Estradiol supplementation modulates neuroendocrine response to M-chlorophenylpiperazine in menstrual status migrainosus triggered by oral contraception-free interval

A scoping review of hormonal clinical trials in menstrual cycle-related brain disorders: Studies in premenstrual mood disorder, menstrual migraine, and catamenial epilepsy

Cyclic variations in hormones during the normal menstrual cycle underlie multiple central nervous system (CNS)-linked disorders, including premenstrual mood disorder (PMD), menstrual migraine (MM), and catamenial epilepsy (CE). Despite this foundational mechanistic link, these three fields operate independently of each other. In this scoping review (N = 85 studies), we survey existing human research studies in PMD, MM, and CE to outline the exogenous experimental hormone manipulation trials conducted in these fields. We examine a broad range of literature across these disorders in order to summarize existing diagnostic practices and research methods, highlight gaps in the experimental human literature, and elucidate future research opportunities within each field. While no individual treatment or study design can fit every disease, there is immense overlap in study design and established neuroendocrine-based hormone sensitivity among the menstrual cycle-related disorders PMD, MM, and CE.

SCOPING REVIEW STRUCTURED SUMMARY

Background. The menstrual cycle can be a biological trigger of symptoms in certain brain disorders, leading to specific, menstrual cycle-linked phenomena such as premenstrual mood disorders (PMD), menstrual migraine (MM), and catamenial epilepsy (CE). Despite the overlap in chronicity and hormonal provocation, these fields have historically operated independently, without any systematic communication about methods or mechanisms.

OBJECTIVE

Online databases were used to identify articles published between 1950 and 2021 that studied hormonal manipulations in reproductive-aged females with either PMD, MM, or CE. We selected N = 85 studies that met the following criteria: 1) included a study population of females with natural menstrual cycles (e.g., not perimenopausal, pregnant, or using hormonal medications that were not the primary study variable); 2) involved an exogenous hormone manipulation; 3) involved a repeated measurement across at least two cycle phases as the primary outcome variable.

CHARTING METHODS

After exporting online database query results, authors extracted sample size, clinical diagnosis of sample population, study design, experimental hormone manipulation, cyclical outcome measure, and results from each trial. Charting was completed manually, with two authors reviewing each trial.

RESULTS

Exogenous hormone manipulations have been tested as treatment options for PMD (N = 56 trials) more frequently than MM (N = 21) or CE (N = 8). Combined oral contraceptive (COC) trials, specifically those containing drospirenone as the progestin, are a well-studied area with promising results for treating both PMDD and MM. We found no trials of COCs in CE. Many trials test ovulation suppression using gonadotropin-releasing hormone agonists (GnRHa), and a meta-analysis supports their efficacy in PMD; GnRHa have been tested in two MM-related trials, and one CE open-label case series. Finally, we found that non-contraceptive hormone manipulations, including but not limited to short-term transdermal estradiol, progesterone supplementation, and progesterone antagonism, have been used across all three disorders.

CONCLUSIONS

Research in PMD, MM, and CE commonly have overlapping study design and research methods, and similar effects of some interventions suggest the possibility of overlapping mechanisms contributing to their cyclical symptom presentation. Our scoping review is the first to summarize existing clinical trials in these three brain disorders, specifically focusing on hormonal treatment trials. We find that PMD has a stronger body of literature for ovulation-suppressing COC and GnRHa trials; the field of MM consists of extensive estrogen-based studies; and current consensus in CE focuses on progesterone supplementation during the luteal phase, with limited estrogen manipulations due to concerns about seizure provocation. We argue that researchers in any of these respective disciplines would benefit from greater communication regarding methods for assessment, diagnosis, subtyping, and experimental manipulation. With this scoping review, we hope to increase collaboration and communication among researchers to ultimately improve diagnosis and treatment for menstrual-cycle-linked brain disorders.

