Brain MRI white matter lesions in migraine patients: is there a relationship with antiphospholipid antibodies and coagulation parameters?

Brain magnetic resonance imaging (MRI) studies in migraine patients have demonstrated lesions consisting of focal regions of increased signal intensity within the white matter. Antiphospholipid antibodies are known to have a role in many diseases including migraine. The aim of the present study was to ascertain the relationship between MRI-visualized cerebral focal hyperintense lesions and serum antiphospholipid antibody levels, as well as blood coagulation parameters in migraine patients. One hundred and two (77 females, 25 males, mean age 33.8 +/- 11.1) consecutive migraine patients and a control group of 94 (70 females, 24 males, mean age 33.2 +/- 10.8) healthy subjects were enrolled. All individuals underwent brain MRI. Complete blood examinations, autoantibodies, antiphospholipids antibodies including anticardiolipin and lupus anticoagulant (aCL, LAC), antithrombin III, Protein C and S serum levels were ascertained in the subjects who presented white matter lesions on MRI. Twenty-seven (26.4%) migraine patients and six (6.3%) healthy subjects in the control group showed focal regions of increased intensity signal within cerebral white matter (odds ratio 5.3, 95% CI: 1.98-16.36). In migraine patients with white matter lesions, antiphospholipid antibodies were not detected and serum levels of antithrombin III, and proteins C and S were normal. White matter lesions in migraine patients are fairly common. This finding is not associated with antiphospholipid antibodies or abnormal coagulation parameters. The significance of such lesions at present remains unclear.

Ocular migraine and antiphospholipid antibodies--where we stand?

There is no doubt that ocular migraine also known as retinal migraine or ophthalmic migraine should not to be confused with ophthalmoplegic migraine. The hallmark of ocular migraine is the unilateral visual loss or "monocular transient loss of vision" associated or followed by the headache. Better safe than sorry, therefore an ophthalmologic examination during the migraine attack is the most diagnostic method. age with typical history for ocular migraine. Importantly supportive data sustain that different neuro-ophthalmologic manifestations as amaurosis fugax, retinal vascular thrombosis and optic neuropathy, may be considered as the ocular hallmarks of the Hughes's syndrome. Clues for the evaluating of antiphospholipid antibodies include recurrent thrombosis especially in young people, recurrent fetal loss, and thrombocytopenia. There are no studies that focus exclusively on the prophylaxis of ocular migraine. Ocular features due to antiphospholipid antibodies - induced thrombosis or Hughes's syndrome should be treated with anticoagulant therapy.

Antiphospholipid antibodies and migraine: a retrospective study of 428 patients with inflammatory connective tissue diseases

The antiphospholipid syndrome (APS) is defined by the presence of antiphospholipid antibodies (aPL), associated with thrombosis or recurrent spontaneous abortions. APS can occur alone or secondary to other conditions, especially associated to inflammatory systemic autoimmune diseases. Among the neurological manifestations associated with aPL, only ischemic stroke is recognized by the actual classification criteria for APS. Other neurological manifestations have been, however, repeatedly reported in case studies of APS patients. Headache, and especially migraine, was commonly reported in APS patients and is one of the classical features described by Hughes as related to aPL, but studies failed to confirm this association. We studied retrospectively the association between headache syndromes and aPL in 428 patients with inflammatory connective tissue diseases admitted in the Neurology and Internal Medicine Departments of Colentina Hospital-Bucharest. We found that migraine alone, not headache of all types, is significantly associated with aPL in patients with systemic immune disease. We studied the presence of cerebral ischemia in patients with headache and aPL. In SLE patients, headache (all types) is significantly associated with positive titers of aPL, and cerebral ischemic lesions are significantly encountered. Even if both migraine and aPL are conditions with high frequency in patients with immune systemic disease and their association may be coincidental, the presence of ischemic lesions in patients showing this association suggests the need to define a sub-group at risk, for whom headache can be a marker and anticoagulants can be discussed.

