Oxidative stress and platelet responsiveness in migraine

Oxidative Stress and Migraine

The pathogenesis of migraine is not completely understood, but inflammation and oxidative stress seem to be involved, according to data from an experimental model of the disease. This narrative review summarizes data from studies on oxidative stress markers in migraine patients, case-control association studies on the possible association of candidate genes related to oxidative stress with the risk for migraine, studies showing the presence of oxidative stress in experimental models of migraine, and studies on the efficacy of antioxidant drugs in migraine therapy. Many studies have addressed the value of concentrations of prooxidant and antioxidant substances or the activity of antioxidant enzymes in different tissues (mainly in serum/plasma or in blood cells) as possible biomarkers for migraine, being thiobarbituric acid (TBA) reactive substances (TBARS) such as malonyl dialdehyde acid (MDA) and 4-hydroxynonenal, and nitric oxide (this at least during migraine attacks in patients with migraine with aura (MWA) the most reliable. In addition, the possible usefulness of antioxidant treatment is not well established, although preliminary short-term studies suggest a beneficial action of some of them such as Coenzyme Q10 and riboflavin. Both topics require further prospective, multicenter studies with a long-term follow-up period involving a large number of migraine patients and controls.

Migraine in Patients Undergoing PFO Closure

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Patients experiencing MHA-PFO on aspirin are characterized by a marked thrombin generation capacity sustained by an elevated number of platelets and MVs expressing a functionally active tissue factor.

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MHA-PFO patients are also characterized by an altered oxidative stress status, ie, increased platelet ROS production and blood GSSG/GSH ratio.

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This prothrombotic condition fully reverts upon PFO closure and is associated with 100% migraine remission.

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MHA-PFO plasma and GSSG, added to blood of healthy subjects, mirrored the in vivo platelet activation and this effect is blunted by N-acetylcysteine, thus supporting the etiopathogenetic role of oxidative stress in this clinical setting.

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Aspirin had little effect on the platelet prothrombotic phenotype that was better controlled by P2Y₁₂ antagonist.

The association between migraine and patent foramen ovale (PFO) has been documented. We aimed to investigate platelet activation, prothrombotic phenotype, and oxidative stress status of migraineurs with PFO on 100 mg/day aspirin, before and 6 months after PFO closure. Data show that, before PFO closure, expression of the classical platelet activation markers is comparable in patients and aspirin-treated healthy subjects. Conversely, MHA-PFO patients display an increased prothrombotic phenotype (higher tissue factor^pos platelets and microvesicles and thrombin-generation potential), sustained by an altered oxidative stress status. This phenotype, which is more controlled by P2Y₁₂-blockade than by aspirin, reverted after PFO closure together with a complete migraine remission. (pLatelEts And MigRaine iN patEnt foRamen Ovale [LEARNER]; NCT03521193)

The efficacy of alpha-lipoic acid in improving oxidative, inflammatory, and mood status in women with episodic migraine in a randomised, double-blind, placebo-controlled clinical trial

AIM

Migraine is a common neurovascular disorder, which is associated with severe to moderate disabling headaches. Oxidative stress and inflammation might play a role in migraine pathogenesis and the mood disorders. Considering the antioxidant and anti-inflammatory properties of alpha-lipoic acid (ALA), this study was designed to investigate its effect on oxidative, inflammatory, and mood conditions in women with episodic migraine.

METHODS

In total, 92 women with episodic migraine participated in the study. The patients were randomly divided into two groups, receiving a 300-mg capsule of ALA or placebo twice daily for 3 months. To assess the oxidative and inflammatory status, the serum levels of total antioxidant capacity (TAC), total oxidant status (TOS), glutathione (GSH), malondialdehyde (MDA), oxidative stress index (OSI), and C-reactive protein (CRP) were determined at the beginning and at the end of the intervention. A depression, anxiety, stress scale (DASS-21-items) questionnaire was used to evaluate mood status.

RESULTS

Finally, 79 patients reached the final analysis stage. At the end of the intervention, a significant decrease in the serum levels of MDA (means difference [MD]: -0.83, 95% confidence intervals (CI): -1.04, -0.62 nmol/mL vs MD: -0.32, CI: -0.48, -0.15 nmol/mL; P < .001) and CRP (MD: -0.78, CI: -1.17, -0.39 mg/L vs MD: -0.63, CI: -1.80, 0.52 mg/L; P < .001) was observed in the ALA as compared with the placebo group, but changes in serum GSH (P = .086), TAC (P = .068), TOS (P = .225), and OSI (P = .404) were not statistically significant. In addition, depression, anxiety, and stress (with P < .001, in all cases) had significantly decreased in the intervention as compared with the control group.

CONCLUSION

The results of this study suggest that ALA supplementation for 3 months has beneficial effects on improving the oxidative, inflammatory, and mood conditions of patients suffering from episodic migraine.

Experimental and Clinical Evidence of the Effectiveness of Riboflavin on Migraines

Riboflavin, a water-soluble member of the B-vitamin family, plays a vital role in producing energy in mitochondria and reducing inflammation and oxidative stress. Migraine pathogenesis includes neuroinflammation, oxidative stress, and mitochondrial dysfunction. Therefore, riboflavin is increasingly being recognized for its preventive effects on migraines. However, there is no concrete evidence supporting its use because the link between riboflavin and migraines and the underlying mechanisms remains obscure. This review explored the current experimental and clinical evidence of conditions involved in migraine pathogenesis and discussed the role of riboflavin in inhibiting these conditions. Experimental research has demonstrated elevated levels of various oxidative stress markers and pro-inflammatory cytokines in migraines, and riboflavin’s role in reducing these marker levels. Furthermore, clinical research in migraineurs showed increased marker levels and observed riboflavin’s effectiveness in reducing migraines. These findings suggest that inflammation and oxidative stress are associated with migraine pathogenesis, and riboflavin may have neuroprotective effects through its clinically useful anti-inflammatory and anti-oxidative stress properties. Riboflavin’s safety and efficacy suggests its usefulness in migraine prophylaxis; however, insufficient evidence necessitates further study.

