The validity of questionnaire-based diagnoses: the third Nord-Trøndelag Health Study 2006-2008

The costs of chronic pain-Long-term estimates

BACKGROUND

Chronic pain is a condition with severe impact on many aspects of life, including work, functional ability and quality of life, thereby reducing physical, mental and social well-being. Despite the high prevalence and burden of chronic pain, it has received disproportionally little attention in research and public policy and the societal costs of chronic pain remain largely unknown. This study aimed to describe the long-term healthcare and work absence costs of individuals with and without self-identified chronic pain.

METHODS

The study population were participants in two Norwegian population health studies (HUNT3 and Tromsø6). Participants were defined as having chronic pain based on a self-reported answer to a question on chronic pain in the health studies in 2008. Individuals in the study population were linked to four national register databases on healthcare resource use and work absence.

RESULTS

In our study, 36% (n = 63,782) self-reported to have chronic pain and the average years of age was 56.6. The accumulated difference in costs between those with and without chronic pain from 2010 to 2016 was €55,003 (CI: 54,414-55,592) per individual. Extrapolating this to the entire population suggests that chronic pain imposes a yearly burden of 4% of GDP. Eighty per cent of the costs were estimated to be productivity loss.

CONCLUSION

Insights from this study can provide a greater understanding of the extent of healthcare use and productivity loss by those with chronic pain and serve as an important basis for improvements in rehabilitation and quality of care, and the education of the public on the burden of chronic pain.

SIGNIFICANCE

This was the first study to estimate the economic burden associated with chronic pain in the general population using linked individual-level administrative data and self-reported survey answers. We provide calculations showing that annual costs of chronic pain may be as high as €12 billion or 4% of GDP. Findings from this study highlight the need for a greater understanding of the substantial healthcare use and productivity losses among individuals with chronic pain.

Validity of self-reported hysterectomy and oophorectomy in a population-based cohort: The HUNT study

OBJECTIVE

To validate self-reported hysterectomy and bilateral oophorectomy.

DESIGN

Validation study.

SETTING

Large population-based cohort study in Norway: The Trøndelag Health Study (HUNT).

POPULATION

The Trøndelag Health Study 2 and 3 (HUNT2 and HUNT3) included questions on gynaecological history. Women who answered questions regarding hysterectomy and/or oophorectomy were included. In total, 30 263 women were included from HUNT2 (1995-1997) and 23 138 from HUNT3 (2006-2008), of which 16 261 attended both HUNT2 and HUNT3.

METHODS

We compared self-reported hysterectomy and bilateral oophorectomy with electronic hospital procedure codes.

MAIN OUTCOME MEASURES

Sensitivity, specificity, positive predictive value and negative predictive value of self-reported hysterectomy and bilateral oophorectomy, by comparing with hospital procedure codes.

RESULTS

Self-reported hysterectomy and bilateral oophorectomy in HUNT2 and/or HUNT3 both had specificity and negative predictive value above 99%. Self-reported hysterectomy had a sensitivity of 95.9%, and for bilateral oophorectomy sensitivity was 91.2%. Positive predictive value of self-reported hysterectomy was 85.8%, but for self-reported bilateral oophorectomy it was 65.4%.

CONCLUSIONS

Self-reported hysterectomy corresponded quite well with hospital data and can be used in epidemiological studies. Self-reported bilateral oophorectomy, on the other hand, had low positive predictive value, and results based on such data should be interpreted with caution. Women who report no previous hysterectomy or bilateral oophorectomy can safely be classified as unexposed to these surgeries.

Migraine and risk of atrial fibrillation: A 9-year follow-up based on the Trøndelag Health Study

BACKGROUND

Data from some population-based studies have indicated an increased risk of atrial fibrillation (AF) among patients with migraine, particularly among individuals with migraine with aura. The present study aimed to assess the association between primary headache disorders and AF.

METHODS

In a population-based 9-year follow-up design, we evaluated the questionnaire-based headache diagnosis, migraine and tension-type headache (TTH) included, collected in the Trøndelag Health Study (HUNT3) conducted in 2006-2008, and the subsequent risk of AF in the period until December 2015. The population at risk consisted of 39,340 individuals ≥20 years without AF at HUNT3 baseline who answered headache questionnaire during HUNT3. The prospective association was evaluated by multivariable Cox proportional hazard models with 95% confidence intervals (CIs).

RESULTS

Among the 39,340 participants, 1524 (3.8%) developed AF during the 9-year follow up, whereof 91% of these were ≥55 years. In the multivariable analyses, adjusting for known confounders, we did not find any association between migraine or TTH and risk of AF. The adjusted hazard ratios (HRs) were respectively 0.84 (95% CI = 0.64-1.11) for migraine, 1.16 (95% CI = 0.86-1.27) for TTH and 1.04 (95% CI = 0.86-1.27) for unclassified headache. However, in sensitivity analyses of individuals aged ≥55 years, a lower risk of AF was found for migraine (HR = 0.53; 95% CI = 0.39-0.73).

CONCLUSIONS

In this large population-based study, no increased risk of AF was found among individuals with migraine or TTH at baseline. Indeed, among individuals aged ≥55 years, migraine was associated with a lower risk for AF.

Changes in work schedule affect headache frequency among Norwegian nurses: a 3-year-follow-up study

OBJECTIVES

To explore whether changes in work schedule, number of night shifts and number of quick returns were related to changes in headache frequencies.

METHODS

A longitudinal study with questionnaire data from 2014 (baseline) and 2017 (follow-up) on work schedule (day only, shift work without nights and shift work with nights), number of night shifts, number of quick returns (less than 11 hours in-between shifts) and validated headache diagnoses among 1104 Norwegian nurses. Associations were explored by adjusted multivariate regression analyses.

RESULTS

The median age at baseline was 37 years (IQR 31-43) and 90.5% were women. In the adjusted logistic regression analysis of changed work schedule between baseline and follow-up, changing from night work was associated with increased odds for reversion from headache >1 days/month to no headache at all last year (OR 2.77 (1.29; 5.95)). Changes towards less night shifts (>10) or quick returns (>10) during the last year were associated with increased odds of reversion of headache to no headache (OR 2.23 (1.20; 4.17) and OR 1.90 (1.04; 3.49)). Only decrease in number of night shifts (>10) during the last year reduced risk of onset of any new headache between baseline and follow-up (OR of 0.39 (0.18; 0.84)).

CONCLUSION

Changing from night work and reducing the number of night shifts and quick returns were associated with less headache in this 3-year-follow-up of Norwegian nurses. This adds to the growing body of evidence that night work may have direct negative health consequences.

The long-term effect of work schedule, shift work disorder, insomnia and restless legs syndrome on headache among nurses: A prospective longitudinal cohort study

BACKGROUND

The preset study aimed to explore whether work schedules and sleep disorders predict the onset of headache.

METHODS

A longitudinal study was conducted with questionnaire data from 2014 (baseline) and 2017 (follow-up) on work schedule, number of night shifts, number of quick returns, insomnia, shift work disorder (SWD), restless legs syndrome (RLS) and validated headache diagnoses among 1560 Norwegian nurses. Associations were explored by multivariate regression analyses.

RESULTS

Work related factors at baseline did not predict onset of headache three years later. In the adjusted logistic regressions, insomnia at baseline predicted increased risk of new onset of migraine (odds ratio (OR) = 1.58; 95% confidence interval (CI) = 1.08-2.33), chronic headache (OR = 2.02; 95% CI = 1.04-4.66) and medication-overuse headache (OR = 3.79; 95% CI = 1.26-11.42) at follow-up. SWD at baseline predicted new onset of migraine (OR = 1.64; 95% CI = 1.07-2.50) and RLS at baseline predicted new onset of headache ≥1 day per month (OR = 1.55; 95% CI = 1.01-2.36) and migraine (OR = 1.55; 95% CI = 1.03-2.32) at follow-up. No factors predicted tension-type headache.

CONCLUSIONS

Overall, work related factors did not predict the onset of headache three years later, whereas insomnia, SWD and RLS at baseline all increased the risk of future headaches.

Brain structural and functional abnormalities in patients with tension-type headache: A systematic review of magnetic resonance imaging studies

Tension-type headache (TTH) stands as the most prevalent form of headache, yet an adequate understanding of its underlying mechanisms remains elusive. This article endeavors to comprehensively review structural and functional magnetic resonance imaging (MRI) studies investigating TTH patients, to gain valuable insights into the pathophysiology of TTH, and to explore new avenues for enhanced treatment strategies. We conducted a systematic search to identify relevant articles examining brain MRI disparities between TTH individuals and headache-free controls (HFC). Fourteen studies, encompassing 312 diagnosed TTH patients, were selected for inclusion. Among these, eight studies utilized conventional MRI, one employed diffusion tensor imaging, and five implemented various functional MRI modalities. Consistent findings across these studies revealed a notable increase in white matter hyperintensity (WMH) in TTH patients. Furthermore, the potential involvement of the specific brain areas recognized to be involved in different dimensions of pain perception including cortical regions (anterior and posterior cingulate cortex, prefrontal cortex, anterior and posterior insular cortex), subcortical regions (thalamus, caudate, putamen, and parahippocampus), cerebellum in TTH pathogenesis was identified. However, no significant association was established between TTH and intracranial abnormalities or total intracranial volume. In conclusion, these findings support the hypotheses regarding the role of central mechanisms in TTH pathophysiology and offer probable brain regions implicated in these mechanisms. Due to the scarce data on the precise role of these regions in the TTH, further preclinical and clinical investigations should be done to advance our knowledge and enhance targeted therapeutic options of TTH.

