no educational credentials, education is associated with anywhere between a 0.1-15% change in the likelihood of reporting pain, depending on pain type and education level, with the greatest change occurring in those with the highest level. Yet, when accounting for family background characteristics in the form of sibling fixed effects, nearly all relationships between education and pain fell by either 50% or were eliminated. We ultimately conclude that failure to consider early life characteristics, such as family background characteristics may lead to inflated estimates of pain, and that future research should delve into early life exposures and their influence on pain in adulthood.

Reciprocal relationships between stress and depressive symptoms: the essential role of the nucleus accumbens

BACKGROUND

Stress and depression have a reciprocal relationship, but the neural underpinnings of this reciprocity are unclear. We investigated neuroimaging phenotypes that facilitate the reciprocity between stress and depressive symptoms.

METHODS

In total, 22 195 participants (52.0% females) from the population-based UK Biobank study completed two visits (initial visit: 2006-2010, age = 55.0 ± 7.5 [40-70] years; second visit: 2014-2019; age = 62.7 ± 7.5 [44-80] years). Structural equation modeling was used to examine the longitudinal relationship between self-report stressful life events (SLEs) and depressive symptoms. Cross-sectional data were used to examine the overlap between neuroimaging correlates of SLEs and depressive symptoms on the second visit among 138 multimodal imaging phenotypes.

RESULTS

Longitudinal data were consistent with significant bidirectional causal relationship between SLEs and depressive symptoms. In cross-sectional analyses, SLEs were significantly associated with lower bilateral nucleus accumbal volume and lower fractional anisotropy of the forceps major. Depressive symptoms were significantly associated with extensive white matter hyperintensities, thinner cortex, lower subcortical volume, and white matter microstructural deficits, mainly in corticostriatal-limbic structures. Lower bilateral nucleus accumbal volume were the only imaging phenotypes with overlapping effects of depressive symptoms and SLEs (B = -0.032 to -0.023, p = 0.006-0.034). Depressive symptoms and SLEs significantly partially mediated the effects of each other on left and right nucleus accumbens volume (proportion of effects mediated = 12.7-14.3%, p < 0.001-p = 0.008). For the left nucleus accumbens, post-hoc seed-based analysis showed lower resting-state functional connectivity with the left orbitofrontal cortex (cluster size = 83 voxels, p = 5.4 × 10-5) in participants with high v. no SLEs.

CONCLUSIONS

The nucleus accumbens may play a key role in the reciprocity between stress and depressive symptoms.

Assessing the association of coffee consumption on the relationship of chronic pain with depression and anxiety

BACKGROUND

A bidirectional relationship between chronic pain (CP) and mental disorders has been reported, and coffee was believed to be associated with both. However, the association of coffee in this bidirectional relationship remains unclear. We aim to analyze the association of coffee consumption on the relationship of CP with depression and anxiety.

METHODS

A total of 376,813 participants from UK Biobank were included. We collected data on anxiety, depression and CP from objects of our study population. The association of coffee consumption on the relationship of CP with depression and anxiety was assessed through logistic/linear regression models. Moreover, seemingly unrelated estimation test (SUEST) was used to compare whether the coefficients differed in two different groups.

RESULTS

We observed significant associations of coffee consumption in the interaction of CP with depression and anxiety, such as the association of multisite chronic pain (MCP) on self-reported depression (βcoffee = 0.421, βnon-coffee = 0.488, PSUEST = 0.001), and the association of MCP on generalized anxiety disorder-7 (GAD-7) scores (βcoffee = 0.561, βnon-coffee = 0.678, PSUEST = 0.004) were significantly different between coffee drinking and non-coffee drinking groups. Furthermore, in analysis stratified by gender, we found headache (βmale = 0.392, βfemale = 0.214, PSUEST = 0.022) and hip pain (βmale = 0.480, βfemale = 0.191, PSUEST = 0.021) had significant associations with self-reported depression between males and females groups in coffee drinkers.

CONCLUSIONS

Our results suggested that coffee consumption has a significant association on the relationship of CP with depression and anxiety.