The Efficacy of Herbal Supplements and Nutraceuticals for Prevention of Migraine: Can They Help?

Migraine is a common neurological disorder associated with or without aura. Although the pathophysiology of migraine is not very well understood, pro-inflammatory cytokines and oxidative stress biomarkers are found to be increased in migraine. Multiple studies have been done to see if alternative medicine such as herbal supplements and nutraceuticals are effective in the prevention and treatment of migraine headaches. This review aimed to evaluate the effect of supplements like coenzyme Q10, riboflavin (vitamin B2), feverfew, and magnesium on the frequency, severity, and duration of migraine attacks. We performed a thorough literature search using mainly PubMed. We included studies published in the last 10 years, those conducted among adult human participants 18-65 years of age, and those published in the English language. Based on the articles selected for the final review, we concluded that herbal supplements and nutraceuticals help reduce the frequency of migraine headaches; however, mixed results were seen regarding the severity and duration of headaches. Moreover, there were no concerning side effects with these supplements. Therefore, physicians can suggest herbal supplements to patients who experience adverse effects from pharmaceutical drugs and desire a more natural treatment.

Mitochondrial function and oxidative stress markers in higher-frequency episodic migraine

Increasing evidence points towards the role of mitochondrial functioning, energy metabolism, and oxidative stress in migraine. However not all previous research has been conclusive and some mitochondrial function/oxidative stress markers have not yet been examined. To this end, alpha-lipoic acid (ALA), total thiols, total plasma antioxidant capacity (TAC), lipid peroxide (PerOx), oxidised LDL (oxLDL), HbA1c and lactate were determined in the serum of 32 higher frequency episodic migraineurs (5-14 migraine days/ months, 19 with aura, 28 females) in this cross-sectional study. The majority of patients had abnormally low ALA and lactate levels (87.5% and 78.1%, respectively). 46.9% of the patients had abnormally high PerOx values, while for thiols and TAC over one third of patients had abnormally low values (31.2% and 37.5%, respectively). 21.9% of patients had abnormally low HbA1c and none had an HbA1c level above 5.6%. oxLDL was normal in all but one patient. This study provides further evidence for a role of oxidative stress and altered metabolism in migraine pathophysiology, which might represent a suitable therapeutic target. ALA, being too low in almost 90% of patients, might represent a potential biomarker for migraine. Further research is needed to replicate these results, in particular a comparison with a control group.This study is part of the trial registration: ClinicalTrials.gov: NCT03132233, registered on 27.04.2017, https://clinicaltrials.gov/ct2/show/NCT03132233 .

Dimethyl fumarate alleviates the nitroglycerin (NTG)-induced migraine in mice

Background

Oxidative stress and inflammatory pathways are involved in migraine and endogenous antioxidant defense system has a role in the prevention of hyperalgesia in migraine. In this study, we aimed to evaluate the role of the most pharmacologically effective molecules among the fumaric acid esters (FAEs), dimethyl fumarate, nuclear factor E2-related factor 2/antioxidant response element (Nrf-2/ARE) pathway-mediated, in regulating the hypersensitivity in a mouse model of nitroglycerine (NTG)-induced migraine.

Methods

Mice were orally administered with DMF at the doses of 10, 30, and 100 mg/kg, 5 min after NTG intraperitoneal injections. We performed histological and molecular analysis on the whole brain and behavioral tests after 4 h by NTG-migraine induction. The expression of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-кB) subunit p65, nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor alpha (IκBα), inducible nitrite oxide synthase (iNOS), cyclooxygenase 2 (COX-2), Nrf-2, manganese superoxide dismutase (Mn-SOD), and heme-oxygenase-1 (HO-1) were detected by Western blot. Tail flick, hot plate, orofacial formalin, and photophobia tests were used to evaluate migraine-like pain and migraine-related light sensitivity.

Moreover, we evaluate Nrf-2-dependent mechanism by the in vitro stimulation of cells extracted by trigeminal ganglia with diethylenetriamine/nitric oxide (DETA/NO), a nitric oxide (NO) donor. The cells were pre-treated with DMF and an antagonist of Nrf-2, trigonelline (TR) 2 h before DETA/NO stimulation.

Results

DMF treatment notably reduced histological damage as showed by cresyl violet staining; also, regulating both NF-κB and Nrf-2 pathway, DMF treatment decreased the severity of inflammation and increased the protective antioxidant action. Moreover, the headache was significantly reduced. The protective effect of DMF treatment, via Nrf-2, was confirmed in in vitro studies, through inhibition of Nrf-2 by trigonelline. Cytotoxicity, iNOS, and MnSOD expression were evaluated.

Conclusion

These results provided the evidence that DMF, by Nrf-2 modulation, has a protective effect on central sensitization induced by NTG, suggesting a new insight into the potential application of DMF as novel candidates in drug development for migraine.

