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

Independent causal effect of migraines on Alzheimer's disease risk: a multivariate Mendelian randomization study

Background

The observational studies investigated the impact of migraine on Alzheimer's Disease (AD). However, these findings were limited by confounding factors and reverse causation, leading to contradictory results.

Methods

We utilized Univariable Mendelian Randomization (UVMR) to explore the link between migraine (13,971 cases/470,627 controls) and AD risk (Bellenguez et al., 39,106 cases/46,828 controls; FinnGen, 111,471 cases/111,471 controls). Meta-analysis was performed for comprehensive synthesis. Employing Multivariable Mendelian Randomization (MVMR), we created models incorporating migraine and 35 potential AD risk factors, examining migraine's independent impact on AD onset risk under considering these factors.

Results

The meta-analysis of inverse variance weighted MR results, combining data from Bellenguez et al. (odds ratio (OR) [95% confidence interval (CI)]: 1.5717 [1.1868-2.0814], p = 0.0016) and FinnGen (OR [95% CI]: 1.2904 [0.5419-3.0730], p = 0.5646), provided evidence for a causal relationship between genetically predicted migraine and the heightened risk of AD occurrence (OR [95% CI]: 1.54 [1.18, 2.00], p < 0.01). After adjusting for Diastolic blood pressure (OR [95% CI]: 1.4120 [0.8487-2.3493], p = 0.1840) and Tumor necrosis factor alpha (OR [95% CI]: 1.2411 [0.8352-1.8443], p = 0.2852), no discernible association was detected between migraine and the risk of AD.

Conclusion

This study offers compelling evidence indicating a significant correlation between genetically predicted migraine and an elevated risk of AD.

Is headache a risk factor for dementia? A systematic review and meta-analysis

OBJECTIVE

In this systematic review and meta-analysis, we critically evaluate available evidence regarding the association between primary headaches and subsequent decline of cognitive function and dementia.

BACKGROUND

Recent studies suggested that headache disorders may increase the risk for dementia. However, available studies are conflicting.

METHODS

To identify qualifying studies, we searched scientific databases, including Pubmed, Scopus, Web of Science, Science Direct and BMC, screening for relevant papers. In order to reduce the heterogeneity between different studies, the analyses were further subdivided according to the clinical diagnoses and the study methodologies.

RESULTS

We identified 23 studies investigating the association between primary headaches and the risk of dementia. Of these, 18 met our inclusion criteria for meta-analysis (covering 924.140 individuals). Overall effect-size shows that primary headaches were associated with a small increase in dementia risk (OR = 1,15; CI 95%: 1,03-1,28; p = 0,02). Analyzing subgroups, we found that migraine was associated with both a moderate increased risk of all-cause dementia (OR = 1,26; p = 0,00; 95% CI: 1,13-1,40) as well as a moderate increased risk of Alzheimer's disease (OR = 2,00; p = 0,00; 95% CI: 1,46-2,75). This association was significant in both case-control and retrospective cohort studies but not in prospective studies.

CONCLUSIONS

Our study supports the presence of a link between primary headaches and dementia. However, in the subgroup analysis, only patients with migraine showed a moderate increase risk for all-cause dementia and for Alzheimer's disease. Additional rigorous studies are needed to elucidate the possible role of primary headaches on the risk of developing cognitive impairment and dementia.

Thirty Risk Factors for Alzheimer's Disease Unified by a Common Neuroimmune-Neuroinflammation Mechanism

One of the major obstacles confronting the formulation of a mechanistic understanding for Alzheimer's disease (AD) is its immense complexity-a complexity that traverses the full structural and phenomenological spectrum, including molecular, macromolecular, cellular, neurological and behavioural processes. This complexity is reflected by the equally complex diversity of risk factors associated with AD. However, more than merely mirroring disease complexity, risk factors also provide fundamental insights into the aetiology and pathogenesis of AD as a neurodegenerative disorder since they are central to disease initiation and subsequent propagation. Based on a systematic literature assessment, this review identified 30 risk factors for AD and then extended the analysis to further identify neuroinflammation as a unifying mechanism present in all 30 risk factors. Although other mechanisms (e.g., vasculopathy, proteopathy) were present in multiple risk factors, dysfunction of the neuroimmune-neuroinflammation axis was uniquely central to all 30 identified risk factors. Though the nature of the neuroinflammatory involvement varied, the activation of microglia and the release of pro-inflammatory cytokines were a common pathway shared by all risk factors. This observation provides further evidence for the importance of immunopathic mechanisms in the aetiopathogenesis of AD.

