Association between Helicobacter pylori cytotoxic type I CagA-positive strains and migraine with aura

Helicobacter pylori infection in migraine headache: a true association or an innocent bystander?

Much concern was directed towards the relationship between migraine and Helicobacter pylori (H. pylori) infection. Some researchers reported a strong association. Meanwhile, others have indicated totally negative results. The aim of this work was to clarify the association between migraine headaches and both H. pylori infection and Gastrointestinal (GIT) symptoms and to study their impact on the frequency and severity of migraine headache attacks.

This is a case control study conducted on 77 migraine patients and 77 healthy controls. History was taken from the included patients regarding the frequency of migraine headache attacks/month and GIT symptoms including dyspepsia, flatulence, weight loss, and epigastric pain. Migraine Disability Assessment Test (MIDAS) and Visual Analogue Scale (VAS) were used for assessment of migraine severity. Helicobacter pylori was detected in the stool of the included patients and controls.

There was a significantly higher prevalence of infection with H. pylori in migraine patients [77.9% (n = 60)] than control group [50.6% (n = 39)] (P-value˂ 0.001, Odds ratio= 3.439, 95% CI =1.708 - 6.923). The prevalence of dyspepsia, flatulence, and epigastric pain. was significantly higher in migraine patients in comparison to control group (P-value= 0.003, 0.017, 0.006 respectively). There was no effect of infection with H. pylori or presence of GIT symptoms on frequency of migraine attacks, MIDAS or VAS scores.

GIT symptoms and H. pylori infection are more prevalent in patients with migraine compared to controls, however, they might not have an impact on the frequency or severity of migraine headache attacks.

Association of Helicobacter pylori with migraine headaches and the effects of this infection and its eradication on the migraine characteristics in adults: A comprehensive systematic review and meta-analysis

BACKGROUND

Migraine is one of the most common neurological disorders that can severely overshadow people's quality of life, and Helicobacter pylori infection is a health problem in different societies. During the last two decades, many original studies have been conducted on the various aspects of the relationship between these two disorders; however, they have reported different and sometimes contradictory results.

METHODS

This study was conducted based on the PRISMA protocol. We performed a comprehensive literature search in the online databases up to May 2023, and 22 studies that contained original data on the relationship between H. pylori infection and migraine headaches in adults were included. For performing the meta-analysis, we calculated the odds ratios (OR) and 95% confidence intervals (CI), using a random-effects model, and to determine the possible causes of heterogeneity, we conducted a subgroup meta-analysis.

RESULTS

The overall OR for the association of H. pylori infection and migraine headaches through 493,794 evaluated individuals was 2.80 [95% CI = 1.75-4.48; I2  = 89.20, p < 0.01], which reveals a statistically significant association between these disorders. It was found that the studies that were conducted in Asian regions and the recently published ones have clearly shown a higher association between migraine and H. pylori infection. On the other hand, migraine patients who are infected with H. pylori have similar signs and symptoms as H. pylori-negative migraineurs; meanwhile, the clinical trials conducted in this field strongly emphasize the benefits of eradicating H. pylori infection in migraine patients and have estimated its effectiveness in improving migraine headaches equivalent to current common migraine treatments. Furthermore, it was reported that white matter lesions were 2.5-fold higher on brain MRI in patients with H. pylori-positive migraine compared with H. pylori-negative migraineurs; however, the evidence does not support the role of oxidative stress in patients suffering from H. pylori infection and migraine and refuses the role of Cag-A-positive strains of H. pylori in migraine headaches.

CONCLUSION

According to the currently available data, it seem reasonable that patients with a definite diagnosis of migraine who also suffer from gastrointestinal problems, undergo the H. pylori detection tests and if the evaluations are positive, H. pylori eradication treatment can be considered even before any migraine treatment.

