The epidemiology of migraine: a retrospective study in Italian emergency departments

This study was conducted to measure the frequency of contact with emergency departments in Italy because of migraine, and to compare the initial diagnosi s of headache with the diagnosis after application of the International Headache Society (IHS) criteria. A retrospective observational method was used, consisting of an analysis of the records of patients admitted to nine Italian emergency departments during different 4-month periods in 1994. Comparison of the initial diagnosis with the diagnosis after application of the IHS diagnostic criteria was performed. More than 31 million emergency department contacts were reported in Italy during 1994. In the same year, 543 630 patients visited the nine emergency departments enrolled in the study, with 169 569 of these contacts occurring in the 4-month period analyzed in the study. We excluded from the analysis all cases of secondary headache fully recognized at the emergency department admission (ie, traumas, intracranial pathology, systemic diseases). The total number of patients included in our analysis was 1043 (0.6%). The 934 patients who could be fully evaluated were initially classified as having migraine; cluster headache; headache not otherwise specified; or diagnosed in the emergency department as suffering from headache, but reclassified by other departments as suffering from a different disease. After retrospective application of the IHS classification, the diagnostic distribution was modified, revealing that 18% of patients with migraine and 5% with cluster headaches had previously been classified as having headache not otherwise specified; a further 6% of cases with migraine and 0.4% of patients with cluster headache had previously been classified as having secondary headaches. The diagnosis of headache not otherwise specified was made with notable frequency, indicating the limits of emergency department logs and the difficulty in carrying out a retrospective analysis and reassessment of diagnosis. The majority (88%) of patients assessed had not taken drugs for headache in the 48 hours before the emergency department contact, suggesting that in Italy emergency departments are used instead of a visit to the general practitioner. Nonsteroidal anti-inflammatory drugs were the most frequently prescribed drugs in the emergency departments for this group of diagnoses. The research revealed, on the one hand, that headache is a numerically significant phenomenon in the emergency department setting and, on the other, the need to apply prospective designs to this kind of survey.     

Red blood cell magnesium levels in migraine patients

In the last few years, it has been suggested that magnesium plays a central role in establishing a threshold for migraine attacks and in intervening with the pathogenetic mechanisms involved in their onset. Accordingly, we determined red blood cell magnesium levels in adult migraine patients with and without aura interictally and in some of them also ictally. In comparison with normal subjects, migraineurs with and without aura had significantly lower red blood cell magnesium levels in the interictal period. Ictal red blood cell magnesium levels did not differ from the interictal values. Low red blood cell magnesium levels could be a peripheral expression of the reduced brain magnesium concentration observed in migraine patients.     

Clinical characteristics of migraine in a population-based twin sample: similarities and differences between migraine with and without aura

OBJECTIVE: To look into clinical differences between migraine with and without aura in a population-based sample of migraineurs. BACKGROUND: Migraine presents in two major forms, migraine with and migraine without aura. With the exception of the aura phase, the clinical characteristics of these entities are very similar. Despite this, however, the recent epidemiological data underline differences between migraine with and without aura. We tried to examine whether other features besides the aura differ between these two major forms of migraine. METHODS: We studied 321 twins suffering from migraine with aura and 166 twins with migraine without aura from the population-based Finnish Twin Cohort. Migraine was diagnosed according to the criteria of the International Headache Society (IHS). Analysis was based on the combination of a mailed questionnaire and a telephone interview by a neurologist. Special attention was paid to differences between migraine with and without aura. RESULTS: Some qualities of headaches differed between IHS defined migraine with and without aura. Unilateral headache (Chi-squared p = 0.039) and photophobia (Chi-squared p = 0.010) were more typical for migraine with aura, while nausea was more typical for migraine without aura (Chi-squared p = 0.002). Duration of headache in migraine without aura was also longer than in migraine with aura (Mann-Whitney U-test 0.007). CONCLUSIONS: There are clinical differences between IHS defined migraine with and without aura; even the headache phase between the two entities differs. It is worthwhile distinguishing between them when looking for the elusive genes for these more common forms of migraine.     