[Antiphospholipid antibodies in children with migraine]

BACKGROUND AND PURPOSE

There are only a few investigations in the literature, that address the occurrence and the role of anticardiolipin antibodies (aCL) in children with migraine. The results of those studies are often contradictory. The aim of the study was to determine if the values of aCL in children with migraine differ from the control group. We tried to assess whether the type of migraine (with aura or without aura) had the influence on those values.

MATERIAL AND METHODS

Sixty patients (mean age: 10.9+/-3.3 years), including 30 children with migraine hospitalized from January 2000 to December 2003 in the Department of Developmental Neurology Medical University of Gdańsk and 30 healthy children, were studied. The values of aCL in class IgA, IgM and IgG were assessed by the immunoenzymatic method (ELISA test).

RESULTS

The values aCL in IgA and IgG class were significantly different between the migraineurs and control group. The mean value of aCL in patients with migraine was 8.7+/-1.27 U/ml, while in the control group--3.81+/-1.74 U/ml. The positive values of aCL in class IgG were found in 11 (37%) children with migraine, and positive values of aCL in class IgM were noted in 6 (20%) cases in the same group. The type of migraine had no influence on the values of aCL.

CONCLUSIONS

Children with migraine present with the higher values of aCL than the control group. The mean values of aCL were within the normal range, therefore their role in pathogenesis of migraine remains unclear. The further observation is needed to assess the reliable role of higher values of aCL in pathophysiology of vascular disorders.

Mast Cell Involvement in the Pathophysiology of Migraine Headache: A Hypothesis

Migraine attacks are triggered by a variety of conditions including endogenous and exogenous factors. Evidence suggests that activation and sensitization of primary afferent meningeal nociceptive neurons, the peripheral arm of the trigeminovascular system, constitutes one of the earliest events promoting the intracranial pain of migraine. However, the link between the varied triggering factors and activation of meningeal nociceptive neurons is not completely understood. Local inflammation with release of mediators from local immune/inflammatory cells is thought to play a critical role in such neuronal response. Meningeal mast cells may play such a role by virtue of their proximity both to meningeal blood vessels and nociceptive axons and their ability to release a host of proinflammatory/algesic mediators. This paper reviews data relevant to the hypothesis that mast cells, upon activation by migraine triggers, contribute to the genesis of migraine headache. Epidemiologic findings, clinical data, and observations on anatomical and physiological characteristics of mast cells converge to suggest an important role of these immune cells in the pathogenesis of migraine. Migraine triggers might directly or indirectly promote mediator secretion from meningeal mast cells, and thereby cause inflammation and activation of the trigeminovascular system. While consistent, the evidence supporting mast cell involvement in the genesis of migraine is largely circumstantial to date. Further studies are needed to test directly the nature of mast cell involvement in the pathogenesis of migraine headache.

Clinical manifestations and antiphosphatidylserine antibodies in patients with systemic lupus erythematosus: is there an association?

OBJECTIVE

Antiphospholipid antibodies are a group of heterogeneous autoantibodies which have been reported in systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS) in association with thrombosis, fetal loss, and thrombocytopenia. In this study, we aimed to reveal the prevalence and correlation of IgG, IgA, and IgM isotypes of antibodies to cardiolipin (aCL) and antiphosphatidylserine (aPS) with clinical and laboratory manifestations of SLE patients.

METHODS

Fifty-nine SLE patients and 41 healthy controls were included. Fifteen of patients (25.4%) had secondary APS. aCL and aPS antibody assays were performed by enzyme-linked immunosorbent assay.

RESULTS

All isotypes of aCL and aPS antibodies except IgG were higher in patients with or without APS than those in the healthy controls (p<0.001). The most significant associations were found among migraine and IgA aCL (p<0.001), livedo reticularis and both IgM aCL and IgM aPS (p<0.001), migraine and IgM aCL (p<0.01), pulmonary involvement and IgM aCL (p<0.01), migraine and IgA aPS (p<0.01), and both thrombosis and migraine with IgM aPS (p<0.01).