Contribution of pain to subsequent cognitive decline or dementia: A systematic review and meta-analysis of cohort studies

BACKGROUND

Dementia is an urgent public health problem worldwide, and the determination of the contribution of pain to cognitive decline or dementia is significant for the prevention of dementia.

OBJECTIVE

To comprehensively explore the contribution of pain to subsequent cognitive decline or dementia and analyze possible influencing factors.

DESIGN

Systematic review and meta-analysis of cohort studies.

METHODS

We systematically searched MEDLINE, EMBASE, PsycINFO, CINAHL, Cochrane Library, China National Knowledge Internet, WANFANG DATA and VIP for cohort studies from database inception to January 21, 2022. Random-effects meta-analysis was used to pool odds ratios (ORs) and 95% confidence intervals (CIs) of incident cognitive decline or dementia among patients with pain. Subgroup analyses and meta-regression were used to explore the sources of heterogeneity.

RESULTS

A total of 35 cohort studies containing 1,122,503 participants were included. As a whole, pain (OR = 1.24; 95% CI = 1.17-1.31) was a risk factor for subsequent cognitive decline or dementia; headache, migraine, tension-type headache, widespread pain, and irritable bowel syndrome, but not burning mouth syndrome, were also risk factors. Pain increased the risk of all-cause dementia (OR = 1.26; 95% CI = 1.18-1.35), Alzheimer's disease (OR = 1.28; 95% CI = 1.12-1.47), and vascular dementia (OR = 1.31; 95% CI = 1.06-1.62). Pain interference (OR = 1.42; 95% CI = 1.16-1.74) was associated with an increased risk of cognitive decline or dementia, while pain intensity was not. Pooled results from studies with sample sizes less than 2000 or with relatively low quality showed that pain did not increase the risk of cognitive decline or dementia. There was no statistically significant increase in the risk of cognitive decline or dementia in people with pain aged ≥75 years.

CONCLUSIONS

Our results demonstrated that pain increased the risk of subsequent cognitive decline or dementia. Sample size, study methodological quality, types of pain, pain severity (pain interference), and age composition of the study population may affect the relationship between pain and cognitive decline or dementia.

REGISTRATION

PROSPERO (CRD42022316406).

Primary headaches increase the risk of dementias: An 8-year nationwide cohort study

Background

Headache, a highly prevalent neurological disorder, has consistently been linked with an elevated risk of dementia. However, most studies are focused on the relationship with migraine in limited age groups. Therefore, the objective of this research was to look at the link between various type of headaches and dementias based on longitudinal population-based data.

Methods and results

Participants diagnosed with headache from 2002 to 2005 were selected and major covariates were collected. The diagnoses of Alzheimer’s disease, vascular dementia, and other dementias were observed from 2006 until 2013. The adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) of dementias according to headache type were calculated by Cox proportional hazards regression. A number of 470,652 participants were observed for a mean of 7.6 years (standard deviation: 1.2), for approximately 3.6 million person-years. Both tension type headache (TTH) and migraine elevated the risk of all-cause dementias (TTH, aHR 1.18, 95% CI 1.13–2.24; migraine, aHR 1.18, 95% CI 1.13–2.24). Headaches had a greater influence in females and non-smokers as a risk factor of dementias. Patients with migraine who consumed alcohol had a higher risk of dementia, however this was not true with TTH patients. Among participants without comorbidities, TTH patients were more susceptible to dementia than migraine patients. Headache patients had a higher proportion of females regardless of headache type and approximately 1.5 times more individuals had three or more comorbidities compared to those without headache.

Conclusions

Headache could be an independent predictor for subsequent dementia risk. Future studies should focus on clarifying pathogenic pathways and possible dementia-related preventive measures in headache populations.

Cognitive Impairment in Primary and Secondary Headache Disorders

Purpose of Review

To critically evaluate the recent literature on cognitive impairment and headache.

Recent Findings

Neurocognitive symptoms are prevalent, debilitating, and occur often with both primary and secondary headache disorders.

Summary

This is a “narrative review of the current literature in PubMed on cognitive function and headache.” Migraine is associated with cognitive impairment years before a migraine diagnosis. In young and middle-aged adults, migraine is associated with deficits in attention, executive function, processing speed, and memory. It is unlikely that migraine is associated with dementia. Although methodologically difficult to assess, there does not seem to be an association between tension-type headache and cognitive dysfunction. In early to midlife, cluster headache seems to be associated with executive dysfunction. Several secondary headache syndromes relevant to clinicians managing headache disorders are associated with poorer cognitive performance or distinctive cognitive patterns, including those attributed to chronic cerebral or systemic vascular disorders, trauma, and derangements of intracranial pressure and volume, including frontotemporal brain sagging syndrome.

