The typical duration of migraine aura: a systematic review

Trigeminal ganglion neurons are directly activated by influx of CSF solutes in a migraine model

Classical migraine patients experience aura, which is transient neurological deficits associated with cortical spreading depression (CSD), preceding headache attacks. It is not currently understood how a pathological event in cortex can affect peripheral sensory neurons. In this study, we show that cerebrospinal fluid (CSF) flows into the trigeminal ganglion, establishing nonsynaptic signaling between brain and trigeminal cells. After CSD, ~11% of the CSF proteome is altered, with up-regulation of proteins that directly activate receptors in the trigeminal ganglion. CSF collected from animals exposed to CSD activates trigeminal neurons in naïve mice in part by CSF-borne calcitonin gene-related peptide (CGRP). We identify a communication pathway between the central and peripheral nervous system that might explain the relationship between migrainous aura and headache.

Cortical spreading depolarization-induced constriction of penetrating arteries can cause watershed ischemia: A potential mechanism for white matter lesions

Periventricular white matter lesions (WMLs) are common MRI findings in migraine with aura (MA). Although hemodynamic disadvantages of vascular supply to this region create vulnerability, the pathophysiological mechanisms causing WMLs are unclear. We hypothesize that prolonged oligemia, a consequence of cortical spreading depolarization (CSD) underlying migraine aura, may lead to ischemia/hypoxia at hemodynamically vulnerable watershed zones fed by long penetrating arteries (PAs). For this, we subjected mice to KCl-triggered single or multiple CSDs. We found that post-CSD oligemia was significantly deeper at medial compared to lateral cortical areas, which induced ischemic/hypoxic changes at watershed areas between the MCA/ACA, PCA/anterior choroidal and at the tip of superficial and deep PAs, as detected by histological and MRI examination of brains 2-4 weeks after CSD. BALB-C mice, in which MCA occlusion causes large infarcts due to deficient collaterals, exhibited more profound CSD-induced oligemia and were more vulnerable compared to Swiss mice such that a single CSD was sufficient to induce ischemic lesions at the tip of PAs. In conclusion, CSD-induced prolonged oligemia has potential to cause ischemic/hypoxic injury at hemodynamically vulnerable brain areas, which may be one of the mechanisms underlying WMLs located at the tip of medullary arteries seen in MA patients.

Mathematical Psychiatry: On Cortical Spreading Depression-A Review

The concept of migraine with aura (MwA) is a widespread condition that can affect up to 30% of migraine patients and manifests itself as a temporary visual illusion followed by a prolonged headache. It was initially pitched as a neurological disease, and observed that the spread of accompanying electrophysiological waves as part of the condition, which came to be known as cortical spreading depression (CSD). A strong theoretical basis for a link between MwA and CSD has eventually led to knowledge of the dynamics between the pair. In addition to experiment-based observations, mathematical models make an important contribution towards a numerical means of expressing codependent neural-scale manifestations. This provides alternate means of understanding and observing the phenomena while helping to visualize the links between the variables and their magnitude in contributing towards the emanation and dynamic pulsing of the condition. A number of biophysical mechanisms are believed to contribute to the MwA-CSD, spanning ion diffusion, ionic currents of membranes, osmosis, spatial buffering, neurotransmission, gap junctions, metabolic pumping, and synapse connections. As part of this review study, the various mathematical models for the description of the condition are expressed, reviewed, and contrasted, all of which vary in their depth, perspective, and level of information presented. Subsequent to this, the review looked into links between electrophysiological data-driven manifestations from measurements such as EEG and fMRI. While concluding remarks forged a structured pathway in the area on sub-themes that need to be investigated in order to strengthen and robustify the existing models, they include an accounting for inter-personal variability in models, sex and hormonal factors, and age groups, i.e., pediatrics vs. adults.

Migraine with aura

This chapter describes the different types of aura including rare aura subtypes such as retinal aura. In addition, aura manifestations not classified in the International Classification of Headache Disorders and auras in headache disorders others than migraine are also described. The differential diagnosis of migraine aura comprises several neurological disorders which should be known to specialists. Migraine aura also has impact on the choice of migraine treatment; recommendations for the treatment of the migraine aura itself are also presented in this chapter.

Efficacy and quality-of-life improvements with fremanezumab treatment in patients with difficult-to-treat migraine with associated neurological dysfunction

BACKGROUND

Fremanezumab, a fully humanised monoclonal antibody (IgG2Δa) that selectively targets calcitonin gene-related peptide (CGRP), has demonstrated efficacy as a preventive treatment for adults with episodic migraine (EM) or chronic migraine (CM) and inadequate response to 2-4 prior preventive treatment classes in the phase 3b FOCUS study. In this post-hoc analysis, we evaluated efficacy and effects on quality-of-life outcomes for fremanezumab in subgroups of patients with and without aura or similar neurological symptoms, here referred to as migraine with or without associated neurological dysfunction.