Development and Validation of a Japanese-Language Questionnaire to Screen for Tension-Type Headaches and Migraines

Introduction Migraine and tension-type headache (TTH) are chronic diseases associated with significant socioeconomic losses and social and psychological impact (current global prevalence: 10% and 38%, respectively). Thus, they require accurate identification and classification. In clinical practice, validated screening tools able to quickly determine migraine and TTH with high sensitivity and specificity help provide an objective and multifaceted understanding of patients' headache symptoms. However, no tool has been developed or validated yet in Japan to ask multifaceted questions about headache-related symptoms in order to identify migraine and TTH and understand these symptoms. This study aimed to develop a questionnaire for screening TTH and migraine. Methods The study was conducted from March to June 2022 at a medical institution in Osaka, Japan. The questionnaire - comprising 24 questions that were generated based on the 3rd edition of the International Classification of Headache Disorders - was used to screen for migraine and TTH, aiming for a deeper understanding of related symptoms. The participants were patients aged ≥18 years with at least one of the following diagnoses: migraine, TTH. The participants were asked to respond in writing or online. The inclusion criteria were age ≥18 years; headache patients attending a hospital; and diagnoses of at least one of the following: migraine, TTH. The informativeness and discriminating ability of the screening items were evaluated using the item response theory. Items with a calculated discrimination ≥1.35 (high or very high) were retained for screening purposes. Basic questions required to screen for primary headaches were retained, despite their limited computational discrimination power. Ultimately, nine and eight screening items were finalized for migraine and TTH, respectively. The previous neurologists' clinical diagnosis of each patient was used as the gold standard reference for calculating sensitivity, specificity, and positive and negative predictive values regarding the screening items. Cohen's kappa coefficients with 95% CIs were also calculated to determine the agreement between the neurologists' clinical diagnosis and the questionnaire results. Results The study population comprised 69 patients aged 19-89 years who were assisted at a hospital division specializing in headache medicine and diagnosed by neurologists. Of these, 22 patients had migraine, 30 had TTH, and 17 had migraine/TTH. Comparing the neurologists' clinical diagnosis with our screening questionnaire results, the sensitivity and specificity were 72.7% and 86.7% for migraine and 50.0% and 86.4% for TTH, respectively. Conclusions Our brief screening tool was highly specific for diagnosing migraine and TTH in individuals with headache symptoms but lacked sufficient sensitivity, especially for TTH. The high specificity for migraine and TTH suggests that the screening tool we developed in this study can correctly identify those who do not have migraine and TTH. The sensitivity was also relatively high for migraine, suggesting that the tool can correctly identify migraine-positive individuals. However, the sensitivity for TTH was low. This tool could help clinicians in providing detailed course assessment of migraine symptoms and TTH symptoms; however, the issue of low sensitivity for TTH needs to be addressed.

Migraine, Tension-Type Headache and Parkinson's Disease: A Systematic Review and Meta-Analysis

Background and Objectives: The relationship between migraine and tension-type headache (TTH) with Parkinson's disease (PD) is controversial, while a common pathophysiological link remains obscure. The aim of this systematic review is to investigate the association between PD, migraine and TTH. Materials and Methods: Following PRISMA, we searched MEDLINE, WebofScience, Scopus, CINAHL, Cochrane Library and ClinicalTrials.gov up to 1 July 2022 for observational studies examining the prevalence and/or associations of PD with migraine and TTH. We pooled proportions, standardized mean differences (SMD) and odds ratios (OR) with random effects models. The risk of bias was assessed with the Newcastle-Ottawa scale (PROSPERO CRD42021273238). Results: Out of 1031 screened studies, 12 were finally included in our review (median quality score 6/9). The prevalence of any headache among PD patients was estimated at 49.1% (760 PD patients; 95% CI 24.8-73.6), migraine prevalence at 17.2% (1242 PD patients; 95% CI 9.9-25.9), while 61.5% (316 PD patients; 95% CI 52.6-70.1) of PD patients with migraine reported headache improvement after PD onset. Overall, migraine was not associated with PD (302,165 individuals; ORpooled = 1.11; 95% CI 0.72-1.72).However, cohort studies demonstrated a positive association of PD among lifetime migraineurs (143,583 individuals; ORpooled = 1.54, 95% CI 1.28-1.84), while studies on 12-month migraine prevalence yielded an inverse association (5195 individuals; ORpooled = 0.64, 95% CI 0.43-0.97). Similar findings were reported by 3 studies with data on the TTH-PD relationship (high prevalence, positive association when examined prospectively and an inverse relationship on 12-month prevalence). These data were not quantitatively synthesized due to methodological differences among the studies. Finally, PD patients suffering from any headache had a lower motor unified Parkinson's disease rating scale (UPDRS) score (503 PD patients; SMD -0.39; 95% CI -0.57 to -0.21) compared to PD patients not reporting headache. There is an unclear association of headaches in genetic PD cohorts. Conclusions: Observational data suggest that migraine and TTH could be linked to PD, but the current literature is conflicting.

Validation studies on migraine diagnostic tools for use in nonclinical settings: a systematic review

Background Migraine underdiagnosis and undertreatment are so widespread, that hence is essential to diagnose migraine sufferers in nonclinical settings. A systematic review of validation studies on migraine diagnostic tools applicable to nonclinical settings can help researchers and practitioners in tool selection decisions.

Objective To systematically review and critically assess published validation studies on migraine diagnostic tools for use in nonclinical settings, as well as to describe their diagnostic performance.

Methods A multidisciplinary workgroup followed transparent and systematic procedures to collaborate on this work. PubMed, Medline, and Web of Science were searched for studies up to January 17, 2022. The QUADAS-2 was employed to assess methodological quality, and the quality thresholds adopted by the Global Burden Disease study were used to tail signaling questions.

Results From 7,214 articles identified, a total of 27 studies examining 19 tools were eligible for inclusion. There has been no high-quality evidence to support any tool for use of migraine diagnosis in nonclinical settings. The diagnostic accuracy of the ID-migraine, structured headache and HARDSHIP questionnaires have been supported by moderate-quality evidence, with sensitivity and specificity above 70%. Of them, the HARDSHIP questionnaire has been the most extensively validated. The remaining 16 tools have provided poor-quality evidence for migraine diagnosis in nonclinical populations.

Conclusions Up till now, the HARDSHIP questionnaire is the optimal choice for diagnosing migraine in nonclinical settings, with satisfactory diagnostic accuracy supported by moderate methodological quality. This work reveals the crucial next step, which is further high-quality validation studies in diverse nonclinical population groups.

Studies on the Role of Knowledge Management in Performance Enhancement and Promotion of Renewable Energy Industries in India

Energy industries are the pioneers in exploiting the knowledge management (KM) for meeting the challenges. Renewable energy industries are emerging to meet the energy security and climate changes and challenges. Therefore, it was of interest to study how the Indian renewable energy (RE) industries are able to exploit the KM practices to boost their organisation performance. Pilot study was undertaken to study the prevalence of the knowledge management (KM) practices in Indian renewable energy industries through the questionnaire and the measurement of Knowledge Management Performance Index (KMPI) value. The questionnaire was modified based on the outcomes of pilot study. The same qualitative analysis and quantitative analysis were done for the pilot study, and the KMPI value was also determined. The relation of all KM concepts, viz. KM creation, KM storage, KM transfer, KM exploitation and KM dissemination was the construct. This study provides one of first insights of KM performance in promoting new and renewable energy technologies. The clarity on the knowledge and technological gap, process of extracting and disseminating information, difficulty in accessing skilled labour, lack of collaborative R and D and research activities and storage of knowledge were found to be major issues in the exploitation of KM in RE industries in India.

The bidirectional temporal relationship between headache and affective disorders: longitudinal data from the HUNT studies

Background

Few prospective population-based studies have evaluated the bidirectional relationship between headache and affective disorder. The aim of this large-scale population-based follow-up study was to investigate whether tension-type headache (TTH) and migraine had increased risk of developing anxiety and depression after 11 years, and vice-versa.

Methods

Data from the Trøndelag Health Study (HUNT) conducted in 2006-2008 (baseline) and 2017-2019 (follow-up) were used to evaluate the bidirectional relationship between migraine and TTH and anxiety and depression measured by Hospital Anxiety and depression Scale (HADS). The population at risk at baseline consisted of respectively 18,380 persons with HADS score ≤ 7 and 13,893 without headache, and the prospective data was analyzed by Poisson regression.

Results

In the multi-adjusted model, individuals with HADS anxiety (HADS-A) and depression scores (HADS-D) of ≥8 at baseline nearly doubled the risk of migraine (Risk rations (RR) between 1.8 and 2.2) at follow-up whereas a 40% increased risk (RR 1.4) was found for TTH. Vice versa, the risk of having HADS-A and HADS-D scores of ≥8 at follow-up were increased for TTH (RR 1.3) and migraine (RR 1.3-1.6) at baseline. Migraine with aura was associated with 81% (RR 1.81, 95% 1.52-2.14) increased risk of HADS-A score of ≥8.

Conclusions

In this large-scale population-based follow-up study we found a bidirectional relationship between anxiety and depression and migraine and TTH. For anxiety, this bidirectional association was slightly more evident for migraine than TTH.

