Migraine in the borderland of epilepsy: “Migralepsy” an overlapping syndrome of children and adults?

Migraine - a borderland disease to epilepsy: near it but not of it

BACKGROUND

Migraine and epilepsy are two paroxysmal chronic neurological disorders affecting a high number of individuals and being responsible for a high individual and socioeconomic burden. The link between these disorders has been of interest for decades and innovations concerning diagnosing and treatment enable new insights into their relationship.

FINDINGS

Although appearing to be distinct at first glance, both diseases exhibit a noteworthy comorbidity, shared pathophysiological pathways, and significant overlaps in characteristics like clinical manifestation or prophylactic treatment. This review aims to explore the intricate relationship between these two conditions, shedding light on shared pathophysiological foundations, genetic interdependencies, common and distinct clinical features, clinically overlapping syndromes, and therapeutic similarities. There are several shared pathophysiological mechanisms, like CSD, the likely underlying cause of migraine aura, or neurotransmitters, mainly Glutamate and GABA, which represent important roles in triggering migraine attacks and seizures. The genetic interrelations between the two disorders can be observed by taking a closer look at the group of familial hemiplegic migraines, which are caused by mutations in genes like CACNA1A, ATP1A2, or SCN1A. The intricate relationship is further underlined by the high number of shared clinical features, which can be observed over the entire course of migraine attacks and epileptic seizures. While the variety of the clinical manifestation of an epileptic seizure is naturally higher than that of a migraine attack, a distinction can indeed be difficult in some cases, e.g. in occipital lobe epilepsy. Moreover, triggering factors like sleep deprivation or alcohol consumption play an important role in both diseases. In the period after the seizure or migraine attack, symptoms like speech difficulties, tiredness, and yawning occur. While the actual attack of the disease usually lasts for a limited time, research indicates that individuals suffering from migraine and/or epilepsy are highly affected in their daily life, especially regarding cognitive and social aspects, a burden that is even worsened using antiseizure medication. This medication allows us to reveal further connections, as certain antiepileptics are proven to have beneficial effects on the frequency and severity of migraine and have been used as a preventive drug for both diseases over many years.

CONCLUSION

Migraine and epilepsy show a high number of similarities in their mechanisms and clinical presentation. A deeper understanding of the intricate relationship will positively advance patient-oriented research and clinical work.

Headache in idiopathic/genetic epilepsies: Cluster analysis in a large cohort

OBJECTIVES

The link between headache and epilepsy is more prominent in patients with idiopathic/genetic epilepsy (I/GE). We aimed to investigate the prevalence of headache and to cluster patients with regard to their headache and epilepsy features.

METHODS

Patients aged 6-40 years, with a definite diagnosis of I/GE, were consecutively enrolled. The patients were interviewed using standardized epilepsy and headache questionnaires and their headache characteristics were investigated by experts in headache. Demographic and clinical variables were analyzed and patients were clustered according to their epilepsy and headache characteristics using an unsupervized K-means algorithm.

RESULTS

Among 809 patients, 508 (62.8%) reported having any type of headache; 87.4% had interictal headache and 41.2% had migraine. Cluster analysis revealed two distinct groups for both adults and children/adolescents. In adults, having a family history of headache, ≥5 headache attacks, duration of headache ≥24 months, headaches lasting ≥ 1 hour, and visual analog scale scores >5 were grouped in one cluster, and juvenile myoclonic epilepsy (JME), myoclonic, and generalized tonic-clonic seizures (GTCS) were clustered in this group (cluster 1). Self-limited epilepsy with centro-temporal spikes and epilepsy with GTCS alone were clustered in cluster 2 with the opposite characteristics. For children/adolescents, the same features as in adult cluster 1 were clustered in a separate group, except for the presence of JME syndrome and GTCS alone as a seizure type. Focal seizures were clustered in another group with the opposite characteristics. In the entire group, the model revealed an additional cluster, including patients with the syndrome of GTCS-alone (50.51%), with ≥ 5 attacks, headache lasting >4 hours, and throbbing headache; 65.66% of patients had a family history of headache in this third cluster (n=99).

SIGNIFICANCE

Patients with I/GE can be clustered into distinct groups according to headache features along with seizures. Our findings may help in management and planning for future studies.