METHODS

In the FOCUS study, 838 patients were randomised (1:1:1) to quarterly fremanezumab, monthly fremanezumab, or matched placebo for 12 weeks of double-blind treatment. For this post-hoc analysis, subgroups of patients with migraine with and without associated neurological dysfunction at baseline were identified based on patient response to questions about symptoms.

RESULTS

In patients with migraine with associated neurological dysfunction at baseline, fremanezumab significantly reduced monthly average days with neurological symptoms (quarterly, -1.7 days; monthly, -1.8 days) compared to placebo (-0.5 days; both P ≤0.01). In comparison with placebo, both dosing regimens of fremanezumab yielded greater reductions in monthly migraine days over 12 weeks (P <0.0001) and improvements in Headache Impact Test-6 and Migraine-specific Quality of Life scores over the last 4 weeks (P <0.05), regardless of neurological dysfunction at baseline.

CONCLUSIONS

Fremanezumab reduced days with neurological symptoms, effectively prevented migraine, and improved quality of life in patients with migraine with associated neurological dysfunction, including those with previous inadequate response to 2-4 migraine preventive medication classes.

Prolonged migraine aura resembling ischemic stroke following CoronaVac vaccination: an extended case series

Background

After the initiation of the COVID-19 vaccination program in Thailand, thousands of patients have experienced unusual focal neurological symptoms. We report 8 patients with focal neurological symptoms after receiving inactivated virus vaccine, CoronaVac.

Case series

Patients were aged 24–48 years and 75% were female. Acute onset of focal neurological symptoms occurred within the first 24 h after vaccination in 75% and between 1-7d in 25%. All presented with lateralized sensory deficits, motor deficits, or both, of 2–14 day duration. Migraine headache occurred in half of the patients. Magnetic resonance imaging of the brain during and after the attacks did not demonstrate any abnormalities suggesting ischemic stroke. All patients showed moderately large regions of hypoperfusion and concurrent smaller regions of hyperperfusion on SPECT imaging while symptomatic. None developed permanent deficits or structural brain injury.

Discussions

Here, we present a case series of transient focal neurological syndrome following Coronavac vaccination. The characteristic sensory symptoms, history of migraine, female predominant, and abnormal functional brain imaging without structural changes suggest migraine aura as pathophysiology. We propose that pain related to vaccine injection, component of vaccine, such as aluminum, or inflammation related to vaccination might trigger migraine aura in susceptible patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10194-022-01385-0.

Cortical mechanisms in migraine

Migraine is the second most prevalent disorder in the world; yet, its underlying mechanisms are still poorly understood. Cumulative studies have revealed pivotal roles of cerebral cortex in the initiation, propagation, and termination of migraine attacks as well as the interictal phase. Investigation of basic mechanisms of the cortex in migraine not only brings insight into the underlying pathophysiology but also provides the basis for designing novel treatments. We aim to summarize the current research literatures and give a brief overview of the cortex and its role in migraine, including the basic structure and function; structural, functional, and biochemical neuroimaging; migraine-related genes; and theories related to cortex in migraine pathophysiology. We propose that long-term plasticity of synaptic transmission in the cortex encodes migraine.

Aura Mapping: Where Vision and Somatosensation Meet

While migraine auras are most frequently visual, somatosensory auras are also relatively common. Both are characterized by the spread of activation across a cortical region containing a spatial mapping of the sensory (retinal or skin) surface. When both aura types occur within a single migraine episode, they may offer an insight into the neural mechanism which underlies them. Could they both be initiated by a single neural event, or do the timing and laterality relationships between them demand multiple triggers? The observations reported here were carried out 25 years ago by a group of six individuals with migraine with aura. They timed, described and mapped their visual and somatosensory auras as they were in progress. Twenty-nine episode reports are summarized here. The temporal relationship between the onset of the two auras was quite variable within and across participants. Various forms of the cortical spreading depression hypothesis of migraine aura are evaluated in terms of whether they can account for the timing, pattern of symptom spread and laterality of the recorded auras.

Relationships between migraine and epilepsy: Pathophysiological mechanisms and clinical implications

Migraine and epilepsy are distinct neurological diseases with specific clinical features and underlying pathophysiological mechanisms. However, numerous studies have highlighted the complex and multifaceted relationships between the two conditions. The relationships between headache and epilepsy manifest themselves in different ways. Firstly, the clinical diagnosis of these disorders may be challenging in view of possible overlapping. While post-ictal headache is a frequent condition, ictal epileptic headache is a rare but challenging diagnosis. Both situations raise the question of the pathophysiological mechanism of headache triggered by seizures. Migraine aura and epilepsy can also exhibit overlapping symptoms leading to their misdiagnosis, in particular in the case of visual aura. Secondly, migraine with aura and epilepsy can occur as a co-morbid condition, particularly in familial hemiplegic migraine (FHM). From a pathophysiological perspective, the identification of genetic mutations in FHM has brought significant advances in the understanding of dysfunctions of neuronal networks leading to hyperexcitability. The purpose of this review is to present clinical situations encompassing headache and epilepsy that can be challenging in neurological practice and to discuss the underlying pathophysiological mechanism of such interactions.