Impact of Environment on Pain among the Working Poor: Making Use of Random Forest-Based Stratification Tool to Study the Socioecology of Pain Interference

Pain interferes with one's work and social life and, at a personal level, daily activities, mood, and sleep quality. However, little research has been conducted on pain interference and its socioecological determinants among the working poor. Noting the clinical/policy decision needs and the technical challenges of isolating the intricately interrelated socioecological factors' unique contributions to pain interference and quantifying the relative contributions of each factor in an interpretable manner to inform clinical and policy decision-making, we deployed a novel random forest algorithm to model and quantify the unique contribution of a diverse ensemble of environmental, sociodemographic, and clinical factors to pain interference. Our analyses revealed that features representing the internal built environment of the working poor, such as the size of the living space, air quality, access to light, architectural design conducive to social connection, and age of the building, were assigned greater statistical importance than other more commonly examined predisposing factors for pain interference, such as age, occupation, the severity and locations of pain, BMI, serum blood sugar, and blood pressure. The findings were discussed in the context of their benefit in informing community pain screening to target residential areas whose built environment contributed most to pain interference and informing the design of intervention programs to minimize pain interference among those who suffered from chronic pain and showed specific characteristics. The findings support the call for good architecture to provide the spirit and value of buildings in city development.

Big data, big consortia, and pain: UK Biobank, PAINSTORM, and DOLORisk

Chronic pain (CP) is a common and often debilitating disorder that has major social and economic impacts. A subset of patients develop CP that significantly interferes with their activities of daily living and requires a high level of healthcare support. The challenge for treating physicians is in preventing the onset of refractory CP or effectively managing existing pain. To be able to do this, it is necessary to understand the risk factors, both genetic and environmental, for the onset of CP and response to treatment, as well as the pathogenesis of the disorder, which is highly heterogenous. However, studies of CP, particularly pain with neuropathic characteristics, have been hindered by a lack of consensus on phenotyping and data collection, making comparisons difficult. Furthermore, existing cohorts have suffered from small sample sizes meaning that analyses, especially genome-wide association studies, are insufficiently powered. The key to overcoming these issues is through the creation of large consortia such as DOLORisk and PAINSTORM and biorepositories, such as UK Biobank, where a common approach can be taken to CP phenotyping, which allows harmonisation across different cohorts and in turn increased study power. This review describes the approach that was used for studying neuropathic pain in DOLORisk and how this has informed current projects such as PAINSTORM, the rephenotyping of UK Biobank, and other endeavours. Moreover, an overview is provided of the outputs from these studies and the lessons learnt for future projects.

A single infusion of intravenous lidocaine for primary headaches and trigeminal neuralgia: a retrospective analysis

Introduction

Intravenous (IV) lidocaine has been used as a transitional treatment in headache and facial pain conditions, typically as an inpatient infusion over several days, which is costly and may increase the risk of adverse effects. Here we report on our experience using a single one-hour IV lidocaine infusion in an outpatient day-case setting for the management of refractory primary headache disorders with facial pain and trigeminal neuralgia.

Methods

This is a retrospective, single-center analysis on patients with medically refractory headache with facial pain and trigeminal neuralgia who were treated with IV lidocaine between March 2018 and July 2022. Lidocaine 5 mg.kg-1 in 60 mL saline was administered over 1 h, followed by an observation period of 30 min. Patients were considered responders if they reported reduction in pain intensity and/or headache frequency of 50% or greater. Duration of response was defined as short-term (< 2 weeks), medium-term (2-4 weeks) and long-term (> 4 weeks).

Results

Forty infusions were administered to 15 patients with trigeminal autonomic cephalalgias (n = 9), chronic migraine (n = 3) and trigeminal neuralgia (n = 3). Twelve patients were considered responders (80%), eight of whom were complete responders (100% pain freedom). The average duration of the treatment effect for each participant was 9.5 weeks (range 1-22 weeks). Six out of 15 patients reported mild and self-limiting side effects (40%).

Conclusion

A single infusion of IV lidocaine might be an effective and safe transitional treatment in refractory headache conditions with facial pain and trigeminal neuralgia. The sustained effect of repeated treatment cycles in some patients may suggest a role as long-term preventive therapy in some patients.

A novel implantable device for sensory and affective assessment of orofacial pain in rats

Background and objective

Orofacial pain, in particular, chronic orofacial pain remains a great challenge in clinical practice. To better understand the underlying mechanism of disease, it is essential to apply a feasible and stable preclinical measurement of facial pain. Here, we introduced a novel electrical noxious stimulator in freely behavioral rodents and examined its validation in both naïve and chronic orofacial pain animals.

Methods

One subcutaneous device of electrical stimulator was implanted in the facial region for delivery of the nociceptive input. The sensory component of orofacial pain was assessed by response scoring tool, and conditioned place aversion (CPA) paradigm for pain affect respectively. To confirm its usage in chronic pain state, the chronic constriction injury of the infraorbital nerve (ION-CCI) model was then applied.

