Serum ionized magnesium levels and serum ionized calcium/ionized magnesium ratios in women with menstrual migraine

Serum Magnesium Levels During the Ictal and Interictal Phase in Patients of Migraine: A Prospective Observational Study

BACKGROUND

Migraine is one of the primary headaches having a global prevalence of 15%. It is characterized by neurovascular dysfunction and recurrent episodes of headache. The hyperexcitability of the cerebral cortex has been recognized as an important factor in the pathogenesis of migraine, and magnesium (Mg) being a regulator of neuronal excitability is thought to participate in migraine pathogenesis.

OBJECTIVES

To determine the serum levels of Mg in patients of migraine during the attack and in between attacks as compared to healthy controls.

METHODS

A total of 50 patients of migraine who fulfilled inclusion criteria were enrolled in the study along with the same number of healthy controls. International Classification of Headache Disorders 3^rd Edition, 2013 (ICHD-III) criteria was used for the diagnosis of migraine.

RESULTS

The mean serum Mg in migraine cases during the interictal phase was lower than healthy controls (1.849 ± 0.135 vs 2.090 ± 0.205, P < 0.001), which was statistically significant. It was also found that mean serum Mg during attacks was significantly lower than in between attacks (1.822 ± 0.149 vs 1.849 ± 0.135, P = 0.003). Serum Mg levels in migraine cases showed an inverse linear relationship with the frequency of attacks.

CONCLUSION

Relatively low serum Mg in migraine cases when compared with healthy controls and inverse relation of serum Mg levels with the frequency of migraine attacks suggests that Mg is significantly involved in mechanisms underlying migraine pathogenesis, which can be explored as a therapeutic option.

Magnesium as an Important Factor in the Pathogenesis and Treatment of Migraine—From Theory to Practice

So far, no coherent and convincing theory has been developed to fully explain the pathogenesis of migraine, although many researchers and experts emphasize its association with spreading cortical depression, oxidative stress, vascular changes, nervous excitement, neurotransmitter release, and electrolyte disturbances. The contribution of magnesium deficiency to the induction of cortical depression or abnormal glutamatergic neurotransmission is a likely mechanism of the magnesium–migraine relationship. Hence, there is interest in various methods of assessing magnesium ion deficiency and attempts to study the relationship of its intra- and extracellular levels with the induction of migraine attacks. At the same time, many clinicians believe that magnesium supplementation in the right dose and form can be a treatment to prevent migraine attacks, especially in those patients who have identified contraindications to standard medications or their different preferences. However, there are no reliable publications confirming the role of magnesium deficiency in the diet as a factor causing migraine attacks. It also seems interesting to deepen the research on the administration of high doses of magnesium intravenously during migraine attacks. The aim of the study was to discuss the probable mechanisms of correlation of magnesium deficiency with migraine, as well as to present the current clinical proposals for the use of various magnesium preparations in complementary or substitute pharmacotherapy of migraine. The summary of the results of research and clinical observations to date gives hope of finding a trigger for migraine attacks (especially migraine with aura), which may turn out to be easy to diagnose and eliminate with pharmacological and dietary supplementation.

Migraine and Its Association with Hyperactivity of Cell Membranes in the Course of Latent Magnesium Deficiency-Preliminary Study of the Importance of the Latent Tetany Presence in the Migraine Pathogenesis

So far, there is no consistent and convincing theory explaining the pathogenesis of migraines. Vascular disorders, the effect of oxidative stress on neurons, and the contribution of magnesium-calcium deficiencies in triggering cortical depression and abnormal glutaminergic neurotransmission are taken into account. However, there are no reliable publications confirming the role of dietary deficits of magnesium and latent tetany as factors triggering migraine attacks. The aim of the study was to evaluate the influence of latent magnesium deficiency assessed with the electrophysiological tetany test on the course of migraine. The study included: a group of 35 patients (29 women and six men; in mean age 41 years) with migraine and a control group of 24 (17 women and seven men; in mean age 39 years) healthy volunteers. Migraine diagnosis was based on the International Headache Society criteria, 3rd edition. All patients and controls after full general and neurological examination were subjected to a standard electrophysiological ischemic tetany test. Moreover, the level of magnesium in blood serum was tested and was in the normal range in all patients. Then, the incidence of a positive tetany EMG test results in the migraine group and the results in the subgroups with and without aura were compared to the results in the control group. Moreover, the relationship between clinical markers of spasmophilia and the results of the tetany test was investigated in the migraine group. As well as the relationship between migraine frequency and tetany test results. There was no statistically significant difference in the occurrence of the electrophysiological exponent of spasmophilia between the migraine and control group. Neither correlation between the occurrence of clinical symptoms nor the frequency of migraine attacks and the results of the tetany test was stated (p > 0.05). However, there was an apparent statistical difference between the subgroup of migraine patients with aura in relation to the control group (p < 0.05). The result raises hope to find a trigger for migraine attacks of this clinical form, the more that this factor may turn out to be easy to supplement with dietary supplementation.