Association of Headache Disorders and the Risk of Dementia: Meta-Analysis of Cohort Studies

Objectives

The purpose of this meta-analysis is to assess whether there is an association between headache disorders and all-cause dementia, Alzheimer's disease (AD), and vascular dementia (VaD).

Methods

PubMed, Cochrane Library, Embase, and Web of Science were searched for cohort studies published from database inception to October 8, 2021, using medical subject headings (MeSH) and keywords. All statistical analyses were performed using Stata statistical software version 14.0. If P > 0.1 and I² ≤ 50%, a fixed-effects model was adopted. If I² > 50% (which indicated great heterogeneity), a random-effects model was adopted. The funnel plot and Egger's test were used to evaluate publication bias.

Results

This meta-analysis included 12 cohort studies covering 465,358 individuals, which were published between 2001 and 2020. The pooling analysis shows that a history of any headache disorder is associated with an increased risk of all-cause dementia (OR = 1.35; 95% CI: 1.21–1.50; I² = 81.6%, P < 0.001). The history of any headache was associated with an increased risk of AD (OR = 1.49; 95% CI: 1.08–2.05; I² = 70.0%, P = 0.003) and VaD (OR = 1.72; 95% CI: 1.32–2.25; I² = 0%, P < 0.001). In the subgroup analysis, females with a history of headache have a slightly higher risk of dementia than males (OR = 1.32; 95% CI: 1.16–1.51; I² = 88.3%, P < 0.001) and the risk of dementia in the retrospective cohort was slightly higher than in the prospective cohort (OR = 1.38; 95% CI: 1.22–1.56; I² = 83.4%, P < 0.001).

Conclusions

Our meta-analysis shows that any headache disorder increases the risk of all-cause dementia, AD, or VaD. These findings provide evidence that headache should be recognized as an independent risk factor for dementia, AD, or VaD.

Increased Odds of Incident Alzheimer's Disease and Related Dementias in Presence of Common Non-Cancer Chronic Pain Conditions in Appalachian Older Adults

BACKGROUND

There is a growing concern regarding the increasing prevalence of common non-cancer chronic pain conditions (NCPCs) and their possible association with Alzheimer's disease and related dementias (ADRD). However, large population-based studies are limited, especially in Appalachian and other predominantly rural, underserved populations who suffer elevated prevalence of both NCPCs and known ADRD risk factors.

OBJECTIVES

We investigated the relation of NCPC to risk of incident ADRD in older Appalachian Medicare beneficiaries and explored the potential mediating effects of mood and sleep disorders.

METHODS

Using a retrospective cohort design, we assessed the overall and cumulative association of common diagnosed NCPCs at baseline to incident ADRD in 161,573 elders ≥65 years, Medicare fee-for-service enrollees, 2013-2015. NCPCs and ADRD were ascertained using claims data. Additional competing risk for death analyses accounted for potential survival bias.

MAIN FINDINGS

Presence of any NCPC at baseline was associated with significantly increased odds for incident ADRD after adjustment for covariates [adjusted odds ratio (AOR) = 1.26 (1.20, 1.32), p < .0001]. The magnitude and strength of this association increased significantly with rising burden of NCPCs at baseline [AOR for ≥4 vs. no NCPC = 1.65 (1.34, 2.03), p-trend = .01]. The addition of depression and anxiety, but not sleep disorders, modestly attenuated these associations [AORs for any NCPC and ≥4 NCPCs, respectively = 1.16 (1.10, 1.22) and 1.39 (1.13, 1.71)], suggesting a partial mediating role of mood impairment. Sensitivity analyses, multinomial logistic regressions accounting for risk of death, yielded comparable findings.

CONCLUSION

In this large cohort of older Appalachian Medicare beneficiaries, baseline NCPCs showed a strong, positive, dose-response relationship to odds for incident ADRD; this association appeared partially mediated by depression and anxiety. Further longitudinal research in this and other high-risk, rural populations are needed to evaluate the causal relation between NCPC and ADRD.