CONCLUSION

A relatively high prevalence of aCL and aPS antibodies was found in our SLE patients. It seems that isotypes of IgM aCL, IgM aPS, IgA aCL, and IgA aPS antibodies are correlated well with migraine and IgM aPS with thrombosis in SLE patients with secondary APS. The assessment of both IgM and IgA isotypes of aPS and aCL antibodies may be helpful in predicting these manifestations.

[Migraine in SLE: role of antiphospholipid antibodies and Raynaud's phenomenon]

OBJECTIVES

To determine the role of antiphospholipid antibodies (aPL) and of Raynaud's phenomenon (RP) in the development of migraine in patients with systemic lupus erythematosus (SLE).

METHODS

50 unselected SLE patients and 20 rheumatoid arthritis (RA) controls underwent an interview to define the presence of migraine according to the guidelines of the International Headache Society (1988). Serological tests for aPL were performed in all patients. SLE patients were divided according to positivity for RP and/or aPL into 4 subsets: R-/aPL-, R-/aPL+, R+/aPL- and R+/aPL+. Data were analysed using Fisher's exact test, Chi-square test and U Mann-Whitney test.

RESULTS

SLE and RA patients were similar for demographic and clinical features; aPL positivity was found in a greater proportion of SLE patients versus RA controls (68% vs 25%, p=0.0036). 31 of the 50 lupic patients (62%) and 7 of the 20 RA controls (35%) suffered from migraine (OR=3, CI:1-8.9). Among SLE and RA patients, migraine was associated with aPL positivity (p=0.027 and p=0.019). Analysing the combined effect of aPL and RP on migraine, in R+/aPL+ patients we detected an higher frequency of migraine (85.7%) with respect to the patients negative for these two features (27%, p=0.0051, OR=16, CI:2.2-118) and to the patients positive only for aPL (65%, p=0.0031, OR=6.2, CI:1.2-32).

CONCLUSIONS

Migraine in SLE and RA associates with aPL positivity. The simultaneous presence of RP increases by 2,5 times the probability of having migraine, suggesting that cerebral vasospasm might be more common in patients with peripheral vasospasm, given the presence of aPL.

Co-morbidity of migraine and Ménière's disease -- is allergy the link?

This study determined the prevalence of migraine and allergy in patients with Ménière's disease (MD) compared with age- and sex-matched controls. We tested the hypothesis that if migraine and MD is linked by allergy, then allergy should be more prevalent in patients with MD and migraine compared with MD patients without migraine. A web-based questionnaire was used to recruit patients with MD (n = 108) while the control group consisted of patients attending the ENT clinic for other problems (n = 100). The prevalence of migraine and allergy was significantly higher in patients with MD compared with age- and sex-matched controls (p > or = 0.005). In addition, the prevalence of allergy was significantly higher in patients who had both MD and migraine (30/42) than MD alone (26/66,p = 0.002). However, there was no link with any specific allergy types. This study suggests that migraine and MD may be linked by an immunological determinant.

The role of mast cells in migraine pathophysiology

Mast cells are critical players in allergic reactions, but they have also been shown to be important in immunity and recently also in inflammatory diseases, especially asthma. Migraines are episodic, typically unilateral, throbbing headaches that occur more frequently in patients with allergy and asthma implying involvement of meningeal and/or brain mast cells. These mast cells are located perivascularly, in close association with neurons especially in the dura, where they can be activated following trigeminal nerve, as well as cervical or sphenopalatine ganglion stimulation. Neuropeptides such as calcitonin gene-related peptide (CGRP), hemokinin A, neurotensin (NT), pituitary adenylate cyclase activating peptide (PACAP), and substance P (SP) activate mast cells leading to secretion of vasoactive, pro-inflammatory, and neurosensitizing mediators, thereby contributing to migraine pathogenesis. Brain mast cells can also secrete pro-inflammatory and vasodilatory molecules such as interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF), selectively in response to corticotropin-releasing hormone (CRH), a mediator of stress which is known to precipitate or exacerbate migraines. A better understanding of brain mast cell activation in migraines would be useful and could lead to several points of prophylactic intervention.