A new hypothesis linking oxytocin to menstrual migraine

OBJECTIVE

To highlight the emerging understanding of oxytocin (OT) and oxytocin receptors (OTRs) in modulating menstrual-related migraine (MRM).

BACKGROUND

MRM is highly debilitating and less responsive to therapy, and attacks are of longer duration than nonmenstrually related migraine. A clear understanding of the mechanisms underlying MRM is lacking.

METHODS

We present a narrative literature review on the developing understanding of the role of OT and the OTR in MRM. Literature on MRM on PubMed/MEDLINE database including clinical trials and basic science publications was reviewed using specific keywords.

RESULTS

OT is a cyclically released hypothalamic hormone/neurotransmitter that binds to the OTR resulting in inhibition of trigeminal neuronal excitability that can promote migraine pain including that of MRM. Estrogen regulates OT release as well as expression of the OTR. Coincident with menstruation, levels of both estrogen and OT decrease. Additionally, other serum biochemical factors, including magnesium and cholesterol, which positively modulate the affinity of OT for OTRs, both decrease during menstruation. Thus, during menstruation, multiple menstrually associated factors may lead to decreased circulating OT levels, decreased OT affinity for OTR, and decreased expression of the trigeminal OTR. Consistent with the view of migraine as a threshold disorder, these events may collectively result in decreased inhibition promoting lower thresholds for activation of meningeal trigeminal nociceptors and increasing the likelihood of an MRM attack.

CONCLUSION

Trigeminal OTR may thus be a novel target for the development of MRM therapeutics.

The efficacy of magnesium oxide and sodium valproate in prevention of migraine headache: a randomized, controlled, double-blind, crossover study

Migraine is a disabling disorder that affects the quality of life of patients. Different medications have been used in prevention of migraine headache. In this study, we evaluated the effectiveness of magnesium oxide in comparison with valproate sodium in preventing migraine headache attacks. This is a single-center, randomized, controlled, crossover trial which is double-blind, 24-week, 2-sequence, 2-period, 2-treatment. After patient randomization into two sequences, the intervention group received magnesium oxide 500 mg and the control group received valproate sodium 400 mg two tablets each day (every 12 h) for 8 weeks. The primary efficacy variable was reduction in the number of migraine attacks and number of days with moderate or severe headache and hours with headache (duration) per month in the final of 8 weeks in comparison with baseline. Seventy patients were randomized and seven dropped out, leaving 63 for analysis. In an intention-to-treat analysis, 31 patients were in group 1 (magnesium oxide-valproate) and 32 patients were in group 2 (valproate-magnesium oxide). The mean number of migraine attacks and days per month was 1.72 ± 1.18 and 2.09 ± 1.70, with a mean duration of 15.50 ± 21.80 h in magnesium group and 1.27 ± 1.27 and 2.22 ± 1.96, with a mean duration 13.38 ± 14.10 in valproate group. This study has shown that 500 mg magnesium oxide appears to be effective in migraine prophylaxis similar to valproate sodium without significant adverse effect.

Non-Pharmacological Approaches for Migraine

Migraine is one of the most common and debilitating neurological disorders. However, the efficacy of pharmacological therapies may have unsatisfactory efficacy and can be poorly tolerated. There is a strong need in clinical practice for alternative approaches for both acute and preventive treatment. Occasionally, this need might arise in the context of low-frequency migraneurs who are not keen to use medication or fear the potential side effects. At the opposite end of the spectrum, clinicians might be faced with patients who have proven refractory to numerous medications. These patients may benefit from invasive treatment strategies. In recent years, promising strategies for migraine therapy have emerged alongside a progressively better understanding of the complex pathophysiology underlying this disease. This review discusses the most recent and evidence-based advances in non-pharmacological therapeutic approaches for migraine, offering alternatives to drug treatment for both the commonly encountered episodic cases as well as the more complex migraine phenotypes, which are capable of challenging even the headache specialist.