The Association of Osteoarthritis and Related Pain Burden to Incident Alzheimer's Disease and Related Dementias: A Retrospective Cohort Study of U.S. Medicare Beneficiaries

BACKGROUND

Emerging evidence suggests osteoarthritis (OA) and related symptom burden may increase risk for Alzheimer's disease and related dementias (ADRD). However, longitudinal studies are sparse, and none have examined the potential mediating effects of mood or sleep disorders.

OBJECTIVE

To determine the association of OA and related pain to incident ADRD in U.S. elders.

METHODS

In this retrospective cohort study, we used baseline and two-year follow-up data from linked Medicare claims and Medicare Current Beneficiary Survey files (11 pooled cohorts, 2001-2013). The study sample comprised 16,934 community-dwelling adults≥65 years, ADRD-free at baseline and enrolled in fee-for-service Medicare. Logistic regression was used to assess the association of OA and related pain (back, neck, joint, neuropathic) to incident ADRD, explore the mediating inlfuence of mood and insomnia-related sleep disorders, and (sensitivity analyses) account for potential survival bias.

RESULTS

Overall, 25.5% of beneficiaries had OA at baseline (21.0% with OA and pain); 1149 elders (5.7%) were subsequently diagnosed with ADRD. Compared to beneficiaries without OA, those with OA were significantly more likely to receive a diagnosis of incident ADRD after adjustment for sociodemographics, lifestyle characteristics, comorbidities, and medications (adjusted odds ratio (AOR) = 1.23 (95% confidence interval (CI) 1.06, 1.42). Elders with OA and pain at baseline were significantly more likely to be diagnosed with incident ADRD than were those without OA or pain (AOR = 1.31, CI 1.08, 1.58). Sensitivity analyses yielded similar findings. Inclusion of depression/anxiety, but not sleep disorders, substantially attenuated these associations.

CONCLUSION

Findings of this study suggest that: OA is associated with elevated ADRD risk, this association is particularly pronounced in those with OA and pain, and mood disorders may partially mediate this relationship.

Tension-type headache

Tension-type headache (TTH) is the most prevalent neurological disorder worldwide and is characterized by recurrent headaches of mild to moderate intensity, bilateral location, pressing or tightening quality, and no aggravation by routine physical activity. Diagnosis is based on headache history and the exclusion of alternative diagnoses, with clinical criteria provided by the International Classification of Headache Disorders, third edition. Although the biological underpinnings remain unresolved, it seems likely that peripheral mechanisms are responsible for the genesis of pain in TTH, whereas central sensitization may be involved in transformation from episodic to chronic TTH. Pharmacological therapy is the mainstay of clinical management and can be divided into acute and preventive treatments. Simple analgesics have evidence-based effectiveness and are widely regarded as first-line medications for the acute treatment of TTH. Preventive treatment should be considered in individuals with frequent episodic and chronic TTH, and if simple analgesics are ineffective, poorly tolerated or contraindicated. Recommended preventive treatments include amitriptyline, venlafaxine and mirtazapine, as well as some selected non-pharmacological therapies. Despite the widespread prevalence and associated disability of TTH, little progress has been made since the early 2000s owing to a lack of attention and resource allocation by scientists, funding bodies and the pharmaceutical industry.

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.

The Potential Contribution of Chronic Pain and Common Chronic Pain Conditions to Subsequent Cognitive Decline, New Onset Cognitive Impairment, and Incident Dementia: A Systematic Review and Conceptual Model for Future Research

BACKGROUND

Growing evidence suggests that chronic pain and certain chronic pain conditions may increase risk for cognitive decline and dementia.

OBJECTIVE

In this systematic review, we critically evaluate available evidence regarding the association of chronic pain and specific common chronic pain conditions to subsequent decline in cognitive function, new onset cognitive impairment (CI), and incident Alzheimer's disease and related dementias (ADRD); outline major gaps in the literature; and provide a preliminary conceptual model illustrating potential pathways linking pain to cognitive change.

METHODS

To identify qualifying studies, we searched seven scientific databases and scanned bibliographies of identified articles and relevant review papers. Sixteen studies met our inclusion criteria (2 matched case-control, 10 retrospective cohort, 2 prospective cohort), including 11 regarding the association of osteoarthritis (N = 4), fibromyalgia (N = 1), or headache/migraine (N = 6) to incident ADRD (N = 10) and/or its subtypes (N = 6), and 5 investigating the relation of chronic pain symptoms to subsequent cognitive decline (N = 2), CI (N = 1), and/or ADRD (N = 3).