Migraine Visual Aura and Cortical Spreading Depression-Linking Mathematical Models to Empirical Evidence

This review describes the subjective experience of visual aura in migraine, outlines theoretical models of this phenomenon, and explores how these may be linked to neurochemical, electrophysiological, and psychophysical differences in sensory processing that have been reported in migraine with aura. Reaction-diffusion models have been used to model the hallucinations thought to arise from cortical spreading depolarisation and depression in migraine aura. One aim of this review is to make the underlying principles of these models accessible to a general readership. Cortical spreading depolarisation and depression in these models depends on the balance of the diffusion rate between excitation and inhibition and the occurrence of a large spike in activity to initiate spontaneous pattern formation. We review experimental evidence, including recordings of brain activity made during the aura and attack phase, self-reported triggers of migraine, and psychophysical studies of visual processing in migraine with aura, and how these might relate to mechanisms of excitability that make some people susceptible to aura. Increased cortical excitability, increased neural noise, and fluctuations in oscillatory activity across the migraine cycle are all factors that are likely to contribute to the occurrence of migraine aura. There remain many outstanding questions relating to the current limitations of both models and experimental evidence. Nevertheless, reaction-diffusion models, by providing an integrative theoretical framework, support the generation of testable experimental hypotheses to guide future research.

Migraine: Calcium Channels and Glia

Migraine is a common neurological disease that affects about 11% of the adult population. The disease is divided into two main clinical subtypes: migraine with aura and migraine without aura. According to the neurovascular theory of migraine, the activation of the trigeminovascular system (TGVS) and the release of numerous neuropeptides, including calcitonin gene-related peptide (CGRP) are involved in headache pathogenesis. TGVS can be activated by cortical spreading depression (CSD), a phenomenon responsible for the aura. The mechanism of CSD, stemming in part from aberrant interactions between neurons and glia have been studied in models of familial hemiplegic migraine (FHM), a rare monogenic form of migraine with aura. The present review focuses on those interactions, especially as seen in FHM type 1, a variant of the disease caused by a mutation in CACNA1A, which encodes the α1A subunit of the P/Q-type voltage-gated calcium channel.

Migraine Pathophysiology

Migraine is the leading cause of years lost due to disability in individuals aged 15 to 49 years. Much has changed over the last three decades about our understanding of this complex neurological disorder. Various phases of migraine have been characterized and are the focus of this review. The premonitory phase involves bothersome symptoms experienced hours to days before migraine pain. Behavioral changes and functional neuroimaging studies point toward hypothalamic involvement during the premonitory and other migraine phases. Migraine aura is a disruptive, reversible neurological phenomenon that affects up to one-third of all migraineurs, and can overlap with the headache phase. The mechanism responsible for this phase is thought to be cortical spreading depolarization through the cortex. This process leads to temporary disruptions in ion homeostasis and the ensuing neuronal dysfunction. The headache phase involves activation of the trigeminocervical complex. Neuropeptides are implicated in trigeminal activation, and calcitonin gene-related peptide in particular has become a promising target of therapeutic intervention for migraine. The final phase of migraine is the postdrome, the period of time from the resolution of headache symptoms until return to baseline following a migraine. People often report neuropsychiatric, sensory, gastrointestinal, and general symptoms during this time, which can limit activity. Elucidating the neuroanatomical, chemical, and neuroimaging correlates of these migraine phases allows for an improved comprehension of the underlying changes associated with migraine symptomatology and can assist with evaluation of arising therapeutics for migraine management.

Symptoms related to the visual system in migraine

Migraine is a common headache disorder characterized by often-severe headaches that may be preceded or accompanied by a variety of visual symptoms. Although a typical migraine aura is not difficult to diagnose, patients with migraine may report several other visual symptoms, such as prolonged or otherwise atypical auras, "visual blurring", "retinal migraine", "ophthalmoplegic migraine", photophobia, palinopsia, and "visual snow". Here, we provide a short overview of these symptoms and what is known about the relationship with migraine pathophysiology. For some symptoms, the association with migraine is still debated; for other symptoms, recent studies indicate that migraine mechanisms play a role.

Migraine and increased risk of developing open angle glaucoma: a population-based cohort study

Background

Migraine is linked to endothelial dysfunction and is considered to be a systemic vasculopathy. Interestingly, systemic vascular diseases also occur in glaucoma patients and are considered to be vascular risk factors. Whether migraine is simply a concomitant condition in glaucoma patients or a risk factor per se for glaucoma remains unknown. Thus, in the present study, we investigated the risk for open angle glaucoma (OAG) in migraineurs using a 10-year follow-up study that employed a nationwide population-based dataset in Taiwan.

