Genomic expression patterns in medication overuse headaches

A Descriptive Review of Medication-Overuse Headache: From Pathophysiology to the Comorbidities

PURPOSE OF REVIEW

Medication-overuse headache (MOH) is an important problem worldwide, with different areas of controversy regarding its entity. This article reviews the risk factors, comorbidities, pathophysiology, clinical presentation, effective management, and prognosis of MOH by summarizing and integrating the results and findings from previously performed more than 15,000 studies (from 2010 to 2023) available from the scientific database of the University Medical Library in the University Clinical Center of Niš, which aimed to investigate and define the complexity of this type of headache.

RECENT FINDING

It has been proposed that all acute migraine medications can lead to MOH, with differences in the propensity of different agents to cause the problem. Early data suggests that triptans and other painkillers used for the acute treatment of migraine may be an exception. Recent studies show that practitioners and the general public are still largely unaware of the problem of medication overuse and its damaging effects.

SUMMARY

Although it is likely that MOH does occur, restricting the number of acute medications is necessary to prevent it. It is also possible that increasing amounts of acute medications are simply a reflection of poorly controlled headaches rather than a cause. Further research needs to be developed to identify more precise mechanisms for effective MOH management and its evolution.

DNA-methylation and immunological response in medication overuse headache

OBJECTIVE

To investigate whether medication-overuse headache patients have differential DNA-methylation pattern.

METHODS

We collected blood samples from 120 medication-overuse headache-patients, 57 controls (29 episodic migraine patients and 28 healthy controls) in a hypothesis-generating cross-sectional case-control pilot study; 100 of the medication-overuse headache-patients were followed for six months and samples were collected at two and six months for the longitudinal methylation analyses. Blood cell proportions of leucocytes (neutrophils, NK-cells, monocytes, CD8+ and CD4+ T-cells, and B-cells) and the neutrophile-lymphocyte ratio were estimated using methylation data as a measure for immunological analysis and a cell type-specific epigenome wide association study was conducted between medication-overuse headache-patients and controls, and longitudinally for reduction in headache days/month among medication-overuse headache-patients.

RESULTS

We found a higher neutrophile-lymphocyte ratio in medication-overuse headache-patients compared to controls, indicating a higher immunological response in medication-overuse headache-patients (false discovery rate (adjusted p-value)<0.001). Reduction in headache days/month (9.8; 95% CI 8.1-11.5) was associated with lower neutrophile-lymphocyte ratio (false discovery rate adjusted p-value = 0.041).Three genes (CORIN, CCKBR and CLDN9) were hypermethylated in specific cell types in medication-overuse headache-patients compared to controls. No methylation differences were associated with reduction in headache days in medication-overuse headache-patients after six months.

CONCLUSION

This pilot study was consistent with higher immunological response in medication-overuse headache-patients which decreased with a reduction in headache days in longitudinal analysis. medication-overuse headache-patients exhibited differential methylation in innate immune cells but did not exhibit longitudinal differences with alterations in headache days. Our study creates hypotheses for further biomarker searches.ClinicalTrials.gov Identifier: NCT02993289.

Medication overuse headache

Medication overuse headache (MOH) is a secondary headache disorder attributed to overuse of acute headache medications by a person with an underlying headache disorder, usually migraine or tension-type headache. MOH is common among individuals with 15 or more headache days per month. Although MOH is associated with substantial disability and reductions in quality of life, this condition is often under-recognized. As MOH is both preventable and treatable, it warrants greater attention and awareness. The diagnosis of MOH is based on the history and an unremarkable neurological examination, and is made according to the diagnostic criteria of the International Classification of Headache Disorders third edition (ICHD-3). Pathophysiological mechanisms of MOH include altered descending pain modulation, central sensitization and biobehavioural factors. Treatment of MOH includes the use of headache preventive therapies, but essential to success is eliminating the cause, by reducing the frequency of use of acute headache medication, and perhaps withdrawing the overused medication altogether. Appropriate treatment is usually highly effective, leading to reduced headache burden and acute medication consumption.

