Magnetic resonance imaging of the brain in patients with migraine

Evaluating migraine with typical aura with neuroimaging

Objective

To provide an up-to-date narrative literature review of imaging in migraine with typical aura, as a means to understand better migraine subtypes and aura biology.

Background

Characterizing subtypes of migraine with typical aura and appreciating possible biological differences between migraine with and without aura, are important to understanding the neurobiology of aura and trying to advance personalized therapeutics in this area through imaging biomarkers. One means of doing this over recent years has been the use of increasingly advanced neuroimaging techniques.

Methods

We conducted a literature review of neuroimaging studies in migraine with aura, using a PubMed search for terms 'imaging migraine', 'aura imaging', 'migraine with aura imaging', 'migraine functional imaging' and 'migraine structural imaging'. We collated the findings of the main studies, excluding small case reports and series with n < 6, and have summarized these and their implications for better understanding of aura mechanisms.

Results

Aura is likely mediated by widespread brain dysfunction in areas involving, but not limited to, visual cortex, somatosensory and insular cortex, and thalamus. Higher brain excitability in response to sensory stimulation and altered resting-state functional connectivity in migraine sufferers with aura could have a genetic component. Pure visual aura compared to visual aura with other sensory or speech symptoms as well, may involve different functional reorganization of brain networks and additional mitochondrial dysfunction mediating more aura symptoms.

Conclusion

There is a suggestion of at least some distinct neurobiological differences between migraine with and without aura, despite the shared phenotypic similarity in headache and other migraine-associated symptoms. It is clear from the vast majority of aura phenotypes being visual that there is a particular predisposition of the occipital cortex to aura mechanisms. Why this is the case, along with the relationships between cortical spreading depression and headache, and the reasons why aura does not consistently present in affected individuals, are all important research questions for the future.

Association between blood coagulability and migraine

Background

An association between migraine and stroke has been suggested for a long period, although conclusive evidence has not been reported. Several theories about hypercoagulability have been proposed for the association of ischemic stroke and migraine especially migraine with aura. This study aimed to assess blood coagulability in patients with migraine.

Results

Mean serum levels of protein S and anti-thrombin III were significantly lower in migraine patients compared to control subjects. Migraine patients showed abnormal MRI findings in the form of white matter hyper-intense lesions and ischemic foci compared to healthy controls. A significant negative correlation was detected between serum protein C level and intensity of migraine headache. Also, a significant correlation was found between deficient serum protein S and abnormal findings in brain MRI. Serum protein C deficiency is an independent predictor for migraine intensity grade.

Conclusions

There is an association between migraine and hypercoagulability, which may indicate increased risk of cerebral ischemic events in migraine patients and suggest adding prophylactic therapy to the management strategies of such patients.

Biologic Therapy in Refractory Non-Multiple Sclerosis Optic Neuritis Isolated or Associated to Immune-Mediated Inflammatory Diseases. A Multicenter Study

We aimed to assess the efficacy of biologic therapy in refractory non-Multiple Sclerosis (MS) Optic Neuritis (ON), a condition more infrequent, chronic and severe than MS ON. This was an open-label multicenter study of patients with non-MS ON refractory to systemic corticosteroids and at least one conventional immunosuppressive drug. The main outcomes were Best Corrected Visual Acuity (BCVA) and both Macular Thickness (MT) and Retinal Nerve Fiber Layer (RNFL) using Optical Coherence Tomography (OCT). These outcome variables were assessed at baseline, 1 week, and 1, 3, 6 and 12 months after biologic therapy initiation. Remission was defined as the absence of ON symptoms and signs that lasted longer than 24 h, with or without an associated new lesion on magnetic resonance imaging with gadolinium contrast agents for at least 3 months. We studied 19 patients (11 women/8 men; mean age, 34.8 ± 13.9 years). The underlying diseases were Bechet's disease (n = 5), neuromyelitis optica (n = 3), systemic lupus erythematosus (n = 2), sarcoidosis (n = 1), relapsing polychondritis (n = 1) and anti-neutrophil cytoplasmic antibody -associated vasculitis (n = 1). It was idiopathic in 6 patients. The first biologic agent used in each patient was: adalimumab (n = 6), rituximab (n = 6), infliximab (n = 5) and tocilizumab (n = 2). A second immunosuppressive drug was simultaneously used in 11 patients: methotrexate (n = 11), azathioprine (n = 2), mycophenolate mofetil (n = 1) and hydroxychloroquine (n = 1). Improvement of the main outcomes was observed after 1 year of therapy when compared with baseline data: mean ± SD BCVA (0.8 ± 0.3 LogMAR vs. 0.6 ± 0.3 LogMAR; p = 0.03), mean ± SD RNFL (190.5 ± 175.4 μm vs. 183.4 ± 139.5 μm; p = 0.02), mean ± SD MT (270.7 ± 23.2 μm vs. 369.6 ± 137.4 μm; p = 0.03). Besides, the median (IQR) prednisone-dose was also reduced from 40 (10-61.5) mg/day at baseline to. 2.5 (0-5) mg/day after one year of follow-up; p = 0.001. After a mean ± SD follow-up of 35 months, 15 patients (78.9%) achieved ocular remission, and 2 (10.5%) experienced severe adverse events. Biologic therapy is effective in patients with refractory non-MS ON.