Usefulness of nutraceuticals in migraine prophylaxis

Several studies have supported the efficacy of complementary and alternative medicine approaches (physical, behavioral and nutraceutical therapies) in the treatment of headache disorders. Nutraceutical treatment consists of taking vitamins, supplements (magnesium, riboflavin, coenzyme Q10, and alpha lipoic acid) and herbal preparations (feverfew and butterbur), and its usage is frequently determined by dissatisfaction with conventional medical therapies. There is a growing body of research on nutraceutical use for migraine prophylaxis. This brief overview provides information about the potential efficacy and side effects of various nutraceutical products summarizing randomized controlled trials of some of the most commonly used non-pharmacological treatments for the prophylaxis and treatment of migraine, including magnesium, coenzyme Q10, riboflavin (vitamin B₂), petasites, and feverfew.

Intravenous caffeine citrate vs. magnesium sulfate for reducing pain in patients with acute migraine headache; a prospective quasi-experimental study

Background

Current evidence suggests that intravenous magnesium sulfate might be effective for reducing migraine pain. In a recent pilot study, we showed that intravenous caffeine citrate could reduce the severity of migraine headache. The objective of this study is to investigate the efficacy of intravenous caffeine citrate vs. magnesium sulfate for management of acute migraine headache.

Methods

We conducted a prospective quasi-experimental study from January until May 2016 in two educational medical centers of Shahid Beheshti University of Medical Sciences (Shoahadaye Tajrish Hospital and Imam Hossein Hospital), Tehran, Iran. The study included patients who were referred to the emergency department and met the migraine diagnosis criteria of the International Headache Society. Patients were allocated into 2 groups receiving either 60 mg intravenous caffeine or 2 g intravenous magnesium sulfate. The pain scores, based on the visual analog scale, were recorded on admission, as well as one and two hours after receiving the drug. A Chi-Square test and student t-test were used for analysis of baseline characteristics. A Mann-Whitney U test and Wilcoxon singed rank test were used to analyze differences in the visual analogue scale (VAS) score between and within the groups respectively.

Results

In total, 70 patients (35 patients in each group) with the mean age of 33.1 ± 11.3 years were included (64.3% female). For the Caffeine citrate group, the median pain score decreased from 9.0 (2.0) to 5.0 (4.0) after one hour and to 3.0 (4.0) after two hours. For the magnesium sulfate group, the pain score decreased from 8.0 (2.0) to 2.0 (2.0) after one hour and to 0.0 (1.0) after two hours. Both intravenous caffeine citrate and intravenous magnesium sulfate reduced pain scores significantly but the magnesium sulfate group showed more improvement than the Caffeine citrate group after one hour (P < 0.001) and after two hours (P < 0.001).

Conclusions

It is likely that both intravenous caffeine and intravenous magnesium sulfate can reduce the severity of migraine headache. Moreover, intravenous magnesium sulfate at a dose of 2 g might be superior to intravenous caffeine citrate 60 mg for the short term management of migraine headache in emergency departments.

The Relationship Between Resistant Tachycardia and Treatment for GERD

The use of medications that block gastric acid secretion, such as proton pump inhibitors, has rapidly escalated in the United States. Although originally intended for short-term treatment of specific conditions, PPIs have expanded to long-term use with unanticipated consequences, including mineral deficiencies related to lack of sufficient stomach acid needed for extraction of minerals from the foods and supplements ingested. Herein, the author reports on a case of a patient with tachycardia and other arrhythmias that had been resistant to the medications prescribed by a series of cardiologists. The patient had been on PPI for several years preceding his arrhythmias, prescribed for stress-related gastritis. The author did comprehensive blood work and discovered that the patient was deficient in many of the minerals tested, including magnesium, known to be essential for normal cardiac function. After the patient slowly weaned himself off the PPIs and took magnesium and other minerals, the tachycardia resolved without any medication.

CONCLUSIONS

This case demonstrates the importance of carefully reviewing the list of medications patients are taking and having a thorough understanding of the possible long-term risks associated with those medications. The patient's presenting symptoms have the potential to be related-directly or indirectly-to the medications that have been prescribed.