Results

We found that responsive scores increased with stimulation intensity, and acted in a dosage-dependent manner, which can be attenuated by the administration of morphine intraperitoneally. Naïve rats displayed significant aversive reaction to the noxious electrical stimulation (25V) in the CPA testing. In addition, an obvious sensory hypersensitivity to electrical stimulation was confirmed by the increased response scores in ION-CCI rats. Furthermore, ION-CCI animal showed significant avoidance to electrical stimulation at relatively low intensity (10V), which was innoxious to naïve rats.

Conclusion

Our findings may provide an alternative pre-clinical measurement of orofacial pain, to quantitively assess both sensory and affective component of orofacial pain.

Does Oral Health-Related Quality of Life Differ by Income Group? Findings from a Nationally Representative Survey

OBJECTIVES

Clarify the association between income group and oral health-related quality of life.

METHODS

Data were used from a nationally representative online survey with n = 3075 individuals. It was conducted in late Summer 2021. The established Oral Health Impact Profile (OHIP-G5) was used to measure oral health-related quality of life. The income group (household net income) was used as key independent variable. It was adjusted for several covariates. Full-information maximum likelihood was used to address missing values.

RESULTS

Individuals in the lowest income decile had a lower oral health-related quality of life (Cohen's d = -0.34) compared to individuals in the second to ninth income deciles. Individuals in the highest income decile had a higher oral health-related quality of life (Cohen's d = 0.20) compared to individuals in the second to ninth income deciles. Consequently, there was a medium difference (Cohen's d = 0.53) between individuals in the lowest income decile and individuals in the highest income decile. Additionally, multiple linear regressions showed significant differences between individuals in the lowest income decile and individuals in the second to ninth income deciles (β = 0.72, p < 0.01). In contrast, only marginal significant differences were identified between individuals in the second to ninth income deciles and individuals in the highest income decile (β = -0.28, p < 0.10).

CONCLUSIONS

The current study particularly stressed the association between low income and low oral health-related quality of life in the general adult population. Increasing oral health-related quality of life in individuals with low income is a major issue which should be targeted.

Orofacial pain disorders: An overview and diagnostic approach

Background:

Non-dental orofacial pain disorders are not uncommon, but idiopathic or primary facial pain syndromes are rare. Inadequate recognition of these disorders usually leads to unsatisfactory and unmet treatment needs.

Methods:

We conducted a narrative review with a literature search in PubMed until December 2021, focusing on current guidelines and the recently published International Classification of Orofacial Pain (ICOP).

Results:

In this paper, we provide an updated overview of the common orofacial pain disorders following the ICOP, covering the classification, epidemiology, pathophysiology, clinical approaches, and treatment options. Additionally, we propose a pragmatic approach focusing on the attack duration to improve distinguishing orofacial disorders.

Conclusion:

The introduction of ICOP offers the opportunity to better coordinate and concentrate scientific efforts, which lays the foundation for the identification of the disease mechanism of facial pain disorders and the optimization of the currently still insufficient therapeutic strategies.

Biobanking in dentistry: A review

Biobanks are not-for-profit services for the collection, processing, storage and distribution of biological samples and data for research and diagnostic purposes. In dentistry, biological materials and data obtained from questionnaires investigating oral conditions can be stored and used for large-scale studies on oral and systemic diseases. To give some examples: gene expression microarrays obtained on biobanked specimens were used in the identification of genetic alterations in oral cancer; efforts to identify genetic mechanisms behind dental caries have been based on an integrative analysis of transcriptome-wide associations and messenger RNA expression. One of the largest studies on facial pain was conducted using Biobank data. Cryopreservation of dental pulp stem cells is a common practice in tooth biobanks. With the exception of teeth and pulp, also leftover oral soft and hard tissues may represent a source of healthy samples that has rarely been exploited as yet. While biobanks are increasingly attracting the attention of the scientific community and becoming economically sustainable, a systematic approach to this resource in dentistry seems to be lacking. This review illustrates the applications of biobanking in dentistry, describing biobanked pathological and healthy samples and data, and discussing future developments.

Factors associated with oral pain and oral health-related productivity loss in the USA, National Health and Nutrition Examination Surveys (NHANES), 2015-2018

Background

Our aim was to identify clinical and sociodemographic factors associated with oral pain and oral health-related productivity loss among US adults.