Drug Targets in Stress-Related Disorders

Nervous and immune systems mutually cooperate via release of mediators of both neurological and immunological derivation. Adrenocorticotropin hormone (ACTH) is a product of the hypothalamus-pituitary adrenal axis (HPAA) which stimulates secretion of corticosteroids from adrenals. In turn, corticosteroids modulate the immune response in virtue of their anti-inflammatory activity. On the other hand, catecholamines, products of the sympathetic nervous system (SNS), regulate immune function by acting on specific beta-adrenergic receptors. Conversely, cytokines released by monocytes/macrophages and lymphocytes, upon antigenic stimulation, are able to cross the blood-brain-barrier, thus modulating nervous functions (e.g., thermoregulation, sleep, and appetite). However, cytokines are locally produced in the brain, especially in the hypothalamus, thus contributing to the development of anorexic, pyrogenic, somnogenic and behavioural effects. Besides pathogens and/or their products, the so-called stressors are able to activate both HPAA and SNS, thus influencing immune responses. In this respect, many studies conducted in medical students taking exams have evidenced an array of stress-induced immune alterations. Phobic disorders and migraine without aura (MWA) represent examples of stress-related disorders in which phagocytic immune deficits, endotoxemia and exaggerated levels of proinflammatory cytokines [Tumor Necrosis Factor-alpha (TNF- alpha), and interleukin- 1 beta] have been detected. Quite interestingly, administration of a thymic hormone could ameliorate clinical symptoms in phobic patients. In MWA patients, a beta-blocker, propranolol, could mitigate migraine, whose cessation coincided with a drop of TNF-alpha serum concentration. In phobic disorders and in MWA, benzodiazepines are very often administered and, in this respect, some of them, such as diazepam, inhibit immune functions, while others, e.g., alprazolam, enhance immune responses. Alprazolam could improve clinical symptoms in MWA patients. Chronic Fatigue Syndrome (CFS) is a disorder whose etiology and pathogenesis are still unknown. In this syndrome both abnormalities of nervous and immune systems have been reported. Despite many immune parameters evaluated in CFS no specific biomarkers of disease have been found. Our own data are in agreement with current literature in that we found decreased levels of serum (IFN)-gamma in these patients, thus indicating a predominance of T helper (h)1 response in CFS. Also leptin, a hormone which regulates food intake, fluctuates within normal ranges in CFS individuals. Quite interestingly, in depressed patients, used as controls, leptinaemia was more elevated than in CFS. Finally, in a series of recent therapeutic trials several immunomodulating agents have been used, such as staphypan Berna, lactic acid bacteria, kuibitang and intravenous immunoglobulin. In conclusion, it seems that major drug targets in stress-related disorders are immune cells in terms of inhibition of proinflammatory cytokines and modulation of Th responses. In particular, according to recent evidences, antidepressants seem to exert beneficial effects in experimental autoimmune neuritis in rats by decreasing IFN- beta release or augmenting NK activity in depressed patients.

[Proinflammatory cytokines in children with idiopathic headache]

OBJECTIVES

The pathogenesis of primary headaches is differential, with a neurogenic inflammation participation.

THE AIM

The aim of this research was to establish whether inflammation participates in the pathogenesis of migraine and tension-type headaches (ETTH). In order to establish this, the levels of interleukin-6 (IL-6), interleukin-1 beta (IL-1beta), tumor necrosis factor (TNF) and soluble TNF receptor type I (sTNFRI) were detected in groups with headaches during headache-free interval and in controls and in the blood of children with idiopathic headaches to detect changes during headache attack.