The Use of Antioxidants in the Treatment of Migraine

Despite numerous studies concerning the pathophysiology of migraine, the exact molecular mechanism of disturbances underlying migraine is still unknown. Furthermore, oxidative stress is considered to play a significant role in migraine pathogenesis. The notion of oxidative stress in migraine patients has been discussed for several decades. Over the past few years, among the substances that could potentially be used for migraine treatment, particular attention has been paid to the so-called nutraceutics, including antioxidants. Antioxidants supplied with food prevent oxidative stress by inhibiting initiation, propagation, and the oxidative chain reaction itself. Additionally, the agents used so far in the prevention of migraine indeed show some anti-oxidative action. The antioxidants discussed in the present paper are increasingly more often used by migraine patients not only due to mild or even a lack of side effects but also because of their effectiveness (decreased frequency of migraine episodes or shortening of an episode duration). The present review provides a summary of the studies on nutraceuticals with antioxidative properties.

The metabolic face of migraine - from pathophysiology to treatment

Migraine can be regarded as a conserved, adaptive response that occurs in genetically predisposed individuals with a mismatch between the brain's energy reserve and workload. Given the high prevalence of migraine, genotypes associated with the condition seem likely to have conferred an evolutionary advantage. Technological advances have enabled the examination of different aspects of cerebral metabolism in patients with migraine, and complementary animal research has highlighted possible metabolic mechanisms in migraine pathophysiology. An increasing amount of evidence - much of it clinical - suggests that migraine is a response to cerebral energy deficiency or oxidative stress levels that exceed antioxidant capacity and that the attack itself helps to restore brain energy homeostasis and reduces harmful oxidative stress levels. Greater understanding of metabolism in migraine offers novel therapeutic opportunities. In this Review, we describe the evidence for abnormalities in energy metabolism and mitochondrial function in migraine, with a focus on clinical data (including neuroimaging, biochemical, genetic and therapeutic studies), and consider the relationship of these abnormalities with the abnormal sensory processing and cerebral hyper-responsivity observed in migraine. We discuss experimental data to consider potential mechanisms by which metabolic abnormalities could generate attacks. Finally, we highlight potential treatments that target cerebral metabolism, such as nutraceuticals, ketone bodies and dietary interventions.

Potential Protective Mechanisms of Ketone Bodies in Migraine Prevention

An increasing amount of evidence suggests that migraines are a response to a cerebral energy deficiency or oxidative stress levels that exceed antioxidant capacity. The ketogenic diet (KD), a diet mimicking fasting that leads to the elevation of ketone bodies (KBs), is a therapeutic intervention targeting cerebral metabolism that has recently shown great promise in the prevention of migraines. KBs are an alternative fuel source for the brain, and are thus likely able to circumvent some of the abnormalities in glucose metabolism and transport found in migraines. Recent research has shown that KBs-D-β-hydroxybutyrate in particular-are more than metabolites. As signalling molecules, they have the potential to positively influence other pathways commonly believed to be part of migraine pathophysiology, namely: mitochondrial functioning, oxidative stress, cerebral excitability, inflammation and the gut microbiome. This review will describe the mechanisms by which the presence of KBs, D-BHB in particular, could influence those migraine pathophysiological mechanisms. To this end, common abnormalities in migraines are summarised with a particular focus on clinical data, including phenotypic, biochemical, genetic and therapeutic studies. Experimental animal data will be discussed to elaborate on the potential therapeutic mechanisms of elevated KBs in migraine pathophysiology, with a particular focus on the actions of D-BHB. In complex diseases such as migraines, a therapy that can target multiple possible pathogenic pathways seems advantageous. Further research is needed to establish whether the absence/restriction of dietary carbohydrates, the presence of KBs, or both, are of primary importance for the migraine protective effects of the KD.

Levothyroxine Replacement Improves Oxidative Status in Primary Hypothyroidism

Objective: Although hypothyroidism has been linked to oxidative stress, data regarding the relationship between thyroid hormone levels and oxidative stress is still inconsistent. This study was designed to evaluate the effect of levothyroxine replacement on oxidative stress in women with primary hypothyroidism. Design: A total of 25 female patients with primary hypothyroidism were included. Oxidative stress markers were measured before and after levothyroxine replacement treatment in all patients. Methods: Oxidative stress was evaluated through the measurement of oxidants (thiobarbituric acid reactive substances [TBARS] and nitrite/nitrate levels), and antioxidants (superoxide dismutase and catalase activity). Results: Antioxidant catalase activity (63.77 ± 23.8 vs. 50.12 ±12.75 atv/min; p = 0.03) was significantly increased and the levels of TBARS (3.02 ± 0.86 vs. 3.55 ± 0.87 μM; p = 0.03) were significantly decreased in the state of euthyroidism after levothyroxine replacement compared to the hypothyroidism before levothyroxine treatment. No significant change in neither nitrite/nitrate concentration (p = 0.18) nor in superoxide dismutase activity (p = 0.93) after L-T4 adjustment was found. Conclusions: Our data demonstrate that levothyroxine replacement improved oxidative status in patients with primary hypothyroidism, indexed by the significantly decreased levels of malonaldehyde (MDA) and increased catalase (CAT) activity.

A study of oxidative stress in migraine with special reference to prophylactic therapy

OBJECTIVE

The role of oxidative stress markers in migraine and effect of treatment on these has been reported.

SUBJECTS AND METHODS

One hundred and fifty patients having > four attacks of migraine headache/month were included. Headache severity, Migraine Index (MI) and frequency of headache were noted. 120 patients received repetitive transcranial magnetic stimulation (rTMS) therapy and 30 patients received Amitriptyline (AMT). Recovery was defined by 50% improvement in frequency, severity or reduction in MI. Oxidative stress and antioxidant markers have been estimated in patients before and after treatment and correlate the clinical and outcome parameters.