Methods

We included adults aged ≥30 years who completed the dental examination, had at least one natural tooth, and provided an answer about their oral pain experience or oral health-related productivity loss in the 2015–2018 National Health and Nutrition and Examination Survey (NHANES). We performed descriptive analyses and multivariable binary logistic regression analyses on weighted data.

Results

One out of four adults had oral pain and 4% reported oral health-related productivity loss occasionally or often within the last year of the survey. The odds of oral pain were higher among non-Hispanic black (OR = 1.35; 95%CI = 1.08–1.62) and non-Hispanic Asian individuals (OR = 1.38; 95%CI = 1.07–1.78) compared to non-Hispanic white individuals, and individuals with untreated dental caries (OR = 2.06; 95%CI = 1.72–2.47). The odds for oral health-related productivity loss were 13.85 times higher among individuals who reported oral pain (95%CI = 8.07–23.77), and 2.18 times higher among individuals with untreated dental caries (95%CI = 1.65–2.89). The odds of oral pain and reported oral health-related productivity loss decreased as family income increased.

Conclusions

Factors including non-Hispanic black race/ethnicity, lower socio-economic status, and untreated dental caries are associated with oral pain experience, which increases the odds of oral health-related productivity losses. Identifying factors associated with oral pain and productivity loss will enable clinicians, policymakers, and employers to proactively target and prioritize the higher-risk groups in early interventions and policies.

Referred Orofacial Pain as an Initial Symptom of Distant, Nonmetastatic Cancer: Report of a Case and Review of the Literature

Referred orofacial pain as the first symptom of an otherwise silent distant, nonmetastatic cancer has been reported, but there is sparse literature on the subject. Referred pain may not be considered in the orofacial pain differential diagnosis because of its rarity; however, this may delay a cancer diagnosis. The authors present a case report and a review of the English literature. Peer-reviewed publications were identified through a systematic search of MEDLINE, Embase, and Cochrane CENTRAL. Historic cases were reviewed, and available data regarding demographics, pain characteristics, treatment, cancer diagnosis, and outcome were extracted. Thirty-seven cases were identified. All cancers were intrathoracic. The average age was 54.1 years with a slight female predominance (3:2). Common pain characteristics were (1) diffuse location affecting the ear (76%), jaw (46%), and temple (30%); (2) constant duration (65%); (3) aching quality (74%); (4) severe intensity (94%); and (5) associated systemic symptoms (68%) such as weight loss and digital clubbing. The average time from the onset of facial pain to seeking medical attention was 9 months, and the average time from seeking medication attention to cancer diagnosis was 8 months. Orofacial pain was often attributed to odontogenic (35%) or neuropathic (25%) causes, and treatments for these conditions were also common. The impact of referred orofacial pain on the cancer prognosis was not possible because of the nature of the reviewed studies (case reports with no comparison group). Cancer-associated referred orofacial pain as a first symptom is rare but should be considered in cases with intractable pain and associated systemic symptoms.

Development of an interdisciplinary specialist facial pain management programme

Aims:

This article aims to describe the development of a specialist chronic facial pain (CFP) management programme within an already well-established pain management service, including the content from a multidisciplinary perspective, and present preliminary descriptive 6-month outcomes from patients who have attended the programme.

Methods:

Authors used their clinical experience of working with people who have a diagnosis of CFP. They researched available literature, liaised with CFP support organisations and visited an existing UK-based CFP programme. Programme content was designed based on findings. The roles of pain interdisciplinary team members involved in delivering the programme are described, as well as a brief description of the structure of the programme and programme sessions provided by each discipline.

Results:

Clinical outcomes from programme participants were collected at assessment, end of treatment and 6 months post-treatment, which measured relevant outcomes for a pain management programme (PMP). Outcomes from 36 participants at both end of programme and 6 months following completion of programme demonstrate promising improvements. Qualitative data from patient satisfaction questionnaires completed at the end of programme suggest that providing a CFP-specific programme was beneficial for participants, with the main critique being that the programme sessions should be longer than 45 minutes.

Conclusion:

Attending a CFP-specific programme demonstrated positive 6-month changes in relevant outcome measures for people with CFP. With a small sample size, there is a need for further research into the effectiveness. It would also be beneficial to compare outcomes from the usual PMP treatment with people who have CFP, with outcomes from a CFP-specific programme.