Assessment of functional somatic disorders in epidemiological research: Self-report questionnaires versus diagnostic interviews

OBJECTIVE

Self-reported symptom questionnaires are often used for identifying individuals with functional somatic disorders (FSD) in epidemiological research. Studies on their validity in establishing clinically valid cases are, however, lacking. We aimed to compare and dissect the processes of identifying participants with FSD with symptom questionnaires and FSD diagnoses established by diagnostic interviews.

METHODS

Individuals from the adult Danish population (n = 1590) filled in symptom questionnaires and participated in a diagnostic research interview, performed over telephone by trained family physicians. The two methods were described and compared in different steps: 1) Agreement on presence of symptoms, 2) agreement after FSD symptom pattern criteria had been applied, and 3) agreement on final FSD diagnoses.

RESULTS

Agreement on symptom presence was high (>82%). Using FSD symptom pattern criteria, the two methods agreed in 30-62% of cases within each category. Discrepancies were mainly due to participants fulfilling symptom patterns in the interview but not in the questionnaires. Agreement between final FSD questionnaire cases and final FSD interview diagnoses was moderate (>68%) with lower FSD prevalence in the interview (26.2% vs 44.5%). Discrepancies were largely explained by the interviewers assessing the symptom patterns to be caused by an alternative physical or mental condition.

CONCLUSION

Prevalence of final FSD diagnoses were markedly lower in the diagnostic interview compared to self-reported questionnaires cases; mainly because of the clinical evaluation of symptom attribution and impairment. Symptom questionnaires may be valuable as screening tools and as trans-diagnostic comparison while diagnostic interviews are necessary in establishing clinically significant FSD diagnoses.

Headache - A Window to Dementia: An Unexpected Twist

Migraine and other types of headaches have several symptoms associated with them. The association between migraine and dementia has been considered. It is a topic of discussion and appears to be multifactorial. Dementia is a cluster of symptoms, with memory loss and cognitive dysfunction being the prominent symptoms. In this review, we discussed the association of headache and cognitive dysfunction in a broader context and how the practiced treatment of headaches may silently lead to dementia. We conducted a thorough literature search using PubMed as our main database. The articles exploring the association between headache (both migraine and non-migraine) and dementia were included. Some risk factors like migraine-induced stroke and inherent vascular diseases in migraine patients channeling to stroke and dementia were not considered. A total of 28 studies were included for review. All the reviewed studies put together showed an association between headache and cognitive dysfunction of any form. They showed that the frequency and duration of headache is a determinant for dementia. Few studies also focused on how treating headaches with certain drugs can lead to dementia. The reviewed published literature showed that headaches of any sort and their treatment are potentially linked to dementia. Not all headache patients will require medical treatment, as the benefit might outweigh the risk sometimes. It is interim to understand these facts and formulate a better protocol for treating headache patients. However, due to some discordant results, further studies are needed.

Caesarean section and the association with migraine: a retrospective register-linked HUNT population cohort study

OBJECTIVES

To evaluate the association between caesarean section and migraine in a population-based register-linked cohort study.

SETTING

Data from the population-based Nord-Trøndelag Health Studies (HUNT2 and HUNT3) were linked to information from the Norwegian Medical Birth Registry.

PARTICIPANTS

65 343 participants responded to the headache questions in any of the two HUNT studies. Only those answering the headache questions in HUNT2 or 3 and had information about mode of delivery in the Norwegian Medical Birth Registry (born after 1967) were included. Our final sample consisted of 6592 women and 4602 men, aged 19-41 years.

OUTCOMES

ORs for migraine given caesarean section. Analyses were performed in multivariate logistic regression models.

RESULTS

After adjusting for sex, age and fetal growth restriction, delivery by caesarean section was not associated with migraine later in life (OR 0.86, 95% CI 0.64 to 1.15). Delivery by caesarean section was associated with a reduced OR of non-migrainous headache (OR 0.77, 95% CI 0.60 to 0.99).

CONCLUSION

No association was found between caesarean section and migraine in this population-based register-linked study.

Migraine, obesity and body fat distribution - a population-based study

BACKGROUND

Obesity has been linked to an increased prevalence of migraine, and to increased migraine attack frequency, but several questions are left unanswered by previous studies. We examined the relationship between obesity and headache in a large, population-based study where we could take into account body fat distribution, migraine subtypes and tension-type headache.

METHODS

The third population-based Nord-Trøndelag Health Study (HUNT3) included validated headache questionnaires and objective anthropometric measurements. Using a cross-sectional design, our sample consisted of 18,191 women and 14,985 men, aged 19 to 96 years. Of these 4290 (12.9%) had migraine, 4447 (13.4%) had frequent tension-type headache (TTH), and 24,439 were headache-free controls. A total of 5049 individuals with unclassified headache were excluded from the analyses. Using logistic regression, we modeled the association between obesity and headache prevalence, adjusting for relevant confounders.

RESULTS

Both total body obesity (TBO) and abdominal obesity (AO) were associated with a higher prevalence of migraine when compared to headache-free controls (OR 1.45 95% CI 1.32-1.59 and OR 1.29 95% CI 1.18-1.41, respectively), in particular for individuals < 50 years of age (OR 1.74 95% CI 1.54-1.98 and OR 1.89 95% CI 1.69-2.11). Similar results were seen for migraine with and without aura. Similar Overall, a weaker associations were as observed between obesity and TTH. There was a dose-response relationship between obesity categories and increased headache frequency in subjects with migraine. TBO was associated with migraine prevalence and attack frequency independent of AO.

CONCLUSION

Both TBO and AO were associated with migraine prevalence and attack frequency. This association was largely limited to individuals < 50 years of age. TBO, rather than AO, may be a better measure of obesity in relation to migraine.

High sensitivity C-reactive protein and risk of migraine in a 11-year follow-up with data from the Nord-Trøndelag health surveys 2006-2008 and 2017-2019

Background

Several previous studies have reported a cross-sectional association between elevated high sensitivity C-reactive protein (hs-CRP) and migraine. The aim of this population-based follow-up study was to investigate the influence of hs-CRP at baseline on the risk of developing migraine 11 years later.

Methods

Data from the Nord-Trøndelag Health Study performed in 2006–2008 (baseline) and 2017–2019 were used. A total of 19,574 participants without migraine at baseline were divided into three groups based on hs-CRP levels (< 3 mg/L, 3–9.99 mg/L and 10.00–20 mg/L). Poisson regression was used to evaluate the associations between hs-CRP levels and risk ratios (RRs) of migraine, and precision of the estimates was assessed by 95% confidence interval (CIs).

Results

In the multi-adjusted model, increased risk of migraine (RR 1.46, 95% CI 1.05–2.04) was found in the highest hs-CRP levels group compared to the lowest group. In the group with the highest hs-CRP levels, a nearly three times higher risk of chronic migraine (RR 2.81, 95% CI 1.12–7.06) was found, whereas no evident relationship was found between high hs-CRP level and risk of developing episodic migraine.

Conclusions

The main finding in this 11-year follow-up was that hs-CRP levels between 10.00–20.00 mg/L at baseline was associated with increased risk of chronic migraine.

Cerebral cortical dimensions in headache sufferers aged 50 to 66 years: a population-based imaging study in the Nord-Trøndelag Health Study (HUNT-MRI)

Based on previous clinic-based magnetic resonance imaging studies showing regional differences in the cerebral cortex between those with and without headache, we hypothesized that headache sufferers have a decrease in volume, thickness, or surface area in the anterior cingulate cortex, prefrontal cortex, and insula. In addition, exploratory analyses on volume, thickness, and surface area across the cerebral cortical mantle were performed. A total of 1006 participants (aged 50-66 years) from the general population were selected to an imaging study of the head at 1.5 T (HUNT-MRI). Two hundred eighty-three individuals suffered from headache, 80 with migraine, and 87 with tension-type headache, whereas 309 individuals did not suffer from headache and were used as controls. T1-weighted 3D scans of the brain were analysed with voxel-based morphometry and FreeSurfer. The association between cortical volume, thickness, and surface area and questionnaire-based headache diagnoses was evaluated, taking into consideration evolution of headache and frequency of attacks. There were no significant differences in cortical volume, thickness, or surface area between headache sufferers and nonsufferers in the anterior cingulate cortex, prefrontal cortex, or insula. Similarly, the exploratory analyses across the cortical mantle demonstrated no significant differences in volume, thickness, or surface area between any of the headache groups and the nonsufferers. Maps of effect sizes showed small differences in the cortical measures between headache sufferers and nonsufferers. Hence, there are probably no or only very small differences in volume, thickness, or surface area of the cerebral cortex between those with and without headache in the general population.

Time trends of major headache diagnoses and predictive factors. Data from three Nord-Trøndelag health surveys

AIMS

The primary aim of this study was to investigate time trends of major headache diagnoses using cross-sectional data from two population-based health surveys. In addition, we aimed to perform a longitudinal assessment of baseline characteristics and subsequent risk for having headache at 22-years' follow-up among those participating in three health surveys.

METHODS

Data from the Nord-Trøndelag Health Study (HUNT) performed in 1995-1997 (HUNT2), 2006-2008 (HUNT3) and 2017-2019 (HUNT4) were used. The 1-year prevalence time trends of major headache diagnoses were estimated among 41,460 participants in HUNT4 and among 39,697 participants in HUNT3, two surveys with identical headache questions. 16,118 persons participated in all three surveys, and among these, a Poisson regression was used to evaluate health-related baseline information in HUNT2 and the risk ratios (RRs) with 95% confidence interval (CIs) of consistently reporting headache during follow-up.