RESULTS

Glutathione (GSH) (P < 0.001), glutathione-S-transferase (GST) (P = 0.049) and total antioxidant activity (TAC) (P < 0.001) level were significantly reduced in migraine patients. GSH (P = 0.02), GST (P = 0.05) and TAC (P < 0.001) were reduced in ictal migraineurs compared to controls. GSH (P < 0.001) and TAC (P = 0.003) levels increased after treatment compared to the base line. There is an increase in GSH levels in the patients who had improved following rTMS (P = 0.003); placebo (P = 0.001) and AMT (P = 0.013). TAC levels were also increased following rTMS (P = 0.009) and AMT (P = 0.020).

CONCLUSION

There is evidence of oxidative stress in migraine pathophysiology. Following treatment, oxidative stress declined following both pharmacological and rTMS.

Neutrophil-Free Radical Generation and Enzymatic Antioxidants in Migraine Patients

The present study was undertaken to elucidate the role of circulating neutrophils if any in oxidative stress in migraine by evaluating free radical generation and activities of enzymatic antioxidants in the blood in 55 patients with migraine and 60 healthy controls. Free radical generation was assessed by flow cytometry, while activity of catalase, superoxide dismutase (SOD) and glutathione peroxidase (GPx) was estimated in blood polymorphonuclear neutrophils (PMNs) by standard procedures. Platelet SOD was also measured. No significant change was found in free radical generation and in the activity of catalase, SOD and GPx in migraine patients. Univariate analysis of PMN catalase level revealed that migraineurs with a positive family history had significantly lower catalase activity compared with those with a negative family history. No correlation was found in the activity of antioxidant enzymes with age, duration of disease, time since last attack and headache index. The platelet SOD also did not show any significant change in patients of migraine without aura. Platelet aggregation in the presence or absence of PMNs was also not altered significantly. Thus the findings of the present study suggest that neutrophils are not the cause of oxidative stress observed in migraine patients.

Platelet Activation and Platelet-Leucocyte Interaction in Patients with Migraine. Subtype Differences and Influence of Triptans

As migraine is the result of an inflammatory mechanism with serotonergic signalling, leucocyte function, platelet function and intercellular communication between those cells is likely to be connected to the final pathway of the disease. We examined P-selectin expression on platelets (platelet activation) and leucocyte-platelet aggregate formation in 72 migraine patients during their attack-free interval and controls using a flow cytometric assay. Patients suffering from migraine without aura had a significantly increased platelet activation and leucocyte-platelet aggregation compared with the control group, unlike the migraine patients with aura. Patients who had taken a triptan within 3 days prior to the investigation showed platelet activation values similar to the control group. The variations in platelet activation patterns of migraine subgroups could indicate different pathomechanisms. Even outside an attack, migraine patients, particularly those without aura, show an increased level of platelet activation which seems to be down-regulated by triptans. This mechanism may account for the triptan-induced increases in headache frequency. The involvement of proinflammatory platelet-leucocyte cross-talk suggests a possible therapeutic strategy using anti-inflammatory drugs.

Oxidative stress and DNA damage in patients with migraine

BACKGROUND

Oxidative stress is implicated in the pathogenesis of migraine, but no published studies have examined both oxidative stress levels and oxidative DNA damage on the same patient group.

METHODS

In this study, total oxidant status (TOS); total antioxidant status (TAS); oxidative stress index (OSI); and 8-hydroxy-2'-deoxyguanosine (8-OHdG), which is an indicator of oxidative DNA damage, were measured in the plasma samples of 50 prophylactic unmediated migraineurs (11 with aura and 39 without aura) and 30 matched healthy volunteers.

RESULTS

No significant differences in TAS, TOS, and OSI values were observed between patients and controls. However, plasma 8-OHdG levels were found to be significantly higher in migraine patients than in the control group (p = 0.001); this increase in plasma 8-OHdG levels was more prominent in cases with migraine without aura than with aura (p = 0.001). Our results suggested an evidence of oxidative stress-related DNA damage in migraine.

CONCLUSION

DNA damage reflected by plasma 8-OHdG did not studied in migraine before. Therefore, further research on oxidative stress-related DNA damage and the extent of its clinical manifestations in migraine may provide additional data to our current knowledge.

Oxidative stress and decreased thiol level in patients with migraine: cross-sectional study

Although migraine is a neurological disorder known since long, its physiopathology remains unclear. Recent studies suggest that migraine is associated with oxidative stress; however, they report divergent results. The aim of the present study was to evaluate total antioxidant status (TAS), total oxidant status (TOS), oxidative stress index (OSI), and serum thiol level in migraine patients with or without aura. The study group consisted of 141 migraine patients. The control group included 70 healthy subjects. TAS, TOS, OSI were evaluated using a method developed by Erel. Serum thiol level was measured using the Hu method. No difference was found in TAS, TOS, OSI between the patients and controls. The level of thiol was significantly lower in patients than in controls. Negative correlations were detected between thiol level and Migraine Disability Assessment score in patients. Although TAS, TOS, and OSI were similar to those of the control group, serum thiol level, an important marker of antioxidant capacity, was significantly lower in migraines compared with controls, and caused more serious disability. Novel treatment approaches may be developed based on these data, and compounds containing thiol, such as alpha lipoic acid and N-acetyl cysteine, may be used in prophylaxis.