RESULTS

Studies yielded consistent evidence for a positive association of osteoarthritis and migraines/headaches to incident ADRD; however, findings regarding dementia subtypes were mixed. Emerging evidence also suggests chronic pain symptoms may accelerate cognitive decline and increase risk for memory impairment and ADRD, although findings and measures varied considerably across studies.

CONCLUSION

While existing studies support a link between chronic pain and ADRD risk, conclusions are limited by substantial study heterogeneity, limited investigation of certain pain conditions, and methodological and other concerns characterizing most investigations to date. Additional rigorous, long-term prospective studies are needed to elucidate the effects of chronic pain and specific chronic pain conditions on cognitive decline and conversion to ADRD, and to clarify the influence of potential confounding and mediating factors.

Association Between Migraine Headaches and Dementia in More than 7,400 Patients Followed in General Practices in the United Kingdom

BACKGROUND

Most previous studies focusing on the migraine headache-dementia relationship have failed to simultaneously adjust for several common comorbidities.

OBJECTIVE

The goal of this retrospective cohort study was to investigate the association between migraine headaches and dementia in general practices in the UK.

METHODS

The current study sample included patients who received a migraine diagnosis in one of 67 general practices in the UK between January 1997 and December 2016 (index date). Patients without migraine diagnoses were matched 1 : 1 to patients with migraine diagnoses based on propensity scores using a greedy algorithm and derived from the logistic regression using age, sex, index year, and co-diagnoses. The main outcome of the study was the association between migraine headaches and the incidence of dementia within 10 years of the index date.

RESULTS

This study included 7,454 individuals with or without migraine diagnoses. Mean age was 67.7 years (SD = 5.8 years), and 72.9% of patients were women. Within 10 years of the index date, 5.2% of participants with and 3.7% of those without migraine headaches were diagnosed with dementia (log-rank p < 0.001). The respective figures were 5.8% and 3.6% in women (log-rank p < 0.001) and 4.5% and 3.4% in men (log-rank p = 0.722). We observed a positive association between migraine diagnoses and all-cause dementia (hazard ratio [HR] = 1.43) as well as Alzheimer's disease (HR = 1.87). Sensitivity analyses further revealed that these associations were only significant in women (all-cause dementia: HR = 1.65; Alzheimer's disease: HR = 2.27).

CONCLUSION

Migraine diagnoses were positively associated with all-cause dementia and Alzheimer's disease in women.

Non-Cancer Chronic Pain Conditions and Risk for Incident Alzheimer's Disease and Related Dementias in Community-Dwelling Older Adults: A Population-Based Retrospective Cohort Study of United States Medicare Beneficiaries, 2001-2013

Accumulating evidence suggests that certain chronic pain conditions may increase risk for incident Alzheimer's disease and related dementias (ADRD). Rigorous longitudinal research remains relatively sparse, and the relation of overall chronic pain condition burden to ADRD risk remains little studied, as has the potential mediating role of sleep and mood disorders. In this retrospective cohort study, we investigated the association of common non-cancer chronic pain conditions (NCPC) at baseline to subsequent risk for incident ADRD, and assessed the potential mediating effects of mood and sleep disorders, using baseline and 2-year follow-up data using 11 pooled cohorts (2001-2013) drawn from the U.S. Medicare Current Beneficiaries Survey (MCBS). The study sample comprised 16,934 community-dwelling adults aged ≥65 and ADRD-free at baseline. NCPC included: headache, osteoarthritis, joint pain, back or neck pain, and neuropathic pain, ascertained using claims data; incident ADRD (N = 1149) was identified using claims and survey data. NCPC at baseline remained associated with incident ADRD after adjustment for sociodemographics, lifestyle characteristics, medical history, medications, and other factors (adjusted odds ratio (AOR) for any vs. no NCPC = 1.21, 95% confidence interval (CI) = 1.04-1.40; p = 0.003); the strength and magnitude of this association rose significantly with increasing number of diagnosed NCPCs (AOR for 4+ vs. 0 conditions = 1.91, CI = 1.31-2.80, p-trend < 0.00001). Inclusion of sleep disorders and/or depression/anxiety modestly reduced these risk estimates. Sensitivity analyses yielded similar findings. NCPC was significantly and positively associated with incident ADRD; this association may be partially mediated by mood and sleep disorders. Additional prospective studies with longer-term follow-up are warranted to confirm and extend our findings.

[Possibilities of using Cytoflavin in the treatment of cognitive and emotional disorders in patients with tension headaches]

OBJECTIVE

To evaluate the efficacy and safety of Сytoflavin in the treatment of cognitive and emotional disorders in patients with tension headache.