RESULTS

Compared with the 1-year prevalence in HUNT3, a higher proportion of participants in HUNT4 had tension-type headache (20.7% vs. 15.9%, p < 0.001), whereas a lower 1-year prevalence was found for migraine (11.1% vs. 12.0%, p < 0.001) and medication overuse headache (MOH) (0.3% vs. 1.0%, p < 0.001). Participants in the age group 20-39 years at baseline nearly three times increased risk (RR = 2.8, 95% CI 2.5-3.1) of reporting headache in HUNT2, HUNT3 and HUNT4 than persons aged 50 years or more. Female sex, occurrence of chronic musculoskeletal complaints and high score of depression or anxiety at baseline doubled the risk of having headache in all three surveys.

CONCLUSIONS

The 1-year prevalence of migraine and MOH was lower in HUNT4 than in HUNT3. Young age, female sex, and occurrence of musculoskeletal complaints and high score of anxiety and/or depression were all associated with substantially increased risk of reporting headache in all three surveys.

Mitochondrial genome-wide association study of migraine - the HUNT Study

BACKGROUND

Variation in mitochondrial DNA (mtDNA) has been indicated in migraine pathogenesis, but genetic studies to date have focused on candidate variants, with sparse findings. We aimed to perform the first mitochondrial genome-wide association study of migraine, examining both single variants and mitochondrial haplogroups.

METHODS

In total, 71,860 participants from the population-based Nord-Trøndelag Health Study were genotyped. We excluded samples not passing quality control for nuclear genotypes, in addition to samples with low call rate and closely maternally related. We analysed 775 mitochondrial DNA variants in 4021 migraine cases and 14,288 headache-free controls, using logistic regression. In addition, we analysed 3831 cases and 13,584 controls who could be reliably assigned to a mitochondrial haplogroup. Lastly, we attempted to replicate previously reported mitochondrial DNA candidate variants.

RESULTS

Neither of the mitochondrial variants or haplogroups were associated with migraine. In addition, none of the previously reported mtDNA candidate variants replicated in our data.

CONCLUSIONS

Our findings do not support a major role of mitochondrial genetic variation in migraine pathophysiology, but a larger sample is needed to detect rare variants and future studies should also examine heteroplasmic variation, epigenetic changes and copy-number variation.

The impact of C-reactive protein levels on headache frequency in the HUNT study 2006-2008

BACKGROUND

Increased high sensitivity C- reactive protein (hs-CRP) levels have been found in many earlier studies on migraine, and recently also in persons with migraine and insomnia. The aim of this study was to see whether these findings could be reproduced in a large-scale population-based study.

METHODS

A total of 50,807 (54%) out of 94,194 invited aged ≥20 years or older participated in the third wave of the Nord-Trøndelag Health Study study performed in 2006-2008. Among these, 38,807 (41%) had valid measures of hs-CRP and answered questions on headache and insomnia. Elevated hs-CRP was defined as > 3.0 mg/L. The cross-sectional association with headache was estimated by multivariate analyses using multiple logistic regression. The precision of the odds ratio (OR) was assessed with 95% confidence interval (CI).

RESULTS

In the fully adjusted model, elevated hs-CRP was associated with migraine (OR 1.14, 95% CI 1.04-1.25) and migraine with aura (OR 1.15, 95% CI 1.03-1.29). The association was strongest among individuals with headache ≥15 days/month for any headache (OR 1.26, 95% CI 1.08-1.48), migraine (OR 1.62, 95% CI 1.21-2.17), and migraine with aura (OR 1.84, 95% CI 1.27-2.67). No clear relationship was found between elevated hs-CRP and headache less than 7 days/month or with insomnia.

CONCLUSIONS

Cross-sectional data from this large-scale population-based study showed that elevated hs-CRP was associated with headache ≥7 days/month, especially evident for migraine with aura.

Change in Headache Suffering and Predictors of Headache after Mild Traumatic Brain Injury: A Population-Based, Controlled, Longitudinal Study with Twelve-Month Follow-Up

Headache attributed to traumatic injury to the head (HAIH) is claimed to be the most common sequela following mild traumatic brain injury (MTBI), but epidemiological evidence is scarce. We explored whether patients with MTBI had an increase in headache suffering following injury compared with controls. We also studied predictors of headache.

The Trondheim MTBI follow-up study is a population-based, controlled, longitudinal study. We recruited patients exposed to MTBI and controls with minor orthopedic injuries from a trauma center and a municipal outpatient clinic, and community controls from the surrounding population. Information on headache was collected through questionnaires at baseline, and 3 and 12 months post-injury. We used a generalized linear mixed model to investigate the development of headache over time in the three groups, and logistic regression to identify predictors of headache.

We included 378 patients exposed to MTBI, 82 trauma controls, and 83 community controls. The MTBI-group had a larger increase in odds of headache from baseline to the first 3 months post-injury than the controls, but not from baseline to 3–12 months post-injury. Predictors for acute HAIH were female sex and pathological imaging findings on computed tomography (CT) or magnetic resonance imaging (MRI). Predictors for persistent HAIH were prior MTBI, being injured under the influence of alcohol, and acute HAIH. Patients who experience HAIH during the first 3 months post-injury have a good chance to improve before 12 months post-injury. Female sex, imaging findings on CT or MRI, prior MTBI, and being injured under the influence of alcohol may predict exacerbation of headache.

Diffusion tensor imaging in middle-aged headache sufferers in the general population: a cross-sectional population-based imaging study in the Nord-Trøndelag health study (HUNT-MRI)

BACKGROUND

Several studies have investigated white matter with diffusion tensor imaging (DTI) in those suffering from headache, but so far only in clinic based samples and with conflicting results.

METHODS

In the present study, 1006 individuals (50-66 years) from the general population (Nord-Trøndelag Health Study) participated in an imaging study of the head at 1.5 T (HUNT-MRI). Hundred and ninety-six individuals were excluded because of errors in the data acquisition or brain pathology. Two hundred and forty-six of the remaining participants reported suffering from headache (69 from migraine and 76 from tension-type headache) the year prior to the scanning. DTI data were analysed with Tract-Based Spatial Statistics and automated tractography. Type of headache, frequency of attacks and evolution of headache were investigated for an association with white matter fractional anisotropy (FA), mean diffusivity (MD), axonal diffusivity (AD), radial diffusivity (RD) and tract volume. Correction for various demographical and clinical variables were performed.

RESULTS

Headache sufferers had widespread higher white matter MD, AD and RD compared to headache free individuals (n = 277). The effect sizes were mostly small with the largest seen in those with middle-age onset headache, who also had lower white matter FA. There were no associations between white matter microstructure and attack frequency or type of headache.

CONCLUSION

Middle-age onset headache may be related to a widespread process in the white matter leading to altered microstructure.

The HUNT4 study: the validity of questionnaire-based diagnoses

BACKGROUND

Questionnaire-based headache diagnoses should be validated against diagnoses made by the gold standard, which is personal interview by a headache expert. The diagnostic algorithm with the best diagnostic accuracy should be used when later analysing the data.

METHODS

The Nord-Trøndelag Health Study (HUNT4) was performed between 2017 and 2019. Among HUNT4 participants, a total of 232 (19.3%) out of 1201 randomly invited were interviewed by a headache expert to assess the sensitivity, specificity and kappa value of the questionnaire-based headache diagnoses.

RESULTS

The median interval between answering the headache questions and the validation interview was 60 days (95% CI 56-62 days). The best agreements were found for self-reported lifetime migraine (sensitivity of 59%, specificity of 99%, and a kappa statistic of 0.65, 95% CI 0.55-0.75), self-reported active migraine (sensitivity of 50%, specificity of 97%, and a kappa statistic of 0.55, 95% 0.39-0.71), liberal criteria of migraine (sensitivity of 64%, specificity of 93%, and a kappa statistic of 0.58, 95% CI 0.43-0.73) and ICDH3-based migraine ≥1 days/month (sensitivity of 50%, specificity of 94%, and a kappa statistic of 0.49, 95% CI 0.30-0.68). For headache suffering ≥1 days/month a sensitivity of 90%, specificity 80%, and a kappa statistic of 0.55, 95% CI 0.41-0-69 were found. For tension-type headache (TTH) ≥ 1 days/month the agreement was 0.33 (95% CI 0.17-0.49).

CONCLUSION

The HUNT4 questionnaire is a valid tool for identifying persons with lifetime migraine, self-reported active migraine and active migraine applying liberal modified criteria. The agreement for TTH was fair.

The diagnostic accuracy of headache measurement instruments: A systematic review and meta-analysis focusing on headaches associated with musculoskeletal symptoms

AIM

To systematically review the available literature on the diagnostic accuracy of questionnaires and measurement instruments for headaches associated with musculoskeletal symptoms.

DESIGN

Articles were eligible for inclusion when the diagnostic accuracy (sensitivity/specificity) was established for measurement instruments for headaches associated with musculoskeletal symptoms in an adult population. The databases searched were PubMed (1966-2018), Cochrane (1898-2018) and Cinahl (1988-2018). Methodological quality was assessed with the Quality Assessment of Diagnostic Accuracy Studies tool (QUADAS-2) and COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) checklist for criterion validity. When possible, a meta-analysis was performed. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) recommendations were applied to establish the level of evidence per measurement instrument.