A meta-analysis of biomarkers related to oxidative stress and nitric oxide pathway in migraine

Background

Oxidative and nitrosative stress are considered key events in the still unclear pathophysiology of migraine.

Methods

Studies comparing the level of biomarkers related to nitric oxide (NO) pathway/oxidative stress in the blood/urine of migraineurs vs. unaffected controls were extracted from the PubMed database. Summary estimates of mean ratios (MR) were carried out whenever a minimum of three papers were available. Nineteen studies were included in the meta-analyses, accounting for more than 1000 patients and controls, and compared with existing literature.

Results

Most studies measuring superoxide dismutase (SOD) showed lower activity in cases, although the meta-analysis in erythrocytes gave null results. On the contrary, plasma levels of thiobarbituric acid reactive substances (TBARS), an aspecific biomarker of oxidative damage, showed a meta-MR of 2.20 (95% CI: 1.65–2.93). As for NOs, no significant results were found in plasma, serum and urine. However, higher levels were shown during attacks, in patients with aura, and an effect of diet was found. The analysis of glutathione precursor homocysteine and asymmetric dimethylarginine (ADMA), an NO synthase inhibitor, gave inconclusive results.

Conclusions

The role of the oxidative pathway in migraine is still uncertain. Interesting evidence emerged for TBARS and SOD, and concerning the possible role of diet in the control of NOx levels.

Isolation of Bioactive Compounds That Relate to the Anti-Platelet Activity of Cymbopogon ambiguus

Infusions and decoctions of Cymbopogon ambiguus have been used traditionally in Australia for the treatment of headache, chest infections and muscle cramps. The aim of the present study was to screen and identify bioactive compounds from C. ambiguus that could explain this plant's anti-headache activity. A dichloromethane extract of C. ambiguus was identified as having activity in adenosine-diphosphate-induced human platelet aggregation and serotonin-release inhibition bioassays. Subsequent fractionation of this extract led to the isolation of four phenylpropenoids, eugenol, elemicin, eugenol methylether and trans-isoelemicin. While both eugenol and elemicin exhibited dose-dependent inhibition of ADP-induced human platelet serotonin release, only eugenol displayed potent inhibitory activity with an IC₅₀ value of 46.6 μM, in comparison to aspirin, with an IC₅₀ value of 46.1 μM. These findings provide evidence to support the therapeutic efficacy of C. ambiguus in the non-conventional treatment of headache and inflammatory conditions.

Efficacy of combined topiramate/thioctic acid therapy in migraine prophylaxis

Migraine cannot be cured and the aim, shared with the patient, is to minimise the impact of the illness on the patient's life and lifestyle. The aim of prophylaxis is to reduce the number of migraine attacks. Prophylaxis should be considered when appropriately used acute management gives inadequate control of symptoms. The efficacy and safety of topiramate 50 mg/d and thioctic acid (α-lipoic acid) 300 mg/d either as monotherapy or in combination were investigated as migraine prophylactic agents. Forty secondary school migraineur girls were enrolled in the study. The study was conducted in two phases, a prospective baseline phase and 1-month treatment phase. Combined topiramate/thioctic acid therapy was more effective than either topiramate or thioctic acid monotherapy as a migraine-preventive treatment. Combined topiramate/thioctic acid therapy decreased the mean monthly migraine frequency from 5.86 ± 1.2 to 2.6 ± 0.98 (p ⩽ 0.05), topiramate (50 mg/d) from 5.71 ± 1.4 to 4.75 ± 1.5 and thioctic acid (300 mg/d) from 5.68 ± 1.6 to 5.22 ± 1.8. Reduction in mean monthly migraine days was also significantly greater in the group receiving combined topiramate/thioctic acid (from 12.32 ± 1.85 to 5.74 ± 1.1) compared to those receiving either topiramate 50 mg/d (from 12.7 ± 1.34 to 11.85 ± 1.35) or thioctic acid 300 mg/d (from 12.5 ± 1.72 to 11.65 ± 1.44). The responder rate (% of patients showing ⩾50% reduction in monthly migraine frequency) was 85% in patients receiving combined topiramate/thioctic acid therapy compared to 30% and 20% in patients receiving either topiramate or thioctic acid, respectively. The incidence of adverse events was higher in patients receiving topiramate (50 mg/d) monotherapy. The most common adverse events were nausea, fatigue, paraesthesia and taste perversion. We conclude that combined topiramate/thioctic acid therapy is more effective and better tolerated than topiramate monotherapy. The combination has lower monthly medication costs compared to the traditionally used topiramate 100 mg monotherapy.

Increased vulnerability to oxidative stress in pediatric migraine patients

Little is known about the role of oxidative stress in the pathogenesis of pediatric migraine. The objective of the present study was to investigate, during a headache-free period, the activities of erythrocyte antioxidant enzymes in children and adolescents diagnosed with migraine. In all, 47 migraine patients (age range, 8-17 years; mean, 14.1 +/- 2.4 years, 14 with aura) and 35 control subjects were included. Superoxide dismutase, glutathione peroxidase, and catalase activities were measured in erythrocytes. Although superoxide dismutase activities did not differ between groups, both catalase and glutathione peroxidase activities were significantly lower in migraine patients (P = 0.001 and P = 0.009, respectively). Activities of all three antioxidant enzymes were similar across migraine subgroups; there was no correlation with age and sex. These results confirm vulnerability to oxidative stress in pediatric migraine. Further studies and search for new therapeutic agents with antioxidant properties are needed.