MATERIAL AND METHODS

30 children with migraine were included (16 with aura and 14 without aura), 17 boys and 13 girls aged 10-17 years (mean 13.5). The group with ETTH consisted of 31 patients, 24 girls and 7 boys, aged 6-17 years (mean 13.5). The control group, 28 children without headache, diagnosed with non-inflammatory orthopedic diseases, consisted of 15 boys and 13 girls, aged 7-17 years (mean 13.0). When the pain started during hospitalization, the blood was sampled in the first hour of the headache, then 3 hours and 6 hours since headache started (if headache persisted), and 6 hours after its termination. Two days after the pain termination, the blood samples were collected in children suffering from headaches, as the headache-free measurements and in controls under the same conditions at 7 a.m. after awakening. The cytokine level was established using Biosource kits, all 326 samples were processed. The statistical assessment was conducted.

RESULTS

No differences were detected in cytokine levels between the groups with migraine and ETTH and with comparison to controls during headache-free interval and during headache attack as well. However, it was established that in 12/30 children with migraine there was a significant increase in IL-6 level in the first hour of the migraine attack. This group consisted of 12 children with TNF level higher and the tendency toward decrease in sTNFRI was established, 3 hours since headache started, as compared to 18/30 children with migraine but without increase in IL-6. The correlation between the level of cytokines and age and weight was not detected. Also no correlation was established between cytokine levels and leukocyte and thrombocyte count.

CONCLUSION

1. Changes of the level of IL-6, IL-1beta, TNF and sTNFRI in the blood of children with idiopathic headache do not indicate a significant role of inflammatory process in its pathogenesis. 2. Although the significant increase in IL-6 levels observed in several children in the first hour of the migraine attack may suggest that neurogenic inflammation participates in the pathogenesis of migraine.

[Blood interleukin-6 level in children with idiopathic headaches]

AIM

Neurogenic inflammation may contribute to the pathogenesis of migraine. IL-6 plays an important role as a proinflammatory cytokine. The aim of this research was to investigate IL-6 level changes in children with migraine and episodic tension-type headache (ETTH) at baseline and during a headache attack, and also factors which may influence these changes (aura, sex, weight, leukocyte and thrombocyte count).

MATERIALS AND METHODS

In 30 children with migraine, 31 with ETTH and 28 controls without headaches, an IL-6 level was established in plasma using Biosource kit in the first, third and sixth hour of headache, and 6 hours after its termination. Two days after pain termination, the headache-free measurements were analyzed, and under the same conditions in controls. A statistical assessment was performed.

RESULTS

In 12/30 children with migraine there was an increase in the IL-6 level in the first hour of the attack. There were no differences between migraine with and without aura, migraine and ETTH, and between headaches at baseline and controls. There was an increase in the IL-6 level in children with prolonged primary headaches (migraine and ETTH) in the third and sixth hour of the attack. No correlation between IL-6 and sex, count of leukocytes and thrombocytes was established.

CONCLUSION

The increase in the IL-6 level in several children with migraine in the first hour of the attack may suggest that neurogenic inflammation contributes to the migraine pathogenesis. IL-6 is not involved in the pathogenesis of ETTH. The increase in the IL-6 level in children with prolonged headache may reflect a stress reaction.

[Proinflammatory cytokines in children with migraine with or without aura]

OBJECTIVES

Migraine is an idiopathic headache of differential pathogenesis.

THE AIM

The aim of this research was to establish whether the pathogenesis of migraine with or without aura is identical. In order to examine this, the differences in the level of interleukin-6 (IL-6), interleukin-1beta (IL-1beta), tumor necrosis factor (TNF) and soluble TNF receptor type I (sTNFRI) were established during a migraine attack with or without aura in children.

MATERIALS AND METHODS

30 children with migraine were included, 17 boys and 13 girls aged 10-17 (mean 13.5). In 14/30 children migraine without aura was diagnosed, in 16/30 with aura, visual in 12 and sensory in 4 children. The headache duration was in 23 children shorter and in 7 children longer than 6 hours. When the pain started during hospitalization, the blood was sampled in the first hour of the headache, then 3 hours and 6 hours since headache started (if headache persisted), and 6 hours after its termination. Two days after pain termination, the blood samples were collected, as the headache-free measurements. The levels of IL-6, IL-1 beta, TNF and sTNFRI were established using Biosource kits, all 146 samples were processed. The statistical assessment was conducted.