Case Report: Migralepsy: The Two-Faced Janus of Neurology

We report three cases of pediatric patients suffering from migraine aura triggered seizures. This entity, also called migralepsy, still does not have a unique definition today. Migraine and epilepsy are both episodic neurological disorders with periods of interictal well-being; this is indicative of similar pathophysiological mechanisms, such as increased neuronal excitation and ion channel dysfunction. The purpose of this paper is to discuss the clinical and instrumental features of migralepsy through the description of three clinical cases in which the symptoms of the usual migraine aura developed into a generalized tonic–clonic or focal seizure.

Differences in visual information processing style between Idiopathic Generalized Epilepsy with and without photosensitivity

PURPOSE

Recently, altered visual cortical processes i.e., lack of habituation to visual evoked potentials (VEP), has been highlighted in both photosensitive epilepsy and in a specific i.e., analytic mode of processing visual inputs. In this study we aimed at evaluating the relationship between photosensitivity (PS) and analytic style of processing visual information, in a sample of 30 patients with Idiopathic Generalized Epilepsy (IGE) and matched healthy controls.

METHODS

At our Epilepsy unit of the Sapienza University of Rome, we consecutively enrolled 15 patients with IGE with PSand matched them with 15 patients with IGE without PS and 15 Healthy Volunteers. All patients underwent EEG recording in basal conditions during hyperventilation (3 Min), and intermittent light stimulation. The most effective frequencies comprised from 12 to 16 Hz. The instruments used to gather psychological cognitive behavioral data, consisted of participation in two tests: the Sternberg-Wagner Self-Assessment Inventory and the Mariani Learning Style Questionnaire.

RESULTS

Compared to controls, both IGE groups show significantly higher scores for the analytic style (One-way ANOVA, F_(2,44) = 110.3, p < 0.0001). Epilepsy groups thereby showed very distinctive cognitive styles as measured with the Sternberg test. In the visual style, scores of the photosensitive Individuals with IGE were significantly higher than the non-photosensitive individuals with IGE (p < 0.0001, Tukey's post hoc test).

CONCLUSIONS

An association between analytic style of processing visual information and PS in IGE has been shown. The common neurophysiological features between these two factors, suggest the possibility to evaluate this cognitive behavior as a potential target for nonpharmacological therapeutic strategies in photosensitive epilepsy.

Borderlands of Migraine and Epilepsy

Background

The complex relationship between migraine and epilepsy has frequently been described to represent a clinical and electrographic "borderland." These two conditions share clinical expressions such as paroxysmal and chronic nature, as well as semiology, particularly visual phenomenon.

Objective

We aimed to review the current literature on the overlapping phenomena of migraine and epilepsy.

Materials and Methods

We searched the PubMed for relevant literature and conducted a narrative review on migraine and epilepsy.

Results

Migraine and epilepsy share a complex and pathophysiologically intriguing relationship. The International Classification of Headache Disorders, 3^rd edition (ICHD-3) makes diagnostic provisions for migraine aura-triggered seizures (Subchapter 1.4.4) and headache attributed to epileptic seizure (Subchapter 7.6), the latter being further categorized as 7.6.1 Ictal epileptic headache, and 7.6.2  post-ictal headache. Neurological conditions such as certain channelopathies and epilepsy syndromes exhibit both conditions within their phenotypic spectrum, suggesting shared genetic and molecular underpinnings. Diagnostic confusion may arise, particularly between occipital epilepsy and the visual aura of migraine. Antiseizure medications may be effective for the treatment of migraines that occur in concert with epilepsy.

Conclusions

Migraine and epilepsy share several clinical features and have intertwined genetic and molecular underpinnings, which may contribute to common pathogenesis. Electroencephalography may be useful as a diagnostic tool in selected cases.

Pathophysiological Bases of Comorbidity in Migraine

Despite that it is commonly accepted that migraine is a disorder of the nervous system with a prominent genetic basis, it is comorbid with a plethora of medical conditions. Several studies have found bidirectional comorbidity between migraine and different disorders including neurological, psychiatric, cardio- and cerebrovascular, gastrointestinal, metaboloendocrine, and immunological conditions. Each of these has its own genetic load and shares some common characteristics with migraine. The bidirectional mechanisms that are likely to underlie this extensive comorbidity between migraine and other diseases are manifold. Comorbid pathologies can induce and promote thalamocortical network dysexcitability, multi-organ transient or persistent pro-inflammatory state, and disproportionate energetic needs in a variable combination, which in turn may be causative mechanisms of the activation of an ample defensive system with includes the trigeminovascular system in conjunction with the neuroendocrine hypothalamic system. This strategy is designed to maintain brain homeostasis by regulating homeostatic needs, such as normal subcortico-cortical excitability, energy balance, osmoregulation, and emotional response. In this light, the treatment of migraine should always involves a multidisciplinary approach, aimed at identifying and, if necessary, eliminating possible risk and comorbidity factors.