Current and Emerging Pharmacotherapy for Menstrual Migraine: A Narrative Review

INTRODUCTION

In this article, we discuss menstrual migraine (MM), which can be categorized as menstrually related migraine (MRM) or pure menstrual migraine (PMM). MM attacks are often longer, more severe, and harder to treat than other migraine attacks. Appropriate treatment strategies include acute treatment, short term preventive treatment, and daily preventive treatment, depending on the patient's pattern of migraine and occurrence of migraine outside the menstrual period.

AREAS COVERED

A PubMed, Cochrane Library, Medline, and Ovid search from inception to October 2022 provided articles relating to MM pathophysiology and treatment.

EXPERT OPINION

In patients for whom standard acute therapy is inadequate, short term or daily preventive treatment should be considered. Patients with PMM may be adequately managed with short term preventive treatment started 2 days prior to the onset of migraine and continued for 5-6 days. Frovatriptan is the mainstay of short-term prevention. Patients who experience additional attacks outside the menstrual period may benefit from daily preventive treatment. Estrogen-containing contraceptive treatment may be effective in appropriately selected patients. Emerging research on the pathophysiology of MM indicates that oxytocin agonists and CGRP antagonists may prove to be effective treatment options.

Role of Estrogens in Menstrual Migraine

Migraine is a major neurological disorder affecting one in nine adults worldwide with a significant impact on health care and socioeconomic systems. Migraine is more prevalent in women than in men, with 17% of all women meeting the diagnostic criteria for migraine. In women, the frequency of migraine attacks shows variations over the menstrual cycle and pregnancy, and the use of combined hormonal contraception (CHC) or hormone replacement therapy (HRT) can unveil or modify migraine disease. In the general population, 18–25% of female migraineurs display a menstrual association of their headache. Here we present an overview on the evidence supporting the role of reproductive hormones, in particular estrogens, in the pathophysiology of migraine. We also analyze the efficacy and safety of prescribing exogenous estrogens as a potential treatment for menstrual-related migraine. Finally, we point to controversial issues and future research areas in the field of reproductive hormones and migraine.

Gender-related differences in migraine

Migraine is considered mostly a woman’s complaint, even if it affects also men. Epidemiological data show a higher incidence of the disease in women, starting from puberty throughout life. The sex-related differences of migraine hold clinical relevance too. The frequency, duration, and disability of attacks tend to be higher in women. Because of this, probably, they also consult specialists more frequently and take more prescription drugs than men. Different mechanisms have been evaluated to explain these differences. Hormonal milieu and its modulation of neuronal and vascular reactivity is probably one of the most important aspects. Estrogens and progesterone regulate a host of biological functions through two mechanisms: nongenomic and genomic. They influence several neuromediators and neurotransmitters, and they may cause functional and structural differences in several brain regions, involved in migraine pathogenesis. In addition to their central action, sex hormones exert rapid modulation of vascular tone. The resulting specific sex phenotype should be considered during clinical management and experimental studies.

Sex and the serotonergic underpinnings of depression and migraine

Most psychiatric disorders demonstrate sex differences in their prevalence and symptomatology, and in their response to treatment. These differences are particularly pronounced in mood disorders. Differences in sex hormone levels are among the most overt distinctions between males and females and are thus an intuitive underpinning for these clinical observations. In fact, treatment with estrogen and testosterone was shown to exert antidepressant effects, which underscores this link. Changes to monoaminergic signaling in general, and serotonergic transmission in particular, are understood as central components of depressive pathophysiology. Thus, modulation of the serotonin system may serve as a mechanism via which sex hormones exert their clinical effects in mental health disorders. Over the past 20 years, various experimental approaches have been applied to identify modes of influence of sex and sex hormones on the serotonin system. This chapter provides an overview of different molecular components of the serotonin system, followed by a review of studies performed in animals and in humans with the purpose of elucidating sex hormone effects. Particular emphasis will be placed on studies performed with positron emission tomography, a method that allows for human in vivo molecular imaging and, therefore, assessment of effects in a clinically representative context. The studies addressed in this chapter provide a wealth of information on the interaction between sex, sex hormones, and serotonin in the brain. In general, they offer evidence for the concept that the influence of sex hormones on various components of the serotonin system may serve as an underpinning for the clinical effects these hormones demonstrate.