RESULTS

The significant differences in cytokine levels were detected between children with migraine with or without aura. During headache-free interval in children without aura the level of IL1-beta was higher than with aura (p = 0.03), during 1st hour of migraine attack as well (p = 0.046). Higher, but non significant was IL-1 beta level 3 hours since headache started and 6 hours after its termination (p = 0.06). Type of migraine influenced also the TNF level (in children with migraine without aura higher 6 hours after pain termination, p = 0.046) and sTNFRI (p = 0.07 during the same period). The differences in IL-6 levels between children with migraine with or without aura were not significant.

CONCLUSION

1. The significant increase in IL-1beta level observed during headache-free interval and early stage of attack of migraine without aura as compared to migraine with aura may reflect differences in pathogenesis of both types of migraine in developmental age. 2. This dissimilarity may be suggested also by the increase in TNF and sTNFRI levels in children with migraine without aura as compared to children with migraine with aura after pain termination.

A correlation between migraine, histamine and immunoglobulin e

Although migraine affects about 15% of population and many studies have been performed to find the mechanism and a successful management, the physiopathology of migraine is still largely unknown. The possibility of an immunoglobulin E (IgE)-mediated allergic mechanism and the role of histamine remain controversial. The aim of the present study was to evaluate serum total IgE and histamine levels in migraine patients and the influence of allergy on them. Seventy patients (18-58 years) with migraine without aura were divided into two groups according to their history of allergy (60% with and 40% without allergy). Serum samples were collected during fasting without allowing any premedication during the two periods of attack and remission. There was a control group containing 45 healthy volunteers. Serum total IgE and histamine levels were measured by enzyme-linked immunosorbent assay and fluorimetric methods, respectively. Mean and standard errors of serum histamine (ng/ml) and total IgE (IU/ml) levels were found in the control group to be 48.16 +/- 2.70 and 38.31 +/- 3.20, in the migraine with allergy group 159.11 +/- 4.60 and 303.30 +/- 42.50 and in the migraine without allergy group 105.01 +/- 8.50 and 79.07 +/- 2.70, respectively. Total IgE levels in migraine with allergy group were found to be significantly (P < 0.0001) above that in the control and another group, suggesting an influence of an IgE-mediated mechanism on migraine. Although the plasma histamine levels, which were significantly elevated (P < 0.0001) in patients with migraine, both during headache and symptom-free periods, when compared with the control group, indicate that there is an increased susceptibility to histamine in allergic conditions, this molecule has also an unrelated role in migraine. The relationship between allergy and migraine can be based, in part, on an IgE-mediated mechanism, and histamine release plays an important role. Thus, the avoidance of allergic conditions in migraine patients may be a simple, helpful way for prophylaxis or their treatment.

Decreased sTNF-RI in migraine patients?

Tumour necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) have recently been found to have a pain-mediating function in addition to their immunological, proinflammatory function. According to the hypothesis of neurovascular inflammation in migraine, these two cytokines could contribute to migraine pain generation. We analysed IL-6 and its soluble receptors sIL-6R and sgp130 as well as TNF-alpha and its soluble receptor sTNF-RI in 27 migraine patients and eight headache-free controls. Migraine patients tended to have less sTNF-RI (794 +/- 158 pg/ml) than controls (945 +/- 137 pg/ml). No differences in cytokine concentrations were observed. If TNF-alpha plays a role in migraine physiopathology, migraine patients may lack sufficient antagonistic sTNF-RI to neutralize hyperalgesic TNF-alpha during a migraine attack.

Health care costs of allergic rhinitis-associated conditions vary with allergy season

BACKGROUND

Studies have documented how allergic respiratory symptoms vary with allergen levels, but the impact of allergen levels on health care expenditures for allergy-related conditions has never been shown using actual data on outdoor allergen levels. Evidence linking respiratory allergy to comorbid conditions has also been scanty.