Myocardial infarction after epilepsy onset: A population-based retrospective cohort study

INTRODUCTION

Cardiovascular comorbidities of epilepsy such as hypertension, hyperlipidemia, and diabetes are associated with myocardial infarction (MI). Little data on the development of subsequent cardiovascular disease (CVD) in persons with epilepsy (PWE) are available, with inconsistent findings regarding the association between epilepsy and subsequent MI. A higher risk of MI among adults (without prior MI) following epilepsy diagnosis compared with that among controls was hypothesized.

METHODS

This retrospective cohort study used statewide hospital and emergency department (ED) encounter data from 2000-2013 for South Carolina residents aged >18 years without prior MI at the onset of epilepsy, or the first encounter for controls. Persons with epilepsy were compared with 1) persons with migraine (PWM), whose neurological condition has characteristics similar to epilepsy; and 2) persons with isolated lower extremity fracture (PWLF). Subsequent MI was defined as a diagnosis of MI after the first clinical encounter for epilepsy, migraine, or lower extremity fracture (LEF); the association was evaluated with Cox proportional hazard modeling methods.

RESULTS

In this study, 2.2% of PWE, 0.6% of PWM, and 1.2% of PWLF had a subsequent MI. Persons with epilepsy were significantly more likely to be non-Hispanic Black (NHB), be covered by Medicaid, and reside in a rural or low income area compared with PWM and PWLF. Specific cardiovascular disease risk factors were more prevalent in PWE than in PWM and PWLF. After adjustment, the hazard of subsequent MI in PWE was 48% higher than in PWM (hazard ratio (HR) = 1.48; 95% confidence intervals (CI) = 1.31-1.67) and 24% higher than in PWLF (HR = 1.24; 95% CI = 1.10-1.39). The hazard of MI increased with increasing age and number of additional comorbidities and was higher in males, those living in rural areas, and those with specific cardiovascular risk factors.

CONCLUSION

Persons with epilepsy had moderately elevated risk of subsequent MI compared with PWM or PWLF. The association between epilepsy and MI needs to be further investigated, and clinical care of PWE should include evaluation and management of risk factors for MI.

Comorbidity of Migraine and Epilepsy in Pediatrics: A Review

Migraine and epilepsy are classified as chronic paroxysmal neurologic disorders sharing many clinical features, as well as possible treatment options. This review highlights the similarities between migraine and epilepsy in pediatrics, focusing on epidemiologic, pathophysiological, genetic, clinical, and pharmacologic aspects. Despite the fact that several syndromes share symptoms of both migraine and epilepsy, further research is needed to clarify the pathophysiological and genetic basis of their comorbidity. Drugs used for prophylactic therapy of migraine and epilepsy have similar pharmacologic properties. The role of epileptic pharmacotherapy in the prophylaxis of migraine is assessed, including the use of conventional antiepileptic drugs, calcium channel blockers, and nonpharmacologic methods such as dietary therapy, supplements, and vagal nerve stimulation. Further randomized, controlled clinical trials assessing pharmacologic and nonpharmacologic methods for the treatment of both disorders are essential, in order to initiate new therapeutic approaches.

Headache and Epilepsy

Headache, especially migraine, has long been associated with epilepsy, based on the common clinical features of these disorders. Both migraine and epilepsy have a genetic predisposition and share common pathophysiological mechanisms including an imbalance between excitatory and inhibitory factors that result in spells of altered brain function and autonomic symptoms. There are well-documented reports on the headache as a sole manifestation of epileptic seizure and headache is commonly associated with as preictal, ictal, and postictal symptoms in epilepsy patients. In addition, migraine and epilepsy are frequently described as highly comorbid conditions and several antiepileptic drugs are used for the patients with migraine as well as epilepsy. In the present review, we briefly discuss the connection between headache and epilepsy in various aspects, including classification, clinical features, epidemiology, genetics, pathophysiology, and treatment.