Serum concentration of magnesium as an independent risk factor in migraine attacks: a matched case-control study and review of the literature

There is controversy over the role of magnesium in the etiology of migraine headaches. We aimed to evaluate and compare serum levels of magnesium between healthy individuals and those with migraine headaches during migraine attacks and between attacks to evaluate the role of magnesium in the etiology of migraine headaches. Forty patients with migraine headaches and 40 healthy individuals were enrolled in this matched case-control study. Malnutrition, digestive system disorders, history of smoking, drug abuse, and history of medications use were recorded at baseline. The pain scores of patients were measured and recorded based on a 10 cm visual analog scale. Subsequently, blood samples were collected at 8-10 in the morning to determine serum levels of magnesium. Analysis of variance, χ-test, and conditional logistic regression were used for data analysis. There were no significant differences in demographic data between the two groups. There were significant differences in magnesium serum levels between the three groups (1.09±0.2 mg/dl during migraine headaches; 1.95±0.3 mg/dl between the attacks; and 1.3±0.4 mh/dl in the control group; P<0.0001). Odds of acute migraine headaches increased 35.3 times (odds ratio=35.3; 95% confidence interval: 12.4-95.2; P=0.001) when serum levels of magnesium reached below the normal level. The odds in patients who are not in the acute attack phase were 6.9 folds higher (odds ratio=6.9; 95% confidence interval: 1.3-2.1; P=0.02). The serum level of magnesium is an independent factor for migraine headaches and patients with migraine have lower serum levels of magnesium during the migraine attacks and between the attacks compared with healthy individuals.

An evidence-based review of oral magnesium supplementation in the preventive treatment of migraine

Background

Migraine is an incompletely understood, debilitating disorder that lacks a universally effective treatment. Magnesium participates in a variety of biochemical processes related to migraine pathophysiology, and a deficiency could contribute to migraine development.

Methods

A review of the literature from 1990 to the present on magnesium and migraine was conducted.

Review

The authors identified 16 studies aimed at magnesium status assessment in migraine, and four intervention trials assessing the efficacy of oral magnesium supplementation, independent of other therapies, in the prevention of migraine.

Conclusion

The strength of evidence supporting oral magnesium supplementation is limited at this time. With such limited evidence, a more advantageous alternative to magnesium supplementation, in patients willing to make lifestyle changes, may be to focus on increasing dietary magnesium intake.

Altered trigeminal system excitability in menstrual migraine patients

To evaluate brainstem excitability in menstrual migraine (MM) patients and compare the electrophysiological parameters of the trigeminocervical reflex (TCR) during the perimenstrual (headache period) and follicular (headache-free) periods with those in healthy controls. Thirty-one patients with MM and 22 volunteer age- and sex-matched healthy women were included in the study. The TCR was studied bilaterally with stimulation of the supraorbital branch of the trigeminal nerve during the perimenstrual period and follicular phase. The electrophysiological parameters of the TCR were compared between MM patients and controls. In controls, there was no statistically significant difference in the mean reflex latencies recorded during the perimenstrual and follicular phases (P > 0.05). In MM patients, the mean reflex latencies recorded during the perimenstrual (headache period) and follicular phase (headache-free) periods were significantly different from each other and from those in controls. The latencies of MM patients during the follicular (headache-free) period were significantly longer than those of controls. Brainstem excitability differed significantly between the perimenstrual (headache period) and follicular phase (headache-free) periods in MM. Furthermore, trigeminal excitability in MM patients was significantly different from that in healthy controls in both phases of the menstrual period.

Stuttering in adults: the acoustic startle response, temperamental traits, and biological factors

The purpose of this study was to investigate the relation between stuttering and a range of variables of possible relevance, with the main focus on neuromuscular reactivity, and anxiety. The explorative analysis also included temperament, biochemical variables, heredity, preonset lesions, and altered auditory feedback (AAF). An increased level of neuromuscular reactivity in stuttering adults has previously been reported by [Guitar, B. (2003). Acoustic startle responses and temperament in individuals who stutter. Journal of Speech Language and Hearing Research, 46, 233-240], also indicating a link to anxiety and temperament. The present study included a large number of variables in order to enable analysis of subgroups and relations between variables. Totally 32 stuttering adults were compared with nonstuttering controls. The acoustic startle eyeblink response was used as a measure of neuromuscular reactivity. No significant group difference was found regarding startle, and startle was not significantly correlated with trait anxiety, stuttering severity, or AAF. Startle was mainly related to calcium and prolactin. The stuttering group had significantly higher scores for anxiety and childhood ADHD. Two subgroups of stuttering were found, with high versus low traits of childhood ADHD, characterized by indications of preonset lesions versus heredity for stuttering. The study does not support the view that excessive reactivity is a typical characteristic of stuttering. The increased anxiety is suggested to mainly be an effect of experiences of stuttering.