Serotonin-estrogen interactions: What can we learn from pregnancy?

We have reviewed the scientific literature related to four diseases in which to serotonin (5-HT) is involved in the etiology, herein named 5-HT-linked diseases, and whose prevalence is influenced by estrogenic status: depression, migraine, irritable bowel syndrome and eating disorders. These diseases all have in common a sex-dimorphic prevalence, with women more frequently affected than men. The co-occurrence between these 5-HT-linked diseases suggests that they have common physiopathological mechanisms. In most 5-HT-linked diseases (except for anorexia nervosa and irritable bowel syndrome), a decrease in the serotonergic tone is observed and estrogens are thought to contribute to the improvement of symptoms by stimulating the serotonergic system. Human pregnancy is characterized by a unique 5-HT and estrogen synthesis by the placenta. Pregnancy-specific disorders, such as hyperemesis gravidarum, gestational diabetes mellitus and pre-eclampsia, are associated with a hyperserotonergic state and decreased estrogen levels. Fetal programming of 5-HT-linked diseases is a complex phenomenon that involves notably fetal-sex differences, which suggest the implication of sex steroids. From a mechanistic point of view, we hypothesize that estrogens regulate the serotonergic system, resulting in a protective effect against 5-HT-linked diseases, but that, in turn, 5-HT affects estrogen synthesis in an attempt to retrieve homeostasis. These two processes (5-HT and estrogen biosynthesis) are crucial for successful pregnancy outcomes, and thus, a disruption of this 5-HT-estrogen relationship may explain pregnancy-specific pathologies or pregnancy complications associated with 5-HT-linked diseases.

[Effectiveness and use of hormonal contraceptives (except for intrauterine devices): CNGOF Contraception Guidelines]

Hormonal contraceptives remain among the most popular methods used by women. The purpose of this work is to review the effectiveness and use of these different methods. In addition, some side-effects are feared and/or frequently reported by users of hormonal contraceptives: unscheduled bleeding, acne, catamenial migraines, weight gain, libido and/or mood disorders. In this review of the literature, the accountability of hormonal contraceptives for the occurrence of some of these side-effects was discussed and a management strategy was proposed.

Treating migraine with contraceptives

At least 18% of women suffers from migraine. Clinically, there are two main forms of migraine: migraine with aura (MA) and migraine without aura (MO) and more than 50% of MO is strongly correlated to the menstrual cycle. The high prevalence of migraine in females, its correlation with the menstrual cycle and with the use of combined hormonal contraceptives (CHCs) suggest that the estrogen drop is implicated in the pathogenesis of the attacks. Although CHCs may trigger or worsen migraine, their correct use may even prevent or reduce some forms of migraine, like estrogen withdrawal headache. Evidence suggested that stable estrogen levels have a positive effect, minimising or eliminating the estrogenic drop. Several contraceptive strategies may act in this way: extended-cycle CHCs, CHCs with shortened hormone-free interval (HFI), progestogen-only contraceptives, CHCs containing new generation estrogens and estrogen supplementation during the HFI.

Modulation of nociceptive threshold by combined hormonal contraceptives in women with oestrogen-withdrawal migraine attacks: a pilot study

Background

Menstrually-related headache and headaches associated with oestrogen withdrawal are common conditions, whose pathophysiology has not been completely elucidated. In this study we evaluated the influence of combined hormonal contraceptives (CHC) on pain threshold in women presenting migraine attacks during hormone-free interval.

Findings

Eleven women with migraine attacks recurring exclusively during the oestrogen-withdrawal period were studied with the nociceptive flexion reflex, a neurophysiological assessment of the pain control systems, during the third week of active treatment and during the hormone-free interval.

During the hormone-free interval, nociceptive withdrawal reflex threshold was significantly lower (12.8 ± 8.0 mA) as compared to the third week of hormonal treatment (15.6 ± 6.6 mA) (p = 0.02). No change was observed in the pain perceived and in the temporal summation.