Management of Chronic Migraine in Children and Adolescents: Where are We in 2022?

Migraine is a neurological disorder that affects millions of children and adolescents worldwide. Chronic migraine is a subtype of migraine in which patients experience headaches for more days than not each month, with accompanying symptoms of phonophobia, photophobia, nausea or vomiting for most of these headaches. The burden and impact of chronic migraine in the daily lives of children and adolescents is substantial, requiring a holistic, multidisciplinary, and biopsychosocial approach to conceptualization and treatment. The purpose of this review is to provide a comprehensive “2022” overview of acute and preventive treatments for the management of chronic migraine in youth. We first describe diagnostic criteria for chronic migraine and highlight the state of evidence for acute and preventive treatment in children and adolescents. We then discuss emerging treatments currently receiving rigorous clinical research effort, special considerations for the treatment of chronic migraine in children and adolescents, and avenues for improving existing treatments and expanding access to evidence-based care.

Medication Overuse Withdrawal in Children and Adolescents Does Not Always Improve Headache: A Cross-Sectional Study

Background: MOH can be diagnosed in subjects with headache occurring 15 days/month in association with a regular medication overuse, but its existence is not universally accepted. ICHD-3 redefined criteria for MOH, removing the criterion associating drug suspension with headache course. The aim of our study was to compare the rate of patients diagnosed with medication overuse headache (MOH) according to ICHD-2 and ICHD-3 criteria, to verify the degree of concordance. The secondary aim was to verify if drug withdrawal was really associated with pain relief. Methods: In this cross-sectional study, we retrospectively analyzed a sample of 400 patients followed for primary chronic headache at the Headache Center of Bambino Gesù Children's Hospital. We then selected those presenting with a history of medication overuse, and we applied both ICHD-2 and ICHD-3 criteria to verify in which patients the criteria would identify a clinical diagnosis of MOH. Results: We identified 42 subjects (10.5%) with MOH; 23 of them (55%) presented a relief of headache withdrawing drug overuse. Regarding the applicability of the ICHD-2 criteria, 43% of patients (18/42) fulfilled all criteria, while all ICHD-3 diagnostic criteria were satisfied in 76% of patients (32/42). Eighteen patients (43%) satisfied both ICHD-2 and ICHD-3 criteria, while 10 patients (24%) did not satisfy either diagnostic criterion. Conclusions: Our study suggests that in children and adolescents, withdrawing medication overuse is not always associated with a clinical benefit. Therefore, though allowing a MOH diagnosis in a higher rate of patients as compared to ICHD-2, the application of ICHD-3 criteria does not guarantee a true a causal relationship between medication overuse and headache worsening.

The Many Faces of Medication-Overuse Headache in Clinical Practice

The management of medication-overuse headache (MOH) is multifaceted and headache experts have different views on the optimal strategy to tackle this type of secondary headache. The purpose of this review is to provide an overview of the literature on the management of MOH, and to highlight important considerations in the clinical evaluation of the MOH patient. Managing MOH in clinical practice starts by evaluating the headache patient with medication overuse, determining the overused drug(s), assessing the impact of headaches on the patient and assessing comorbid conditions and disorders. Withdrawal of the overused medication is the cornerstone of treatment. An inpatient or outpatient setting is chosen based on the clinical profile of the patient. There is evidence for abrupt withdrawal combined with headache preventive treatment. Bridging therapy to bring relief to withdrawal headaches and/or symptoms should be offered. Education and motivational work through multidisciplinary assessment show benefits in sustaining withdrawal and preventing relapse. Although the reversal of chronic headache after cessation of overused acute medication has been noticed worldwide, different aspects of the management of MOH, such as complete or gradual withdrawal, or preventive treatment with or without withdrawal are still debated.