MATERIAL AND METHODS

Fifty patients with tension headache, aged from 18 to 50 years, were studied. The following methods and tests were used: neurological examination, NPRS, STAI, CFQ, RAVLT, TOVA, electroencephalography (routine and spectral analysis). The patients were treated with Сytoflavin.

RESULTS

After the treatment, clinical improvement was observed in 62.0% of the patients. A significant decrease in trait anxiety and inattention, as well as an improvement of memory performance were observed. A comparative analysis of neurophysiological results before and after the treatment showed a decrease in the manifestations of dysfunction of nonspecific regulation of the brain.

CONCLUSION

The results of this study demonstrate the efficacy of Cytoflavin in the treatment of tension headache and associated emotional and cognitive impairments.

Migraine and the risk of all-cause dementia, Alzheimer's disease, and vascular dementia: A prospective cohort study in community-dwelling older adults

OBJECTIVES

Dementia is the most common neurological disease in older adults; headaches, including migraines, are the most common neurological disorder across all ages. The objective of this study was to explore the relationship between migraines and dementia, including Alzheimer's disease (AD) and vascular dementia (VaD).

METHODS

Analyses were based on 679 community-dwelling participants 65+ years from the Manitoba Study of Health and Aging, a population-based, prospective cohort study. Participants screened as cognitively intact at baseline had complete data on migraine history and all covariates at baseline and were assessed for cognitive outcomes (all-cause dementia, AD, and VaD) 5 years later. The association of exposure (lifetime history of migraines), confounding (age, gender, education, and depression), and intervening variables (hypertension, myocardial infarction, other heart conditions, stroke, and diabetes) with all-cause dementia and dementia subtypes (AD and VaD) was assessed using multiple logistic regression models.

RESULTS

A history of migraines was significantly associated with both all-cause dementia (odds ratio [OR]=2.97; 95% confidence interval [CI]=1.25-6.61) and AD (OR=4.22; 95% CI=1.59-10.42), even after adjustment for confounding and intervening variables. Migraines were not significantly associated with VaD either before (OR=1.83; 95% CI=0.39-8.52) or after (OR=1.52; 95% CI=0.20-7.23) such adjustment.

CONCLUSIONS

Migraines were a significant risk factor for AD and all-cause dementia. Despite the vascular mechanisms involved in migraine physiology, migraines were not significantly associated with VaD in this study. Recognition of the long-term detrimental consequences of migraines for AD and dementia has implications for migraine management, as well as for our understanding of AD etiology.

Association between abdominal hernia and the risk of subsequent dementia

OBJECTIVE

Matrix metalloproteinases (MMPs) may play a role in the pathophysiology of neurodegenerative disease and hernia formation. This retrospective cohort study was designed to assess whether there is an association between hernia and the risk of dementia.

MATERIALS AND METHODS

Patients (≥45 years) with hernias were identified between 2000 and 2008 from a longitudinal claims data of one million beneficiaries from Taiwan's National Health Insurance program. A control group of patients with comparable distributions of sex, age, socioeconomic status, urbanization, and medical comorbidities without hernia were chosen for matching in a ratio of 1:1. Patients previously diagnosed with dementia were excluded. Follow-up ended on December 31, 2013. Incidence rate of dementia was compared between patients with hernias and those without. Cox proportional hazards models were used to estimate hazards relative to those of the control group.

RESULTS

After matching, there were 4,784 hernia and 4,784 nonhernia patients. Hernia patients showed a higher incidence rate and hazard ratio of dementia than those in nonhernia group (8.82 vs. 7.19/1,000 person-years; adjusted hazard ratio [aHR], 1.24; 95% CI, 1.07 to 1.45; p < .01). Advanced age (p < .0001), hypertension (p = .0139), head injury (p = .0003), and stroke (p = .041) were found to be risk factors for dementia, while patients with high socioeconomic status (p < .01) and history of coronary artery disease (p = .0292) were unlikely to develop dementia in our cohort study.

CONCLUSION

Patients with hernias were associated with a higher incidence of dementia than those without. Our finding should be validated in further prospective studies with larger samples.

Association of osteoarthritis and pain with Alzheimer's Diseases and Related Dementias among older adults in the United States

BACKGROUND

Emerging evidence suggests that Pain Interference (PI) and certain chronic pain conditions, including Osteoarthritis (OA) may be associated with risk for Alzheimer's disease and Related Dementias (ADRD). However, research exploring the relation of OA and PI to ADRD remains sparse.