Methods

This retrospective matched-cohort study used data sourced from the Longitudinal Health Insurance Database 2000. We included 17,283 subjects with migraine in the study cohort and randomly selected 69,132 subjects from the database for the comparison group. Each subject in this study was individually traced for a 10-year period to identify those subjects who subsequently received a diagnosis of OAG. The age-adjusted Charlson’s comorbidity index (ACCI) score was utilized to compute the burden of comorbidity in each subject. Multivariate regression analysis was used to assess risk factors for OAG in migraineurs. Cox proportional hazards regression was performed to compare the 10-year risk of OAG between the migraineurs and the comparison cohort.

Results

Migraineurs had more vascular comorbidities than the comparison cohort. The overall incidence of OAG (per 1000 person-years) was 1.29 and 1.02, respectively, for migraineurs and the comparison cohort during the 10-year follow-up period. Age, hyperlipidemia, and diabetes mellitus were three significant risk factors for OAG in migraineurs. After adjusting for patients’ age and vascular comorbidities, migraineurs were found to have a 1.68-fold (95% confidence interval [CI], 1.20–2.36) greater risk of developing OAG than the comparison cohort, in subjects with an ACCI score of 0. This association became statistically nonsignificant in subjects with ACCI scores of 1–2 or ≥ 3.

Conclusion

Migraine is associated with a higher risk of OAG for patients with no comorbidity who are aged under 50 years.

Visual symptoms and childhood migraine: Qualitative analysis of duration, location, spread, mobility, colour and pattern

AIM

To examine the characteristics of visual symptoms during attacks of migraine in children and adolescents.

METHOD

A qualitative analysis of prospectively collected data over 5 years, on characteristics of visual symptoms during migraine attacks. Diagnosis of migraine and aura was based on the International Classification of Headache Disorders 3^rd edition beta version. We also provided the opportunity for patients to illustrate their visual aura symptoms to aid in diagnosis.

RESULTS

Visual symptoms were reported by 387/1079 (36%) of migraineurs. Of these, 172 (16%) patients fulfilled the International Classification of Headache Disorders Criteria A, B, C iv and D, but missed one (n = 75; 43.5%) or two (n = 97; 56.5%) of the remaining items of criteria C as the visual symptoms were of non-gradual spread (n = 35; 20%), appeared in both visual fields (n = 99; 58%), or lasted less than 5 minutes or more than 60 minutes (n = 129; 75%).

CONCLUSION

The International Classification of Headache Disorders 3^rd edition beta version criteria are useful in diagnosis of migraine with visual aura in children and adolescents, but visual symptoms varied considerably in duration, pattern, mobility, location, mode of onset and colours. Providing opportunity for patients to illustrate their symptoms can provide additional diagnostic information. The pathophysiology and the clinical concept of typical MVA is still to an extent an assumption and needs further evaluation.

APPROVAL

The study was approved by the Health Research Authority - London and the local Research and Innovation Department at Barking Havering and Redbridge National Health Service Trust. Formal parental consent was not considered essential for this type of study.

[Migraine 'masks': differential diagnosis of acute headache]

Differential diagnosis of migraine, can be difficult, especially of migraine with aura. On the one hand, some diseases can produce symptoms similar to migraine (cerebral aneurysm before rupture, reversible cerebral vasoconstriction syndrome). On the other hand, migraine with aura and some other disorders are conditions that have common pathophysiological mechanisms (e.g., CADASIL and MELAS syndrome, antiphospholipid syndrome). Thirdly, clinical presentations of migraine are often difficult to distinguish from features of other headache conditions (migraine with aura - transient ischemic attack, migraine with visual aura - occipital epilepsy). The author discusses the differential diagnosis of acute headache, especially thunderclap headache, and main strategies of effective treatment of migraine attacks.

Migraine with prolonged aura: phenotype and treatment

We review the published literature on migraine with prolonged aura (PA), specifically with regards to the phenotype and treatment options. PA is not uncommon. A recent study found that about 17% of migraine auras are prolonged and that 26% of patients with migraine with aura have experienced at least one PA. The characteristics of PA are similar to most typical auras with the exception of a higher number of aura symptoms (in particular sensory and/or dysphasic). There are no well-established treatments at present which target the aura component of migraine. Other than case reports, there have been open-label studies of lamotrigine and greater occipital nerve blocks. The only randomised, blinded, controlled trial to date has been of nasal ketamine showing some reduction in aura severity but not duration. A small open-labelled pilot study of amiloride was also promising. Larger randomised, controlled trials are needed to establish whether any of the existing or novel compounds mentioned are significantly effective and safe.