Cerebrovascular reactivity in migraine during headache-free intervals

Alterations of intracranial vessel tone have been implicated in the pathophysiology of migraine. The cerebrovascular reactivity was measured by means of transcranial Doppler in 60 migraine patients with ( n =30) or without aura ( n =30) during the headache-free interval and in 30 healthy controls. The vasomotor response was evaluated during hypercapnia induced by inhalation of a mixture of CO_z 5% and O₂ 95% and during hypocapnia obtained after voluntary hyperventilation. To improve the power of the study in detecting possible abnormalities of cerebrovascular reactivity, two different measures were performed at 1 week intervals in migraine patients and controls. Reactivity index values during CO₂ inhalation were significantly different ( p =0.01) among the three groups during the first and second measurements; in particular, lower values were found in patients suffering from migraine without aura with respect to controls ( p <0.05, Scheffe's test). Values of reactivity index obtained following induction of hypocapnia did not differ between migraine patients and controls (all p values >0.05). Our data suggest a reduced vasodilatory response to hypercapnia of cerebral arterioles in patients suffering from migraine without aura with respect to controls that might be related to baseline arteriolar vasodilation.     

Migraine with aura versus migraine without aura: pain intensity and associated symptom intensities after placebo

OBJECTIVE: To compare the intensity of pain and associated symptoms after placebo administration in patients with migraine with aura and migraine without aura. BACKGROUND: Studies that evaluate drugs used in the acute treatment of migraine ideally should include a placebo arm. The International Headache Society also recommends stratification according to age and sex but not by the presence versus absence of aura. METHODS: The study was conducted as part of a placebo controlled randomized survey comparing four active drugs against placebo in the acute treatment of migraine. Patients were blinded as to treatment received. Placebo consisted of 10 mL of normal saline (0.9%) intravenously. Pain intensity was evaluated by a 10-point analogical-verbal scale. Nausea, photophobia, and phonophobia were evaluated by a four-point analogical-verbal scale. For statistical analysis, unpaired t-test with Welch correction was used. RESULTS: After placebo administration, reduction of symptom intensity (pain, nausea, photophobia, and phonophobia) in patients with migraine without aura was significantly greater than that observed in patients with migraine with aura. CONCLUSIONS: Our findings suggest that studies comparing placebo against an active drug should use stratification according to the presence versus absence of aura.     

Early treatment of migraine with rizatriptan: a placebo-controlled study

OBJECTIVE: To evaluate the efficacy of rizatriptan when administered early during a migraine attack. BACKGROUND: Several studies indicate that triptans are more efficacious when administered early during a migraine attack, when the pain is still mild. METHODS: One hundred and twelve rizatriptan-na?ve patients aged 20 to 64 years with a history of migraine with or without aura that progressively worsened when left untreated were instructed to treat a total of three migraine attacks with either rizatriptan 10 mg or placebo as early as possible during each attack. Seventy-four patients (68 women and 6 men) were assigned to use the active drug and 38 (35 women and 3 men) to placebo. The primary efficacy endpoint was pain-free response at 2 hours after administration of the study drug. Secondary efficacy measures were pain-free response at 1 hour and sustained pain-free response lasting between 2 and 24 hours. RESULTS: A total of 216 attacks were treated in the rizatriptan group and 109 in the placebo group. Pain-free response at 2 hours after early treatment was noted in 151 (70%) of attacks in the rizatriptan group and in 24 (22%) in the placebo group (P < .01). Pain-free response at 1 hour occurred in 97 (45%) and 9 (8%) attacks, respectively (P < .01). When the attacks were categorized by headache severity at the time of treatment, the pain-free response at 2 hours was higher for mild attacks than for moderate or severe attacks (P < .01). Sustained pain-free response after treatment was significantly higher for attacks treated with rizatriptan (60%) than for those treated with placebo (17%) (P < .001). Adverse events were observed in 62 patients in the rizatriptan group and 15 in the placebo group. Only 1 patient taking rizatriptan discontinued the study because of adverse events, and no serious adverse events were reported. CONCLUSIONS: Rizatriptan is significantly more likely than placebo to produce a pain-free response within 2 hours when the drug is administered early in the migraine attack, when pain is mild rather than moderate or severe.     