Novel missense mutation in the ATP1A2 gene associated with atypical sporapedic hemiplegic migraine

Hemiplegic migraine (HM) is a rare subtype of migraine with aura in which attacks include transient motor weakness or hemiparesis that can last several days. HM is linked to mutations in three different genes, CACNA1A, ATP1A2 and SCN1A, which encode for ion transporters. The clinical spectrum includes atypical symptoms such as impaired consciousness, epileptic seizures, permanent cerebellar ataxia or mental retardation. We describe a novel mutation found in the ATP1A2 gene in a patient with late-onset HM. His attacks were characterised by motor weakness associated with altered mental status, diplopia and ataxia. He also showed up MRI abnormalities and incomplete response to prophylactic therapy with verapamil. Late-onset HM should be considered among the possible causes of focal neurological deficits even in older patients with cerebrovascular risk factors when a stroke appears to be more likely.

The relationship between right-to-left shunt and brain white matter lesions in Japanese patients with migraine: a single center study

BACKGROUND

There may be a link between right-to-left shunt (RLs) and brain white matter lesions (WMLs) in patients with migraine. In this study, we assessed the relationship between WMLs and RLs in Japanese migraine patients.

METHODS

A total of 107 consecutive patients with migraine with (MA) and without aura (MWOA) were included in this study. Contrast transcranial Doppler ultrasound was used to detect RLs. WMLs were graded using brain magnetic resonance imaging based on well-established criteria.

FINDINGS

The prevalence of RLs was significantly increased in the WMLs positive group (n = 24) compared with the WMLs negative group (n = 83) (75.0% vs. 47.0%, p = 0.015). In prevalence of WMLs between MA and MWOA patients, there were no statistical differences (p = 0.410). Logistic regression analysis adjusted by age and disease duration of migraine identified an RLs-positive status as the sole determinant for the presence of WMLs (OR = 6.15; 95% CI 1.82-20.8; p = 0.003) CONCLUSION: Our study suggests a possible link between RLs and WMLs in Japanese patients with migraine.

Sneddon's Syndrome

Sneddon's syndrome refers to the enigmatic association of ischaemic stroke and livedo reticularis. We review the Sneddon's syndrome literature examining the association of this condition with headache, including migraine. Case reports and series are stratified into two groups based on headache reference. In the group without a reference to headache, there are 208 persons, with a female to male ratio of 3 : 1. In the headache reference group, there are 175 persons, with a female to male ratio of 3.5 : 1. The proportion with headache in this second group is 58% (102 individuals), with headache described as migraine in 28 (27.5%) of the headache subjects, including six with migraine with aura. The frequency of headache is not significantly higher in persons with positive anti-phospholipid antibodies compared with the negative cohort (43% vs. 32%, P = 0.07). A review of the histopathological, radiological and serological data in Sneddon's syndrome and migraine underscores the plausibility of an association. Considered in the context of increased risk of stroke with migraine, a higher frequency of livedo in migraineurs with stroke, and the association of migraine and livedo reticularis, the question of whether livedo reticularis may be a risk marker for stroke in migraineurs is an area for further study.

[Formalized consensus: clinical practice recommendations for the management of the migraine in African adult patients]

Migraine is a primary headache disorder (according to the latest International Headache Society criteria) affecting approximately 8% of African population. Women are more often affected than men and attacks usually occur before the age of 40 years Although some treatments, hygienic-dietary measures and other non-pharmacological methods can reduce the intensity and frequency of attacks, medicinal treatment of migraine attack is often necessary. Availability of treatments and access to care differ in Africa and led to the implementation of the first expert consensus recommendations for the management of the migraine in african adult patients. This multinational collaborative study is intended for health practitioners. It aims to provide 16 simple, evidence-based recommendations and is adapted to african medical practice.

White matter lesion burden in migraine with aura may be associated with reduced cerebral blood flow

Objective The objective of this study was to determine whether white matter hyperintensities (WMHs) in subjects with migraine are related to alterations in resting cerebral blood flow (CBF). Methods Migraine with aura (MWA), migraine without aura (MwoA), and control subjects were enrolled in a 1:1:1 ratio. WMH load was scored based on fluid-attenuated inversion recovery/T2-weighted magnetic resonance imaging (MRI) using a previously established semi-quantitative scale. Global and regional CBFs were quantified using arterial spin labelled perfusion MRI. Integrity of the circle of Willis was assessed with magnetic resonance angiography (MRA). Results A total of 170 subjects were enrolled (54 controls, 56 MWA, and 60 MwoA). There was no significant difference in subjects with ≥1 WMH across groups (22% controls, 29% MWA, 35% MwoA; p = NS). Similarly, high WMH load was not significantly different across groups (16.7% controls, 21.4% MWA, 25.0% MwoA; p = NS). High WMH load was strongly associated with increasing age (odds ratio: 1.08 per year, 95% confidence interval: 1.02-1.13, p = 0.01). Resting CBF was similar across groups, but was significantly higher in women. In MWA subjects with high WMH load, CBF was substantially lower ( p = 0.03). No association between WMH load and CBF was seen in control or MwoA subjects. Conclusions WHMs in MWA may be related to alterations in resting CBF.