Association Between Helicobacter pylori Infection and Migraine: A Systematic Review

Migraine is a highly debilitating disease affecting humans worldwide. Despite having known this disease for a long time, not many studies have been done to search for a chronic infectious cause of migraine. The goal of this study was to look for an association between migraine and Helicobacter pylori infection. Following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) standards, we conducted the analysis and literature search using PubMed, Google Scholar and Cochrane databases. After applying the inclusion and exclusion criteria, the search technique produced a total of 10 articles including one cross-sectional study, two randomized controlled trials (RCTs), one cohort study, five case-control studies and one meta-analysis. Analysis of these studies revealed that there could be an association between Helicobacter pylori infection and migraine, especially in the Asian population. However, the mechanism by which the infection could possibly cause this extra-gastric disorder needs further research and analysis.

Helicobacter pylori Infection in Children: A Possible Reason for Headache?

(1) Background: The correlation between infection with Helicobacter pylori (H. pylori) and headache has been argued and explored for a long time, but a clear association between the simultaneous presence of the two in children has not been established yet. In this study, we aimed to explore this relationship in children from the Northeast region of Romania. (2) Methods: A retrospective study exploring the correlation between children having H. pylori infection and headache or migraine was conducted on a batch of 1757 children, hospitalized over 3 years in a pediatric gastroenterology department in Northeast Romania. (3) Results: A total of 130 children of both sexes had headache. From 130 children, 54 children (41.5%) also presented H. pylori infection. A significant association between headache and H. pylori infection (χ2; p < 0.01) was noticed. (4) Conclusions: More studies are needed on this relationship, and we emphasize the importance of further analyses, as they present great clinical importance for both prompt diagnosis and treatment.

Prevalence and association of lifestyle and medical-, psychiatric-, and pain-related comorbidities in patients with migraine: A cross-sectional study

BACKGROUND AND OBJECTIVES

Migraine has been associated with many comorbidities. However, lifestyle factors and the presence of comorbid diseases have not previously been extensively studied in the same sample. This study aimed to compare the prevalence of unhealthy lifestyle factors and comorbid diseases between patients with migraine and migraine-free controls with subgroup analyses to determine the pathophysiology and possible consequences.

METHODS

This cross-sectional study recruited 1257 patients with migraine between the ages of 20 and 65 years from a headache outpatient clinic in Taiwan and 496 non-migraine controls. All participants completed questionnaires regarding demographics, migraine diagnosis, sleep, headache burden, and medical, pain, and psychiatric conditions. Participants also underwent a structured interview. The associations between comorbidities and migraine were investigated and further stratified by sex and aura.

RESULTS

Patients with migraine with aura had an unhealthier lifestyle compared with controls in the form of current smoking status (15.5% [67/431] vs. 11.5% [57/496], p = 0.013). Furthermore, medical- (e.g., thyroid disease; 7.2% [91/1257 vs. 2.8% [14/496]; p = 0.006), psychiatric- (e.g., depression; 6% [76/1257 vs. 2.6% [13/496]; p = 0.031), and pain-related (e.g., fibromyalgia; 8% [101/1257 vs. 3.2% [16/496]; p = 0.006) comorbidities were more prevalent in patients compared with controls. Subgroup analyses revealed that chronic migraine, migraine with aura, and female sex were associated with a greater number of significant comorbidities than episodic migraine, migraine without aura, and male patients with migraine, respectively.

CONCLUSION

Individuals seeking treatment for migraine reported greater levels of smoking and medical, psychiatric, and pain conditions than non-treatment-seeking healthy controls who were recruited from the community. Understanding the relationship between migraine and comorbid diseases may improve medical care as well as the quality of life.