Comparison of oxidative stress among migraineurs, tension-type headache subjects, and a control group

BACKGROUND

A primary headache, particularly migraine, is associated with oxidative stress during the attack. However, data regarding the interictal state in migraineurs and in those with tension-type headache (TTH) is limited.

OBJECTIVES

(1) To assess the oxidative stress in migraineurs and TTH subjects in between the episodes and (2) to see if there is a difference in the degree of oxidative stress in the different subtypes of migraine and TTH.

MATERIALS AND METHODS

Fifty migraineurs, 50 patients with TTH, and 50 control subjects were included in this study after screening for the exclusion criteria. Diagnosis of headache was made according to the International Classification of Headache Disorders (ICHD)-2 criteria. A venous blood sample was collected from the antecubital vein at least 3 days after the last attack of headache. The sample was centrifuged immediately and the plasma was stored at -70 degrees C. The ferric reducing activity of plasma (FRAP) and the malondialdehyde (MDA) levels were assessed using colorimetric methods. Statistical analysis was done with the help of SPSS for Windows, v 11.0. One way ANOVA with post hoc Tukey test, independent sample t test, univariate regression, and multivariate regression analysis were done as indicated.

RESULTS

Migraineurs had higher values of MDA and FRAP than the subjects in the other two groups (P<0.001). No difference was observed between the TTH group and the control group. FRAP levels were significantly higher in subjects who had mixed migraine (migraine with aura and without aura) as compared to those with only migraine without aura (mean difference 196.1; 95% CI = 27.3 to 364.9; P = 0.01). Similarly, oxidative stress was significantly higher in patients with episodic TTH as compared to those with chronic TTH (FRAP t = 3.16; P = 0.003 and MDA t = 2.75; P = 0.008).

CONCLUSIONS

This study suggests that oxidative stress continues even between headache episodes in migraineurs but not in those with TTH. This could probably be consequent to the different pathophysiological mechanisms of TTH and migraine.

Resting brain glucose uptake in headache-free migraineurs

BACKGROUND AND OBJECTIVE

To compare metabolism in the brains of migraineurs during headache-free periods with those obtained from healthy volunteers.

METHODS

Eleven migraineurs (defined by the International Headache Society's criteria) presented during spontaneous headache-free intervals to undergo (18)FDG PET brain imaging of glucose metabolism. The control group consisted of 14 healthy volunteers. Comparison of images was done using Statistical Parametric Mapping to detect significant (P < .05) differences in brain glucose metabolism between the 2 groups.

RESULTS

Two regions of significant increase in glucose uptake were identified in migraineurs relative to the control population. The 2 regions were mapped predominantly to the posterior white matter of the cerebrum and cerebellum.

CONCLUSIONS

Our study demonstrates the presence of what may be a primary metabolic disturbance in the posterior white matter of the brain in migraineurs.

Oxidative stress in migraine with and without aura

Migraine is the most common neurological disorder, but the molecular basis is still not completely understood. An impairment of mitochondrial oxidative metabolism might play a role in the pathophysiology. The goal of this study was to investigate the differences in oxidative stress status with the measurement of erythrocyte superoxide dismutase (SOD), catalase activity, and malondialdehyde (MDA) levels in the migraine patients with or without aura and attack. There were 56 patients (46 female, 10 male) in the migraine group and 25 matched healthy subjects in the control group. The patients comprised 37 with migraine without aura (MWoA], 19 with migraine with aura (MWA), and 22 with headache attack. The MDA levels of patients in the migraine group were significantly higher than that in the control group. The SOD activity was significantly higher in the MWA as compared to MWoA. There was no significant correlation between these levels and headache attack period. Conclusively, in this preliminary study, we had found increased oxidative stress in the migraine patients especially the patients with MWA. Further knowledge about this issue may contribute the cause and complications of migraine and may be essential for development of treatment approaches.

New and future migraine therapy

Modern neuroscience advanced our understanding of putative migraine mechanisms, which led to improved therapeutics. Indeed, mechanism-based acute migraine therapy gained steam in the early 1990s after the introduction of the triptans (5-HT1B,D agonists). Post-triptans, novel targets such as calcitonin gene-related peptide (CGRP) antagonists, inhibitors of excitatory glutamatergic receptors, and nitric oxide synthase (NOS) inhibitors are leading the pack in this exploding field of discovery research. In contrast, novel therapeutic targets for migraine prevention are lacking despite a hugely unmet need. To date, migraine prophylactic drugs are advanced based on expanded indications for already approved pharmaceuticals (e.g., topiramate, valproate, propranolol, and timolol). An improved understanding of the predisposition to an attack, genomic discoveries, valid and reliable biomarkers and surrogates, and predictive preclinical models likely will unravel the neuronal substrates for central hyperexcitability and nociceptive dysmodulation, hopefully leading us to better mechanism-based targets for prevention, and ultimately yielding drugs with optimal therapeutic ratios or indices.

Proinflammatory cytokines, adhesion molecules, and lymphocyte integrin expression in the internal jugular blood of migraine patients without aura assessed ictally

OBJECTIVE

The aim of the present research was to verify the levels of the soluble adhesion molecules sL- and sE-selectins, intercellular adhesion molecule (sICAM)-1, and vascular cell adhesion molecule-1 in serial samples of internal jugular venous blood taken from migraine patients without aura (MWoA) during attacks. The expression of leukocyte function antigen (LFA)-1 and very late activation antigen (VLA)-4 was also assessed on lymphocytes obtained from jugular venous blood. Levels of certain proinflammatory cytokines (tumor necrosis factor-alpha[TNF-alpha], interleukin-1beta[IL-1beta], IL-4, and IL-6) were also determined and correlated with those of adhesion molecules.