Progress in Clinical Neurosciences: Migraine-Stroke: A Causal Relationship, but Which Direction?

A significant association between migraine and ischemic stroke has been demonstrated in population and case-control studies. The risk of ischemic stroke appears to be higher in migraine with aura (MWA) than migraine without aura (MwoA). Migraine-stroke comprises a number of distinct entities, including migrainous infarction, in which ischemic stroke occurs during an attack of MWA and migraine-related stroke, in which the causal link is less clear. Migrainous infarction accounts for only one-third of migraine-stroke, strokes may occur during attacks of MwoA, and a number of cerebrovascular disorders may present as MWA or MwoA. Migraine may occur as a consequence of conditions that are known to cause stroke; therefore it remains to be determined whether migraine predisposes to stroke in the absence of any known disease associations, if it is an epiphenomenon of an underlying stroke diathesis, or if it requires the presence of another stroke risk factor to produce cerebral ischemia. Furthermore, it is unclear if ischemia results in migraine more often than migraine results in ischemia. Careful clinical studies that evaluate this bidirectional relationship are needed to determine why migraine patients are subject to a higher risk of ischemic stroke.

Migraine patients should be cautiously followed for risk factors leading to cardiovascular disease

Migraine and ischemic strokes are two of the most prevalent diseases worldwide. Besides having a coincident symptomatology, for long researchers have been searching for a possible causal relation between these diseases. Current evidence based on data suggest that patients with aura migraine could have a doubled risk of developing an ischemic stroke, when compared to the rest of the population. At the same time, migraine sufferers apparently have higher incidences of risk factors for cardiovascular events. The aim of this review was not only to dissect some of the more compelling evidence based on data regarding this association, but also to discuss the possible clinical and therapeutic implications.

Endothelium-dependent vasodilatation in migraine patients

BACKGROUND

Endothelial dysfunction could be involved in the pathophysiology of migraine. The results obtained from a few studies on endothelial dysfunction in migraine are controversial. We investigated brachial flow-mediated dilatation (FMD), which reflects systemic endothelial dysfunction, in migraine patients without comorbidities. By employing strict inclusion criteria we avoided the possible changes to FMD from confounding factors.

METHODS

Forty migraine patients without comorbidities (20 with and 20 without aura) and 20 healthy subjects were included. FMD of brachial arteries and carotid intima-media thickness were measured by using standard procedures.

RESULTS

We did not find any difference in FMD between migraine patients and healthy subjects (p = .96). Also, no differences were found among healthy subjects, migraine patients with aura and without aura (p = .99).

CONCLUSION

Our study showed that systemic endothelial function is not impaired in migraine patients without comorbidities, neither in those with or without aura. Considering these findings, the investigation of cerebral endothelial function would be useful in a further investigation of the role of endothelial (dys)function in migraine pathophysiology.

Migraine is associated with an increased risk of deep white matter lesions, subclinical posterior circulation infarcts and brain iron accumulation: the population-based MRI CAMERA study

Previous studies have suggested that migraine is a risk factor for brain lesions, but methodological issues hampered drawing definite conclusions. Therefore, we initiated the magnetic resonance imaging (MRI) ‘CAMERA’ (Cerebral Abnormalities in Migraine, an Epidemiological Risk Analysis) study. We summarize our previously published results. A total of 295 migraineurs and 140 controls were randomly selected from a previously diagnosed population-based sample (n = 6039), who underwent an interview, physical examination and a brain MRI scan. Migraineurs, notably those with aura, had higher prevalence of subclinical infarcts in the posterior circulation [odds ratio (OR) 13.7; 95% confidence interval (CI) 1.7, 112]. Female migraineurs were at independent increased risk of white matter lesions (WMLs; OR 2.1; 95% CI 1.0, 4.1), and migraineurs had a higher prevalence of brainstem hyperintense lesions (4.4% vs. 0.7%, P = 0.04). We observed a higher lifetime prevalence of (frequent) syncope and orthostatic insufficiency in migraineurs; future research needs to clarify whether autonomic nervous system dysfunction could explain (part of) the increased risk of WMLs in female migraineurs. Finally, in migraineurs aged < 50 years, compared with controls, we found evidence of increased iron concentrations in putamen (P = 0.02), globus pallidus (P = 0.03) and red nucleus (P = 0.03). Higher risks in those with higher attack frequency or longer disease duration were found consistent with a causal relationship between migraine and lesions. This summary of our population-based data illustrates that migraine is associated with a significantly increased risk of brain lesions. Longitudinal studies are needed to assess whether these lesions are progressive and have relevant (long-term) functional correlates.