Objective assessment of cortical excitability in migraine with and without aura

Recent progress in the genetics of migraine has refocused attention on cortical dysfunction as an important component of the pathophysiology of this disorder. In previous work, we have demonstrated functional changes in the visual cortex of migraine patients, using an objective transcranial magnetic stimulation technique, termed magnetic suppression of perceptual accuracy (MSPA). This study aimed to replicate previous findings in migraine with aura (MA) and to use the technique to examine migraine without aura (MoA). Eight MA patients, 14 MoA patients and 13 migraine-free controls participated. MSPA assessments were undertaken using a standardized protocol in which computer-presented letter targets were followed at a variable delay interval by a single magnetic pulse delivered over the occiput. MSPA performance is expressed as a profile of response accuracy across target-pulse delay intervals. The profiles of migraine-free controls exhibited a normal U-shape. MA patients had significantly shallower profiles, showing little or no suppression at intermediate delay intervals. MoA patients had profiles that were similar to controls. Recent animal evidence strongly indicates that the U-shape of the normal MSPA function is caused by preferential activation of inhibitory neurons. Shallower MPSA profiles in MA patients are therefore likely to indicate a functional hyperexcitability caused by impaired inhibition. The finding of normal MPSA profiles in MoA patients is novel and will require further investigation.     

Transient visual disturbances during migraine without aura attacks

OBJECTIVE: To evaluate the prevalence and clinical features of transient visual disturbances (TVDs) during migraine without aura (MO) attacks and to point out any similarities with the disturbances listed among the diagnostic criteria of the International Headache Society (IHS) classification for migraine with aura (MA). METHODS: We studied a sample of 191 patients (145 women and 46 men) with MO and no other associated forms of primary headache who had been referred to the University of Parma Headache Centre between December 1, 1999 and December 1, 2000. RESULTS: A total of 165 patients reported that they had never experienced TVDs during their MO attacks. In the remaining 26 patients (19 women and 7 men), MO attacks were at times accompanied by TVDs, which were present in over 30% of MO attacks in 65.4% of patients. In about 60% of cases, TVDs lasted less than half a minute. TVDs consisted of phosphenes in most patients, general blurring of vision in about one-fourth, and scintillating scotomas in 15%. In 73% of cases, TVDs occurred during the headache phase, whereas in the remainder they preceded it. Strict application of the IHS diagnostic criteria would have led to a diagnosis of MA in 12 cases, corresponding to 46% of our MO patients with TVDs and to 6.3% of all patients with an established clinical diagnosis of MO. CONCLUSION: The results of our study suggest that current IHS diagnostic criteria for MA may lead to an overestimation of MA cases.     

Migraine without aura and migraine with aura are distinct clinical entities: a study of four hundred and eighty-four male and female migraineurs from the general population

The clinical characteristics of migraine without aura (MO) and migraine with aura (MA) were compared in 484 migraineurs from the general population. We used the criteria of the International Headache Society. The lifetime prevalence of MO was 14.7% with a M:F ratio of 1:2.2; that of MA was 7.9% with a M:F ratio of 1:1.5. The female preponderance was significant in both MO and MA. The female preponderance was present in all age groups in MA, but was first apparent after menarche in MO, suggesting that female hormones are an initiating factor in MO, but not likely so in MA. The age at onset of MO followed a normal distribution, whereas the age at onset of MA was bimodally distributed, which could be explained by a composition of two normal distributions. The estimated separation between the two groups of MA was at age 26 years among the females and age 31 years among the males. The observed number of persons with co-occurrence of MO and MA was not significantly different from the expected number. The specificity and importance of premonitory symptoms are questioned, but prospective studies are needed. Bright light was a precipitating factor in MA, but not in MO. Menstruation was a precipitating factor in MO, but not likely in MA. Both MO and MA improved during pregnancy. The clinical differences indicate that MO and MA are distinct entities.     

Migraine without aura and migraine with aura are distinct disorders. A population-based twin survey