PATIENTS AND METHODS

Seven MWoA patients were admitted in the hospital during attacks and blood samples were taken immediately after catheter insertion, at 1, 2, and 4 hours after attack onset, and within 2 hours after its termination. The levels of adhesion molecules and cytokines were measured with ELISA method. The expression of LFA-1 and VLA-4 was assessed by flow cytometry.

RESULTS

A parallel transient increase of sICAM-1, TNF-alpha, and IL-6 was observed in the first 2 hours after attack onset compared with the time of catheter insertion (P < .0001, <.001, and <.003, respectively). The proportion of CD4+ and CD8+ T-cells expressing high levels of LFA-1 showed instead a progressive down-regulation with significantly lower percentages at 2 and 4 hours after attack onset (P < .01 and <.022, respectively). No variation in the percentage of VLA-4 expressing cells was observed at any time of the study.

CONCLUSIONS

The transient increase in sICAM-1 and TNF-alpha found in the internal jugular blood of MWoA patients assessed ictally can be induced by sensory neuropeptides released from activated trigeminal endings. The progressive decrease in sICAM-1 levels during attacks and the down-regulation of LFA-1 expression by lymphocytes could antagonize their transvascular migration, supporting the hypothesis of sterile inflammation in the dura mater during migraine attacks.

Future pharmacologic targets for acute and preventive treatments of migraine

Advances in investigative research (e.g., functional magnetic resonance imaging) have made it possible to study putative migraine processes and better understand the pathophysiology of the disorder. Consequently, the apparent opposing vascular and neuronal theories of migraine are now reconciled into a neurovascular hypothesis that pieces together migrainous events and allows us to better target such events in the hope of providing safe and effective therapies. Parallel discoveries in the fields of pharmacology, physiology, genetics and other biomedical disciplines will lead to the development of optimal migraine therapeutics. Such discoveries have already yielded some major enhancement in acute migraine treatment with the development of sumatriptan (Imitrex, GlaxoSmithKline) and other triptans and the trajectory is likely to be exponential. Novel targets, such as calcitonin gene-related peptide antagonists and inhibitors of excitatory glutamatergic receptors, are leading the pack but many other promising targets are in development. The post-sumatriptan decades will witness treatment strategies that will improve the therapeutic index of acute therapies and others which will effectively and safely prevent migraine attacks.

Infarcts in the posterior circulation territory in migraine. The population-based MRI CAMERA study

In a previous study, migraine cases from the general population were found to be at significantly increased risk of silent infarct-like lesions in the posterior circulation (PC) territory of the brain, notably in the cerebellum. In this study we describe the clinical and neuroimaging characteristics of migraine cases with and without aura and controls with PC lesions. In total, 39 PC infarct-like lesions represented the majority (65%) of all 60 identified brain infarct-like lesions in the study sample (n = 435 subjects with and without migraine). Most lesions (n = 33) were located in the cerebellum, often multiple, and were round or oval-shaped, with a mean size of 7 mm. The majority (88%) of infratentorial infarct-like lesions had a vascular border zone location in the cerebellum. Prevalence of these border zone lesions differed between controls (0.7%), cases with migraine without aura (2.2%) and cases with migraine with aura (7.5%). Besides higher age, cardiovascular risk factors were not more prevalent in cases with migraine with PC lesions. Presence of these lesions was not associated with supratentorial brain changes, such as white matter lesions. The combination of vascular distribution, deep border zone location, shape, size and imaging characteristics on MRI makes it likely that the lesions have an infarct origin. Previous investigators attributed cases of similar 'very small' cerebellar infarcts in non-migraine patients to a number of different infarct mechanisms. The relevance and likelihood of the aetiological options are placed in the context of known migraine pathophysiology. In addition, the specific involvement of the cerebellum in migraine is discussed. The results suggest that a combination of (possibly migraine attack-related) hypoperfusion and embolism is the likeliest mechanism for PC infarction in migraine, and not atherosclerosis or small-vessel disease.

Platelet-leukocyte interaction and platelet activation in migraine: a link to ischemic stroke?

OBJECTIVES

Migraine has been identified as an independent risk factor for ischemic stroke. Both neurogenic inflammation and platelet activation have been linked to the pathophysiology of migraine. Increased platelet activation results in up-regulation of specific binding to leukocytes which promotes pro-inflammatory leukocyte secretion and their tethering to endothelium, a mechanism that has been demonstrated in stroke and which could provide a link to migraine. We aimed to determine whether platelet-leukocyte aggregation is increased in migraine patients outside an acute attack.

METHODS

Seventy two patients with migraine according to IHS criteria were compared to a control group (n = 72). Whole blood flow cytometry was used to quantify the activation dependent P selectin on the platelet, and to assess the fraction of platelets bound to the different leukocyte subsets.

RESULTS

Migraine patients showed significantly more platelet-leukocyte aggregates compared to the control subjects (p = 0.003). This effect was driven by an increased polymorphonuclear cell-platelet aggregation (p = 0.003) whereas platelet aggregation with monocytes and lymphocytes was not. Platelet activation was also increased (p = 0.001).

CONCLUSIONS

In migraine pro-inflammatory platelet adhesion to leukocytes occurs during the headache free interval similar to that seen in acute coronary and cerebrovascular syndromes. This may suggest a link between migraine and stroke on a cellular level.