Role of Helicobacters in Neuropsychiatric Disease: A Systematic Review in Idiopathic Parkinsonism

Interest in an aetiopathogenic role for Helicobacter in neuropsychiatric diseases started with idiopathic parkinsonism (IP), where the cardinal signs can be assessed objectively. This systematic review, using an EMBASE database search, addresses Oxford Centre for Evidence-Based Medicine based questions on the inter-relationship of Helicobacter and IP, the benefits of eradicating Helicobacter in IP and the outcome of not treating. The search strategy was based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines: 21 of 204 articles met the inclusion criteria. The results show that the assumption that any benefit of Helicobacter eradication results from improved levodopa bioavailability is unjustified. The inter-relationship between Helicobacter and IP is well-established. H. pylori virulence markers (associated with autoimmunity and immune tolerance) influence the risk, severity and progression of IP. The birth cohort effect for virulence marker antibodies, seen in controls, is obliterated in IP, suggesting causality. Successful H. pylori eradication in IP is disease-modifying (even in anti-parkinsonian treatment-naïve patients) but not preventive. Hypokinesia regresses with eradication and overall motor severity lessens. Eradication may influence gastrointestinal microbiota adversely, unlocking the next stage in the natural history, the development of rigidity. Failed eradication worsens hypokinesia, as does the presence/persistence of H. pylori at molecular level only. Adequate prognostic assessment of the consequences of not treating Helicobacter, for IP, is prevented by a short follow-up. We conclude that Helicobacter is a pathophysiological driver of IP.

Clinical Implications of Associations between Headache and Gastrointestinal Disorders: A Study Using the Hallym Smart Clinical Data Warehouse

Background

The brain and gastrointestinal (GI) tract are strongly connected via neural, endocrine, and immune pathways. Previous studies suggest that headaches, especially migraines, may be associated with various GI disorders. However, upper GI endoscopy in migraineurs has shown a low prevalence of abnormal findings. Also, the majority of studies have not demonstrated an association between Helicobacter pylori (HP) infection and migraine, although a pathogenic role for HP infection in migraines has been suggested. Further knowledge concerning the relation between headaches and GI disorders is important as it may have therapeutic consequences. Thus, we sought to investigate possible associations between GI disorders and common primary headaches, such as migraines and tension-type headaches (TTH), using the Smart Clinical Data Warehouse (CDW) over a period of 10 years.

Methods

We retrospectively investigated clinical data using a clinical data analytic solution called the Smart CDW from 2006 to 2016. In patients with migraines and TTH who visited a gastroenterology center, GI disorder diagnosis, upper GI endoscopy findings, and results of HP infection were collected and compared to clinical data from controls, who had health checkups without headache. The time interval between headache diagnosis and an examination at a gastroenterology center did not exceed 1 year.

Results

Patients were age- and sex-matched and eligible cases were included in the migraine (n = 168), the TTH (n = 168), and the control group (n = 336). Among the GI disorders diagnosed by gastroenterologists, gastroesophageal reflux disorder was more prevalent in the migraine group, whereas gastric ulcers were more common in the migraine and TTH groups compared with controls (p < 0.0001). With regard to endoscopic findings, there were high numbers of erosive gastritis and chronic superficial gastritis cases in the migraine and TTH groups, respectively, and the severity of gastritis was significantly higher in patients with TTH compared with controls (p < 0.001). However, no differences were observed in the prevalence of HP infection between the groups.

Conclusion

The observed association in this study may suggest that primary headache sufferers who experience migraines or TTH are more prone to GI disorders, which may have various clinical implications. Further research concerning the etiology of the association between headaches and GI disorders is warranted.

[Headache immunology]

The overview is dedicated to the neuroimmunological mechanisms of headache development and chronification. Based on the analyzed data, the authors determined the relationship between immunological parameters and duration, intensity and other characteristics of this disease. These findings confirm that immunocompetent cells can be used as headache biomarkers and predictors of treatment efficacy. Questions about the role of separate parts of the immune system in the development and maintenance of a headache require further research. Studies of humoral immunity appeared to be very promising.