Association between signs of hyperalgesia and reported frequent pain in jaw-face and head

OBJECTIVE

To analyze the relationship between different sites of elicited pain to muscle palpation (PtP), and reported frequent pain in jaw-face and head.

MATERIALS AND METHODS

The analysis was based on an epidemiological sample of 1200 randomly selected individuals, of which 779 (65%) both completed a questionnaire and participated in a clinical examination. The questionnaire addressed the presence of pain in the jaw-face region and headache, respectively. Part of the clinical examination entailed palpation of the jaw, neck, shoulder, arm, thumb and calf muscles. Logistic regression was applied with pain and headache as dependent variables. A p-value < .05 determined statistical significance.

RESULTS

Five percent of participants reported frequent pain in jaw-face, and 17% reported frequent headaches. In the regression analysis, frequent headaches were significantly associated with jaw muscle PtP (OR 2.1, CI 1.4-3.4), regional PtP (OR 4.5, CI 2.6-7.6), and generalized PtP (OR 6.1, CI 2.2-17.0). Jaw-face pain was significantly associated with regional PtP (OR 5.3, CI 2.2-13.0) and generalized PtP (OR 30.1, CI 9.3-97.0). The relationship between pain prevalence and PtP showed a dose-response pattern.

CONCLUSIONS

The study indicates that frequent jaw-face pain and headache are primarily associated with signs of regional and widespread hyperalgesia, which may be linked to the central sensitization mechanism. Signs of widespread hyperalgesia should be accounted for in the diagnostic algorithms when examining patients with pain in the jaw, face, and head regions.

Evaluation of orofacial pain and psychological comorbidities in health sciences university students

Introduction: Orofacial pain (OP) is a common public health problem among the general population however, its distribution among the young population like students has not been evaluated so far. The objectives of this study were to investigate the self-reported prevalence, and characteristics of OP, and to evaluate its association with psychological comorbidities such as anxiety and depression. Materials and Methods: A questionnaire-based study was conducted on students studying health sciences programs at SEGi University, Malaysia. A well-designed, structured questionnaire was utilized to assess the prevalence and characteristics of OP. Hospital Anxiety and Depression (HAD) scale was used to evaluate the psychological status of the students. The collected data was subject to statistical analysis by using the SPSS version 22 software. Results: Overall 494 university students had participated in the study of which, 78% (n = 375) of students had suffered from OP and it was significantly higher among the female students (p < 0.03). Headache was the most common type of OP (66.2%) followed by pain in temple region (47.2%), in and around eyes (29.1%), facial region (23.3%), and tooth/gingival pain (20.9%). The association between the prevalence of OP and anxiety was statistically significant (p < 0.019). About 35.4% of the health sciences students had first OP episode started three months ago, 4.2% had daily pain, 14.3% suffered from continuous pain, and only 14% of the students had consulted professionals and 36.1% of them took medication. Conclusion: A significantly higher prevalence of self-reported OP was evident among the health sciences university students and students with different types of OP had higher anxiety and depression scores. Early recognition of OP symptoms and associated comorbidities must be considered for the prevention and successful management of these conditions to circumvent its negative academic impact on the students.

Clinical presentations on a facial pain clinic

Introduction The complex nature of facial pain conditions creates a diagnostic challenge which may necessitate specialist referral.Aim To identify the case mix presenting to a specialist tertiary care facial pain clinic.Methods A retrospective review of 112 patient records was undertaken. Trends in provisional diagnoses from referrers and the correlation to diagnoses made following specialist consultation were reviewed.Results The most common provisional diagnoses recorded in referral letters were painful temporomandibular disorders, trigeminal neuralgia and persistent idiopathic facial pain (PIFP). Over a quarter of referrals did not include a provisional diagnosis. Following assessment, only one case was not given a definitive diagnosis and no patients were diagnosed with PIFP. A causative factor was identified in all the initially queried PIFP cases, and painful post-traumatic trigeminal neuropathic pain was found in multiple patients.Conclusions Painful post-traumatic trigeminal neuropathic pain should be considered if pain onset coincides with dental treatment or other traumatic events. PIFP is a rare facial pain diagnosis and may be over-diagnosed by dental and medical practitioners. It is important to systematically exclude other causes before reaching this diagnosis. This will facilitate effective treatment, manage patient expectations and potentially reduce unnecessary referrals.