Protein-Protein Interaction Network Analysis Reveals Several Diseases Highly Associated with Polycystic Ovarian Syndrome

Based on clinical observations, women with polycystic ovarian syndrome (PCOS) are prone to developing several other diseases, such as metabolic and cardiovascular diseases. However, the molecular association between PCOS and these diseases remains poorly understood. Recent studies showed that the information from protein-protein interaction (PPI) network analysis are useful in understanding the disease association in detail. This study utilized this approach to deepen the knowledge on the association between PCOS and other diseases. A PPI network for PCOS was constructed using PCOS-related proteins (PCOSrp) obtained from PCOSBase. MCODE was used to identify highly connected regions in the PCOS network, known as subnetworks. These subnetworks represent protein families, where their molecular information is used to explain the association between PCOS and other diseases. Fisher's exact test and comorbidity data were used to identify PCOS-disease subnetworks. Pathway enrichment analysis was performed on the PCOS-disease subnetworks to identify significant pathways that are highly involved in the PCOS-disease associations. Migraine, schizophrenia, depressive disorder, obesity, and hypertension, along with twelve other diseases, were identified to be highly associated with PCOS. The identification of significant pathways, such as ribosome biogenesis, antigen processing and presentation, and mitophagy, suggest their involvement in the association between PCOS and migraine, schizophrenia, and hypertension.

Cognitive Behavioral Therapy for Pediatric Headache and Migraine: Why to Prescribe and What New Research Is Critical for Advancing Integrated Biobehavioral Care

PURPOSE OF REVIEW

To highlight current evidence supporting the prescription of cognitive behavioral therapy (CBT) as part of first-line preventive treatment for children and adolescents with headache and discuss a research strategy aimed at: (1) understanding how and why CBT works, and (2) developing effective and efficient approaches for integrating CBT into headache specialty, neurology, and primary care settings.

RECENT FINDINGS

Although preventive medications for pediatric headache and migraine are commonly prescribed, recent meta-analyses and an NIH-funded, multi-center clinical trial suggests that the effect of pill-taking therapies may be mostly due to a placebo effect. These findings have led to greater consideration of prescription of non-pharmacological therapies as first-line interventions (either alone or in combination with pill-based therapy). A literature that extends back to the 1980s and includes recent clinical trials and meta-analyses demonstrates that CBT decreases headache frequency and related disability in youth with headache and migraine and has a favorable benefit to risk profile with almost no negative side effects.

SUMMARY

CBT has been repeatedly demonstrated as effective in treating pediatric headache and migraine. As such, it should be considered as part of first-line preventive treatment for pediatric headache (either alone or in combination with a pill-based therapy). We need to better understand how this therapy works and what makes it distinct (if anything) from the placebo effect. What we need to achieve is empirical support for efficient access to this evidence-based treatment and clarity on how to match the intensity of non-pharmacological intervention to the needs of our patients at the time they present for care.

Genome-wide analysis of blood gene expression in migraine implicates immune-inflammatory pathways

Background Typical migraine is a frequent, debilitating and painful headache disorder with an estimated heritability of about 50%. Although genome-wide association (GWA) studies have identified over 40 single nucleotide polymorphisms associated with migraine, further research is required to determine their biological role in migraine susceptibility. Therefore, we performed a study of genome-wide gene expression in a large sample of 83 migraine cases and 83 non-migraine controls to determine whether altered expression levels of genes and pathways could provide insights into the biological mechanisms underlying migraine. Methods We assessed whole blood gene expression data for 17994 expression probes measured using IlluminaHT-12 v4.0 BeadChips. Differential expression was assessed using multivariable logistic regression. Gene expression probes with a nominal p value < 0.05 were classified as differentially expressed. We identified modules of co-regulated genes and tested them for enrichment of differentially expressed genes and functional pathways using a false discovery rate <0.05. Results Association analyses between migraine and probe expression levels, adjusted for age and gender, revealed an excess of small p values, but there was no significant single-probe association after correction for multiple testing. Network analysis of pooled expression data identified 10 modules of co-expressed genes. One module harboured a significant number of differentially expressed genes and was strongly enriched with immune-inflammatory pathways, including multiple pathways expressed in microglial cells. Conclusions These data suggest immune-inflammatory pathways play an important role in the pathogenesis, manifestation, and/or progression of migraine in some patients. Furthermore, gene-expression associations are measurable in whole blood, suggesting the analysis of blood gene expression can inform our understanding of the biological mechanisms underlying migraine, identify biomarkers, and facilitate the discovery of novel pathways and thus determine new targets for drug therapy.