Gastrointestinal disorders associated with migraine: A comprehensive review

Migraine is a recurrent and commonly disabling primary headache disorder that affects over 17% of women and 5%-8% of men. Migraine susceptibility is multifactorial with genetic, hormonal and environmental factors all playing an important role. The physiopathology of migraine is complex and still not fully understood. Many different neuropeptides, neurotransmitters and brain pathways have been implicated. In connection with the myriad mechanisms and pathways implicated in migraine, a variety of multisystemic comorbidities (e.g., cardiovascular, psychiatric and other neurological conditions) have been found to be closely associated with migraine. Recent reports demonstrate an increased frequency of gastrointestinal (GI) disorders in patients with migraine compared with the general population. Helicobacter pylori infection, irritable bowel syndrome, gastroparesis, hepatobiliary disorders, celiac disease and alterations in the microbiota have been linked to the occurrence of migraine. Several mechanisms involving the gut-brain axis, such as a chronic inflammatory response with inflammatory and vasoactive mediators passing to the circulatory system, intestinal microbiota modulation of the enteric immunological milieu and dysfunction of the autonomic and enteric nervous system, have been postulated to explain these associations. However, the precise mechanisms and pathways related to the gut-brain axis in migraine need to be fully elucidated. In this review, we survey the available literature linking migraine with GI disorders. We discuss the possible physiopathological mechanisms, and clinical implications as well as several future areas of interest for research.

Association between Helicobacter pylori infection and migraine: A meta-analysis

AIM: To quantify the association between Helicobacter pylori (H. pylori) infection and migraine.

METHODS: A systematic literature search of PubMed and EMBASE was conducted from inception to December 2013. Studies that provided data dealing with H. pylori infection in patients with migraine, as well as healthy controls, were selected. Meta-analysis was carried out using the odds ratio (OR) with a fixed or random effects model, and a 95%CI for the OR was calculated. An unconditional logistic regression model was used to analyze potential parameters related to H. pylori prevalence. Subgroup analyses were conducted as methods of detection and evidence grade.

RESULTS: Five case-control studies published between 2000 and 2013 were finally identified, involving 903 patients, with a total H. pylori infection rate of 39.31%. The prevalence of H. pylori infection was significantly greater in migraineurs than in controls (44.97% vs 33.26%, OR = 1.92, 95%CI: 1.05-3.51, P = 0.001). A sensitivity test indicated that no single study dominated the combined results. Univariate regression analysis found that publication year, geographical distribution and evidence grade were relevant to the results and were the main reason for the heterogeneity. Subgroup analysis found a significantly greater infection rate of H. pylori in Asian patients with migraine, but no statistically significant infection rate in European patients. The ORs were 3.48 (95%CI: 2.09-5.81, P = 0.000) and 1.19 (95%CI: 0.86-1.65, P = 0.288), respectively.

CONCLUSION: The pooled data suggest a trend of more frequent H. pylori infections in patients with migraine.

Clinical effects of Helicobacter pylori outside the stomach

The discovery of Helicobacter pylori infection in the stomach could be considered as one of the most important events of modern gastroenterology. Understanding of the natural history of many disorders of the upper gastrointestinal tract, including chronic gastritis, peptic ulcer disease, gastric cancer and MALT lymphoma, was altered by this discovery. Interestingly, epidemiological studies have also revealed a correlation between H. pylori infection and some diseases localized outside the stomach, especially those characterized by persistent and low-grade systemic inflammation. Of note, H. pylori has an important role in iron deficiency anaemia, idiopathic thrombocytopenic purpura and vitamin B12 deficiency. Moreover, the association of this bacterial pathogen with many other diseases, including hepatobiliary, pancreatic, cardiovascular and neurodegenerative disorders is currently under investigation. In this Review, we summarize the results of the most important studies performed to date surrounding the association of H. pylori infection with extragastric diseases, as well as the strength of the evidence. We also provide information concerning bacterial-host interactions and the mechanisms implicated in the pathogenesis of each of these extragastric diseases.

Evaluation of Helicobacter pylori infection in patients with common migraine headache

INTRODUCTION

Migraine can cause headache in different communities so that 12-15% are suffering worldwide. Recently the relationship between infectious diseases such as Helicobacter pylori infection and migraine headache has been the focus of many studies. The current study was designed to evaluate IgG and IgM antibodies to H. pylori in patients suffering from migraine headaches.