Facial Pain: A Comprehensive Review and Proposal for a Pragmatic Diagnostic Approach

BACKGROUND

Facial pain, alone or combined with other symptoms, is a frequent complaint. Moreover, it is a symptom situated at, more than any other pain condition, a crosspoint where several disciplines meet, for example, dentists; manual therapists; ophthalmologists; psychologists; and ear-nose-throat, pain, and internal medicine physicians besides neurologists and neurosurgeons. Recently, a new version of the most widely used classification system among neurologists for headache and facial pain, the International Classification of Headache Disorders, has been published.

OBJECTIVE

The aims of this study were to provide an overview of the most prevalent etiologies of facial pain and to provide a generic framework for the neurologist on how to manage patients presenting with facial pain.

METHODS

An overview of the different etiologies of facial pain is provided from the viewpoint of the respective clinical specialties that are confronted with facial pain. Key message: Caregivers should "think outside their own box" and refer to other disciplines when indicated. If not, a correct diagnosis can be delayed and unnecessary treatments might be given. The presented framework is aimed at excluding life- or organ-threatening diseases, providing several clinical clues and indications for technical investigations, and ultimately leading to the correct diagnosis and/or referral to other disciplines.

The Treatment of Orofacial Pain by Using Transcranial Direct Current Stimulation

Neurostimulation methods are used in the treatment of chronic pain, although mainly for pharmacology resistant pain. Transcranial Direct Current Stimulation (tDCS) is a non-invasive neurostimulation method using low direct current (0.029-0.08 mA/cm2) applied to a cathode and anode, which directly stimulates the cranial surface. The applied current causes the most significant changes directly under the electrodes: the cathode reduces the excitability of cortical neurons, whereas the anode increases excitability. The effect of stimulation usually lasts a few hours up to a few days. We observed 19 patients with chronic orofacial pain. Inclusion criteria for the study were the following: orofacial pain, stable analgesic medication for at least one week before the beginning of stimulation and during its course, and age 18-75 years old. Patients with severe organic brain damage or seizure disease (epilepsy) were not included. The most common diagnosis was secondary trigeminal neuralgia after dental surgery. We measured thermal and tactile stimulation on the face before and after tDCS, then at 14 days. The total follow-up period lasted six months. We evaluated pain on a numerical scale (0-10) at each follow-up. We used sets of inventories focused on the examination of pain (a short form of McGill inventory), depression, anxiety, and pain interference with daily activities. tDCS is a non-invasive stimulation technique that is affordable and can be easily administered, especially when compared to other neurostimulation techniques. Only 15 patients out of the total number of 19 responded to the questionnaires.

Anatomical selectivity in overlap of chronic facial and bodily pain

Supplemental Digital Content is Available in the Text.

Background:

Chronic facial pain often overlaps with pain experienced elsewhere in the body, although previous studies have focused on a few, selected pain conditions when assessing the degree of overlap.

Aim:

To quantify the degree of overlap between facial pain and pain reported at multiple locations throughout the body.

Methods:

Data were from a case–control study of US adults participating in the Orofacial Pain: Prospective Evaluation and Risk Assessment (OPPERA) project. They were interviewed to determine the presence of chronic facial pain (n = 424 cases) or its absence (n = 912 controls). A mailed questionnaire with a body drawing asked about pain at other locations. Odds ratios (ORs) and 95% confidence limits (95% CLs) quantified the degree of overlap between facial pain and pain at other locations. For replication, cross-sectional data were analyzed from the UK Biobank study (n = 459,604 participants) and the US National Health Interview Survey (n = 27,731 participants).

Results:

In univariate analysis, facial pain had greatest overlap with headache (OR = 14.2, 95% CL = 9.7–20.8) followed by neck pain (OR = 8.5, 95% CL = 6.5–11.0), whereas overlap decreased substantially (ORs of 4.4 or less) for pain at successively remote locations below the neck. The same anatomically based ranking of ORs persisted in multivariable analysis that adjusted for demographics and risk factors for facial pain. Findings were replicated in the UK Biobank study and the US National Health Interview Survey. The observed anatomical selectivity in the degree of overlap could be a consequence of neurosensory and/or affective processes that differentially amplify pain according to its location.

Thermovision: a new diagnostic method for orofacial pain?

BACKGROUND

Infrared thermography can be used to obtain more complete information about a patient's condition. The method can be used in various medical applications for monitoring acute and chronic orofacial pain syndrome. With this diagnostic method, thermal differences in the examined region are usually compared to the same reference region on the opposite side of the body.