Headache, migraine, and structural brain lesions and function: population based Epidemiology of Vascular Ageing-MRI study

OBJECTIVE

To evaluate the association of overall and specific headaches with volume of white matter hyperintensities, brain infarcts, and cognition.

DESIGN

Population based, cross sectional study.

SETTING

Epidemiology of Vascular Ageing study, Nantes, France.

PARTICIPANTS

780 participants (mean age 69, 58.5% women) with detailed headache assessment.

MAIN OUTCOME MEASURES

Brain scans were evaluated for volume of white matter hyperintensities (by fully automated imaging processing) and for classification of infarcts (by visual reading with a standardised assessment grid). Cognitive function was assessed by a battery of tests including the mini-mental state examination.

RESULTS

163 (20.9%) participants reported a history of severe headache and 116 had migraine, of whom 17 (14.7%) reported aura symptoms. An association was found between any history of severe headache and increasing volume of white matter hyperintensities. The adjusted odds ratio of being in the highest third for total volume of white matter hyperintensities was 2.0 (95% confidence interval 1.3 to 3.1, P for trend 0.002) for participants with any history of severe headache when compared with participants without severe headache being in the lowest third. The association pattern was similar for all headache types. Migraine with aura was the only headache type strongly associated with volume of deep white matter hyperintensities (highest third odds ratio 12.4, 1.6 to 99.4, P for trend 0.005) and with brain infarcts (3.4, 1.2 to 9.3). The location of infarcts was predominantly outside the cerebellum and brain stem. Evidence was lacking for cognitive impairment for any headache type with or without brain lesions.

CONCLUSIONS

In this population based study, any history of severe headache was associated with an increased volume of white matter hyperintensities. Migraine with aura was the only headache type associated with brain infarcts. Evidence that headache of any type by itself or in combination with brain lesions was associated with cognitive impairment was lacking.

The association of migraine with ischemic stroke

Migraine is a common, chronic-intermittent primary headache disorder affecting mostly women. The migraine pathophysiology involves both the neuronal and vascular systems, and in some patients, transient neurologic symptoms occur, which are known as migraine aura. A large body of literature supports an association between migraine and ischemic stroke, which is apparent mostly in young women with migraine with aura. Further increased risks have been observed particularly in smokers and women who use oral contraceptives. The vast majority of individual studies, as well as a recent meta-analysis, did not find an association between migraine without aura and ischemic stroke. Although there are several hypotheses about potential biological mechanisms linking migraine with aura to ischemic stroke, the precise causes remain unclear. Because the absolute risk of stroke is considerably low in patients with migraine, the vast majority of migraine patients will not experience a stroke event because of the migraine.

Cerebral distribution of white matter lesions in migraine with aura patients

OBJECTIVE

The objective of the study was to compare the cerebral distribution of white matter lesions (WMLs) between migraine patients with different aura symptoms.

METHODS

Migraine with aura (MA) patients were consecutively enrolled as part of the Shunt-Associated Migraine (SAM) study. According to clinical symptoms, aura was classified as motor, aphasic, sensory, visual or vertebrobasilar. Standard and FLAIR (fluid attenuated inversion recovery) T(2)-weighted MRI sequences were inspected for WMLs by three independent raters blinded to clinical data. WMLs were assessed in the periventricular areas (PV-WMLs) with the Fazekas scale and in the deep white matter (D-WMLs) with the Schelten's scale. Interobserver agreement was good to excellent (k = 0.64 to 0.96, p < .0001).

RESULTS

One hundred and eighty-five patients (77% women) were included. Aura symptoms were classified as visual in 172 (99%) patients, sensory in 76 (42%), aphasic in 54 (30%), motor in 39 (21%) and vertebrobasilar in 17 (9%) patients. One hundred and four patients (57%) exhibited more than one type of aura. D-WMLs were mainly detected in the frontal lobes (86%). There was no association between type of aura and the presence of WMLs in any cerebral location.

CONCLUSION

Aura symptoms do not influence the cerebral distribution of WMLs associated with migraine disease.

Migraine as a systemic vasculopathy

Epidemiological studies suggests that migraine is associated with disorders of the cerebral, coronary, retinal, dermal and peripheral vasculature. There is evidence that migraine is associated with endothelial dysfunction, both as a cause and a consequence. Endothelial dysfunction, a vascular risk factor, is characterized by endothelial activation and impaired vascular reactivity. Plasma and genetic biomarkers for these conditions have been identified. The clinical significance lies in the potential for the rapid identification of migraineurs at increased risk of ischaemic stroke and vascular disease through ascertainment of endothelial dysfunction biomarkers. It is uncertain whether stroke, myocardial infarction and other vasculopathies can be prevented by migraine prophylaxis, endothelial repair, platelet inhibition or a combination of these strategies.