OBJECTIVE

To assess the association of OA and PI to ADRD using cross-sectional data from a representative sample of USA adults aged ≥65 years.

DESIGN

Retrospective cross-sectional.

STUDY SAMPLE

Older adults (age ≥ 65 years) drawn from the Medical Expenditure Panel Survey (MEPS, 2009-2015).

METHODS

OA was identified using both medical conditions files and participant responses to arthritis-specific queries. ADRD was ascertained using the medical conditions files. PI was defined as reported frequent PI with normal activities (PIA). OA and PIA were categorized as a composite variable: 1) OA with PIA; 2) OA without PIA; 3) No OA with PIA; and 4) No OA and no PIA (reference group). Adjusted associations of OA and PIA to ADRD were assessed using logistic regression and adjusted for biological, demographic, socio-economic, lifestyle, and health conditions.

RESULTS

Overall, 27.1% had OA, of whom 47.6 % reported PIA vs 31.1% of those without OA; 2.8% had diagnosed ADRD. Adults with PIA either with or without OA had significantly higher odds of ADRD relative to those without OA or PIA (Adjusted odd ratios (AOR's) = 1.37, 95%CI - 1.01, 1.86 (p = 0.04) and 1.44, 95%CI - 1.13, 1.82 (p = 0.003), respectively).

CONCLUSION

PIA in both the presence and absence of OA remained significantly and positively associated with ADRD after adjustment for multiple confounders.

A model of lipid dysregulation and altered nutrient status in Alzheimer's disease

INTRODUCTION

Dysregulated lipid metabolism and nutrient status are thought to play a role in the pathophysiology of Alzheimer's disease (AD). However, the precise involvement is not well understood, and it remains unclear exactly how such dysregulated lipid metabolism and altered nutrient status, especially changes in phosphatidylcholine, B12, and folate, are connected to the hallmark pathology in AD (i.e., amyloidogenesis).

METHODS

We have postulated that genetic susceptibility (i.e., APOE ε4/ε4) to environmental exposure to emissions of nitrous oxide (N2O) could underlie the onset of AD and its early neuropsychiatric correlates.

RESULTS AND DISCUSSION

The current theoretical editorial describes, using clinical, preclinical, and in vitro evidences, how this model contributes not only to amyloidogenesis but also other nonopioid effects, specifically altered lipid metabolism, depletion of vitamin B12, and disruption of the folate-mediated one carbon metabolic pathway.

Associations of Elderly Onset Headache With Occurrence of Poor Functional Outcome, Cardiovascular Disease, and Cognitive Dysfunction During Long-term Follow-up

Background

Although the frequency and intensity of headaches decrease in older adults, headaches in this population are still an important neurological disorder. The purpose of this study was to investigate the associations of headache characteristics in older adults with the development of cardiovascular disease and cognitive dysfunction.

Methods

We prospectively enrolled 125 older (≥65 years old) patients with headache who were making their first visit to outpatient clinics and who had no prior history of cognitive dysfunction from 11 hospitals in Korea between August 2014 and February 2015. We investigated the occurrence of newly developed/or recurrent headache, cardiovascular disease, cognitive dysfunction, and poor functional outcomes.

Results

The mean age of all included patients was 72.6 years, 68.8% were women, and 43 (34.4%) had newly developed/or recurrent headache during follow-up. During a median follow-up of 31 months (interquartile range, 28–34 months), 21 participants (16.8%) experienced cardiovascular disease, and 26 (20.8%) developed cognitive dysfunction. Upon multivariate analysis and after adjusting for sex, age, and other factors, presence of newly developed/or recurrent headache was found to be associated with cardiovascular disease (hazard ratio [HR], 4.03; 95% confidence interval [CI], 1.28–12.61; p=0.017) and frequency of headache for the recent 3 months was related with cognitive dysfunction (HR, 1.05; 95% CI, 1.00–1.09; p=0.017) and poor functional outcomes (HR, 1.06; 95% CI, 1.01–1.11; p=0.011).

Conclusion

Our study demonstrated that there is an increased risk of cardiovascular disease, cognitive dysfunction, and poor functional outcomes in older patients with frequent, newly developed, or recurrent headache.

Headache disorder and the risk of dementia: a systematic review and meta-analysis of cohort studies

Background

Until now, headache disorders have not been established as a risk factor for dementia. The aim of this study was to determine whether headache was associated with an increased risk of dementia.