LEARNING OUTCOMES

As a result of reading this article, the reader will be able to: (a) critically discuss the literature regarding stuttering in relation to acoustic startle, anxiety, and temperament; (b) describe the effect of calcium on neuromuscular reactivity; (c) discuss findings supporting the importance of early neurological incidents in some cases of stuttering, and the relation between such incidents and traits of ADHD or ADD; and (d) discuss the role of genetics in stuttering.

The effect of estrogen and progesterone on spreading depression in rat neocortical tissues

Although gender differences in the incidence of migraine with aura appear to be related to high circulating levels of ovarian hormones, the underlying mechanisms are not yet fully understood. Several studies have suggested a major role for spreading depression (SD) in the pathogenesis and symptomatology of migraine with aura. To investigate a possible role of SD in the association of high female hormones and attacks of migraine with aura, the effects of beta-estradiol and progesterone on SD were studied in rat neocortical tissues. Application of both hormones enhanced the repetition rate as well as the amplitude of SD in neocortical slices treated with hypotonic artificial cerebrospinal fluid. beta-Estradiol and progesterone also dose dependently increased the amplitude of SD induced by KCl microinjection. Both hormones exhibited a pronounced, persisting, and significant enhancement of long-term potentiation of the field excitatory postsynaptic potential in the neocortical tissues. The changes in SD characteristics in the presence of estrogen and progesterone may responsible for increased migraine with aura attacks associated by high female hormones. These hormones may exert their effects on SD via facilitation of synaptic transmission.

Treatment of headaches with botulinum toxin

Primary headache disorders, such as migraine, chronic daily headache (CDH), and chronic tension-type headache (CTTH), are some of the most frequent disorders encountered by physicians in the outpatient setting. Chronic headache disorders cause significant morbidity and functional impairment. Despite important advances in both pharmacological and behavioral management of headache disorders, a number of patients remain treatment resistant. Botulinum toxin (BT) is emerging as a new therapeutic alternative in the preventative treatment of headaches. BT has several advantages over current prophylactic strategies, such as reduced side-effect profile and improved patient compliance. Furthermore, there have been several studies supporting the safety and tolerability of BT in the treatment of headache disorders. Although additional large-scale studies are needed to clarify clinical predictors of response as well as optimal dosing, injection sites and mechanism of action, BT has demonstrated efficacy in the treatment of migraines and CDH. The evidence for the treatment for CTTH is less compelling.

Is Low Blood Magnesium Level Associated With Hemodialysis Headache?

OBJECTIVE

The aim of this study was to evaluate the prevalence, demographic, clinical features, and possible risk factors for hemodialysis headache (HDH).

BACKGROUND

HDH has been recognized for many years, but the pathophysiology of this condition is not known. High arterial blood pressure, decreased serum osmolality, sodium washout, and high blood urea nitrogen level are reported risk factors for HDH. Low serum magnesium (Mg) level is known to cause some types of headache, including migraine (menstrual migraine in particular), tension-type headaches, and cluster and posttraumatic headaches. Low Mg has also been reported in HDH patients.

METHODS

A total of 250 hemodialysis (HD) patients were questioned about problems with headache. Of these, 75 were diagnosed with HDH according to the revised International Headache Society criteria for 2003. Eighty age- and sex-matched HD patients without HDH were selected as a control group. For each HDH and control subject, arterial diastolic and systolic blood pressure, body weight, and serum levels of sodium, blood urea nitrogen, creatinine, and Mg were measured before and after one HD session. Urea reduction rate and ultrafiltration were determined. Serum levels of phosphorus, calcium, albumin, and parathormone were measured only before the session. Findings in the HDH and control group were statistically compared.

RESULTS

As noted, 75 (30%) of the total 250 HD patients surveyed were diagnosed with HDH. The mean headache duration in this group was 5.17 +/- 5 hours. Vertex location, bilateral headache, dull nature, and moderate severity were the most prevalent features of HDH. There were no statistically significant differences between the HDH and control groups with respect to causes of end-stage renal disease. There were no significant differences between the HDH and control groups with respect to predialysis values for blood urea nitrogen, body weight, and arterial blood pressure (P > .05), and the same was true for comparisons of the postdialysis values for these parameters. The mean predialysis sodium level in the HDH group was higher than in the control group (P= .003). Both the mean predialysis and mean postdialysis Mg levels in the HDH group were significantly lower than the corresponding levels in the control group (P= .05 and P= .02, respectively).