Blood gene expression studies in migraine: Potential and caveats

BACKGROUND

Global gene expression analysis may be used to obtain insights into the functional processes underlying migraine. However, there is a shortage of high-quality post-mortem brain tissue samples for genetic analysis. One approach is to use a more accessible tissue as a surrogate, such as peripheral blood.

PURPOSE

Discuss the benefits and caveats of blood genomic profiling in migraine and its potential application in the development of biomarkers of migraine susceptibility and outcome. Demonstrate the utility of blood-based expression profiles in migraine by analysing pilot Illumina HT-12 expression data from 76 (38 case, 38 control) whole-blood samples.

CONCLUSION

Current evidence suggests peripheral blood is a biologically valid substrate for genetic studies of migraine, and may be used to identify biomarkers and therapeutic pathways. Pilot blood gene expression data confirm that expression profiles significantly differ between migraine case and non-migraine control individuals.

Neural Plasticity in Common Forms of Chronic Headaches

Headaches are universal experiences and among the most common disorders. While headache may be physiological in the acute setting, it can become a pathological and persistent condition. The mechanisms underlying the transition from episodic to chronic pain have been the subject of intense study. Using physiological and imaging methods, researchers have identified a number of different forms of neural plasticity associated with migraine and other headaches, including peripheral and central sensitization, and alterations in the endogenous mechanisms of pain modulation. While these changes have been proposed to contribute to headache and pain chronification, some findings are likely the results of repetitive noxious stimulation, such as atrophy of brain areas involved in pain perception and modulation. In this review, we provide a narrative overview of recent advances on the neuroimaging, electrophysiological and genetic aspects of neural plasticity associated with the most common forms of chronic headaches, including migraine, cluster headache, tension-type headache, and medication overuse headache.

Medication overuse in children and adolescents

Medication overuse is not uncommon among children and adolescents with primary headache disorders. Medication overuse in adults is associated with increased headache frequency and reduced effectiveness of acute and preventive medications. These issues probably exist in children. While withdrawal of overused medications is generally recommended, it may not result in improved headache frequency in all patients. This review summarizes what is known about predicting the response to medication withdrawal. Strategies for managing children and adolescents with medication overuse are also offered.

The relationship between opioids and immune signalling in the spinal cord

Opioids are considered the gold standard for the treatment of moderate to severe pain. However, heterogeneity in analgesic efficacy, poor potency and side effects are associated with opioid use, resulting in dose limitations and suboptimal pain management. Traditionally thought to exhibit their analgesic actions via the activation of the neuronal G-protein-coupled opioid receptors, it is now widely accepted that neuronal activity of opioids cannot fully explain the initiation and maintenance of opioid tolerance, hyperalgesia and allodynia. In this review we will highlight the evidence supporting the role of non-neuronal mechanisms in opioid signalling, paying particular attention to the relationship of opioids and immune signalling.

Pediatric headache: where have we been and where do we need to be

In this article, we hope to summarize current understanding of pediatric headache. We discuss epidemiology, genetics, classification, diagnosis, outpatient, emergency and inpatient treatment options, prevention strategies, and behavioral approaches. For each section, we end with a series of questions for future research and consideration.

Outcomes of greater occipital nerve injections in pediatric patients with chronic primary headache disorders

BACKGROUND

Chronic migraine is common in pediatrics and generally disabling. In adults, infiltration of the area around the greater occipital nerve can provide short- to medium-term benefit in some patients. This study reports the efficacy of greater occipital nerve infiltrations in pediatric patients with chronic primary headache disorders.

METHODS

Retrospective chart review of patients <18 years with a chronic primary headache disorder undergoing a first-time injection. Infiltrations were unilateral and consisted of a mixture of methylprednisolone acetate, adjusted for weight, and lidocaine 2%.