Exploring two novel cases of suspected ictal epileptic headache, a rare form of paediatric epilepsy

AIM

Ictal epileptic headache (IEH) is a rare and underestimated epileptic form, characterised by epileptiform discharges and headache attacks without any other ictal sensory-motor manifestations. IEH is difficult to diagnose, because the epileptiform discharges have to be registered during the headache attack and the headache has to disappear after the intravenous administration of an anti-epileptic drug, according to the last diagnostic criteria. This study explored the clinical, neuro-physiological and therapeutic features of IEH in the paediatric population.

METHODS

We analysed two novel cases of adolescent female patients with chronic headache and a long history of unsuccessful analgesic oral therapy and without any other ictal sensory-motor events. We also reviewed the entire literature on paediatric IEH.

RESULTS

The clinical history and diagnostic process led us to highly suspect IEH in both patients, and the successful therapy with oral anti-epileptic drugs, namely topiramate and ethosuximide, which resolved the chronic headache, enforced our diagnostic hypothesis. Our literature review highlighted the rarity of IEH clinical reports, particularly in the paediatric population, mainly due to the stringent diagnostic criteria.

CONCLUSION

Our study sheds further light on IEH in the paediatric population and on the importance of diagnostic electroencephalograms in the clinical management of paediatric patients suffering from chronic headache.

Behavioral health in young adults with epilepsy: Implications for transition of care

AIM

Neurodevelopmental and behavioral health disorders commonly occur with epilepsy, yet risk for young adults is unknown. The aim of this study was to determine the distribution and risk characteristics of neurodevelopmental and behavior health comorbidities among young adults with epilepsy compared with those among young adults with migraine and healthy controls.

METHOD

A case-control study examining hospital admission, outpatient, and emergency department (ED) visits for young adults with an ICD-9-CM diagnosis of epilepsy, migraine, or lower extremity fracture (LEF) was conducted. The association of epilepsy, migraine, or LEF with comorbidities was evaluated with univariate and multivariate polytomous logistic regression.

RESULTS

From 2000 to 2013, 29,139 young adults ages 19 to 25years were seen in hospitals and EDs for epilepsy (5666), migraine (17,507), or LEF (5966). Young adults with epilepsy had higher proportions of behavioral health comorbidities (51.8%) compared with controls with migraine (37.6%) or LEF (21.6%). In young adults with epilepsy compared with migraine, the increased risk of having any behavioral health comorbidity was 76%, and neurodevelopmental comorbidity was 297%. After adjustment, young adults with epilepsy showed significantly higher odds of each behavioral health comorbidity compared with controls with migraine and LEF.

INTERPRETATION

Young adults with epilepsy are particularly susceptible to behavioral health and neurodevelopmental disorders. Results are discussed within the context of transition to adult care.

Epilepsy and the Sensory Systems

The relations of epilepsy and the sensory systems are bidirectional. Epilepsy may act on sensory systems by producing sensory seizure symptoms, by altering sensory performance, and by epilepsy treatment causing sensory side effects. Sensory system activity may have an important role in both generation and inhibition of seizures.

The borderland of migraine and epilepsy in children

OBJECTIVE

To provide a review on the spectrum of migraine-epilepsy disorders in children.

BACKGROUND

The migraine-epilepsy continuum covers a fascinating array of disorders that share many clinical similarities but also differ fundamentally in pathophysiology. In the pediatric population, its study can be complicated by the young age of those affected and the lack of clear understanding of the neurobiology of these disorders within the developing brain.

DISCUSSION

This review serves to discuss the borderland of migraine and epilepsy in children. It will focus on epidemiology and comorbidity of the two disorders, possible mechanisms for shared pathophysiology informed by basic and translational science, and an overview of clinical similarities and differences. It will also discuss differentiation of migraine aura from childhood occipital epilepsies. Finally, the review concludes with a discussion of current classification methods for capturing cases on the migraine-epilepsy spectrum and a call for a united approach towards a better definition of this spectrum of disorders.