OBJECTIVE: To investigate the co-occurrence of migraine without aura (MWOA) and migraine with aura (MWA) in a population-based twin survey. BACKGROUND: Migraine without aura and MWA are multifactorial disorders. If MWOA and MWA share common genes, co-occurrence should be observed more frequently than expected, ie, the product of the prevalence in the general population. MATERIAL AND METHODS: The study population included all living Danish monozygotic (MZ) and same-gender dizygotic (DZ) twin pairs born between 1953 and 1960: 5360 twins (2026 MZ, 3334 DZ). The sample included 2840 men and 2520 women. All received a posted questionnaire, and those with possible migraine were interviewed via telephone by trained physicians (V.U. or M.G.). Twins who did not respond to the questionnaire and who had a co-twin with possible migraine were contacted by telephone. The questionnaire response rate was 87% (4660 of 5360), and the telephone interview was participated in by 90% (2035 of 2272). The physician interviewers were unaware of questionnaire answers, zygosity, and the clinical diagnosis of the co-twin. The criteria of the International Headache Society were used to establish a diagnosis of migraine. RESULTS: Lifetime prevalence in the twin sample: 7% of men and 19% of women had MWOA, while 7% of men and 8% of women had MWA. Lifetime prevalence of MWA in twin pairs with MWOA: MZ men, 2% (1 of 47); MZ women, 6% (5 of 90); DZ men, 9% (7 of 75); and DZ women, 10% (19 of 182). Lifetime prevalence of MWOA in twin pairs with MWA: MZ men, 3% (1 of 33); MZ women, 5% (3 of 58); DZ men, 9% (4 of 44); and DZ women, 13% (10 of 76). The observed and the expected numbers of twins with co-occurrence of MWOA and MWA based on the prevalence in the general population were not significantly different in either men or women (men, P=.1 and women, P=.5). CONCLUSION: The results strongly suggest that MWOA and MWA are distinct disorders, and identification of common genes for MWOA and MWA, thus, should not be expected to result from future genetic research.     

Intravenous dipyrone in the acute treatment of migraine without aura and migraine with aura: a randomized,double blind,placebo controlled study

BACKGROUND: Dipyrone (Metamizol) has been used in the acute treatment of migraines in Brazil. Some investigators have found it to be a highly effective medication for migraine pain and associated symptoms. OBJECTIVE: To conduct a randomized, placebo controlled, double blind study to assess the effect of dipyrone on the pain and symptoms associated with migraine without aura or with aura and the adverse effect profile of this medication. METHODS: For the migraine without aura group, 44 patients were assigned at random to receive 1 g intravenous dipyrone, and 30 patients received 10 mL 0.9% physiological saline. For the migraine with aura group, 30 patients received both dipyrone or placebo. We used seven parameters of analgesic evaluation and an analog scale to assess nausea, photophobia, and phonophobia. RESULTS: Patients receiving dipyrone demonstrated a statistically superior improvement (P<.05 and P<.01) in pain and all associated symptoms compared with control subjects. CONCLUSIONS: Dipyrone is an effective drug for the relief of acute migraine pain and associated symptoms.     

Platelet levels of dopamine are increased in migraine and cluster headache

OBJECTIVE: To measure plasma and platelet levels of dopamine in patients with migraine with aura, migraine without aura, and cluster headache. BACKGROUND: Clinical, genetic, and pharmacological evidences suggest that an abnormality of dopaminergic system plays a role in migraine pathogenesis. Direct evidence of an abnormal metabolism of dopamine in migraine, however, is lacking. METHODS: Plasma and platelet levels of dopamine were measured in patients with migraine with aura or migraine without aura during headache-free periods and in patients with cluster headache during the remission and active periods, as compared with healthy control subjects, using a multichannel electrochemical high-performance liquid chromatography system. RESULTS: Plasma levels of dopamine were not detectable with our methodology. Platelet levels of dopamine were higher in both types of migraine (migraine without aura = .20 +/- .17 ng/10(8) platelets; migraine with aura = .16 +/- .19 ng/10(8) platelets) than in control subjects (.10 +/- .11 ng/10(8) platelets), although in migraine with aura patients the difference was not significant. Patients with cluster headache showed the highest levels of platelet dopamine (.34 +/- .36 ng/10(8) platelets). CONCLUSIONS: Our results support the hypothesis that the dopaminergic system is impaired in migraine and cluster headache and suggest that high platelet levels of dopamine may represent an abnormal biochemical phenotypic trait of these primary headaches.     