RESULTS

Forty-six patients were treated. Thirty-five (76%) had chronic migraine, 9 (20%) new daily persistent headache (NDPH), and 2 (4%) a chronic trigeminal autonomic cephalalgia. Medication overuse was present in 26%. Ages ranged from 7 to 17 years. Follow-up data were available for 40 (87%). Overall, 53% (21/40) benefitted, and 52% (11/21) benefitted significantly. Benefit onset ranged from 0 to 14 days, mean 4.7 (SD 4.3), with mean benefit duration of 5.4 (SD 4.9) weeks. In chronic migraine, 62% (18/29) benefitted, and 56% (10/18) significantly benefitted. In NDPH, 33% (3/9) benefitted; 33% (n = 1) significantly. Neither child with a chronic trigeminal autonomic cephalalgia benefitted. In logistic regression modeling, medication overuse, age, sex, and sensory change in the distribution of the infiltrated nerve did not predict outcome. There were no serious side effects.

CONCLUSIONS

Greater occipital nerve injections benefitted 53% of pediatric patients with chronic primary headache disorders. Efficacy appeared greater in chronic migraine than NDPH. Given the benign side effect profile, a greater occipital nerve infiltration seems appropriate before more aggressive approaches.

Capillary earlobe blood may be used for RNA isolation, gene expression assays and microRNA quantification

An increasing number of studies examining gene expression associated with diseases in children is likely, in the near future, to provide simple and easy to use methods for the isolation of RNA for gene expression profiling. Prerequisites for such studies are likely to encompass the use of small amounts of blood, as well as less invasive blood collection methods. In the current study, RNA was isolated from 20 µl capillary blood samples from the earlobes of 10 adults for quantitative PCR experiments. The results were compared with RNA isolated from venipuncture samples of the 10 samples. The expression of 4 mRNAs and 1 microRNA (miRNA), miRNA‑126, was measured. The quantitative PCR results obtained with the capillary blood probes were similar to results using venous blood samples. The few differences observed may result from a variation in the blood cell composition. The use of capillary blood samples from the earlobe for gene expression analysis is likely to allow this method to be used in newborns, babies and children. In addition, such a method, using microliters of blood samples, may also be useful for other medical studies e.g., in cases where repetitive blood sampling is necessary or in patients with bleeding disorders.

Medication Overuse Headache: The Reason of Headache That Common and Preventable

Medication overuse headache (MOH) is well-defined clinically and is one of the common reasons of chronic daily headache, but its pathophysiology has not been elucidated yet. MOH has varying clinical features in regard to regional, psychosocial, medical and economic factors. Even though, the studies have shown that many factors may play a role, MOH is likely to occur in patients who are prone to primary headaches. Mainstay of the treatment is to withdraw the excessively used analgesic drugs. The primary prevention with education of the patients as well as early diagnosis and treatment of MOH will reduce its increasing financial burden on both patients and countries. Meticulous and multifactorial evaluation of the disease besides the diagnosis and treatment of the comorbid diseases will reduce the risk of recurrences.

Childhood and Adolescent Migraine Prevention (CHAMP) study: a double-blinded, placebo-controlled, comparative effectiveness study of amitriptyline, topiramate, and placebo in the prevention of childhood and adolescent migraine

BACKGROUND

Migraine is one of the most common health problems for children and adolescents. If not successfully treated, it can impact patients and families with significant disability due to loss of school, work, and social function. When headaches become frequent, it is essential to try to prevent the headaches. For children and adolescents, this is guided by extrapolation from adult studies, a limited number of small studies in children and adolescents and practitioner preference. The aim of the Childhood and Adolescent Migraine Prevention (CHAMP) study is to determine the most effective preventive agent to use in children and adolescents.

METHODS

CHAMP is a double-blinded, placebo-controlled, multicenter, comparative effectiveness study of amitriptyline and topiramate for the prevention of episodic and chronic migraine, designed to mirror real-world practice, sponsored by the US National Institute of Neurological Disorders and Stroke/National Institutes of Health (U01NS076788). The study will recruit 675 subjects between the ages of 8 and 17 years old, inclusive, who have migraine with or without aura or chronic migraine as defined by the International Classification of Headache Disorders, 2nd Edition, with at least 4 headaches in the 28 days prior to randomization. The subjects will be randomized in a 2:2:1 (amitriptyline: topiramate: placebo) ratio. Doses are weight based and will be slowly titrated over an 8-week period to a target dose of 1 mg/kg of amitriptyline and 2 mg/kg of topiramate. The primary outcome will be a 50% reduction in headache frequency between the 28-day baseline and the final 28 days of treatment (weeks 20-24).