OBJECTIVE

To investigate the link between respiratory allergy and presumably associated conditions by documenting seasonal patterns in their severity and co-occurrence, and to suggest a plan for future research.

METHODS

A retrospective, cross-sectional analysis of medical claims data from 1995 to 1996 were linked to monthly data from federal counting stations on outdoor allergen levels. Participants were employed persons and their dependents, living within 15 miles of an allergen-counting station, continuously enrolled in a health plan for 1995 and 1996, and identified through medical claims data as having asthma, allergic rhinitis (AR), migraines, sinusitis, tonsillitis, otitis media, depression, or anxiety disorder.

RESULTS

All conditions studied were more likely to occur during allergy season than during nonallergy season. For persons with health care claims for a condition of interest in both seasons, total health care costs during allergy season were significantly higher than during nonallergy season. Predicted condition-related expenditures were higher in allergy season for every condition even after controlling for the effect of AR.

CONCLUSION

Allergy effects appear to extend beyond AR symptoms. Other conditions may be affected by outdoor allergen levels even in the absence of AR symptoms, implying that these conditions may be etiologically related to allergy, irrespective of their co-existence with allergic rhinitis, further implying that allergic sensitization can independently affect different parts of the respiratory tract as well as the brain.

Delayed inflammation in rat meninges: implications for migraine pathophysiology

Nitric oxide (NO) has been implicated in migraine pathogenesis based on the delayed development of typical migraine headache 4-6 h after infusing the NO donor nitroglycerin [glyceryl trinitrate (GTN)] to migraineurs. Furthermore, inhibiting the synthesis of NO by treatment with a NO synthase (NOS) inhibitor attenuates spontaneous migraine headaches in 67% of subjects. Because NO has been linked to inflammation and cytokine expression, we investigated the delayed consequences of brief GTN infusion (30 min) on the development of meningeal inflammation in a rat model using doses relevant to the human model. We found dose-dependent Type II NOS [inducible NOS (iNOS)] mRNA upregulation in dura mater beginning at 2 h and an increase in the corresponding protein expression at 4, 6 and 10 h after infusion. Type II NOS immunoreactivity was expressed chiefly within resident meningeal macrophages. Consistent with development of a delayed inflammatory response, we detected induction of interleukin 1beta in dura mater at 2 and 6 h and increased interleukin 6 in dural macrophages and in rat cerebrospinal fluid at 6 h after GTN infusion. Myeloperoxidase-positive cells were rarely found. Leakage of plasma proteins from dural blood vessels was first detected 4 h after GTN infusion, and this was suppressed by administering a specific Type II NOS inhibitor [L-N(6)-(1-iminoethyl)-lysine (L-NIL)]. In addition to cytokine induction, macrophage iNOS upregulation and oedema formation after GTN infusion, dural mast cells exhibited granular changes consistent with secretion at 4 and 6 h. Because iNOS was expressed in dural macrophages following topical GTN, and in the spleen after intravenous injection, the data suggest that the inflammatory response is mediated by direct actions on the dura and does not develop secondary to events within the brain. Our findings point to the importance of new gene expression and cytokine expression as fundamental to the delayed response following GTN infusion, and support the hypothesis that a similar response develops in human meninges after GTN challenge.

[The immune system and primary headache syndromes]

The association between pain and inflammation and certain clinical signs led physicians to suspect a connection between immunological mechanisms and headache syndromes even years ago. This review intends to give an overview of the literature which deals with immunological mechanisms in headache syndromes--with divergent results. Thus, a food allergy as a cause of migraine only seems to be relevant in a few isolated cases. Immunoglobulins or infections do not seem to play a role. Whether the complement system, auto-antibodies, immune cells or cytokines are involved in migraine pathophysiology, still remains to be determined. With regards to cluster headache, a participation of the immune system seems more probable. Although a systemic vasculitis or auto-antibodies probably do not contribute to cluster headache pathophysiology, reports of an immune activation, especially of T-cells, predominate the literature. Nevertheless, the evidence for an immunogenically triggered cluster attack is still lacking. In summary, only a mutual modulation of the immune and the pain system can be assumed with certainty.