CONCLUSION

Recent advances examining the migraine-epilepsy spectrum show clinicopathological similarities between the two disorders in children. Epidemiology demonstrates reciprocally increased incidences of epilepsy in migraineurs and of migraines in children with epilepsy, however, prospective longitudinal in children are currently lacking. Clinically, the two disorders show similarity in preictal, ictal, and postictal phenomena, with close temporal association of the two conditions described by the controversial term of "migralepsy." Basic science research has contributed significant improvements in understanding the generation of both of these episodic neurological conditions, with common links seen at a cellular level involving synaptic glutamate release and the provocation of varying propagation methods including cortical spreading depression in migraine and the paroxysmal depolarizing shift in epilepsy. Despite these significant gains in understanding, improved classification methods are required to identify and further study these interrelated conditions and move towards improved diagnosis and treatment of disorders on the migraine-epilepsy continuum in children.

Mutations in the sodium channel gene SCN2A cause neonatal epilepsy with late-onset episodic ataxia

Mutations in SCN2A cause epilepsy syndromes of variable severity including neonatal-infantile seizures. In one case, we previously described additional childhood-onset episodic ataxia. Here, we corroborate and detail the latter phenotype in three further cases. We describe the clinical characteristics, identify the causative SCN2A mutations and determine their functional consequences using whole-cell patch-clamping in mammalian cells. In total, four probands presented with neonatal-onset seizures remitting after five to 13 months. In early childhood, they started to experience repeated episodes of ataxia, accompanied in part by headache or back pain lasting minutes to several hours. In two of the new cases, we detected the novel mutation p.Arg1882Gly. While this mutation occurred de novo in both patients, one of them carries an additional known variant on the same SCN2A allele, inherited from the unaffected father (p.Gly1522Ala). Whereas p.Arg1882Gly alone shifted the activation curve by -4 mV, the combination of both variants did not affect activation, but caused a depolarizing shift of voltage-dependent inactivation, and a significant increase in Na(+) current density and protein production. p.Gly1522Ala alone did not change channel gating. The third new proband carries the same de novo SCN2A gain-of-function mutation as our first published case (p.Ala263Val). Our findings broaden the clinical spectrum observed with SCN2A gain-of-function mutations, showing that fairly different biophysical mechanisms can cause a convergent clinical phenotype of neonatal seizures and later onset episodic ataxia.

[Migraine and epilepsy]

Migraine and epilepsy are both common episodic disorders that share many clinical features and underlying pathophysiological mechanisms. The comorbidity of these two conditions is well known. However, the temporal association between migraine and epilepsy is a controversial issue, since these two conditions may occur in numerous ways. Four types of association between headache and epileptic seizure are recognized: pre-ictal headache, headache as the expression of an epileptic manifestation, post-ictal headache, and inter-ictal headache. The classification of epilepsy by the International League Against Epilepsy did not refer to the epileptic headache. On the other hand, the International Classification of Headache Disorders, 3rd edition (ICHD-3) defines three entities: migraine aura-triggered seizure which sometimes referred to as migralepsy, hemicrania epileptica, and post-ictal headache. However, ICHD-3 mentions that there is a complex and bidirectional association between migraine and epilepsy. Most of the previous reports of migralepsy corresponded to occipital seizures that mimic migraine with aura. The term migralepsy has recently been criticized. Migraine and epilepsy share several pathophysiological mechanisms which involve neurotransmitters and iron channel dysfunctions. There is the hypothesis of a shared genetic susceptibility to migraine and epilepsy. Strong support of a shared genetic basis comes from familial hemiplegic migraine.

Diagnostic criteria currently proposed for "ictal epileptic headache": Perspectives on strengths, weaknesses and pitfalls

PURPOSE

When we published the diagnostic criteria for "ictal epileptic headache" in 2012, we deliberately and consciously chose to adopt restrictive criteria that probably underestimate the phenomenon, rather than spread panic among patients and physicians who are reluctant to accept this entity.

METHODS

Here we discuss four intriguing clinical cases to highlight why we believe, to this day, that it is necessary to follow these restrictive diagnostic criteria.

CONCLUSIONS

EEG is not recommended as a routine examination for children diagnosed with headache, but it is mandatory and must be carried out promptly in cases of prolonged headache that does not respond to antimigraine drugs, if epilepsy is suspected or has been diagnosed previously. This is not a marginal or irrelevant question because possible isolated, non-motor, ictal manifestations should be taken into account before declaring that an epileptic patient is "seizure free" so as to ensure that any decision taken to suspend anticonvulsant therapy is safe.