CONCLUSIONS

The goal of the CHAMP study is to obtain level 1 evidence for the effectiveness of amitriptyline and topiramate in the prevention of migraine in children and adolescents. If this study proves to be positive, it will provide information to the practicing physician as how to best prevent migraine in children and adolescents and subsequently improve the disability and outcomes.

mRNA blood expression patterns in new-onset idiopathic pediatric epilepsy

PURPOSE

Determine if blood messenger RNA (mRNA) expression patterns in children with newly diagnosed untreated idiopathic epilepsy are different from those in healthy controls. Determine the differential expression patterns between epilepsy patients with generalized onset or partial onset seizures compared to healthy controls.

METHODS

Whole blood was obtained from otherwise healthy pediatric patients with newly diagnosed untreated idiopathic epilepsy along with healthy pediatric controls. mRNA was isolated and hybridized to Affymetrix HGU 133 2.0+ microarrays. Analysis was performed using Genespring. Differentially expressed gene lists resulted from comparison of (1) epilepsy and control groups and (2) seizure type subgroups with controls. Tissue expression and gene ontology analysis was performed using DAVID.

KEY FINDINGS

Thirty-seven epilepsy patients and 28 controls were included. Overall, 575 genes were differentially expressed in subjects with epilepsy compared to controls. The generalized seizure subgroup versus control (GvC) gene list and the partial seizure subgroup versus control (PvC) gene list were different (p < 0.05). Tissue expression analysis identified almost half of the genes in GvC and PvC as brain based. Functional group analysis identified several biologically relevant pathways. In GvC, these included mitochondria and lymphocyte activation. In PvC, we identified apoptosis, inflammatory defense, and cell motion pathways.

SIGNIFICANCE

A unique, biologically meaningful mRNA expression pattern is detectable in whole blood of pediatric subjects with new-onset and untreated epilepsy. This analysis finds many similar pathways to those identified in brain studies examining lesional intractable epilepsy. Blood mRNA expression patterns show promise as a target for biomarker development in pediatric epilepsy.

Medication-overuse headache and opioid-induced hyperalgesia: A review of mechanisms, a neuroimmune hypothesis and a novel approach to treatment

Introduction

Patients with chronic headache who consume large amounts of analgesics are often encountered in clinical practice. Excessive intake of analgesics is now considered to be a cause, rather than simply a consequence, of frequent headaches, and as such the diagnosis “medication-overuse headache” (MOH) has been formulated. Despite the prevalence and clinical impact of MOH, the pathophysiology behind this disorder remains unclear and specific mechanism-based treatment options are lacking.

Discussion

Although most acute headache treatments have been alleged to cause MOH, here we conclude from the literature that opioids are a particularly problematic drug class consistently associated with worsening headache. MOH may not be a single entity, as each class of drug implicated may cause MOH via a different mechanism. Recent evidence indicates that chronic opioid administration may exacerbate pain in the long term by activating toll-like receptor-4 on glial cells, resulting in a pro-inflammatory state that manifests clinically as increased pain. Thus, from the available evidence it seems opioid-overuse headache is a phenomenon similar to opioid-induced hyperalgesia, which derives from a cumulative interaction between central sensitisation, due to repeated activation of nociceptive pathways by recurrent headaches, and pain facilitation due to glial activation.

Conclusion

Treatment strategies directed at inhibiting glial activation may be of benefit alongside medication withdrawal in the management of MOH.