Methods

We systematically searched electronic databases, including PubMed, Embase, and Web of Science, for studies investigating the association between headache and dementia. We then conducted a meta-analysis to determine a pooled-effect estimate of the association.

Results

We identified 6 studies (covering 291,549 individuals) to investigate the association between headache and the risk of all-cause dementia or Alzheimer’s disease (AD). Pooled analyses showed that any headache was associated with a 24% greater risk of all-cause dementia (relative risk [RR] = 1.24; 95% confidential interval [CI]: 1.09–1.41; P = 0.001), and that any headache was not statistically significantly associated with an increased risk of AD (RR = 1.47; 95% CI: 0.82–2.63; P = 0.192).

Conclusions

Our results indicated that any headache was associated with an increased risk of all-cause dementia. However, additional studies are warranted to further confirm and understand the association.

Electronic supplementary material

The online version of this article (10.1186/s10194-018-0925-4) contains supplementary material, which is available to authorized users.

[Primary headache - risk factor or comorbid pathology in cognitive impairment]

Currently, the relationship between headache and dementia is considered more widely than just a comorbidity. The severity of migraine and tension-type headache and the severity of cognitive impairment are strongly correlated. Common pathophysiological mechanisms underlie the relationship between primary headache and cognitive impairment. Antinociceptive changes in primary headaches and in glutamate excitotoxicity in dementia developed due to hyper excitability of NMDA receptors are strongly interdependent. It is important in the aspect of possible correction of this pathology by NMDA-antagonists. Memantine not only slows the progression of cognitive symptoms in dementia, but also significantly influences the frequency and severity of primary headache.

Headaches and Risk of Dementia

BACKGROUND

Primary headaches include migraines, tension-type headaches and other primary headache syndromes. Migraines and tension-type headaches are associated with patient discomfort and other diseases. This study aimed to investigate the association between primary headaches and the risk of developing dementia, and to clarify the association between different types of headaches and dementia.

MATERIALS AND METHODS

We conducted a nationwide matched cohort population-based study. A total of 3,620 patients with newly diagnosed primary headaches, including migraines and tension-type headaches, between January 1 and December 31, 2000 were selected from the National Health Insurance Research Database of Taiwan, along with 10,860 controls matched for sex and age. After adjusting for confounding factors, Fine and Gray׳s competing risk analysis was used to compare the risk of developing dementia during 10 years of follow-up.

RESULTS

Of the study subjects, 170 (4.70 %) developed dementia compared with 433 (3.99%) of the controls. Fine and Gray׳s competing risk analysis revealed that the study subjects were more likely to develop dementia (hazard ratio = 2.057; 95% CI: 1.718-2.462; P < 0.001). After adjusting for sex, age, monthly income, urbanization level, geographic region of residence and comorbidities, the hazard ratio for dementia was 2.048 (95% CI: 1.705-2.461, P < 0.001). Migraines and tension-type headaches were associated with nonvascular dementia but not vascular dementia.

CONCLUSIONS

The patients with headaches had a 105% increased risk of dementia. Further studies are needed to elucidate the underlying mechanisms.

Are Chronic Periodontitis and Gingivitis Associated with Dementia? A Nationwide, Retrospective, Matched-Cohort Study in Taiwan

BACKGROUND

Chronic periodontitis and gingivitis are associated with various diseases; however, their impact on dementia is yet to be elucidated. This study is aimed at investigating the association between chronic periodontitis and gingivitis, and the risk of developing dementia.

METHODS

A total of 2,207 patients, with newly diagnosed chronic periodontitis and gingivitis between January 1, 2000 and December 31, 2000, were selected from the National Health Insurance Research Database of Taiwan, along with 6,621 controls matched for sex and age. After adjusting for confounding factors, Cox proportional hazards analysis was used to compare the risk of developing dementia during the 10-year follow-up period.

RESULTS

Of the study subjects, 25 (1.13%) developed dementia compared to 61 (0.92%) in the control group. Cox proportional hazards regression analysis revealed that the study subjects were more likely to develop dementia (hazard ratio (HR) 2.085, 95% CI 1.552-4.156, p < 0.001). After adjusting for sex, age, monthly income, urbanization level, geographic region, and comorbidities, the HR for dementia was 2.54 (95% CI 1.297-3.352, p = 0.002).

CONCLUSIONS

Patients with chronic periodontitis and gingivitis have a higher risk of developing dementia. However, further studies on other large or national data sets are required to support the current findings.