MATERIAL AND METHODS

Patients who had diagnostic criteria for migraine were chosen as cases compared to some healthy individuals as the control group amongst which immunoglobulin G (IgG), immunoglobulin M (IgM), age, job, gastro-intestinal (GI) disorders, history of migraine, special meals, medications, sleeping disorders, stress, environmental factors etc were analysed.

RESULTS

The prevalence of disease was 38.6%. Household women had the highest prevalence (40%). Among them menstruation was related to high prevalence of migraine. 75.6% of patients had gastrointestinal disorders of which the gastric reflux was the most important sign (47.1%). The mean optical density (OD) value of IgG and IgM antibody to H. pylori was 60.08 ±7.7 and 32.1 ±8.7 for the case group, 21.82 ±6.2 and 17.6 ±9.4 for the control group, respectively.

CONCLUSIONS

There was a significant difference in mean OD value of both antibodies to H. pylori amongst the case and control groups. As a result, active H. pylori infection is strongly related to the outbreak and severity of migraine headaches, and H. pylori treatment reduces migraine headaches significantly. Hopefully, the definite treatment and eradication of this infection can cure or reduce the severity and course of migraine headaches significantly if not totally.

14C-urea breath test is safe for pediatric patients

Helicobacter pylori (H. pylori) infection, quite prevalent in the developing countries, is considered to be one of the causative factors for various gastric pathologies and other nongastric diseases. It is believed that H. pylori infection is almost always acquired in early childhood and persists throughout life unless specific treatment is given. The (13/14)C-urea breath test (UBT) is now considered to be a 'gold standard' technique for the detection of H. pylori infection. However, because of the lack of facilities and high cost, the preferred nonradioactive ¹³C-UBT cannot be performed on pediatric patients in developing countries, whereas the radioactive ¹⁴C-UBT is not used on children because of the fear of radiation exposure. When using 37 kBq (1 μCi) of ¹⁴C-urea for the ¹⁴C-UBT, the patient is not exposed to more radiation than is acquired from the natural environment in one day, as almost all the ingested radioactivity is excreted from the body (urine and breath) within 72-120 h. This article reviews the importance of the ¹⁴C-UBT for the detection of H. pylori and justifies the radiation safety aspects of its use in children without any fear of 'radiation phobia' where the facility for ¹³C-UBT is lacking.

Infection by CagA-positive Helicobacter pylori strains may contribute to alter the sperm quality of men with fertility disorders and increase the systemic levels of TNF-alpha

This study was aimed to address the possibility that Helicobacter pylori infection may play a detrimental role in semen quality of men with idiopathic infertility. Infection by H. pylori and by strains expressing CagA was determined in 80 male infertile patients by Western blotting and ELISA. Semen analysis was performed by light microscopy and transmission electron microscopy quantitatively elaborated (fertility index, immaturity, necrosis, and apoptosis percentages). Systemic levels of IL-6 and TNF-alpha were evaluated. Infertile patients infected with H. pylori showed a low sperm quality respective to uninfected patients. Particularly, in CagA-positive patients we observed a significant reduction in sperm motility and in the fertility index, while apoptosis and necrosis were increased. In these patients, the means of systemic TNF-alpha levels were higher than those of uninfected patients. The negative influence of CagA-positive H. pylori infection on sperm quality may help to understand the role of chronic infections in reproductive disorders.

Helicobacter pylori infection as an environmental risk factor for migraine without aura