Conclusions

Oestrogen withdrawal may mediate an increased sensitivity to somatosensory stimuli in women with migraine attacks recurring during the hormone-free interval.

Migraine and reproductive life

Migraine is prevalent in women during the fertile age. Indeed, both neuroendocrine events related to reproductive stages (menarche, pregnancy, and menopause) and menstrual cyclicity and the use of exogenous sex hormones, such as hormonal contraception and replacement therapy, may cause significant changes in the clinical pattern of migraine. Menstrual migraine may be more severe, long-lasting, and refractory to both acute and prophylactic treatment and, therefore, requires tailored strategies. The use of headache diaries, which makes it possible to record prospectively the characteristics of every attack, is of paramount importance for evaluating the time pattern of headache and for identifying a clear link with menstrual cycle-related features. Estrogen variations are highly implicated in modulating the threshold to challenges by altering neuronal excitability, cerebral vasoactivity, pain sensitivity, and neuroendocrine axes throughout the menstrual cycle and not only at the time of menstruation. On the other hand, estrogen withdrawal may really constitute a triggering factor for migraine in women with peculiar characteristics of vulnerability with menstruation or following the discontinuation of exogenous estrogen, as happens with hormonal contraception during the fertile age or with hormone therapy at menopause. In addition, exogenous estrogen may contribute to the occurrence of neurological symptoms, such as aura. When aura occurs, hormonal treatment should be discontinued.

The use of progestogen-only pill in migraine patients

Migraine is a debilitating neurovascular disorder which is estimated to affect 18% of women and 6% of men. Two main forms of this neurological disorder must be considered: Migraine without Aura and Migraine with Aura. Migraine without aura often has a strict menstrual relationship: the International Headache Society classification gives criteria for Pure Menstrual Migraine and Menstrually Related Migraine. The higher prevalence of migraine among women suggests that this sex difference probably results from the trigger of fluctuating hormones during the menstrual cycle. Safe and effective contraception is essential for all women of childbearing age, but Combined Oral Contraceptives have been associated with worsening of attacks and cardiovascular risk in these patients. We analyzed characteristics, effects and benefits of progestogen-only pill, a possible alternative for contraception in women with migraine.

Mechanisms of pain modulation by sex hormones in migraine

A number of pain conditions, acute as well as chronic, are much more prevalent in women, such as temporomandibular disorder (TMD), irritable bowel syndrome, fibromyalgia, and migraine. The association of female sex steroids with these nociceptive conditions is well known, but the mechanisms of their effects on pain signaling are yet to be deciphered. We reviewed the mechanisms through which female sex steroids might influence the trigeminal nociceptive pathways with a focus on migraine. Sex steroid receptors are located in trigeminal circuits, providing the molecular substrate for direct effects. In addition to classical genomic effects, sex steroids exert rapid nongenomic actions to modulate nociceptive signaling. Although there are only a handful of studies that have directly addressed the effect of sex hormones in animal models of migraine, the putative mechanisms can be extrapolated from observations in animal models of other trigeminal pain disorders, like TMD. Sex hormones may regulate sensitization of trigeminal neurons by modulating expression of nociceptive mediator such as calcitonin gene-related peptide. Its expression is mostly positively regulated by estrogen, although a few studies also report an inverse relationship. Serotonin (5-Hydroxytryptamine [5-HT]) is a neurotransmitter implicated in migraine; its synthesis is enhanced in most parts of brain by estrogen, which increases expression of the rate-limiting enzyme tryptophan hydroxylase and decreases expression of the serotonin re-uptake transporter. Downstream signaling, including extracellular signal-regulated kinase activation, calcium-dependent mechanisms, and cAMP response element-binding activation, are thought to be the major signaling events affected by sex hormones. These findings need to be confirmed in migraine-specific animal models that may also provide clues to additional ion channels, neuropeptides, and intracellular signaling cascades that contribute to the increased prevalence of migraine in women.