Diagnostic testing for migraine and other primary headaches

Most primary headaches can be diagnosed using the history and examination. Judicious use of neuroimaging and other testing, however, is indicated to distinguish primary headaches from the many secondary causes that may share similar features. This article evaluates the reasons for diagnostic testing and the use of neuroimaging, electroencephalography, lumbar puncture, and blood testing. The use of diagnostic testing in adults and children who have headaches and a normal neurologic examination, migraine, trigeminal autonomic cephalalgias, hemicrania continua, and new daily persistent headache are reviewed.

From migraine to stroke

An association between migraine and ischemic stroke has been observed for many years but the exact mechanisms by which migraine can lead to stroke are currently still under investigation. Migraine seems to affect neurovascular factors and substances that increase the risk of stroke during and in between migraine attacks. Ischemic stroke can occur as a complication of an attack of migraine with aura. Epidemiological studies suggest that vascular risk factors are increased in migraineurs, thus increasing the incidence of stroke. Another important issue is a patent foramen ovale (PFO), which is a well-known risk factor for stroke and which, on the other hand, seems to be more frequent in migraineurs than in people without. The purpose of this review is to summarize the current literature linking the two neurological diseases: migraine and stroke.

Associations between migraine and cardiovascular disease

Migraine is a common chronic, intermittent headache disorder that in some patients is accompanied by neurological symptoms, particularly visual symptoms, known as migraine aura. Several population-based studies have linked migraine, and particularly migraine with aura, with increased risk of ischemic stroke. Recent prospective data suggest an association between migraine with aura and any ischemic vascular events, including coronary heart disease. The precise biological mechanism by which migraine with aura may increase the risk of vascular events is currently unknown and likely complex. Potential mechanisms involve shared risk factors, inter-relationships between migraine and vascular pathologies, migraine treatments, as well as genetic components. This review aims to summarize the epidemiologic evidence linking migraine with ischemic vascular events, discuss potential mechanisms and to outline potential consequences.

Migraine and ischaemic vascular events

An association between migraine and ischaemic vascular events, particularly ischaemic stroke, has been debated for many years. The pathophysiology of migraine has been explored in detail, and it is known that a dysfunction of brain cells and arteries is a major component of this disorder. The involvement of cerebral arteries during the migraine attack as well as the high prevalence of migraine among young individuals with ischaemic stroke has led to the hypothesis that migraine may be a risk factor for ischaemic stroke. Furthermore, there is evidence that the vascular nature of migraine is not limited to meningeal blood vessels and that migraine and overall cardiovascular disease may share aetiological pathways. The aim of this review is to summarize the epidemiological evidence that links migraine with ischaemic stroke and ischaemic heart disease and to discuss potential biological mechanisms.

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

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

Differential Diagnosis of Multiple Sclerosis

There are a number of illnesses that can mimic multiple sclerosis (MS). This pretty much includes any pathological process that can reflect injury to the central nervous system either in a transient or progressive basis. Typically, MS presents itself in individuals in their teens up to their late 30s. On occasion, however, one can see MS present in patients in their 60s. However, in retrospect, many of these patients might have had subtle manifestations of MS in their younger years. Visual obscuration or visual loss can be a manifestation of retinal ischemia, retinal migraine, or optic neuritis which might or might not evolve into a clinical picture compatible with MS. Cranial neuropathy, long tract signs, sensory disturbance, and/or gait ataxia can be related to a number of different processes such as illicit drug use, neurosarcoidosis, neuro-Behcet's disease, neuroborreliosis, HIV-related disease, neurosyphilis, vascular occlusive disease including vasculitis, connective tissue disorders, acute disseminated encephalomyelitis (ADEM), idiopathic transverse myelitis, neuromyelitis optica (NMO), or tropical spastic paraparesis. In addition, a constellation of symptoms, with questionable objective findings, along with normal MRI imaging, normal CSF results, and normal evoked response testing, when indicated, might identify a conversion disorder or possibly malingering. There are now established criteria for the diagnosis of MS, but initial presentations can be less than "textbook" in nature. With the advent of immunomodulating therapy, it has become more important to diagnose MS more effectively earlier on in the course of the illness. Prior to specific therapy for MS, astute clinicians did not necessarily move with alacrity to establish the diagnosis in patients with subtle or transient manifestations. This was in recognition of the fact that little could be offered to alter the course of the illness and a number of patients might never experience further problems if they were lucky enough to have their illness go into permanent remission after one minor exacerbation.

"Benign" imaging abnormalities in children and adolescents with headache

OBJECTIVE

To study the frequency of "benign" abnormalities on brain imaging in children with headache, compare it with the frequency of imaging findings that dictate a change in patient management, and determine the association of benign findings with headache.