METHODS

Infrared quantitative thermography is a non-invasive method for contactless monitoring of dynamic thermal fields on a surface, or in this case, the human body. This method is based on detection of infrared radiation, which is naturally emitted from the surface of the body. In a pilot project with a patient having orofacial pain, changes before and after repetitive transcranial magnetic brain stimulation treatment were assessed.

RESULTS

First-day measurements found significantly higher maximum, minimum, and average temperatures, before and after therapy, in the area where the patient subjectively reported pain. The fifth and final measurements, before and after therapy, found only a slight elevation of the maximum temperature of the assessed regions, relative to the same regions on the opposite side of the face.

CONCLUSION

During the measurements on the fifth day, a thermal difference greater than 0.4°C was only observed relative to the minimum temperatures associated with the regions of self-reported pain before and after therapy. For validation of the effects, this method will need to be tested using a randomized, double-blind study with a larger number of patients.

AAPT Diagnostic Criteria for Peripheral Neuropathic Pain: Focal and Segmental Disorders

Peripheral neuropathic pain is among the most prevalent types of neuropathic pain. No comprehensive peripheral neuropathic pain classification system that incorporates contemporary clinical, diagnostic, biological, and psychological information exists. To address this need, this article covers the taxonomy for 4 focal or segmental peripheral neuropathic pain disorders, as part of the Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks (ACTTION) public-private partnership and the American Pain Society (APS) collaborative to develop a standardized, evidence-based taxonomy initiative: the ACTTION-APS Pain Taxonomy (AAPT). The disorders-postherpetic neuralgia, persistent posttraumatic neuropathic pain, complex regional pain disorder, and trigeminal neuralgia-were selected because of their clinical and clinical research relevance. The multidimensional features of the taxonomy are suitable for clinical trials and can also facilitate hypothesis-driven case-control and cohort epidemiologic studies. PERSPECTIVE: The AAPT peripheral neuropathic pain taxonomy subdivides the peripheral neuropathic pain disorders into those that are generalized and symmetric and those that are focal or segmental and asymmetric. In this article, we cover the focal and segmental disorders: postherpetic neuralgia, persistent posttraumatic neuropathic pain, complex regional pain disorder, and trigeminal neuralgia. The taxonomy is evidence-based and multidimensional, with the following dimensions: 1) core diagnostic criteria; 2) common features; 3) common medical and psychiatric comorbidities; 4) neurobiological, psychosocial, and functional consequences; and 5) putative neurobiological and psychosocial mechanisms, risk factors, and protective factors.

Trigeminal Neuralgia

PURPOSE OF REVIEW

Although trigeminal neuralgia is well known to neurologists, recent developments in classification and clinical diagnosis, new MRI methods, and a debate about surgical options necessitate an update on the topic.

RECENT FINDINGS

Currently, a worldwide controversy exists regarding the classification, diagnostic process, and surgical treatment of trigeminal neuralgia. This controversy has been caused on one side by the recognition that some 50% of patients with trigeminal neuralgia, apart from characteristic paroxysmal attacks, also have continuous pain in the same territory, which results in greater diagnostic difficulties and is associated with a lower response to medical and surgical treatments. In contrast, recent developments in MRI methods allow differentiation between a mere neurovascular contact and an effective compression of the trigeminal root by an anomalous vessel, which implies more difficulties in the choice of surgical treatment, with the indication for microvascular decompression becoming more restricted.

SUMMARY

This article proposes that the diagnosis of trigeminal neuralgia, with or without concomitant continuous pain, must rely on clinical grounds only. Diagnostic tests are necessary to distinguish three etiologic categories: idiopathic trigeminal neuralgia (nothing is found), classic trigeminal neuralgia (an anomalous vessel produces morphologic changes of the trigeminal root near its entry into the pons), and secondary trigeminal neuralgia (due to major neurologic disease, such as multiple sclerosis or tumors at the cerebellopontine angle). Carbamazepine and oxcarbazepine (ie, voltage-gated, frequency-dependent sodium channel blockers) are still the first-choice medical treatment, although many patients experience significant side effects, and those with concomitant continuous pain respond less well to treatment. The development of sodium channel blockers that are selective for the sodium channel 1.7 (Nav1.7) receptor will hopefully help. Although all the surgical interventions (percutaneous ganglion lesions, gamma knife radiosurgery, and microvascular decompression) are very efficacious, precise MRI criteria for differentiating a real neurovascular compression from an irrelevant contact will be of benefit in better selecting patients for microvascular decompression.