Transdermal hormonal therapy in perimenstrual migraine: why, when and how?

Experimental and clinical evidence is strongly in favor of a role for estrogens in migraine. It is clear that estrogen fluctuations represent trigger factors for the attacks, while the resolution of these fluctuations (menopause) may be associated to the remission or, conversely, to the worsening of the disease. However, the exact mechanisms and mediators underlying the effects of estrogens in migraine are largely unknown. The exact mechanisms and mediators underlying the effects of estrogens in migraine are largely unknown. In this review, we summarize clinical and preclinical data that are relevant for the role of estrogens in migraine and we discuss how estrogen modulation can be exploited positively to improve hormonal-related migraine.

Effect of a contraceptive pill containing estradiol valerate and dienogest (E2V/DNG) in women with menstrually-related migraine (MRM)

BACKGROUND

Combined hormonal contraception might worsen migraine in sensitive women, especially during the free-hormone interval, and raise concerns about the vascular risk. The characteristics of a contraceptive pill containing estradiol valerate/dienogest (E2V/DNG) might be of potential benefit in women with menstrually related migraine (MRM) who choose to use oral contraception for birth control.

STUDY DESIGN

This was a prospective diary-based pilot study. Thirty-two women (age >35 years) [n=18 who had never used combined oral contraceptives (COCs) and n=14 who had previously used COCs] diagnosed with MRMs according to the International Headache Society criteria were included. During the observational period, women filled in a diary with the clinical characteristics of migraine attacks. After a three-cycle run-in period, each subject received a COC containing E2V/DNG (Qlaira®/Natazia®; Bayer HealthCare, Berlin, Germany) administered using an estrogen step-down and progestogen step-up approach. Follow-up evaluations were scheduled at the last cycle of run-in and at the third and sixth cycles of treatment.

RESULTS

The number of migraine attacks was significantly reduced at the third (p<.001) and sixth cycles (p<.001) in comparison with the run-in period. A similar result was evident for the duration (p<.001 at the third and p<.001 at the sixth cycle) as well as for the severity of head pain (p<.001 at the third and p<.001 at the sixth month). Indeed, a significantly lower number of analgesics were used at the third cycle (p<.001) in comparison with baseline, and a further decrease was evident at the sixth cycle (p<.001) in comparison with the third cycle of E2V/DNG use. Interestingly, duration and severity of head pain were significantly correlated with the number of days of dysmenorrhea at the third cycle (r=.89, p=.000 and r=.67, p=.02; respectively) and at the sixth cycle (r=.76, p=.000 and r=.62, p=.04; respectively) in women without complete remission of menstrual cramps during the study period.

CONCLUSIONS

The present diary-based pilot study indicates that the use of a pill containing EV2/DNG for six cycles has a positive effect in women with MRM and suggests an association between dysmenorrhea with COCs use as a potential feature of refractory head pain.

Neuroendocrine aspects of migraine in women

Migraine is a complex disabling disease influenced mainly by age and gender during the life span. Neuroendocrine events related to reproductive stages and to the menstrual cycle may cause significant change in the clinical pattern of migraine over time, as a consequence of failure in adaptation higher in women than in men. Indeed, the individual threshold of vulnerability to manifest migraine is modulated by hormonal fluctuations naturally occurring throughout the menstrual cycle and at the time of reproductive transitions. In the present short review, the role of endogenous estrogen at the level of brain circuitries which are involved in multiple cellular, neurochemical and neurophysiological processes associated with migraine will be summarized in the context of reproductive milestones. In addition, some clues to recognize hormonally sensitive women on the basis of their migraine history, i.e. onset, association with menstruation or premenstrual syndrome, course during pregnancy and menopause, will be discussed in order to expand the knowledge of reproductive endocrinology in the management of migraine in women.