Cortical response to somatosensory stimulation in medication overuse headache patients is influenced by angiotensin converting enzyme (ACE) I/D genetic polymorphism

BACKGROUND

Medication overuse headache (MOH) is a disabling health problem. Convincing evidence attributes a pathophysiologic role to central sensitization. By recording somatosensory evoked potentials (SSEPs) in patients with MOH, we observed increased sensitization and deficient habituation to repetitive sensory stimuli consistent with drug overuse. The renin-angiotensin system in the brain seems to play a relevant role in neural plasticity and dependence behavior. We therefore sought differences in SSEP sensitization and habituation in patients with MOH who underwent angiotensin converting enzyme (ACE) I/D polymorphism analysis.

METHODS

We recorded median-nerve SSEPs (two blocks of 100 sweeps) in 43 patients with MOH. We measured N20-P25 amplitudes, and assessed sensitization using the first block amplitudes, and habituation using amplitude changes between the two sequential blocks. According to their genotype, subjects were divided into three groups: "D/D", "D/I" and "I/I" carriers.

RESULTS

The habituation slope of the two SSEP block amplitudes was significantly increased in the D/D subgroup (n = 16) with respect to that of the I/I subgroup (n = 6), with the D/I subgroup (n = 21) falling in between. In D/D carriers, the habituation slope correlated positively with the duration of the overuse headache, and the first SSEP block amplitudes, a measure of sensitization, increased in strict relationship with the type of overused medication in the MOH patients overall and in the D/D subgroup; this was not so in the D/I and I/I subgroups.

CONCLUSION

In patients with MOH, the homozygote D/D ACE polymorphism influences habituation and sensitization to repeated sensory stimuli in strict relationship with medication overuse. We suggest that angiotensin peptides influence neuronal mechanisms of plasticity by interacting with central monoaminergic synaptic transmission.

Pediatric headache: update on recent research

Primary headache are one of the most common health complaints in children and adolescents, yet there remain significant gaps in our understanding of the underlying pathophysiology of these conditions. Recently, there have been several areas of research that have assisted with filling this gap in our knowledge. These areas include a better understanding of the disease characteristics including additional associated symptoms and the refinement of the description of related conditions and comorbidities; continued examination of the epidemiology of primary headaches; the progression of migraine across these developmental ages; the molecular and physiological changes; and the potential role for vitamins and cofactor deficiencies in the pathophysiology. These studies continue to add to our fund of knowledge on the basis of migraine and tension-type headache as primary neurological conditions and their impact on the developing brain.

Genomic expression patterns in menstrual-related migraine in adolescents

BACKGROUND

Exacerbation of migraine with menses is common in adolescent girls and women with migraine, occurring in up to 60% of females with migraine. These migraines are oftentimes longer and more disabling and may be related to estrogen levels and hormonal fluctuations.

OBJECTIVE

This study identifies the unique genomic expression pattern of menstrual-related migraine (MRM) in comparison to migraine occurring outside the menstrual period and headache-free controls.

METHODS

Whole blood samples were obtained from female subjects having an acute migraine during their menstrual period (MRM) or outside of their menstrual period (non-MRM) and controls (C)--females having a menstrual period without any history of headache. The messenger RNA was isolated from these samples, and genomic profile was assessed. Affymetrix Human Exon ST 1.0 (Affymetrix, Santa Clara, CA, USA) arrays were used to examine the genomic expression pattern differences between these 3 groups.

RESULTS

Blood genomic expression patterns were obtained on 56 subjects (MRM = 18, non-MRM = 18, and controls = 20). Unique genomic expression patterns were observed for both MRM and non-MRM. For MRM, 77 genes were identified that were unique to MRM, while 61 genes were commonly expressed for MRM and non-MRM, and 127 genes appeared to have a unique expression pattern for non-MRM. In addition, there were 279 genes that differentially expressed for MRM compared to non-MRM that were not differentially expressed for non-MRM. Gene ontology of these samples indicated many of these groups of genes were functionally related and included categories of immunomodulation/inflammation, mitochondrial function, and DNA homeostasis.

CONCLUSIONS

Blood genomic patterns can accurately differentiate MRM from non-MRM. These results indicate that MRM involves a unique molecular biology pathway that can be identified with a specific biomarker and suggest that individuals with MRM have a different underlying genetic etiology.