Urinary nitric oxide metabolites and lipid peroxidation by-products in migraine

Enhanced endothelium nitric oxide (NO) and superoxide anion release may cause migraine through related cerebral blood flow changes. Thirty subjects suffering from migraine with and without aura and 20 healthy controls were investigated. Urine samples collected for 24 h during and after the migraine attack, and during the headache-free period, were assayed for urinary NO stable metabolites (NOx) and thiobarbituric acid reactive substances (TBARS). During the headache-free period urinary NOx and TBARS levels were higher in migraine sufferers than in controls (NOx 0.77 +/- 0.14 vs. 0.28 +/- 0.15 mmol/mmol creatinine, P < 0.05; TBARS 0.40 +/- 0.19 vs. 0.26 +/- 0.13 micro mol/mol creatinine, P < 0.05). Also, NOx excretion was higher during the headache-free period than during or after the migraine attack (P < 0.05). Urinary TBARS were increased during the attack with respect to the headache-free period (P < 0.05). No differences were observed in the same parameters between sufferers of migraine with and without aura. Urinary NOx and TBARS might be promising as markers of their systemic levels to evaluate the increased vulnerability to oxidative stress in migraine sufferers.

Molecular Mechanisms of Migraine

Migraine is a common complex disorder that affects a large portion of the population and thus incurs a substantial economic burden on society. The disorder is characterized by recurrent headaches that are unilateral and usually accompanied by nausea, vomiting, photophobia, and phonophobia. The range of clinical characteristics is broad and there is evidence of comorbidity with other neurological diseases, complicating both the diagnosis and management of the disorder. Although the class of drugs known as the triptans (serotonin 5-HT(1B/1D) agonists) has been shown to be effective in treating a significant number of patients with migraine, treatment may in the future be further enhanced by identifying drugs that selectively target molecular mechanisms causing susceptibility to the disease.Genetically, migraine is a complex familial disorder in which the severity and susceptibility of individuals is most likely governed by several genes that may be different among families. Identification of the genomic variants involved in genetic predisposition to migraine should facilitate the development of more effective diagnostic and therapeutic applications. Genetic profiling, combined with our knowledge of therapeutic response to drugs, should enable the development of specific, individually-tailored treatment.

Sumatriptan scavenges superoxide, hydroxyl, and nitric oxide radicals: in vitro electron spin resonance study

BACKGROUND

The molecular mechanisms of migraine have not yet been clarified. Oxygen free radicals have been implicated in the genesis of many pathological processes, including migraine. Sumatriptan succinate is known to be a very effective drug for acute relief of migraine attack.

OBJECTIVE

To investigate the direct scavenging activities of sumatriptan for superoxide, hydroxyl, and nitric oxide (NO) radicals using electron spin resonance (ESR) spectroscopy.

METHODS

Measurement of superoxide and hydroxyl radical scavenging activities was performed by ESR using 5,5-dimethyl-1-pyrroline-N-oxide as a spin trap. NO was generated from 1-hydroxy-2-oxo-3-(N-3-methyl-3-aminopropyl)-3-methyl-1-triazene and analyzed by 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl produced from the reaction between 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide and NO.

RESULTS

The ESR study demonstrated that sumatriptan scavenged superoxide, hydroxyl, and NO in a dose-dependent manner.

CONCLUSIONS

Sumatriptan has direct scavenging activity on free radicals and NO. Acute migraine drugs with antioxidant properties may provide heretofore unheralded benefits via this mechanism.

Helicobacter pylori infection and migraine

The study is aimed to ascertain whether the Helicobacter pylori (Hp) infection is responsible for the vulnerability to oxidative stress observed in migraineurs. Hp serological positivity was assessed by ELISA evaluation of specific IgA and IgG antibodies in 30 subjects (11 males and 19 females) suffering from migraine without aura during the headache-free period. The Hp infection was detected in 16.7% of migraineurs. Plasma accumulation of peroxidative substances (TBA-RS), an index of systemic oxidative status, was increased in migraineurs without Hp infection with respect to controls (P< 0.001), while no significant differences of TBA-RS were found in migraineurs with or without Hp infection. Unmodified values of plasma nitrite/nitrate concentrations, expression of systemic nitric oxide (NO), were obtained in migraineurs in comparison to controls indicating that Hp infection does not modify the plasma oxidative status and the systemic NO bioavailability of migraineurs. In conclusion, our results do not support any specific correlation between Hp infection and migraine.

Direct superoxide scavenging activity of nonsteroidal anti-inflammatory drugs: determination by electron spin resonance using the spin trap method

Nonsteroidal anti-inflammatory drugs (NSAIDs), which are used widely to manage pain, are known to inhibit cyclooxygenase, but details of the mechanisms of NSAID action remain unclear. We investigated the ability of three NSAIDs (indomethacin, loxoprofen, and etodolac) to eliminate and inhibit free radicals. Superoxide scavenging activity of these NSAIDs was measured in vitro by electron spin resonance spectrometry using 5,5-dimethyl-1-pyrroline-1-oxide (DMPO) as a spin trap. Electron spin resonance demonstrated that formation of superoxide-DMPO spin adduct was completely inhibited by two nonselective cyclooxygenase inhibitors, indomethacin (3 mmol) and loxoprofen (3 mmol). The electron spin resonance study also demonstrated that the formation of superoxide-DMPO spin adduct was strongly inhibited by a selective cyclooxygenase-2 inhibitor, etodolac, in a concentration-dependent manner. These results indicate that NSAIDs, including indomethacin, loxoprofen, and etodolac, have direct superoxide scavenging activity.