A comparative study of the effect of 17β-estradiol and estriol on peripheral pain behavior in rats

Although estradiol has been reported to influence pain sensitivity, the role of estriol (an estradiol metabolite and another widely used female sex hormone) remains unclear. In this study, pain behavior tests, whole-cell patch clamp recording and Western blotting were used to determine whether estriol plays a role in pain signal transduction and transmission. Either systemic or local administration of 17β-estradiol produced a significant rise of mechanical pain threshold, while estriol lacked this effect in normal and ovariectomized (OVX) rats following estriol replacement. Local administration of 17β-estradiol or estriol significantly decreased ATP-induced spontaneous hind-paw withdrawal duration (PWD), which was blocked by an estrogen receptor antagonist, ICI 182, 780. However, systemic application of estriol in normal or OVX rats lacked this similar effect. In cultured dorsal root ganglion neurons, estriol attenuated α,β-methylene ATP-induced transient currents which were blocked by ICI 182, 780. In complete Freund's adjuvant treated (CFA) rats, systemic application of 17β-estradiol or estriol decreased the mechanical pain threshold significantly, but did not change the inflammatory process. Similar effects were observed after estriol replacement in OVX rats. The expression of c-fos in lumbosacral spinal cord dorsal horn (SCDH) was increased significantly by administration of 17β-estradiol but not estriol, and not by estriol replacement in OVX rats. These results suggest that 17β-estradiol but not estriol plays an anti-hyperalgesic role in physiological pain. However, both peripheral 17β-estradiol and estriol play anti-hyperalgesic roles in ATP-induced inflammatory pain. Systemic application of estriol as well as 17β-estradiol plays hyperalgesic roles in CFA-induced chronic pain.

Bilateral SUNCT-like headache in a patient with prolactinoma responsive to lamotrigine

Short-lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT) syndrome is a rare trigeminal autonomic cephalalgia. The cases of SUNCT with attacks that affected both sides simultaneously have only rarely been reported and some of them had underlying pathology. We have reported a case of bilateral SUNCT-like headache secondary to a prolactinoma and responsive to lamotrigine treatment.

Hormonal management of migraine at menopause

In this review, we underline the importance of linking migraine to reproductive stages for optimal management of such a common disease across the lifespan of women. Menopause has a variable effect on migraine depending on individual vulnerability to neuroendocrine changes induced by estrogen fluctuations and on the length of menopausal transition. Indeed, an association between estrogen 'milieu' and attacks of migraine is strongly supported by several lines of evidence. During the perimenopause, it is likely to observe a worsening of migraine, and a tailored hormonal replacement therapy (HRT) to minimize estrogen/progesterone imbalance may be effective. In the natural menopause, women experience a more favourable course of migraine in comparison with those who have surgical menopause. When severe climacteric symptoms are present, postmenopausal women may be treated with continuous HRT. Even tibolone may be useful when analgesic overuse is documented. However, the transdermal route of oestradiol administration in the lowest effective dose should be preferred to avoid potential vascular risk.

Oral contraceptive-induced menstrual migraine. Clinical aspects and response to frovatriptan

Oral contraceptive-induced menstrual migraine (OCMM) is a poorly defined migraine subtype mainly triggered by the cyclic pill suspension. In this pilot, open-label trial we describe its clinical features and evaluate the efficacy of frovatriptan in the treatment of its acute attack. During the first 3 months of the study 20 women (mean age 32.2+/-7.0, range 22-46) with a 6-month history of pure OCMM recorded, in monthly diary cards, clinical information about their migraine. During the 4th menstrual cycle they treated an OCMM attack with frovatriptan 2.5 mg. The majority of attacks were moderate/severe and lasted 25-72 h or more, in the presence of usual treatment. Generally an OCMM attack appeared within the first 5 days after the pill suspension, but in 15% of cases it started later. After frovatriptan administration, headache intensity progressively decreased (2.4 at onset, 1.6 after 2 h, 1.1 after 4 h and 0.8 after 24 h; p=0.0001). In 55% of patients pain relief was reported after 2 h. Ten percent of subjects were pain-free subjects after 2 h, 35% after 4 h and 60% after 24 h (p=0.003 for trend); 36% relapsed within 24 h. Rescue medication was needed by 35% of patients; 50% of frovatriptan-treated required a second dose. Concomitant nausea and/or vomiting, photophobia and phonophobia decreased significantly after drug intake. OCMM is a severe form of migraine; actually its clinical features are not always exactly identified by the ICHD-II classification. However, treatment with frovatriptan 2.5 mg might be effective in its management.