RESULTS

From 3450 articles identified, 31 articles were included in this review. Eleven measurement instruments for migraine were identified, of which the ID-Migraine is recommended with a moderate level of evidence and a pooled sensitivity of 0.87 (95% CI: 0.85-0.89) and specificity of 0.75 (95% CI: 0.72-0.78). Six measurement instruments examined both migraine and tension-type headache and only the Headache Screening Questionnaire - Dutch version has a moderate level of evidence with a sensitivity of 0.69 (95% CI 0.55-0.80) and specificity of 0.90 (95% CI 0.77-0.96) for migraine, and a sensitivity of 0.36 (95% CI 0.21-0.54) and specificity of 0.86 (95% CI 0.74-0.92) for tension-type headache. For cervicogenic headache, only the cervical flexion rotation test was identified and had a very low level of evidence with a pooled sensitivity of 0.83 (95% CI 0.72-0.94) and specificity of 0.82 (95% CI 0.73-0.91).

DISCUSSION

The current review is the first to establish an overview of the diagnostic accuracy of measurement instruments for headaches associated with musculoskeletal factors. However, as most measurement instruments were validated in one study, pooling was not always possible. Risk of bias was a serious problem for most studies, decreasing the level of evidence. More research is needed to enhance the level of evidence for existing measurement instruments for multiple headaches.

Does insomnia modify the association between C-reactive protein and migraine? The Tromsø Study 2015-2016

BACKGROUND

The relationship between high sensitivity C-reactive protein and migraine is unclear. The aim of this cross-sectional population-based study was to investigate the association between high sensitivity C-reactive protein and types of headache, and to evaluate the impact of insomnia on this association.

METHODS

A total of 20,486 (63%) out of 32,591 invited, aged ≥40 years or older, participated in the seventh wave of the Tromsø study conducted in 2015-2016 and had valid information on headache, insomnia and high sensitivity C-reactive protein. The influence of insomnia on the association between questionnaire-based diagnoses of headache and elevated high sensitivity C-reactive protein defined as >3.0 mg/L was assessed using multiple logistic regression, estimating prevalence odds ratio with 95% confidence intervals.

RESULTS

A total of 6290 participants (30.7%) suffered from headache during the last year. Among these, 1736 (8.5%) fulfilled the criteria of migraine, 991 (4.8%) had migraine with aura, 746 (3.6%) migraine without aura (3.8%), and 4554 (22.2%) had non-migrainous headache. In the final multi-adjusted analysis, elevated high sensitivity C-reactive protein was associated with headache (odds ratio 1.10, 95% confidence interval 1.01-1.20), migraine (odds ratio 1.17, 95% confidence interval 1.01-1.35), and migraine with aura (odds ratio 1.23, 95% confidence interval 1.01-1.53). No association was found between elevated high sensitivity C-reactive protein and migraine without aura or non-migrainous headache. The association between high sensitivity C-reactive protein and migraine was strongly dependent on insomnia status. Among individuals with insomnia, elevated high sensitivity C-reactive protein was associated with migraine (odds ratio 1.49, 95% confidence interval 1.02-2.17), and migraine with aura (odds ratio 1.59, 95% confidence interval 1.03-2.45), whereas no such relationship was found among those without insomnia.

CONCLUSIONS

In this cross-sectional study, participants with migraine, in particular migraine with aura, were more likely to have elevated high sensitivity C-reactive protein, evident only among those with insomnia.

Parental migraine in relation to migraine in offspring: Family linkage analyses from the HUNT Study

Background

Migraine is known to run in families. While some clinical studies have indicated that migraine is disproportionally transmitted through the maternal line, this has not been examined in a population-based setting.

Methods

We utilized a large, population-based cohort study from Norway, the HUNT Study. Using a cross-sectional design, our sample consisted of 13,731 parents and 8970 offspring. Logistic regression was used to calculate odds ratios with 95% confidence intervals for active migraine and non-migrainous headache in offspring, given active maternal or paternal headache.

Results

There was a significant association between maternal migraine and offspring migraine (odds ratio 2.76, 95% confidence interval 2.18–3.51). A weaker association ( p = 0.004 for comparison with maternal migraine) was found between paternal migraine and offspring migraine (odds ratio 1.67, 95% confidence interval 1.33–2.28). For non-migrainous headache, there was a significant association between mothers and offspring (odds ratio 1.25, 95% confidence interval 1.10–1.43), but not between fathers and offspring.

Conclusions

Parental migraine is associated with offspring migraine, with a stronger association for maternal migraine. This may indicate maternal-specific transmission.

Migraine, tension-type headache and medication-overuse headache in a large population of shift working nurses: a cross-sectional study in Norway

OBJECTIVES

To investigate associations between different types of headaches and shift work.

DESIGN, PARTICIPANTS AND OUTCOME MEASURES

Nurses with different work schedules (day work, two-shift rotation, night work, three-shift rotation) participated in a cohort study with annual surveys that started in 2008/2009. In 2014 (wave 6), a comprehensive headache instrument was included in the survey, in which 1585 nurses participated. Headaches were assessed according to the International Classification of Headache Disorders IIIb. Frequent headache (≥1 day per month), migraine, tension-type headache, chronic headache (headache >14 days per month) and medication-overuse headache (chronic headache + acute headache medication ≥10 days last month) comprised the dependent variables. Adjusted (for sex, age, percentage of full-time equivalent, marital status, children living at home) logistic regression analyses were conducted with work schedule, number of night shifts worked last year, number of quick returns (<11 hours in-between shifts) last year, shift work disorder and insomnia disorder as predictors.

RESULTS

Frequent headache, migraine and chronic headache were associated with shift work disorder (OR 2.04, 95% CI 1.62 to 2.59; 1.60, 1.21 to 2.12; 2.45, 1.25 to 4.80, respectively) and insomnia disorder (OR 1.79, 95% CI 1.43 to 2.23; 1.55, 1.18 to 2.02; 3.03, 1.54 to 5.95, respectively), but not with work schedule, number of night shifts or number of quick returns. Tension-type headache was only associated with >20 night shifts last year (OR 1.41, 95% CI 1.07 to 1.86). Medication-overuse headache was only associated with insomnia disorder (OR 7.62, 95% CI 2.48 to 23.41).

CONCLUSIONS

We did not find any association between different types of headaches and work schedule. However, tension-type headache was associated with high number of night shifts. Nurses with sleep disorders (insomnia disorder and shift work disorder) reported higher prevalence of frequent headaches, migraine, chronic headache and medication-overuse headache (only insomnia) compared with nurses not having insomnia disorder and shift work disorder, respectively.

Diagnostic and classification tools for chronic headache disorders: A systematic review

Background or aim

Despite guidelines and the International Classification of Headache Disorders (ICHD-III beta) criteria, the diagnosis of common chronic headache disorders can be challenging for non-expert clinicians. The aim of the review was to identify headache classification tools that could be used by a non-expert clinician to classify common chronic disorders in primary care.

Methods

We conducted a systematic literature review of studies validating diagnostic and classification headache tools published between Jan 1988 and June 2016 from key databases: MEDLINE, ASSIA, Embase, Web of Knowledge and PsycINFO. Quality assessment was assessed using items of the Quality of Diagnostic Accuracy Studies (QUADAS-2).

Results

The search identified 38 papers reporting the validation of 30 tools designed to diagnose, classify or screen for headache disorders; nine for multiple headache types, and 21 for one headache type only. We did not identify a tool validated in a primary care that can be used by a non-expert clinician to classify common chronic headache disorders and screen for primary headaches other than migraine and tension-type headache in primary care.

Conclusions

Despite the availability of many headache classification tools we propose the need for a tool that could support primary care clinicians in diagnosing and managing chronic headache disorders within primary care, and allow more targeted referral to headache specialists.

The causal role of smoking on the risk of headache. A Mendelian randomization analysis in the HUNT study

BACKGROUND AND PURPOSE

Headache has been associated with various lifestyle and psychosocial factors, one of which is smoking. The aim of the present study was to investigate whether the association between smoking intensity and headache is likely to be causal.

METHOD

A total of 58 316 participants from the Nord-Trøndelag Health (HUNT) study with information on headache status were genotyped for the rs1051730 C>T single-nucleotide polymorphism (SNP). The SNP was used as an instrument for smoking intensity in a Mendelian randomization analysis. The association between rs1051730 T alleles and headache was estimated by odds ratios with 95% confidence intervals. Additionally, the association between the SNP and migraine or non-migrainous headache versus no headache was investigated. All analyses were adjusted for age and sex.

RESULTS

There was no strong evidence that the rs1051730 T allele was associated with headache in ever smokers (odds ratio 0.99, 95% confidence interval 0.95-1.02). Similarly, there was no association between the rs1051730 T allele and migraine or non-migrainous headache versus no headache.

CONCLUSION

The findings from this study do not support that there is a strong causal relationship between smoking intensity and any type of headache. Larger Mendelian randomization studies are required to examine whether higher smoking quantity can lead to a moderate increase in the risk of headache subtypes.

Volume and shape of subcortical grey matter structures related to headache: A cross-sectional population-based imaging study in the Nord-Trøndelag Health Study

BACKGROUND

The relationship between subcortical nuclei and headache is unclear. Most previous studies were conducted in small clinical migraine samples. In the present population-based MRI study, we hypothesized that headache sufferers exhibit reduced volume and deformation of the nucleus accumbens compared to non-sufferers. In addition, volume and deformation of the amygdala, caudate, hippocampus, pallidum, putamen and thalamus were examined.