Pattern reversal visual evoked potentials in migraine with aura and migraine aura without headache

Pattern reversal visual evoked potentials (PVEPs) were recorded in 20 patients with migraine with aura (MA), 19 patients with migraine without headache (migraine equivalent; ME.) during interictal periods, and 34 normal subjects. All migraine patients had hemianopsia or fortification spectra during attacks. In both MA and ME patients of less than 49 years of age, there were significant ( p <0.01) differences in amplitude of PVEPs at the mid-occipital and contralateral to visual aura electrode sites compared to normal subjects. Amplitude of PVEPs in MA and ME showed significant ( p <0.001) increases when recorded soon after attacks, especially within 10 days. There was a significant ( p <0.0l) correlation between percentage asymmetries and the duration of illness in both MA and ME. We conclude from our PVEP findings that cortical spreading depression remains the most likely explanation for the migraine visual aura.     

Sporadic hemiplegic migraine is an aetiologically heterogeneous disorder

In order to better understand sporadic hemiplegic migraine (SHM) and particularly its relation to familial hemiplegic migraine (FHM), migraine without aura (MO) and typical migraine with aura (typical MA), we investigated the occurrence of MO and typical MA among probands with SHM and their first-degree relatives. The pattern of familial aggregation of MO and typical MA was assessed by population relative risk calculations. A total of 105 SHM probands and 483 first-degree relatives were identified in the Danish population. Compared with the general population, SHM probands had no increased risk of MO, but a highly increased risk of typical MA. First-degree relatives of all SHM probands had an increased risk of both MO and typical MA, whereas first-degree relatives of probands with exclusively SHM had no increased risk of MO but an increased risk of typical MA. Our data suggest that SHM is a genetically heterogeneous disorder.     

The 1246G-->A polymorphism of the HCRTR2 gene is not associated with migraine

Studies in experimental animals have suggested that the hypocretin/orexin system may be involved in migraine pathophysiology. Using a case-control design study, we genotyped 246 migraine patients and 239 healthy controls for the 1246G-->A polymorphism of the hypocretin receptor 2 (HCRTR2) gene. Genotypic and allelic frequencies of the examined polymorphism were similarly distributed between cases and controls (chi2 = 2.22, P = 0.14 and chi2 = 2.45, P = 0.29, respectively). When different migraine subgroups were compared (migraine with aura vs. migraine without aura and episodic vs. chronic migraine) no significant difference was found. Comparison of the clinical features of the disease with the 1246G-->A genotypes showed no significant difference. Our data suggest that the HCRTR2 gene is not a genetic risk factor in migraine.     

Familial occurrence of migraine with aura in a population-based study

OBJECTIVE: To better define a possible genetic basis for migraine with aura (MWA). METHODS: We investigated the familial occurrence of migraine with aura in a sample of (MWA) subjects recruited from an epidemiologic study of migraine with aura involving the general population. The sample with migraine with aura (n = 26) was selected out of a total of 1392 subjects (842 women and 550 men) representative of the general population aged 18 to 65 years in the southern Italian town of San Severo. A family history of migraine with aura was determined via direct interviews with all living first-degree relatives of the 26 subjects who could be reached by investigators, 119 people: 71 women and 48 men. The diagnosis of migraine with aura was made according to the 1988 International Headache Society (IHS) criteria. RESULTS: Of the 26 subjects with migraine with aura, 7 (6 women and 1 man) had a positive family history, with a total of 7 first-degree relatives affected by the disease (1 mother, 2 fathers, 1 brother, 1 sister, and 2 children). Based on the lifetime prevalence rate of migraine with aura (1.6%) in the San Severo general population, the relative risk of migraine with aura in the first-degree relatives of the subjects was 3.68 (4.16 for women and 2.77 for men). CONCLUSION: Our subjects' relative risk rate for familial occurrence of migraine with aura was similar to that reported by one investigator, but markedly lower than that reported by another group.     