Pattern Recognition of the Multiple Sclerosis Syndrome

During recent decades, the autoimmune disease neuromyelitis optica spectrum disorder (NMOSD), once broadly classified under the umbrella of multiple sclerosis (MS), has been extended to include autoimmune inflammatory conditions of the central nervous system (CNS), which are now diagnosable with serum serological tests. These antibody-mediated inflammatory diseases of the CNS share a clinical presentation to MS. A number of practical learning points emerge in this review, which is geared toward the pattern recognition of optic neuritis, transverse myelitis, brainstem/cerebellar and hemispheric tumefactive demyelinating lesion (TDL)-associated MS, aquaporin-4-antibody and myelin oligodendrocyte glycoprotein (MOG)-antibody NMOSD, overlap syndrome, and some yet-to-be-defined/classified demyelinating disease, all unspecifically labeled under MS syndrome. The goal of this review is to increase clinicians’ awareness of the clinical nuances of the autoimmune conditions for MS and NMSOD, and to highlight highly suggestive patterns of clinical, paraclinical or imaging presentations in order to improve differentiation. With overlay in clinical manifestations between MS and NMOSD, magnetic resonance imaging (MRI) of the brain, orbits and spinal cord, serology, and most importantly, high index of suspicion based on pattern recognition, will help lead to the final diagnosis.

Headache symptoms from migraine patients with and without aura through structure-validated self-reports

Background

Headache symptoms self-reported by migraine patients are largely congruent with the clinician-used diagnostic criteria, but not always so. Patients’ self-reports of headache symptoms might offer additional clues to characterize migraine with (MA) and without (MO) aura more precisely.

Methods

Firstly, we invited 324 participants with a life-long headache attack to answer an item-matrix measuring symptoms of primary headaches, then we performed both exploratory and confirmatory factor analyses to their answers and refined a headache symptom questionnaire. Secondly, we applied this questionnaire to 28 MA and 52 MO patients.

Results

In participants with a life-long headache, we refined a 27-item, structure-validated headache symptom questionnaire, with four factors (scales) namely the Somatic /Aura Symptoms, Gastrointestinal and Autonomic Symptoms, Tightness and Location Features, and Prodromal/Aggravating Symptoms. Further, we found that MA patients reported higher than did MO patients on the Somatic/Aura Symptoms and Tightness and Location Features scales.

Conclusions

Compared to MO, MA was conferred with more prominent tightness and location features besides its higher somatic or aura symptoms. Patients’ self-reports of headache symptoms might offer more clues to distinguish two types of migraine besides their clinician-defined criteria.

Magnetic resonance imaging arterial-spin-labelling perfusion alterations in childhood migraine with atypical aura: a case-control study

AIM

Atypical migraine with aura can be challenging to diagnose. Arterial-spin-labelling (ASL) is able to non-invasively quantify brain perfusion. Our aim was to report cerebral blood flow (CBF) alterations using ASL, at the acute phase of atypical migraine with aura in children.

METHOD

Paediatric patients were retrospectively included if (1) referred for acute neurological deficit(s), (2) underwent brain magnetic resonance imaging (MRI) at presentation with ASL sequence, and (3) had subsequent diagnosis of migraine with aura. Neurological symptom-free controls were matched for age. Twenty-eight regions of interest (ROIs) were drawn on CBF maps for each participant/control.

RESULTS

Ten patients were included (median age 13y, range 8-16y). Eight of 10 had multiple aura symptoms during the episode. For every patient, CBF was decreased in a brain region consistent with symptoms when MRI was performed less than 14 hours after onset (n=7 patients) and increased if the MRI was performed 17 hours or more after (n=4 MRIs).

INTERPRETATION

MRI-ASL appears to be a promising tool for the diagnostic workup and differentials exclusion in paediatric migraine with aura. Constant and time-consistent non-territorial CBF modifications were found in our sample providing additional insight to migraine with aura pathophysiology. The authors encourage implementing this sequence at the acute phase of unexplained paediatric neurological deficits, with or without accompanying headache.

Case Studies of Uncommon and Rare Headache Disorders

The following 6 case studies are presented: a 12-day migraine with recurring aura?; a migraineur with a new constant headache for 1 month; an orthostatic headache; a unilateral headache; migraine with aura and limb pain without headache; and nocturnal headaches. These cases illustrate the fascinating diversity and challenges of primary and secondary headaches that neurologists commonly encounter.

Migraine with brainstem aura presenting as recurrent hypersomnia (Kleine-Levin syndrome)

Recurrent hypersomnia, or Kleine-Levin syndrome, is rare and frequently causes substantial diagnostic anxiety and delay. Patients often undergo multiple investigations to rule out other causes of encephalopathy. The treatment options are unsatisfactory. Migraine with brainstem aura has not previously been widely considered in the medical literature as a differential diagnosis. We describe two patients referred to a tertiary sleep neurology service with a putative diagnosis of Kleine-Levin syndrome. Each described attacks of hypersomnia with elements of migraine with brainstem aura, in addition to having a history of migraine with aura. Simple acute migraine treatment clearly attenuated further attacks. These cases generate discussion as to the common features and potential mechanisms underlying both disorders. Furthermore, they highlight a hitherto underexplored alternative diagnosis of Kleine-Levin syndrome. This provides scope for offering established and effective migraine treatment options to patients who with a potential misdiagnosis of Kleine-Levin syndrome, providing scope for offering established and effective migraine treatment to some patients originally diagnosed with a rare condition for which there is no current consistently effective therapeutic options.