Modulation of pain by estrogens

It has become increasingly apparent that women suffer a disproportionate amount of pain during their lifetime compared to men. Over the past 15 years, a growing number of studies have suggested a variety of causes for this sex difference, from cellular to psychosocial levels of analysis. From a biological perspective, sexual differentiation of pain appears to occur similarly to sexual differentiation of other phenomena: it results in large part from organizational and activational effects of gonadal steroid hormones. The focus of this review is the activational effects of a single group of ovarian hormones, the estrogens, on pain in humans and animals. The effects of estrogens (estradiol being the most commonly examined) on experimentally induced acute pain vs. clinical pain are summarized. For clinical pain, the review is limited to a few syndromes for which there is considerable evidence for estrogenic involvement: migraine, temporomandibular disorder (TMD) and arthritis. Because estrogens can modulate the function of the nervous, immune, skeletal, and cardiovascular systems, estrogenic modulation of pain is an exceedingly complex, multi-faceted phenomenon, with estrogens producing both pro- and antinociceptive effects that depend on the extent to which each of these systems of the body is involved in a particular type of pain. Forging a more complete understanding of the myriad ways that estrogens can ameliorate vs. facilitate pain will enable us to better prevent and treat pain in both women and men.

Frovatriptan vs. transdermal oestrogens or naproxen sodium for the prophylaxis of menstrual migraine

Acute treatment of menstrual migraine (MM) attacks is often incomplete and unsatisfactory, and perimenstrual prophylaxis with triptans, oestrogen supplementation or naproxen sodium may be needed for decreasing frequency and severity of the attack. In this pilot, open-label, non-randomised, parallel group study we evaluated, in 38 women with a history of MM, the efficacy of frovatriptan (n=14) 2.5 mg per os or transdermal oestrogens (n=10) 25 microg or naproxen sodium (n=14) 500 mg per os once-daily for the short-term prevention of MM. All treatments were administered in the morning for 6 days, beginning 2 days before the expected onset of menstrual headache. All women were asked to fill in a diary card, in the absence of (baseline) and under treatment, in order to score headache severity. All women reported at least one episode of MM at baseline. During treatment all patients taking transdermal oestrogens or naproxen sodium and 13 out of the 14 patients (93%) taking frovatriptan had at least one migraine attack (p=0.424). Daily incidence of migraine was significantly (p=0.045) lower under frovatriptan than under transdermal oestrogens or NS. At baseline, the overall median score of headache severity was 4.6, 4.2 and 4.3 in the group subsequently treated with frovatriptan, transdermal oestrogens and naproxen sodium, respectively (p=0.819). During treatment the median score was significantly lower under frovatriptan (2.5) than under transdermal oestrogens (3.0) and naproxen sodium (3.9, p=0.049). This was evident also for each single day of observation (p=0.016). Among treatments differences were particularly evident for the subgroup of patients with true MM (n=22) and for frovatriptan vs. naproxen sodium. This study suggests that short-term prophylaxis of MM with frovatriptan may be more effective than that based on transdermal oestrogens or naproxen sodium.