METHODS

In all, 1006 participants (50-66 years) from the third Nord-Trøndelag Health Survey, were randomly selected to undergo a brain MRI at 1.5 T. Volume and shape of the subcortical nuclei from T1 weighted 3D scans were obtained in FreeSurfer and FSL. The association with questionnaire-based headache categories (migraine and tension-type headache included) was evaluated using analysis of covariance. Individuals not suffering from headache were used as controls. Age, sex, intracranial volume and Hospital Anxiety and Depression Scale were used as covariates.

RESULTS

No effect of headache status on accumbens volume and shape was present. Exploratory analyses showed significant but small differences in volume of caudate and putamen and in putamen shape between those with non-migrainous headache and the controls. A post hoc analysis showed that caudate volume was strongly associated with white matter hyperintensities.

CONCLUSION

We did not confirm our hypothesis that headache sufferers have smaller volume and different shape of the accumbens compared to non-sufferers. No or only small differences in volume and shape of subcortical nuclei between headache sufferers and non-sufferers appear to exist in the general population.

Remission of chronic headache: An 11-year follow-up study. Data from the Nord-Trøndelag Health Surveys 1995-1997 and 2006-2008

OBJECTIVES

To estimate remission rates of chronic headache and predictors of remission.

METHODS

In this longitudinal population-based cohort study, we used validated headache questionnaire data from the second (1995-1997, baseline; n = 51,856 aged ≥ 20 years, response rate: 55%) and third wave (2006-2008, follow-up, response rate: 42%) of the Nord-Trøndelag Health Study. Chronic headache was defined as ≥15 headache days/month during the last year. Chronic headache remission was defined as headache less than 15 days/month at follow-up. Potential predictors of remission were evaluated using logistic regression.

RESULTS

At baseline, 1266 (2.4%) participants reported chronic headache. Of these, 605 (48%) answered headache questions at follow-up. Remission was observed in 452 (74.7%), the proportion being almost identical in men and women (74.4% vs. 74.9, p = 0.92). In analyses adjusting for age, gender and education level, remission at follow-up was more than two times more likely among individuals without medication overuse headache (OR = 2.4, 95% CI 1.7-3.6) and without chronic musculoskeletal complaints (OR = 2.9, 95% CI 1.5-5.0) at baseline.

CONCLUSIONS

In this longitudinal population-based cohort study, three-quarters of chronic headache participants remitted from chronic headache. Remission was associated with no medication overuse headache and no chronic musculoskeletal complaints at baseline.

White matter hyperintensities and headache: A population-based imaging study (HUNT MRI)

Objective

To examine the relationship between white matter hyperintensities and headache.

Methods

White matter hyperintensities burden was assessed semi-quantitatively using Fazekas and Scheltens scales, and by manual and automated volumetry of MRI in a sub-study of the general population-based Nord-Trøndelag Health Study (HUNT MRI). Using validated questionnaires, participants were categorized into four cross-sectional headache groups: Headache-free (n = 551), tension-type headache (n = 94), migraine (n = 91), and unclassified headache (n = 126). Prospective questionnaire data was used to further categorize participants into groups according to the evolution of headache during the last 12 years: Stable headache-free, past headache, new onset headache, and persistent headache. White matter hyperintensities burden was compared across headache groups using adjusted multivariate regression models.

Results

Individuals with tension-type headache were more likely to have extensive white matter hyperintensities than headache-free subjects, with this being the case across all methods of white matter hyperintensities assessment (Scheltens scale: Odds ratio, 2.46; 95% CI, 1.44–4.20). Migraine or unclassified headache did not influence the odds of having extensive white matter hyperintensities. Those with new onset headache were more likely to have extensive white matter hyperintensities than those who were stable headache-free (Scheltens scale: Odds ratio, 2.24; 95% CI, 1.13–4.44).

Conclusions

Having tension-type headache or developing headache in middle age was linked to extensive white matter hyperintensities. These results were similar across all methods of assessing white matter hyperintensities. If white matter hyperintensities treatment strategies emerge in the future, this association should be taken into consideration.

Lifestyle factors and risk of migraine and tension-type headache. Follow-up data from the Nord-Trøndelag Health Surveys 1995-1997 and 2006-2008

AIMS

The aim of this population-based historical cohort study was to investigate the influence of lifestyle factors on the risk of developing migraine or tension-type headache (TTH).

METHODS

Data from the Nord-Trøndelag Health Study performed in 1995-1997 and 2006-2008 was used. A total of 15,276 participants without headache at baseline were included. A Poisson regression was used to evaluate the associations between lifestyle factors and risk ratios (RRs) of migraine and TTH 11 years later. Precision of the estimates was assessed by 95% confidence interval (CIs).

RESULTS

Increased risk of migraine (RR 1.30, 95% CI 1.11-1.52) was found in smokers (past or current) compared to those who had never smoked. Hard physical exercise 1-2 hours per week reduced the risk of migraine (OR 0.71, 95% CI 0.54-0.94) compared to inactivity, and the risk of migraine was also lower among those who consumed alcohol (RR 0.73, 95% CI 0.57-0.94) compared to abstainers. No association was found between smoking, physical activity, alcohol use and risk of TTH.

CONCLUSIONS

The main finding was that current and previous smoking was associated with increased risk of migraine, but not of TTH.

Headache following head injury: a population-based longitudinal cohort study (HUNT)

Background

Headache is the most frequent symptom following head injury, but long-term follow-up of headache after head injury entails methodological challenges. In a population-based cohort study, we explored whether subjects hospitalized due to a head injury more often developed a new headache or experienced exacerbation of previously reported headache compared to the surrounding population.

Methods

This population-based historical cohort study included headache data from two large epidemiological surveys performed with an 11-year interval. This was linked with data from hospital records on exposure to head injury occurring between the health surveys. Participants in the surveys who had not been hospitalized because of a head injury comprised the control group. The head injuries were classified according to the Head Injury Severity Scale (HISS). Multinomial logistic regression was performed to investigate the association between head injury and new headache or exacerbation of pre-existing headache in a population with known pre-injury headache status, controlling for potential confounders.

Results

The exposed group consisted of 294 individuals and the control group of 25,662 individuals. In multivariate analyses, adjusting for age, sex, anxiety, depression, education level, smoking and alcohol use, mild head injury increased the risk of new onset headache suffering (OR 1.74, 95% CI 1.05–2.87), stable headache suffering (OR 1.70, 95% CI 1.15–2.50) and exacerbation of previously reported headache (OR 1.93, 95% CI 1.24–3.02). The reference category was participants without headache in both surveys.

Conclusion

Individuals hospitalized due to a head injury were more likely to have new onset and worsening of pre-existing headache and persistent headache, compared to the surrounding general population. The results support the entity of the ICHD-3 beta diagnosis “persistent headache attributed to traumatic injury to the head”.

Increased risk of Parkinson's disease following tension-type headache: a nationwide population-based cohort study

PURPOSE

Previous studies have suggested associations between primary headache and neurodegenerative diseases; however, the relationship between tension-type headache (TTH), which is the most common type of primary headache, and Parkinson's disease (PD) remains controversial. Hence, in this nationwide, population-based, retrospective cohort study, we explored the temporal association between TTH and PD.

METHODS

Using claims data in the National Health Insurance Research Database of Taiwan, we evaluated 12,309 subjects aged ≥20 years who were newly diagnosed with TTH from 2000 to 2005. The non-TTH group included 49,236 randomly selected sex- and age-matched patients without TTH. Subjects were followed up until the end of 2011, diagnosis of PD, or death. The incidence of PD was compared between the two groups. A Cox multivariable proportional hazards model was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) to estimate the risk of PD.

RESULTS

The overall incidence of PD (per 1,000 person-years) in the TTH and non-TTH groups was 3.01 and 1.68, respectively. After adjustment for sex, age, and comorbidities, the association between TTH and PD remained statistically significant (adjusted HR = 1.37, 95% CI = 1.19-1.57). The TTH group had a higher risk of PD than the non-TTH group did, regardless of subjects' sex, age, and comorbidity status.

CONCLUSIONS

These findings demonstrate that patients diagnosed with TTH exhibit an increased risk of PD. Additional studies should investigate the potential shared pathophysiological mechanisms of TTH and PD. Clinicians should be aware that TTH is a potential risk factor for PD.

The effect of foetal growth restriction on the development of migraine and tension-type headache in adulthood. The HUNT Study

BACKGROUND

There is little knowledge about how factors early in life affect the development of migraine and tension-type headache. We aimed to examine whether growth restriction in utero is associated with development of migraine and frequent tension-type headache in adults.

METHODS

The population-based Nord-Trøndelag Health Study (HUNT 3) contained a validated headache questionnaire, which differentiated between migraine and tension-type headache. These data were linked to information on weight and gestational age at birth from the Norwegian Medical Birth Registry. In total 4557 females and 2789 males, aged 19-41 years, were included in this registry-based study. Participants were categorized as appropriate for gestational age (AGA, 10th-90th percentile), small for gestational age (SGA, 3rd-10th percentile) or very small for gestational age (VSGA, < 3rd percentile). Logistic regression was used to calculate odds ratios (OR) with 95% confidence intervals (CI) for migraine and tension-type headache, with exposure being growth restriction at birth.