CONCLUSIONS

The results suggest that low blood Mg level and high blood sodium level may be risk factors for HDH. Magnesium supplementation may help patients with HDH whose serum Mg levels are found to be low.

Menstrual migraine: A review of prophylactic therapies

Menstrual migraine is commonly encountered in women who are experiencing attacks of migraine without aura. It remains controversial whether attacks of menstrually associated migraine are more severe and have a longer duration than non-menstrually associated attacks. The pathogenesis of menstrual migraine is not understood completely, but it may be related to estrogen withdrawal or prostaglandin release. Preventative therapies may be considered in those who have failed abortive medications or have attacks lasting longer than 2 days. They can be administered short-term during the perimenstrual time period or continuously throughout the menstrual cycle. Short-term prophylactics should be tried first because menstrual migraines generally last for 1 to 4 days only. Continuous prophylactics may be considered in those with attacks refractory to short-term therapies.

Modulation of intercellular calcium signaling in astrocytes by extracellular calcium and magnesium

The extracellular concentrations of Ca(2+) and Mg(2+) are well known to play important roles in the function of the central nervous system. We examined the effects of extracellular Ca(2+) and Mg(2+) on ATP release and intercellular signaling in astrocytes. The extent of propagation of intercellular Ca(2+) waves evoked by mechanical stimulation was increased by reduction of extracellular Ca(2+) ([Ca(2+)](o)) or Mg(2+) concentration ([Mg(2+)](o)) and was decreased by elevated [Mg(2+)](o). Reduction of extracellular Ca(2+) concentration ([Ca(2+)](o)) evokes intercellular Ca(2+) signaling in astrocytes; a similar effect was observed in response to change from 5 mM [Mg(2+)](o) to 0 [Mg(2+)](o). Release of low-molecular-weight dyes and ATP was also activated by low [Ca(2+)](o) or [Mg(2+)](o) and inhibited by high [Ca(2+)](o) or [Mg(2+)](o). Astrocytes showed low [Ca(2+)](o)-activated whole cell currents consistent with currents through connexin hemichannels. These currents were inhibited by extracellular Mg(2+). We conclude that extracellular divalent cations modulate intercellular Ca(2+) signaling in astrocytes by modulating the release of ATP, possibly via connexin hemichannels.

Oral magnesium oxide prophylaxis of frequent migrainous headache in children: a randomized, double-blind, placebo-controlled trial

OBJECTIVE

To assess whether, in children, oral magnesium oxide reduces migrainous headache frequency, severity, and associated features compared to placebo.

BACKGROUND

There is no single, safe, widely well-tolerated, and effective prophylactic treatment for all children and adolescents with frequent migrainous headache.

DESIGN

Randomized, double-blind, placebo-controlled, parallel-group trial.

METHODS

This study was conducted between June 1997 and January 2000 using 7 selected Northern California Kaiser Permanente sites. We recruited children of ages 3 to 17 years who reported a 4-week history of at least weekly, moderate-to-severe headache with a throbbing or pulsatile quality, associated anorexia/nausea, vomiting, photophobia, sonophobia, or relief with sleep, but no fever or evidence of infection. Subjects were randomly assigned to receive either magnesium oxide (9 mg/kg per day by mouth divided 3 times a day with food) (n = 58) or matching placebo (n = 60) for 16 weeks. The number of headache days (days with at least one headache) during each of eight 2-week intervals was chosen to be the primary outcome variable.

RESULTS

Of those enrolled, 86 (73%) completed the study (42 received magnesium oxide and 44 placebo); 74 of 192 eligible subjects declined to participate. Baseline information on demographic factors, health status, and headache history was similar comparing the 2 groups. By intention-to-treat analysis, we found a statistically significant decrease over time in headache frequency in the magnesium oxide group (P =.0037) but not in the placebo group (P =.086), although the slopes of these 2 lines were not statistically significantly different from each other (P =.88). The group treated with magnesium oxide had significantly lower headache severity (P =.0029) relative to the placebo group.

CONCLUSIONS

This study does not unequivocally determine whether oral magnesium oxide is or is not superior to placebo in preventing frequent migrainous headache in children, but treatment with the active agent did lead to a significant reduction in headache days. Larger trials involving this safe, appealing complementary therapy are needed.