METHODS

A database of 681 headache patients from the pediatric outpatient neurology department over 2 years was reviewed. Patients with benign imaging abnormalities were compared to those with nonbenign findings. Benign abnormalities were defined as those that did not result in a change in patient management. Using literature review, we discuss the benign findings and their possible association with headache.

RESULTS

Two-hundred and forty-one patients (35.4%) had imaging at our facility. Two-hundred and eighteen had brain magnetic resonance imaging and 23 had brain computed tomography (CT) only. Twenty-two patients had CT of the sinuses in addition to brain imaging. Forty-six (19.1%) were found to have 50 benign abnormalities including 13 sinus disease, 11 Chiari I malformations, 7 nonspecific white matter abnormalities, 5 venous angiomas, 5 arachnoid cysts, 4 enlarged Virchow-Robin spaces, 2 pineal cysts, 1 mega cisterna magna, 1 fenestration of the proximal basilar artery, and 1 periventricular leukomalacia. Twenty-three patients (9.5%) had findings requiring a change in management. These included 5 sinus disease, 4 tumors, 4 old infarcts, 3 Chiari I, 2 moyamoya, 1 intracranial vascular stenosis, 1 internal jugular vein occlusion, 1 arteriovenous malformation, 1 demyelinating disease, and 1 intracerebral hemorrhage. When excluding sinusitis, which was evident clinically prior to imaging, 3 patients had absence of abnormal neurologic symptoms and signs and imaging findings that resulted in a change in management.

CONCLUSIONS

Approximately 20% of pediatric headache patients with brain imaging have benign abnormalities that do not result in a change in headache management. Imaging findings that require a change in management are rare in patients with an absence of abnormal neurologic symptoms and signs, occurring in 1.2% of patients imaged in this study.

Imaging Findings of Migraine

Increasingly sophisticated neuroimaging techniques have allowed researchers to begin to define functional and anatomical characteristics of migraine. This paper reviews current knowledge and techniques employed. Assessing present-day knowledge limitations it concludes that with parallel advances in the technology of imaging and the pathophysiologic understanding of migraine, a reliable biomarker may be discovered in the future.

Assessment of MRI abnormalities of the brainstem from patients with migraine and multiple sclerosis

BACKGROUND

In patients with migraine, functional changes have been described in the red nucleus (RN), substantia nigra (SN) and periaqueductal gray matter (PAG).

PURPOSE

To evaluate whether and at which frequency these structures are involved by MRI-detectable structural abnormalities in migraineurs and to investigate the pathogenic role of these abnormalities by assessing their frequency and extent in patients with multiple sclerosis (MS) and migraine.

METHODS

On brain dual-echo scans obtained from 58 migraineurs (40 without and 18 with aura), 37 MS patients with migraine without aura and 42 MS patients without migraine, the presence of hyperintense lesions involving the brainstem structures was recorded. A test of heterogeneity between groups was used to compare the presence of lesions among patient groups.

RESULTS

Lesions of RN, SN and PAG were found in all patient groups, with frequency from 57.5% to 86.5%. Significant between-group differences for all these regions were found. No difference was found between migraine patients with and without aura. Compared with MS patients without migraine, MS patients with migraine had more significant involvement of the SN (p=0.02) and RN (p<0.0001). Compared with migraine patients, MS patients with migraine had more significant involvement of the SN and PAG (p ranging from 0.009 to 0.02).

CONCLUSIONS

T2-visible lesions in the brainstem are frequent in patients with migraine, but do not seem to be associated with the presence of aura. Demyelinating lesions in the RN, SN and PAG might be among the factors responsible for the presence of migraine in patients with MS.

Migraine and white matter hyperintensities

Patients with migraine are at increased risk for white matter hyperintensities detected on magnetic resonance imaging. The presence of nonspecific white matter hyperintensities may cause uncertainty for physicians and anxiety for patients. The pathophysiology and long-term consequences of these lesions are unknown. Occasionally, white matter lesions in a migraineur may indicate an underlying disease such as cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), mitochondrial encephalopathy with lactic acidosis and stroke-like episodes (MELAS), or central nervous system vasculitis. The ability to distinguish between nonspecific and disease-specific patterns of white matter hyperintensities in migraine sufferers is important for the practicing clinician.

Relation between migraine and stroke

A complex bidirectional relation between migraine, mostly migraine with aura (MA), and ischaemic stroke is known. A cerebral infarction can occur during a MA, and MA is a risk factor for ischaemic stroke, particularly in young women. Conversely, cerebral ischaemia can induce MA. Both ischaemic stroke and MA might be consequences of many underlying vascular disorders. Despite the relation between migraine and stroke, migraine as a primary headache disorder is mostly benign.