RESULTS

The effect of growth restriction on migraine was modified by sex, with a significant association in males (p<0.001), but not in females (p = 0.20). In particular, males born VSGA were at increased risk of developing migraine (OR 2.73, 95% CI 1.63-4.58, p<0.001), with an intermediate risk among those born SGA (OR 1.50, 95% CI 0.96-2.35, p = 0.08) compared to those born AGA. There was no significant association between growth restriction and frequent TTH (p = 0.051).

CONCLUSION

Growth restriction was associated with increased risk of migraine in adulthood among males, but not among females. This suggests that migraine might, in part, be influenced by early life events, and that males seem to be particularly vulnerable.

Use of Swedish smokeless tobacco (snus) and the risk of Type 2 diabetes and latent autoimmune diabetes of adulthood (LADA)

AIMS

It has been suggested that moist snuff (snus), a smokeless tobacco product that is high in nicotine and widespread in Scandinavia, increases the risk of Type 2 diabetes. Previous studies are however few, contradictory and, with regard to autoimmune diabetes, lacking. Our aim was to study the association between snus use and the risk of Type 2 diabetes and latent autoimmune diabetes of adulthood (LADA).

METHOD

Analyses were based on incident cases (Type 2 diabetes, n = 724; LADA, n = 200) and population-based controls (n = 699) from a Swedish case-control study. Additional analyses were performed on cross-sectional data from the Norwegian HUNT study (n = 21 473) with 829 prevalent cases of Type 2 diabetes. Odds ratios (OR) were estimated adjusted for age, BMI family history of diabetes and smoking. Only men were included.

RESULTS

No association between snus use and Type 2 diabetes or LADA was seen in the Swedish data. For Type 2 diabetes, the OR for > 10 box-years was 1.00 [95% confidence interval (CI), 0.47 to 2.11] and for LADA 1.01 (95% CI, 0.45 to 2.29). Similarly, in HUNT, the OR for Type 2 diabetes in ever-users was estimated at 0.91 (95% CI, 0.75 to 1.10) and in heavy users at 0.92 (95% CI, 0.46 to 1.83).

CONCLUSION

The risk of Type 2 diabetes and LADA is unrelated to the use of snus, despite its high nicotine content. This opens the possibility of the increased risk of Type 2 diabetes seen in smokers may not be attributed to nicotine, but to other substances in tobacco smoke.

Inverse relationship between type 1 diabetes mellitus and migraine. Data from the Nord-Trøndelag Health Surveys 1995-1997 and 2006-2008

Aims The aim of this cross-sectional population-based study was to investigate the associations between migraine and type 1 and type 2 diabetes mellitus (DM). Methods We used data from the second (1995-1997) and third survey (2006-2008) in the Nord-Trøndelag Health Study. Analyses were made for the 26,121 participants (30-97 years of age, median 58.3 years) with known headache and DM status in both surveys, and for the 39,584 participants in the third survey (20-97 years, median 54.1 years). The diagnosis of migraine was given to those who fulfilled the questionnaire-based migraine diagnosis in the second and/or third survey. Associations were assessed using multiple logistic regression, estimating prevalence odds ratio (OR) with 95% confidence intervals (CIs). Results In the multivariate analysis of the 26,121 participants in both surveys, adjusting for age, gender, years of education, and smoking, classical type 1 DM (n = 81) was associated with a lower prevalence of any headache (OR = 0.55, 95% CI 0.34-0.88),and migraine (OR = 0.47, 95% CI 0.26-0.96) compared to those without DM (n = 24,779). Correspondingly, the merged group of classical type 1 DM and latent autoimmune diabetes of adults (LADA) (n = 153) were less likely to have migraine (OR = 0.53, 95% CI 0.31-0.91). Similarly, an inverse relationship between type 1 DM and migraine was found in analyses of 39,584 participants in the third survey. No clear association was found between headache and type 2 DM. Conclusions In this cross-sectional population-based study of mainly middle-aged participants, type 1 DM was inversely associated with headache, in particular migraine.

Epigenetic DNA methylation changes associated with headache chronification: A retrospective case-control study

Background

The biological mechanisms of headache chronification are poorly understood. We aimed to identify changes in DNA methylation associated with the transformation from episodic to chronic headache.

Methods

Participants were recruited from the population-based Norwegian HUNT Study. Thirty-six female headache patients who transformed from episodic to chronic headache between baseline and follow-up 11 years later were matched against 35 controls with episodic headache. DNA methylation was quantified at 485,000 CpG sites, and changes in methylation level at these sites were compared between cases and controls by linear regression analysis. Data were analyzed in two stages (Stages 1 and 2) and in a combined meta-analysis.

Results

None of the top 20 CpG sites identified in Stage 1 replicated in Stage 2 after multiple testing correction. In the combined meta-analysis the strongest associated CpG sites were related to SH2D5 and NPTX2, two brain-expressed genes involved in the regulation of synaptic plasticity. Functional enrichment analysis pointed to processes including calcium ion binding and estrogen receptor pathways.

Conclusion

In this first genome-wide study of DNA methylation in headache chronification several potentially implicated loci and processes were identified. The study exemplifies the use of prospectively collected population cohorts to search for epigenetic mechanisms of disease.

Migraine and frequent tension-type headache are not associated with multiple sclerosis in a Norwegian case-control study

Background

Inconsistent results have been obtained with regard to headache comorbidity in multiple sclerosis (MS).

Objective

Investigate the one-year prevalence of migraine and tension-type headache (TTH) in Norwegian MS patients and relate this to clinical parameters.

Methods

A questionnaire concerning headache was administered to 756 MS patients and 1090 controls and used to determine the one-year prevalence of migraine and frequent TTH.

Results

No significant differences were seen between patients and controls or between patients with different disease course. Less migraine was observed in patients with Expanded Disability Status Scale score (EDSS) ≥4.0.

Conclusions

This case-control study does not support an association between migraine or TTH and MS.

Migraine and endothelial function: The HUNT3 Study

Background

Reduced endothelial function is associated with elevated risk of cardiovascular disease, but evidence on the association between migraine and endothelial function is conflicting. The aim of this population-based study was to examine the relationship between flow-mediated dilatation (FMD) and migraine with aura, migraine without aura and tension-type headache.

Methods

In the third Nord-Trøndelag Healthy Study (HUNT3) FMD was measured by ultrasound during reactive hyperaemia of the brachial artery in a sample of 4739 healthy adult participants, 3929 of whom answered headache questions. The cross-sectional association between different headache diagnoses and FMD was evaluated by logistic regression, using a categorical approach.

Results

Mean FMD did not differ between the headache groups and headache-free controls. In multi-adjusted analyses, no consistent association was found between FMD quintiles and headache groups.

Conclusions

There was no relationship between FMD and migraine or other headache diagnoses in this large cross-sectional study of otherwise healthy respondents including freedom from pulmonary and cardiovascular diseases.

Headaches in patients with previous head injuries: A population-based historical cohort study (HUNT)

Background Headache attributed to head injury is claimed to be among the most common secondary headache disorders, yet available epidemiological evidence is scarce. We evaluated the prevalence of headache among individuals previously exposed to head injury by a comparison to an uninjured control group. Methods This population-based historical cohort study used data from hospital records on previous exposure to head injury linked to a large epidemiological survey with data on headache occurrence. Participants without head injury, according to hospital records, were used as controls. The head injuries were classified according to the Head Injury Severity Scale (HISS) and the International Classification of Headache Disorders (ICHD-3 beta). Binary logistic regression was performed to investigate the association between headache and head injury, controlling for potential confounders. Results The exposed group consisted of 940 individuals and the control group of 38,751 individuals. In the multivariate analyses, adjusting for age, sex, anxiety, depression and socioeconomic status, there were significant associations between mild head injury and any headache, migraine, chronic daily headache and medication overuse headache. Conclusion Headache was more likely among individuals previously referred to a hospital for a mild head injury compared to uninjured controls.

Increased Risk of Dementia in Patients with Tension-Type Headache: A Nationwide Retrospective Population-Based Cohort Study

PURPOSE

The association between primary headaches, including tension-type headache (TTH) as one of the most common primary headache disorders, and dementia remains controversial. In this nationwide, population-based, retrospective, cohort study, we explored the potential association between TTH and dementia and examined sex, age, and comorbidities as risk factors for dementia.

METHODS

Using the Taiwan National Health Insurance Research Database (NHIRD) claims data, the sample included 13908 subjects aged ≥20 years with newly-diagnosed TTH in 2000-2006. The non-TTH group included 55632 randomly selected sex- and age-matched TTH-free individuals. All subjects were followed until dementia diagnosis, death, or the end of 2011. Patients with dementia, including vascular and non-vascular (including Alzheimer's) subtypes, were identified using International Classification of Diseases Ninth Revision, Clinical Modification codes. Multivariate Cox proportional hazards regression models were used to assess the risk of dementia and dementia-associated risk factors, such as migraine and other medical comorbidities.

RESULTS

During the average follow-up of 8.14 years, the incidence density rates of dementia were 5.30 and 3.68/1,000 person-years in the TTH and non-TTH groups, respectively. Compared with the non-TTH group, the risks of dementia were 1.25 (95% confidence interval [CI], 1.11-1.42) and 1.13 (95% CI, 1.01-1.27) times higher in the women and >65-year-old TTH group, respectively. TTH patients with comorbidities had a higher risk of dementia. TTH patients had a greater risk of non-vascular dementia (hazard ratio, 1.21; 95% CI, 1.09-1.34) than the non-TTH group.