Helicobacter pylori (H. pylori) infection has recently been associated with various extraintestinal pathologies and migraine. The aim of this study was to investigate the correlation of the H. pylori infection with the pathogenesis of migraine without aura, especially in cases not affected by endogenous risk factors, like hereditary pattern or hormonal fluctuations.A total of 49 outpatients (37 females and 12 males; age range: 19-47 years; mean age: 31,+/-14 years) affected by migraine without aura was evaluated. We divided them in 2 subgroups: a) with positive familial history, and/or with menstrual type of migraine b) with negative familial history and with menstrual unrelated type of migraine. H. pylori infection was diagnosed by the 13 C- urea breath test (INFAI - test). Control subjects consisted of 51 patients without any primary headache history (38 females; mean age of 32,+/-14,4 years; range 21-49 years), who underwent upper gastrointestinal (GI) endoscopy for investigation of anaemia or non ulcer dyspepsia. H. pylori detection was based on the histologic analysis of gastric mucosa biopsy. The prevalence of H. pylori infection was significantly higher in the migraineurs without aura compared to controls (p=0.016). The prevalence of H. pylori infection was significantly high in the mixed and in the female group of our patients without other predisposing factors for migraine without aura (81 and 87% respectively), while in the same groups with predisposing factors (menstruation and/or family history) the prevalence was only 36 and 37% respectively (p=0,001 for the first group and p=0,002 for the second group). Our results seem to highlight the role of H. pylori infection as a probable independent environmental risk factor for migraine without aura, especially in patients that are not genetically or hormonally susceptible to migraine.

Entzündliche Erkrankungen des ZNS sowie immunmodulatorische Therapie und ihr Einfluss auf primäre Kopfschmerzen

Headaches are a well known symptom in systemic or local inflammatory diseases such as pneumonia or meningitis. These headaches may mimic primary headaches and are thought to be generated by inflammatory mediators acting directly on nociceptors or indirectly - via facilitation of neurons. Apart from prostaglandin and nitric oxide also cytokines (TNF-alpha or interleukin-6) may play a role. In primary headaches such as migraine inflammatory mechanisms also have been acclaimed to contribute to pain generation. The recently observed increase of migraine attacks under immunmodulatory therapy in multiple sclerosis has focussed attention on primary headaches in states of altered immunity, for instance in autoimmune disorders like lupus erythematosus, rheumatoid arthritis, or in patients treated with immunosuppressants. This article describes the standard of knowledge and tries to shed light on possible mechanisms of pain generation in the respective conditions.

Noxious compounds in exhaled air, a potential cause for ocular manifestations of H. pylori gastrointestinal infection

Helicobacter pylori infection is one of the most common chronic bacterial infections worldwide. In the past few years, a variety of extradigestive disorders have been associated with H. pylori infection. This infection has also been linked to some ophthalmic disorders, including glaucoma, central serous chorioretinopathy, uveitis and blepharitis. Several possible theories to explain pathogenetic mechanism underlying the observed associations have been provided. H. pylori infection causes elaboration of some noxious compounds, including ammonia, hydrogen nitrate and hydrogen cyanide, in exhaled breath of infected individuals. Herein we hypothesize that chronic exposure of ocular surface to these compounds may explain some ophthalmic and also respiratory manifestations of the chronic gastrointestinal infection.

Production of reactive oxygen species in peripheral blood is increased in individuals with Helicobacter pylori infection and decreased after its eradication

BACKGROUND

Helicobacter pylori infection has been reported to cause gastroduodenal ulcer, mucosa-associated lymphoid tissue lymphoma, and gastric cancer. Recent studies have suggested that H. pylori infection may also associate with other diseases, including hematologic and dermatologic disorders, and cardiovascular injury, by unknown mechanisms.

METHODS

Production of reactive oxygen species (ROS) was determined in peripheral blood samples from 86 patients (34 H. pylori-negative and 52 H. pylori-positive subjects) using a highly sensitive chemiluminescence probe, L-012 (8-amino-5-chloro-7-phenylpyrido(3,4-d) pyridazine-1 and 4 (2H, 3H) dione). Eleven H. pylori-positive individuals were also analyzed their ROS production in peripheral blood after H. pylori eradication.

RESULTS

ROS production was significantly higher in individuals with H. pylori infection than in those without infection. Enhanced production of ROS was decreased significantly after eradication of H. pylori. No correlation was found between the extent of ROS production and sex, age, smoking status, alcohol ingestion, use of medications, or serum level of C-reactive protein.

CONCLUSION

These findings suggest that ROS production was enhanced in peripheral blood by H. pylori infection. Chemiluminescence analysis of blood samples using L-012 permits evaluation of systemic oxidative stress in patients with H. pylori infection.