Greater occipital nerve block for the acute treatment of prolonged or persistent migraine aura

Background

Presently, there is no evidence to guide the acute treatment of migraine aura. We aimed to describe the effect of greater occipital nerve (GON) anaesthetic block as a symptomatic treatment for long-lasting (prolonged or persistent) migraine aura.

Methods

Patients who presented with migraine aura lasting > 2 hours were consecutively recruited during one year at the Headache Unit and the Emergency Department of a tertiary hospital. All patients underwent a bilateral GON block with bupivacaine 0.5%. Patients were followed up for 24 hours.

Results

A total of 22 auras were treated in 18 patients. Auras consisted of visual ( n = 13), visual and sensory ( n = 4) or sensory symptoms alone ( n = 5). Eleven episodes met diagnostic criteria for persistent aura (>1 week) without infarction. The response was complete without early recurrence in 11 cases (50%), complete with recurrence in < 24 hours in two cases (9.1%), and partial with ≥ 50% improvement in six cases (27.3%). Complete responses without recurrence were more common in cases with prolonged auras lasting < 1 week than in those with persistent auras (72.7% vs. 27.3%; p = 0.033).

Conclusions

GON block could be an effective symptomatic treatment for prolonged or persistent migraine aura. Randomised controlled trials are still required to confirm these results.

Migraine aura: new ideas about cause, classification, and clinical significance

PURPOSE OF REVIEW

The migraine aura is a dramatic spontaneous change in brain activity resulting in a variety of transient neurological symptoms. The purpose of this review is to address recent advances in the understanding of aura and its role in migraine.

RECENT FINDINGS

The formal classification of migraine aura is becoming both broader and more detailed. Traditionally viewed as a primary event that triggers a migraine attack, studies regarding the timing of aura relative to other symptoms of migraine indicate that it may not in fact play a primary role in initiating an attack. Careful recording and analysis of visual aura symptoms provides new insight into the initiation and propagation of the underlying brain phenomenon, and the different regions of visual cortex that produce different visual perceptions. Migraine with aura may have different responses to acute and preventive therapies.

SUMMARY

There has been significant evolution of concepts regarding the causes of migraine aura, how it is best defined, and how it fits into the picture of the migraine disorder as a whole. Regardless of its exact role in the genesis of migraine, an increased understanding of aura has the potential to provide important new insight into not only migraine but also fundamental mechanisms of brain physiology.

Hemiplegia and headache: a review of hemiplegia in headache disorders

The most common scenario wherein the practicing neurologist is likely to encounter a patient with headache and hemiplegia will vary depending on his/her specific type of practice. A neurologist providing consultative service to an emergency department is far more likely to see patients with "secondary" headache and hemiplegia in the setting of either ischemic or hemorrhagic stroke than hemiplegia as a transient feature of a primary headache disorder. Neurologists subspecializing in headache medicine who practice in a tertiary referral headache clinic are more likely to encounter hemiplegic migraine, but even in that clinical setting hemiplegic migraine is by no means a frequent diagnosis. The acute onset of hemiplegia can be very frightening not only to the patient but also to the medical personnel. Given the abundance of mimicry, practitioners must judiciously ascertain the correct diagnosis as treatment may greatly vary depending on the cause of both headache and hemiplegia. In this review, we will address the most common causes of hemiplegia associated with headache.

Migraine aura symptoms: Duration, succession and temporal relationship to headache

Background

As there are no biological markers, a detailed description of symptoms, particularly temporal characteristics, is crucial when diagnosing migraine aura. Hitherto these temporal aspects have not been studied in detail.

Methods

We conducted a prospective diary-aided study of the duration and the succession of aura symptoms and their temporal relationship with headache.

Results

Fifty-four patients completed the study recording in a diary the characteristics of three consecutive auras ( n = 162 auras). The median duration of visual, sensory and dysphasic symptoms were 30, 20 and 20 minutes, respectively. Visual symptoms lasted for more than one hour in 14% of auras ( n = 158), sensory symptoms in 21% of auras ( n = 52), and dysphasic symptoms in 17% of auras ( n = 18). Twenty-six percent of patients had at least one aura out of three with one symptom lasting for more than one hour. In aura with multiple symptoms the subsequent symptom, second versus first one or third versus second, might either start simultaneously (34 and 18%), during (37 and 55%), with the end (5 and 9%), or after (24 and 18%) the previous aura symptom. The headache phase started before the aura (9%), simultaneously with the onset of aura (14%), during the aura (26%), simultaneously with the end of aura (15%) or after the end of aura (36%).

Conclusion

We provide data to suggest that symptoms may last longer than one hour in a relevant proportion of auras or migraine with aura patients, and that there is a high variability of scenarios in terms of time relationship among aura symptoms and between aura and headache.