Immunological aspects in migraine: increase of IL-10 plasma levels during attack

In the present study, 23 patients with migraine without aura were monitored during a migraine attack. Plasma levels of interleukin (IL)-4, IL-5, IL-10, and interferon-gamma were measured by enzyme-linked immunosorbent assay techniques. Interestingly, we observed low to undetectable IL-5 and IL-4 levels, whereas high IL-10 levels were seen in 52.2% of the patients. Interferon-gamma plasma levels were undetectable in all patients. After treatment with sumatriptan, 10 patients showed a subsequent decrease in IL-10 and an increase in both IL-4 and IL-5 plasma levels. Although these findings are derived from a limited number of patients, the apparent return to the IL-4 and IL-5 cytokine profile observed during the interictal period leads us to speculate that a preferential enhancement of TH2-type cytokine production may contribute to the pathogenesis of migraine.

Neurologic manifestations of the antiphospholipid syndrome

Neurologic disorders are among the most prominent clinical manifestations associated with the antiphospholipid syndrome. Such neurologic disorders are predominantly related to focal central nervous system thrombo-occlusive events. This review summarizes the latest data regarding the clinical aspects of stroke and other neurologic manifestations associated with antiphospholipid antibodies.

Migraine and function of the immune system: a meta-analysis of clinical literature published between 1966 and 1999

Mechanisms underlying migraine precipitation are largely unknown. A role of the immune system in migraine precipitation is a matter of debate because of the association of atopic disorders and migraine. Recently, it was demonstrated that migraineurs benefit from eradication of a Helicobacter pylori infection, which substantiates a possible role for (sub-clinical) infections in precipitation of migraine. Since 1966, about 45 clinical investigations have reported on alterations of immune function in migraine patients, which we present in this review. Changes of serum levels of complement and immunoglobulins, histamine, cytokines and immune cells were found in some of these studies but in most cases not corroborated by others. Migraineurs suffering from comorbid atopic disorders show elevated plasma IgE levels but not patients without a type I hypersensitivity. Histamine plasma levels are chronically elevated in migraineurs, and interictally decreased lymphocyte phagocytotic function and increased plasma tumor necrosis factor alpha (TNFalpha) levels were found, and may be related to increased infection susceptibility. The cause of this increased susceptibility is unclear but most likely is a result of chronic stress, a well-known suppressor of the immune system. Stress relief enhances immune activity and triggers a burst of circulating vasoactive compounds that function as mediators of inflammation and potential precipitators of a migraine attack in vulnerable subjects. In conclusion, in the clinical literature of the past decades, there is no clear-cut evidence of an immune dysfunction in migraineurs, but we cannot totally exclude the possibility of an altered immune function in migraineurs. Discrepancies in the literature most likely are caused by the divergent patterns of sample collection relative to the time of the attack. We propose stringent definition of sample collection times for future studies of immune function in migraine patients.

[Effect of migraine medications on monocyte chemotaxis]

Monocytes play an important role in humoral as well as in cell-mediated immunity. In the present study, the influences of the anti-migraine preparations metoprolol, propranolol, metoclopramide, acetylsalicylic acid, dihydro-ergotamine and sumatriptan on monocyte chemotaxis were examined in vitro. First, mononuclear cells were isolated by centrifugation from venous blood samples obtained from 10 healthy male volunteers. Chemotaxis was determined using a microchemotaxis chamber. While metoprolol, metoclopramide, dihydroergotamine and sumatriptan did not influence monocyte chemotaxis, high doses of propranolol and acetylsalicylic acid caused a significant (p < or = 0.001) inhibition of this important cellular function. Therefore, it is quite possible that both drugs produce adverse immunological effects in vivo in cases of high dosage or obstruction of elimination.