Rifaximin-based regimens for eradication of Helicobacter pylori: a pilot study

BACKGROUND

Triple therapy is the treatment of choice for Helicobacter pylori-infected patients with an eradication rate ranging from 70 to 85%. Poor compliance and antibiotic resistance are the main causes of treatment failure. The aim of the present study was to assess the efficacy of rifaximin, a poorly absorbed antibiotic, for H. pylori eradication.

METHODS

We enrolled 48 consecutive H. pylori-positive patients affected. They were randomized to receive two 7-day rifaximin-based triple therapies: rifaximin tablets 400 mg t.i.d., esomeprazole 40 mg o.d. and clarithromycin 500 mg b.i.d. (CRE) or levofloxacin 500 mg o.d. (LRE). H. pylori eradication was assessed using a (13)C-urea breath test 4 weeks after the end of therapy. Treatment compliance and the incidence of side effects were also evaluated.

RESULTS

No dropouts were observed. The eradication rate both on intention-to-treat and per-protocol analysis did not show significant differences between groups: 58% (14/24 patients) in group 1 and 42% (10/24 patients) in group 2 (p = 0.24, OR 1.96, 95% CI 0.62-6.18). No significant differences in patients' compliance and incidence of side effects were found between groups.

CONCLUSIONS

Rifaximin-based therapy showed optimal compliance but a limited eradication rate compared to standard first-line treatment. Further investigations are needed to evaluate different dosages and combinations.

The comorbidity of migraine

This review addresses the methodologic issues relevant to the study of comorbidity and provides a broad overview of the medical and psychiatric conditions associated with migraine. Since the body of literature examining the comorbidity of migraine is enormous, the scope of this review will largely focus on community and case-control studies. Among the selected comorbid medical conditions, including disorders of the cardiovascular, respiratory, neurologic, gastrointestinal and immunologic systems, stroke, asthma, and allergies appear to be most strongly associated with migraine. Among the psychiatric illnesses, mood and anxiety disorders have been shown to be most strongly associated with migraine in the general population. Further research is indicated and necessary to elucidate the precise mechanism of migraine comorbidity.

Shared rearing environment in migraine: results from twins reared apart and twins reared together

BACKGROUND

Studies of twins who are separated from each other early in life and are reared in different environments offer the opportunity to resolve variation in liability to disease.

OBJECTIVE

To evaluate the importance of genetic and environmental influences in migraine; in particular, addressing the role of the shared rearing environment.

METHODS

A population-based cohort of twins, including a subsample of 314 pairs reared apart and 364 matched control pairs reared together, was drawn from the Swedish Twin Registry. Data on lifetime migraine was collected via self-administered questionnaires mailed to twins aged 42 to 81 years. Quantitative genetic models and regression models were used to analyze sources of twin similarity.

RESULTS

We found nonsignificant shared rearing environmental influences on migraine for men (17%) and no rearing effects at all for women. The heritability of migraine was estimated at 38% (95% confidence interval, 0 to 73) for men and 48% (95% confidence interval, 27 to 65) for women. Among monozygotic twins reared apart, those separated at 3 years of age or earlier were more similar for lifetime migraine than those separated later, and this was especially true for women.

CONCLUSION

In agreement with previous twin data, family resistance in migraine is mainly due to genetic factors, whereas environmental influences make family members different, not similar.

The neurology of gluten sensitivity: separating the wheat from the chaff

Coeliac disease is the prototypical gluten-sensitive disease. Clinico-pathological features heal on a gluten-free diet and relapse when gluten is reintroduced. An immunopathology is suspected. A number of neurological syndromes may be associated with coeliac disease but it is unclear whether these are directly or indirectly caused by gluten ingestion. It has been proposed that idiopathic ataxias and central nervous system white matter disease are gluten-sensitive syndromes. This is an exciting hypothesis because it offers new therapeutic possibilities including simple exclusion diets. However, interpretation is difficult because occult sub-clinical coeliac disease occurs commonly and background prevalence needs to be accounted for in population-based studies. This review will attempt to summarize the pertinent literature on this fascinating topic.