Biphasic neurovascular changes in prolonged migraine aura in familial hemiplegic migraine type 2

OBJECTIVE

To report biphasic changes in cerebral blood flow (CBF) in the acute phase of hemiplegic migraine with prolonged aura (HMPA), in which aura symptoms lasted longer than 24 h, in three patients with familial hemiplegic migraine (FHM) carrying a p.H916L mutation in ATP1A2 gene.

METHODS

We assessed neurovascular changes with time in the affected cerebral hemisphere corresponding to aura symptoms during the acute phase of HMPA. Arterial spin labelling MRI, SPECT for CBF measurement and EEG in three attacks, in one attack FDG-PET measurement for cerebral metabolism was performed. We evaluated CBF at different phases of aura symptoms in 11 attacks of HMPA.

RESULTS

In two attacks, we found biphasic CBF changes beginning with hypoperfusion followed by persistent hyperperfusion. FDG-PET revealed increased cerebral glucose metabolism in the regions corresponding to hyperperfusion on day 4 when aura symptoms still persisted. In four attacks, Z-score-based CBF mapping revealed multifocal hypoperfusion in the early phase. Hypoperfusion in our study was seen within 19 h of the onset of the symptoms in five of seven attacks, while hyperperfusion was seen 18 h or later in eight of nine attacks. EEG showed attenuated alpha activity without paroxysmal discharge.

CONCLUSIONS

This is the first report showing biphasic CBF changes during the prolonged aura of FHM2. This study suggested that the results of cross-sectional CBF studies should be interpreted carefully. Initial multifocal hypoperfusion is likely due to functional depression of multifocal origin in the affected hemisphere, but the mechanism of persistent hyperperfusion requires further investigation.

Transient CNS deficits and migrainous auras in individuals without a history of headache

OBJECTIVE

To demonstrate that benign transient focal neurological symptoms represent equivalents of migraine auras without headache.

BACKGROUND

Benign focal neurological symptoms suggesting cerebral dysfunction are common and usually prompt an extensive diagnostic workup, but their etiology is often not elucidated. We hypothesized that benign transient focal neurological symptoms represent equivalents of migraine auras without headache, even in subjects who have never experienced migraine headaches.

METHODS

We led a cross-sectional study and identified individuals who presented at least 1 episode of unexplained transient focal neurological symptoms suggestive of cerebral dysfunction, but no history of migraine headache, among physicians and inpatients of an academic hospital. Cortical hyperexcitability, assessed by occipital transcranial magnetic stimulation (oTMS), was used as a marker of possible migraine auras without headache.

RESULTS

Frequency of transient focal neurological symptoms suggestive of cerebral dysfunction among the physicians who responded was 9% (21/233), vs 0.09% (6/690) of inpatients. Most episodes resembled typical visual migrainous auras. Motor, sensory, and language dysfunction were more common among inpatients than among physicians. oTMS induced phosphenes in 12/16 (75%) subjects and in none of 10 controls.

CONCLUSION

Benign focal neurological symptoms were common in our population and likely represent migraine aura without headache. Non-visual symptoms are less common and lead to medical consultation. oTMS is abnormal in most cases, supporting the diagnosis of migraine aura without headache and helping separate this benign condition from transient ischemic attacks.

Prolonged acute migraine with aura and reversible brain MRI abnormalities after liquid sclerotherapy

Transient visual disturbances constitute the most commonly reported neurological side effect during and immediately after sclerotherapy. A few studies, based on clinical and diffusion-weighted MRI assessments, have suggested that these transient neurological symptoms correspond to migraine with aura. Recently, it has been reported that brain magnetic resonance imaging can reveal transient T2*-weighted abnormalities during the acute phase of migraine with aura. We reported a 36-year-old man who presented with transient neurological symptoms and concomitant T2*-weighted abnormalities on brain magnetic resonance imaging immediately after liquid sclerotherapy. We hypothesize that the reversible nature of the patient's T2*-weighted abnormalities may indicate a relationship with the post-sclerotherapy migraine with aura attack.

Aura status: A not so frequent aura

Background

Migraine aura status is a variety of migraine aura with unvalidated research criteria.

Aim and methods

We conducted a systematic review of published cases and a retrospective analysis of 500 cases of migraine with aura to evaluate the applicability and clinical features of ICHD-III beta criteria, compared to a more liberal definition for its diagnosis: ≥3 aura episodes for up to three consecutive days.

Results

Many publications under this title correspond to persistent or formerly designated prolonged auras. Nine cases fulfilled ICHD-III beta status criteria. In our series, either 1.7% or 4.2% cases fulfilled ICDH-III beta or our definition, respectively. Regardless of the criteria, aura status patients were older at onset of status than those with typical aura, had a predominance of visual symptoms, normal neuroimaging and no sequelae. Status recurred in a few.

Conclusion

Both criteria identify a similar population in terms of age, gender, main symptoms, imaging and outcome. Since patients with closely recurring auras might raise the same approach independently of the criteria, the use of more liberal criteria will allow more cases for detailed diagnosis and therapeutic analysis, eventually leading to the identification of subtypes.