The risk of stroke in patients with migraine and implications for migraine management

Assessing the risk of stroke in persons with migraine is complicated by the intricate relationship between these two conditions. Both migraine and stroke are common and co-morbidity may, in some cases, be coincidental. Given the overlap of clinical symptoms in stroke and migraine, each condition may also mimic the other. Numerous studies have, however, shown that migraine is an independent risk factor for stroke both during, and remote from, the migraine attack. Women of childbearing age and those with aura are at greatest risk of migraine-related stroke. Additional risk of stroke in migraineurs occurs in those using oral contraceptive pills and who smoke cigarettes. Elevated blood pressure, an important stroke risk factor, is less common in migraineurs. Acquired antiphospholipid antibodies, not clearly a cause of migraine per se, may raise the risk of infarction in migraineurs. Hereditary conditions, including CADASIL (cerebral autosomal dominant arteriopathy with sub-cortical infarcts and leukoencephalopathy), MELAS (mitochondrial myopathy, encephalopathy, lactacidosis and stroke) and hereditary haemorrhagic telangiectasia, appear to predispose to both migraine and stroke. Purported mechanisms for migraine-associated stroke include involvement of the vasculature (including vasospasm, arterial dissection and small vessel arteriopathy), hypercoagulability (elevated von Willebrand Factor, platelet activation) and elevated risk of cardioembolism (patent foramen ovale, atrial septal aneurysm). Triptans and ergotamines, used to treat acute migraine attacks, appear to be safe in low-risk populations. These medications should be avoided in persons with haemiplegic migraine, basilar migraine, vascular risk factor and prior cerebral or cardiac ischaemia.

MR Imaging in the Evaluation of Chronic or Recurrent Headache

PURPOSE

To evaluate ability of magnetic resonance (MR) imaging to depict an abnormality in patients with chronic or recurrent headache without neurologic abnormality.

MATERIALS AND METHODS

Institutional review board approval and patient informed consent were not required. A total of 306 patients with normal neurologic findings and chronic or recurrent headache were examined with MR imaging. Patients were divided into three groups: those with no abnormality, those with minor abnormality, and those with clinically important intracranial abnormality, which may result in chronic or recurrent headache. Literature review was also performed. Upper 99.5% confidence bound for frequency of abnormal MR findings was calculated.

RESULTS

A total of 169 patients (55.2%) were placed in the first group, 135 (44.1%) were placed in the second group, and two (0.7%) were placed in the third group because they had a clinically important abnormality at MR imaging. Neither contrast material enhancement (n = 195) nor repeated MR imaging (n = 23) contributed to the diagnosis. Literature review revealed two previous studies concerning unspecified headache (in addition to the current study), including a total of 1036 MR imaging results and 22 (2.1%) clinically important results (upper 99.5% confidence bound, 3.4%). Twelve studies of migraine headache were found, with a total of 790 MR imaging examinations. Excluding the 19 patients with complicated migraine, the 99.5% confidence bound of the frequency of clinically important abnormality at MR imaging was estimated as 0.68%. Clinically important infarctions were noted on MR images in five (26.3%) of 19 patients with complicated migraine.

CONCLUSION

MR imaging is an unrewarding technique in the evaluation of patients with chronic or recurrent headache and normal neurologic findings. Neither contrast enhancement nor repeated MR imaging contributed to diagnosis, although the number of patients in the latter category was small.

Central nervous system abnormalities in migraine

Migraine is associated with structural and functional CNS changes, for example, ictal hyperalgesia and allodynia and interictal neural excitation. Structural abnormalities, most notably white matter changes, occur in greater prevalence in migraineurs (16 - 40%). Several studies have examined the neuropsychological correlates of migraine and/or white matter abnormalities. These studies suggest mild, interictal dysfunction in migraineurs. More research is needed to correlate migraine severity, frequency and/or treatment with neuropsychological testing. Additional studies should: identify interictal cognitive changes; clarify the contribution to long-term cognitive changes from migraine genotype, sequelae of repeated pain episodes or their treatment and the consequences of co-morbid vascular disease; and include cognitive measures as secondary end points in clinical trials.

Migraine and Cerebral White Matter Lesions

BACKGROUND

Patients with migraine are at an increased risk for white matter lesions, typically multiple, small, punctate hyperintensities in the deep or periventricular white matter, best observed on magnetic resonance imaging utilizing T2-weighted or FLAIR sequences. The underlying pathogenesis of white matter lesions in migraineurs is unknown, and the lesions are usually nonspecific and of unclear clinical significance.

REVIEW SUMMARY

Often the presence of white matter lesions causes uncertainty for physicians and anxiety for patients and may lead to a variety of diagnostic tests and treatments. Occasionally, white matter lesions may represent a secondary cause for headaches such as CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy). CADASIL is underrecognized and underdiagnosed; it should be suggested by (i) 1 or more of recurrent subcortical ischemic strokes (especially before age 60 and in the absence of vascular risk factors), migraine (especially with aura, including atypical or prolonged auras) and/or early cognitive decline or subcortical dementia; (ii) bilateral, multifocal, T2/FLAIR hyperintensities in the deep white matter and periventricular white matter with lesions involving the anterior temporal pole, external capsule, basal ganglia, and/or pons; and (iii) an autosomal-dominant family history of migraine, early-onset stroke, or dementia. The clinical spectrum of CADASIL is broad, and there is a poor genotype-phenotype correlation. In certain individuals or families, migraine may be the only clinical manifestation.