The psychosocial impact of orofacial pain in trigeminal neuralgia patients: a systematic review

Trigeminal neuralgia (TN) is characterized by sharp, electric shock-like pain, which can be triggered by trivial stimuli. Although medical and surgical treatments are available for TN, some patients experience refractory pain, which has a significant impact on their quality of life. The aim of this systematic review was to determine the psychosocial impact of orofacial pain in patients with diagnosed TN. A search was initiated in three electronic databases (Embase, MEDLINE, PubMed) to identify potential studies for inclusion in the review. All types of study published in English that reported psychosocial measures using validated psychometric questionnaires were included. A total of 585 articles were retrieved from the search. These were screened thoroughly, leading to the selection of 13 articles for data extraction and final analysis. The results show the chronic overwhelming nature of TN, with pain levels varying from mild to severe. Psychometric scores indicated mild to moderate depression, moderate to severe anxiety, and moderate to severe functional limitation of daily life activities in TN patients. Therefore, psychological support within a multidisciplinary team is recommended for TN patients to help them cope better with their chronic disorder and to improve the efficacy of treatment.

Orofacial pain - an update on diagnosis and management

The diagnosis and management of orofacial pain may be challenging due to complex histories, pathophysiology and associated psychosocial co-morbidities such as depression and anxiety. Neuropathic facial pain conditions such as burning mouth syndrome (BMS), persistent idiopathic facial pain (PIFP), atypical odontalgia (AO) and trigeminal neuralgia (TN) require early recognition by primary care clinicians and referral to secondary care. Acute pain-related temporomandibular disorder (TMD) may be managed in the primary care setting, with identification of those at risk of developing chronic TMD receiving an early referral to secondary care. Adopting a biopsychosocial approach, consisting of physical therapies, pharmacotherapy and psychological support can lead to effective management and may limit the negative impact of facial pain upon quality of life and daily functioning.

Genome-wide association analysis identifies novel loci for chronotype in 100,420 individuals from the UK Biobank

Our sleep timing preference, or chronotype, is a manifestation of our internal biological clock. Variation in chronotype has been linked to sleep disorders, cognitive and physical performance, and chronic disease. Here we perform a genome-wide association study of self-reported chronotype within the UK Biobank cohort (n=100,420). We identify 12 new genetic loci that implicate known components of the circadian clock machinery and point to previously unstudied genetic variants and candidate genes that might modulate core circadian rhythms or light-sensing pathways. Pathway analyses highlight central nervous and ocular systems and fear-response-related processes. Genetic correlation analysis suggests chronotype shares underlying genetic pathways with schizophrenia, educational attainment and possibly BMI. Further, Mendelian randomization suggests that evening chronotype relates to higher educational attainment. These results not only expand our knowledge of the circadian system in humans but also expose the influence of circadian characteristics over human health and life-history variables such as educational attainment.

Can large surveys conducted on highly selected populations provide valid information on the epidemiology of common health conditions? An analysis of UK Biobank data on musculoskeletal pain

INTRODUCTION

Biobank-type studies are typically large but have very low participation rates. It has been suggested that these studies may provide biased estimates of prevalence but are likely to provide valid estimates of association. We test these hypotheses using data collected on pain in a large Biobank study in the United Kingdom.

METHODS

UK Biobank recruited 503,325 persons aged 40-69 years (participation rate 5.5%). Participants completed questionnaires, including pain, lifestyle and environment factors. As a comparison, we used both a large population study of pain (MUSICIAN: n = 8847, aged: 40-69 years) conducted 2008-2009 and the National Child Development study (NCDS) which recruited all persons in Great Britain born during one week of 1958 and followed them up at age 44 years (n = 9377).

RESULTS

'Any pain' (UK Biobank 61.0%; MUSICIAN 63.9%), chronic pain (42.9%, 52.2%) and site-specific musculoskeletal pain (back 26.2%, 29.7%; shoulder/neck 23.3%, 25.3%) were generally similar in UK Biobank and MUSICIAN. The prevalence of chronic pain and most regional musculoskeletal pains in UK Biobank were all within 2% of that in NCDS.

CONCLUSION

UK Biobank has provided estimates of the prevalence of pain which are similar to those from previous large-scale studies, although a formal comparison of the estimates cannot be made. It has also confirmed known associations with the reporting of pain. Despite its very low participation rate, such a study provides the opportunity to investigate novel exposure-pain relationships and investigate rarer exposures and characteristics to further our knowledge of the epidemiology of pain.