A pharmacogenomic evaluation of migraine therapy

Migraine is a common idiopathic primary headache disorder with significant mental, physical and social health implications. Accompanying an intense unilateral pulsating head pain other characteristic migraine symptoms include nausea, emesis, phonophobia, photophobia and in approximately 20-30% of migraine cases, neurologic disturbances associated with the aura phase. Although selective serotonin (5-HT) receptor agonists (i.e., 5-HT(1B/1D)) are successful in alleviating migrainous symptoms in < or = 70% of known sufferers, for the remaining 30%, additional migraine abortive medications remain unsuccessful, not tested or yet to be identified. Genetic characterization of the migrainous disorder is making steady progress with an increasing number of genomic susceptibility loci now identified on chromosomes 1q, 4q, 5q, 6p, 11q, 14q, 15q, 17p, 18q, 19p and Xq. The 4q, 5q, 17p and 18q loci involve endophenotypic susceptibility regions for various migrainous symptoms. In an effort to develop individualized pharmacotherapeutics, the identification of these migraine endophenotypic loci may well be the catalyst needed to aid in this goal. In this review the authors discuss the present treatment of migraine, known genomic susceptibility regions and results from migraine (genetic) association studies. The authors also discuss pharmacogenomic considerations for more individualized migraine prophylactic treatments.

Potential role of female sex hormones in the pathophysiology of migraine

Clinical evidence indicates that female sex steroids may contribute to the high prevalence of migraine in women, as well as changes in the frequency or severity of migraine attacks that are in tandem with various reproductive milestones in women's life. While female sex steroids do not seem to be involved in the pathogenesis of migraine per se, they may modulate several mediators and/or receptor systems via both genomic and non-genomic mechanisms; these actions may be perpetuated at the central nervous system, as well as at the peripheral (neuro)vascular level. For example, female sex steroids have been shown to enhance: (i) neuronal excitability by elevating Ca(2+) and decreasing Mg(2+) concentrations, an action that may occur with other mechanisms triggering migraine; (ii) the synthesis and release of nitric oxide (NO) and neuropeptides, such as calcitonin gene-related peptide CGRP, a mechanism that reinforces vasodilatation and activates trigeminal sensory afferents with a subsequent stimulation of pain centres; and (iii) the function of receptors mediating vasodilatation, while the responses of receptors inducing vasoconstriction are attenuated. The serotonergic, adrenergic and gamma-aminobutyric acid (GABA)-ergic systems are also modulated by sex steroids, albeit to a varying degree and with potentially contrasting effects on migraine outcome. Taken together, female sex steroids seem to be involved in an array of components implicated in migraine pathogenesis. Future studies will further delineate the extent and the clinical relevance of each of these mechanisms, and will thus expand the knowledge on the femininity of migraine.

Sex and hormonal cycle differences in rat brain levels of pain-related cannabimimetic lipid mediators

One important function of endocannabinoids and related lipid mediators in mammalian central nervous system is modulation of pain. Evidence obtained during the last decade shows that altered levels of these compounds in the brain accompany decreases in pain sensitivity. Such changes, if sexually dimorphic, could account for sex differences in pain and differences that occur during different phases of the hormonal cycle in females. To examine this possibility, we measured the levels of the pain-modulatory lipids anandamide, 2-arachidonoyl glycerol, N-arachidonoyl glycine, N-arachidonoyl gamma amino butyric acid, and N-arachidonoyl dopamine in seven different brain areas (pituitary, hypothalamus, thalamus, striatum, midbrain, hippocampus, and cerebellum) in male rats, and in female rats at five different points in the estrous cycle. The cerebellum did not demonstrate a change in endocannabinoid production across the estrous cycle, whereas all other areas tested showed significant differences in at least one of the compounds measured. These changes in levels occurred predominantly within the 36-h time period surrounding ovulation and behavioral estrus. Differences between males and females were measured as either estrous cycle-independent (all estrous cycles combined) or cycle-dependent (comparisons of males to each estrous cycle). In cycle-independent analyses, small sex differences were observed in the pituitary, hypothalamus, cerebellum, and striatum, whereas no differences were observed in the thalamus, midbrain, and hippocampus. In cycle-dependent analyses, the hypothalamus and pituitary showed largest sex differences followed by the striatum, midbrain, and hippocampus, whereas no sex differences were measured in thalamus and cerebellum. These data provide a basis for investigations into how differences in sex and hormonal status play a role in mechanisms regulating endocannabinoid production and pain.