CONCLUSION

TTH patients have a future risk of dementia, indicating a potentially linked disease pathophysiology that warrants further study. The association between TTH and dementia is greater in women, older adults, and with comorbidities. Clinicians should be aware of potential dementia comorbidity in TTH patients.

Paranasal sinus opacification in headache sufferers: A population-based imaging study (the HUNT study-MRI)

Background

The association between headache and paranasal sinus disease is still unclear. Because of symptom overlap, the two conditions are not easily studied on the basis of symptoms alone. The aim of the present study was to investigate whether paranasal sinus opacification on magnetic resonance imaging (MRI) was associated with migraine, tension-type headache (TTH) or unclassified headache.

Methods

This was a cross-sectional study of 844 randomly selected participants (442 women, age range 50–65 years, mean age 57.7 years). Based on 14 headache questions, participants were allocated to four mutually exclusive groups: migraine, TTH, unclassified headache or headache free. On MRI, opacifications as mucosal thickening, polyps/retention cysts and fluid in the five paired sinuses were measured and recorded if ≥1 mm. For each participant, opacification thickness was summed for each sinus and, in addition, a total sum of all sinuses was calculated. Opacification in each sinus was compared between headache-free participants and the headache groups using non-parametric tests, and the total sum was compared by logistical regression.

Results

No significant association was found between paranasal sinus opacification and headache in general, nor when headache was differentiated into migraine, TTH and unclassified headache. This was also true in separate analyses of mucosal thickening and fluid and of opacification from each paranasal sinus.

Conclusion

Migraine, TTH and unclassified headache were found not to be associated with an increased degree of paranasal sinus opacification at MRI.

Pituitary Adenoma and Non-acute Headache: Is There an Association, and Does Treatment Help?

OBJECTIVE

Headache is a controversial indication for treatment of pituitary adenoma. We studied the possible relationship between pituitary adenomas and headache as well as the symptomatic effects of treatment.

METHODS

Current and prior headache complaints were assessed in structured telephone interviews in 201 patients with pituitary adenoma. Clinical variables and headache history were retrieved from medical records. Headache prevalence among patients was compared with a regional population-based cohort.

RESULTS

The presence of headache was higher in patients before the diagnosis of pituitary adenoma compared with the general population (P < 0.001). At follow-up, overall prevalence was lower (P < 0.001), but chronic headache was more prevalent (P = 0.001) than in the general population. With the exception of family history, no associations between headache and clinical or radiologic variables were identified. At follow-up evaluation, 77% of patients with headache reported improvement, 5% reported worsening, and 11% reported new headaches. Patients with nonfunctional adenoma who underwent surgical treatment reported improvement more often (85%) than patients who did not undergo surgery (58%) (P = 0.042).

CONCLUSIONS

In a cohort with both treated and untreated patients with pituitary adenoma, headache prevalence was low compared with the general population. We found no link between clinical or radiologic variables and headache. Although a higher proportion of patients who underwent surgical treatment reported symptomatic relief, most patients who did not undergo treatment also improved. We believe that the unpredictable dynamics of headache over time and the lack of predictive and modifiable tumor-related variables associated with headache or treatment of headache weaken headache as a sole indication for pituitary adenoma treatment.

Population-based approaches to genetics of migraine

BACKGROUND

While the most accurate diagnosis of migraine typically requires a clinical interview guided by strict diagnostic criteria, an alternative approach that ascertains migraine by questionnaire in population-based settings has been instrumental in the discovery of common genetic variants influencing migraine risk. This result may be surprising. Population-based approaches are often criticized for limited ability to distinguish migraine from other forms of primary headache. It is thus useful to revisit prevailing ideas about population-based ascertainment of migraine to evaluate the extent to which this approach has potential for additional insights into migraine genetics and therefore pathophysiology.

OVERVIEW

We review recent findings suggesting that the success of the population-based approach is derived from the possibility of collecting much larger samples than in the clinic-based setting even at the risk of introducing phenotypic and genetic heterogeneity. The findings are also consistent with new appreciations for the genetic basis of many other common, complex clinical characteristics. However, clinic-based ascertainment and other settings will remain more effective than population-based approaches for investigating certain, often very specific aspects of migraine genetics.

CONCLUSION

We argue that the detailed genetic architecture of migraine, various aspects of methodology, and the ultimate sample size achieved by population-based ascertainment will be critical determinants of the future success of this approach to genetic analysis of migraine and its comorbidities.

Headache as a predictor for dementia: The HUNT Study

BACKGROUND

The impact of headache on dementia is largely unknown. This study examined the association between headache and dementia using data from a large population-based study.

METHODS

This population-based study used data from the Nord-Trøndelag Health Surveys performed in 1995-1997 (HUNT2) and 2006-2008 (HUNT3). The reference group (controls) was participants aged ≥55 years who answered the headache questions in HUNT2 and later participated in HUNT3 (n = 15,601). The association with headache status in HUNT2 was investigated in sample of confirmed non-demented elderly evaluated with psychometric tests after HUNT3 (n = 96), and HUNT2 participants later diagnosed with dementia during 1997-2011 (n = 746). The association with headache was evaluated by logistical regression with adjustment for age, gender, level of education, comorbidity, smoking, and anxiety and depression.

RESULTS

Any headache was more likely to be reported in HUNT2 among those who later were included in the dementia registry (OR 1.24; 95 % CI 1.04-1.49) compared to the reference group, but less likely among the confirmed non-demented individuals (OR 0.62; 95 % CI 0.39-0.98). This relationship was even stronger for non-migrainous headache, whereas such association was not found for migraine.

CONCLUSIONS

Compared to the reference group, individuals with dementia were more likely to report non-previous migrainous headache in HUNT2, whereas a sample of confirmed non-demented were less likely to report previous non-migrainous headache.

Headache and peak oxygen uptake: The HUNT3 study

Background

Evidence on the association between headache and physical fitness is conflicting. The aim of this population-based study was to examine the relationship between peak oxygen uptake (VO2peak) and headache, including migraine and tension-type headache (TTH).

Methods

In the third Nord-Trøndelag Health study (HUNT3), VO2peak was measured by ergospirometry in a sample of 4631 healthy adult participants. Of these, 3899 (54% women) also answered headache questions. The cross-sectional association between headache and VO2peak was evaluated by logistic regression using a categorical approach based on quintiles. Scores in the upper quintile were used as reference.

Results

Participants age 20–50 years had significant trends of increasing prevalence of any headache ( p < 0.001), migraine ( p < 0.001), TTH ( p = 0.002) and unclassified headache ( p = 0.027) with lower VO2peak. The highest prevalence odds ratios (ORs) were found in those with VO2peak in the lower quintile: For any headache the OR was 2.3 (95% confidence interval (1.6–3.3), for TTH 1.8 (1.2–2.8), for unclassified headache 1.9 (1.1–3.8), and for migraine 3.7 (2.1–6.6). Similar results were also found among those who reported physical activity levels in accordance with current recommendations of the American College of Sports Medicine but nevertheless had low VO2peak. Being in the lowest VO2peak quintile was also strongly associated with migraine aggravated by physical activity (OR 4.1, 2.1–8.1). No significant association was found between VO2peak and headache for those 50 years or older.

Conclusions

In this large cross-sectional study, an inverse relationship was found between VO2peak and headache for adults younger than 50 years of age.

Using Web-Based Questionnaires and Obstetric Records to Assess General Health Characteristics Among Pregnant Women: A Validation Study

Background

Self-reported medical history information is included in many studies. However, data on the validity of Web-based questionnaires assessing medical history are scarce. If proven to be valid, Web-based questionnaires may provide researchers with an efficient means to collect data on this parameter in large populations.

Objective

The aim of this study was to assess the validity of a Web-based questionnaire on chronic medical conditions, allergies, and blood pressure readings against obstetric records and data from general practitioners.

Methods

Self-reported questionnaire data were compared with obstetric records for 519 pregnant women participating in the Dutch PRegnancy and Infant DEvelopment (PRIDE) Study from July 2011 through November 2012. These women completed Web-based questionnaires around their first prenatal care visit and in gestational weeks 17 and 34. We calculated kappa statistics (κ) and the observed proportions of positive and negative agreement between the baseline questionnaire and obstetric records for chronic conditions and allergies. In case of inconsistencies between these 2 data sources, medical records from the woman’s general practitioner were consulted as the reference standard. For systolic and diastolic blood pressure, intraclass correlation coefficients (ICCs) were calculated for multiple data points.

Results

Agreement between the baseline questionnaire and the obstetric record was substantial (κ=.61) for any chronic condition and moderate for any allergy (κ=.51). For specific conditions, we found high observed proportions of negative agreement (range 0.88-1.00) and on average moderate observed proportions of positive agreement with a wide range (range 0.19-0.90). Using the reference standard, the sensitivity of the Web-based questionnaire for chronic conditions and allergies was comparable to or even better than the sensitivity of the obstetric records, in particular for migraine (0.90 vs 0.40, P=.02), asthma (0.86 vs 0.61, P=.04), inhalation allergies (0.92 vs 0.74, P=.003), hay fever (0.90 vs 0.64, P=.001), and allergies to animals (0.89 vs 0.53, P=.01). However, some overreporting of allergies was observed in the questionnaire and for some nonsomatic conditions sensitivity of both measurement instruments was low. The ICCs for blood pressure readings ranged between 0.72 and 0.92 with very small mean differences between the 2 methods of data collection.

Conclusions

Web-based questionnaires can be used to validly collect data on many chronic disorders, allergies, and blood pressure readings among pregnant women.