CONCLUSIONS

While the prevalence of nonspecific white matter lesions in migraineurs is increased, the white matter lesions may occasionally represent a secondary cause for headache such as CADASIL. Greater awareness of the unique clinical, neuroimaging, and pathologic features, as well as the availability of diagnostic genetic testing, should enhance the recognition and diagnosis of this fascinating condition.

Cranial magnetic resonance imaging findings in patients with migraine

OBJECTIVE

To investigate the frequency of cranial magnetic resonance imaging abnormalities in patients with migraine and their relationship to type, duration, and frequency of migraine attacks.

METHODS

Forty-five patients (43 women, 2 men) with migraine whose ages ranged between 19 and 53 years (mean, 40.91 [SD, 7.69]) were evaluated. Of the 45 patients, 20 had migraine with aura and 25 had migraine without aura, according to the diagnostic criteria of the International Headache Society.

RESULTS

In 13 (28.8%) of 45 patients, white matter foci were present on magnetic resonance imaging. Eight of these patients (61.5%) had migraine with aura, and 5 patients (38.4%) had migraine without aura. The presence of white matter foci was significantly higher in the patients with aura (8 [40%] of 20) than in those without aura (5 [20%] of 25). It was found that as the frequency of attacks per month increased, the number of patients with white matter foci also increased. Although the mean duration of migraine was longer in patients with white matter foci (149.5 months [SD, 87.9]) than in those without white matter foci (134.1 months [SD, 88.3]), there was no significant difference (P >.05).

CONCLUSION

Although there are no specific magnetic resonance imaging findings peculiar to migraine, detection of white matter foci should be taken into consideration in patients with migraine (especially migraine with aura). Frequency of attacks is an important indicator of existence of white matter foci.

45(th) Annual Scientific Meeting of the American Headache Society June 19 -22, 2003, Chicago, IL, USA

The 45(th) Annual Scientific Meeting of the American Headache Society focused on new areas of headache research: revised diagnostic criteria, increased the understanding of the pathogenesis of migraine and expansion of identified physiological changes in migraine beyond head pain to include cognitive, sleep and vestibular disturbances. A preview of the new International Headache Society criteria described changes in diagnostic categories, including special criteria for research. New definitions to categorise chronic daily headache, menstrual migraine and secondary headaches were the main highlights of the modified criteria. In addition, novel data on activation within trigeminovascular pathways expand the understanding of the pathogenesis of migraine. Identification of the ability of treatment to impact activation and sensitisation of peripheral and central neurons results in: an explanation for initial headache worsening and neck/chest tightness that commonly occur with triptans, a better understanding of the mechanisms of triptans, and a strong recommendation for early triptan intervention (within 20 min of headache onset). Application of matrix metalloproteinase models to migraine helps explain the ability of medications to cross the blood-brain barrier during a migraine episode, as well as describe possible ischaemia with repeated migraine (e.g., white matter abnormalities seen on magnetic resonance scanning). Improved classification of headache disorders, along with increased understanding of the physiology of migraine and mechanism of action of common treatments, should enhance future development and evaluation of effective headache therapy.

No change in the structure of the brain in migraine: a voxel-based morphometric study

Migraine is a common, disabling form of primary neurovascular headache. For most of the twentieth century it was regarded as a vascular headache whose primary pathophysiology lay in the cranial vasculature. Functional brain imaging using positron emission tomography has demonstrated activation of the rostral brain stem in acute migraine. Voxel-based morphometry is a new fully automated whole brain technique that is sensitive to subtle macroscopic and mesoscopic structural differences between groups of subjects. In this study 11 patients suffering from migraine with aura (10 females, one male: 23-52 years, mean 31); 11 controls (10 females, one male: 23-52, mean 31); 17 patients with migraine without aura (16 females, one male: 24-57, mean 34); 17 controls (16 females, one male: 24-57, mean 34) were imaged with high resolution volumetric magnetic resonance imaging. There was no significant difference in global grey or white matter volumes between either patients with migraine and controls, or patients with aura and without aura. This study did not show any global or regional macroscopic structural difference between patients with migraine and controls, with migraine sufferers taken as homogenous groups. If structural changes are to be found, other methods of phenotyping migraine, such as by genotype or perhaps treatment response, may be required to resolve completely whether there is some subtle structural change in the brain of patients with migraine.

Magnetic resonance angiogram evidence of vasospasm in familial hemiplegic migraine

We report a case of familial hemiplegic migraine in an 11-year-old girl who presented with coma and left hemiparesis. Magnetic resonance imaging showed reversible vasospasm and evidence of oligemia, bringing new information regarding neurovascular changes in familial hemiplegic migraine.