Migraine with aura and migraine without aura: an epidemiological study

In a cross-sectional study of headache disorders in a representative general population of 1,000 persons the epidemiology of migraine with aura (MA) and migraine without aura (MO) was analysed in relation to sex and age distribution, symptomatology and precipitants. The headache disorders were classified on the basis of a clinical interview as well as a physical and a neurological examination using the operational diagnostic criteria of the International Headache Society (IHS). Lifetime prevalence of MA was 5%, male:female ratio 1:2. Lifetime prevalence of MO was 8%, M:F ratio 1:7. Women, but not men, were significantly more likely to have MO than MA. Neither MA nor MO showed correlation to age in the studied age interval (25-64 years). Premonitory symptoms occurred in 16% of subjects with MA and in 12% with MO. One or more precipitating factor was present in 61% with MA and in 90% with MO. In both MA and MO the most conspicuous precipitating factor was stress and mental tension. Visual disturbances were the most common aura phenomenon occurring in 90% of subjects with MA. Aura symptoms of sensory, motor or speech disturbances rarely occurred without coexisting visual disturbances. The pain phase of MA fulfilled the criteria for MO of the IHS. Headache was, however, less severe and shorter lasting in MA than in MO. Onset at menarche, menstrual precipitation, menstrual problems, influence of pregnancy and use of oral contraceptives all showed some relationship with the presence of MO and less with MA. The present findings suggest that MA and MO share the pain phase.(ABSTRACT TRUNCATED AT 250 WORDS)     

Trigemino-cervical reflex abnormalities in patients with migraine and cluster headache

BACKGROUND: Head pain arises within the trigeminal nociceptive system. Current theories propose that the trigeminal system is intimately involved in the pathogenesis of migraine. Short-latency responses can be recorded in sternocleidomastoid muscles after stimulation of the trigeminal nerve (trigemino-cervical reflex). This brainstem reflex could be a suitable method to evaluate the trigeminal system in migraine and CH. OBJECTIVE: The aim of the present study was to further elucidate the pathophysiology of migraine and cluster headache (CH) with special reference to the involvement of the central trigeminal system in the different forms of primary headache. METHODS: The trigemino-cervical reflex was investigated in 15 healthy subjects, in 15 patients having migraine with aura, in 15 patients with migraine without aura, and in 10 patients with CH. RESULTS: Significant abnormalities were observed in a great number of patients with both types of migraine and CH during the headache attacks, but only in migraine patients during the interictal period. The alterations are bilateral in migraine, unilateral in CH. CONCLUSIONS: Our results further support the relevance of brainstem mechanisms in the pathogenesis of migraine rather than of CH. These data, taken together with that from experimental head pain and functional imaging studies, demonstrate that primary headache syndromes may be distinguished on a functional basis by areas of activation specific to the clinical syndrome.     

Abnormal platelet trace amine profiles in migraine with and without aura

Trace amines, including tyramine, octopamine and synephrine, are closely related to classic biogenic amines. In one study, where these substances were found elevated in plasma of migraineurs, it was hypothesized that trace amine metabolism is deranged in migraine. To confirm these findings, we studied, using a multichannel electrochemical high-performance liquid chromatography system, the concentrations of trace amines in platelets of migraine without aura (MoA) and migraine with aura (MA) patients in headache-free period, compared with controls. Platelet concentrations of trace amines, although elevated in both migraine types, showed a different profile in MoA and MA. Octopamine was significantly higher in MoA sufferers (0.69 +/- 0.43 ng/10(8) platelets) compared with both control subjects (0.22 +/- 0.16 ng/10(8) platelets) and MA patients (0.39 +/- 0.37 ng/10(8) platelets). Synephrine was significantly higher in MA patients (0.72 +/- 0.44 ng/10(8) platelets) with respect to both controls (0.33 +/- 0.25 ng/10(8) platelets) and MoA sufferers (0.37 +/- 0.29 ng/10(8) platelets). These results strengthen the hypothesis that tyrosine metabolism is deranged in migraine and may participate in its pathophysiology.     

Cerebrospinal fluid tyrosine and 3,4-dihydroxyphenylacetic acid levels in migraine patients

We studied biochemical parameters related with central dopaminergic neurotransmission in migraine patients during crisis. We determined tyrosine and 3,4-dihydroxyphenylacetic acid (DOPAC) levels in cerebrospinal fluid (CSF) of 47 patients, 29 suffering migraine without aura and 18 suffering migraine with aura, comparing them with 27 control subjects. Tyrosine levels did not differ significantly between patients and controls. The CSF concentration of DOPAC was 0.73±0.55 ng/ml in the control population, 3.84±2.08 ng/ml in patients with migraine without aura and 3.30±l.49ng/ml in patients suffering migraine with aura. The concentration of DOPAC correlated positively with the intensity of headache. These results suggest that patients with migraine have a central dopaminergic hyperfunction, probably related to a coexisting central dysfunction of noradrenergic neurotransmision.