Rare clinical findings in a patient with sporadic hemiplegic migraine: FDG-PET provides diminished brain metabolism at 10-year follow-up

BACKGROUND

Sporadic hemiplegic migraine (SHM) is defined as migraine attacks associated with some degree of motor weakness during the aura phase and where no first-degree relative has identical attacks. SHM has a wide inter- and intraindividual clinical spectrum and, in case of prolonged aura symptoms and disturbed consciousness, can mimic several other acute neurological diseases.

CASE

In 1996, during his wedding night, a 28-year-old man developed left face, arm and leg weakness, nausea and a throbbing headache. Neurological examination on presentation revealed stupor, fever, meningism and left hemiplegia. There were no abnormalities on emergency magnetic resonance. Lumbar puncture showed mild lymphocytic pleocytosis and slightly elevated protein. He received symptomatic treatment. Subsequent genetic analysis revealed the T666M mutation in the CACNA1A gene of chromosome 19. He was diagnosed with SHM. In 2005, at the end of another episode of hemiplegic migraine (HM), he for the first time developed an episode of paranoid psychosis with anxiety and visual hallucinations. The psychiatric symptoms resolved within a week.

DISCUSSION

All perfusion SPECT and transcranial Doppler studies performed in the first days of HM attacks were consistent with hyperemia of the hemisphere contralateral to the neurological signs. FDG-PET/CT in January 2013 revealed a diffusely reduced glucose metabolism of the supratentorial cortex and marked asymmetric hypometabolism of the left cerebellum. The finding of progressive cortical metabolic dysfunction over years appears as a new finding. Glucose hypometabolism may indicate primary neuronal dysfunction as the cause of the prolonged deficits.

Migraine: mimics, borderlands and chameleons

Diagnostically, headache is the easy part of migraine. It is the surrounds of migraine--the aura, prodrome and postdrome--that can be most challenging, and confused with other pathologies. This article examines the definition and variants of migraine; alternative diagnoses for which migraine may be mistaken (mimics); conditions that lie between migraine and other diagnoses (borderlands) and the possible presentations of migraine posing as other conditions (chameleons). The focus is on adults, with only passing reference to children. Migraine is more often a chameleon than a mimic; and it is the careful history that usually makes the distinction. Given migraine's prevalence of 10-15%, relatively uncommon features of migraine occur quite often, in comparison with frequent manifestations of less common diseases. Thus, even rare or under-recognised presentations of migraine come into the differential diagnosis of many presentations.

Studies on the pathophysiology and genetic basis of migraine

Migraine is a neurological disorder that affects the central nervous system causing painful attacks of headache. A genetic vulnerability and exposure to environmental triggers can influence the migraine phenotype. Migraine interferes in many facets of people's daily life including employment commitments and their ability to look after their families resulting in a reduced quality of life. Identification of the biological processes that underlie this relatively common affliction has been difficult because migraine does not have any clearly identifiable pathology or structural lesion detectable by current medical technology. Theories to explain the symptoms of migraine have focused on the physiological mechanisms involved in the various phases of headache and include the vascular and neurogenic theories. In relation to migraine pathophysiology the trigeminovascular system and cortical spreading depression have also been implicated with supporting evidence from imaging studies and animal models. The objective of current research is to better understand the pathways and mechanisms involved in causing pain and headache to be able to target interventions. The genetic component of migraine has been teased apart using linkage studies and both candidate gene and genome-wide association studies, in family and case-control cohorts. Genomic regions that increase individual risk to migraine have been identified in neurological, vascular and hormonal pathways. This review discusses knowledge of the pathophysiology and genetic basis of migraine with the latest scientific evidence from genetic studies.

Transient localized wave patterns and their application to migraine

Transient dynamics is pervasive in the human brain and poses challenging problems both in mathematical tractability and clinical observability. We investigate statistical properties of transient cortical wave patterns with characteristic forms (shape, size, duration) in a canonical reaction-diffusion model with mean field inhibition. The patterns are formed by ghost behavior near a saddle-node bifurcation in which a stable traveling wave (node) collides with its critical nucleation mass (saddle). Similar patterns have been observed with fMRI in migraine. Our results support the controversial idea that waves of cortical spreading depression (SD) have a causal relationship with the headache phase in migraine and, therefore, occur not only in migraine with aura (MA), but also in migraine without aura (MO), i.e., in the two major migraine subtypes. We suggest a congruence between the prevalence of MO and MA with the statistical properties of the traveling waves' forms according to which two predictions follow: (i) the activation of nociceptive mechanisms relevant for headache is dependent upon a sufficiently large instantaneous affected cortical area; and (ii) the incidence of MA is reflected in the distance to the saddle-node bifurcation. We also observed that the maximal instantaneous affected cortical area is anticorrelated to both SD duration and total affected cortical area, which can explain why the headache is less severe in MA than in MO. Furthermore, the contested notion of MO attacks with silent aura is resolved. We briefly discuss model-based control and means by which neuromodulation techniques may affect pathways of pain formation.