Electroclinical features in children and adolescents with epilepsy and/or migraine, and occipital epileptiform EEG abnormalities

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.

[Comorbidity of migraine and epilepsy in childhood]

Migraine and epilepsy represent prevalent chronic neurological disorders of childhood. Migraine and epilepsy comorbidity relies on the common pathophysiologic and genetic mechanisms of the paroxysmal disorders the similarity of their precipitating factors, clinical manifestations and therapeutic approaches. The problems of differential diagnosis of migraine and epilepsy are related to peculiarities of migraine manifestations in children. Some forms of epilepsy could be accompanied by cephalgic seizures. The diagnostic criteria of headaches in epileptic patients are presented. A number of genetic diseases accompanying by migraine and epilepsy could be a model for delineation of shared pathogenetic mechanisms of these paroxysmal disorders in which genetically determined channelopathies may play an important role. The efficacy of antiepileptic drugs has been proven as the prophylactic treatment of migraine in pediatric patients. The advantages of levetiracetam as the prophylactic treatment for migraine and epilepsy comorbidity in children are discussed.

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.

The Comorbidity of Migraine and Epilepsy in Children and Adolescents

Migraine and epilepsy share a number of clinical attributes, including pathophysiology and clinical expression. Both are paroxysmal in nature and thus constitute episodic disorders, yet either may be chronic and/or recurrent. Epileptic seizures and migraine headaches may be mistaken one for the other and may even overlap. In particular, occipital lobe seizures may be misdiagnosed as migraine auras. In this article, we review the relationship between migraine and epilepsy, including the known genetic contributions to both conditions, prodromal, ictal, and postictal headache and shared pathophysiology and treatment options. We describe clinical conditions in which both migraine and epilepsy are prominent features. Lastly, we discuss electronecephaographic abnormalities that have been known to occur in individuals with migraine.

Electroencephalogram variations in pediatric migraines and tension-type headaches

This study evaluates specific electroencephalogram abnormalities in pediatric migraine and tension-type headaches, and demonstrates the clinical value of these abnormalities. We studied 50 migraine patients and 50 tension-type headache patients. Their mean age ± SD was 10.62 ± 3.21 (range, 5-16) years in the migraine group, and 13.00 ± 2.37 (7-16) years in the tension-type headache group. Diagnoses were rendered according to the International Classification of Headache Disorders, 2nd Edition, First Revision, of the International Headache Society. All patients underwent two waking-state electroencephalograms, one during a headache, and the other when headache-free. Thirty-six percent (18/50) of migraine patients and 12% (6/50) of tension-type headache patients revealed specific electroencephalogram abnormalities in headache attack electroencephalograms (P < 0.05). In headache-free period electroencephalograms, 16% (8/50) of the migraine group and 2% (1/50) of the tension-type headache group revealed abnormalities (P < 0.05). Our results indicate that electroencephalogram abnormalities are particularly prevalent in migraines, especially during headache attacks. This study is the first, to the best of our knowledge, on electroencephalographic evaluation of pediatric migraine and tension-type headache patients during both headache attacks and headache-free periods.

Headache in children

Headache is an extremely frequent symptom in childhood and adolescence, and a common reason for neurological consultation. The prevalence of primary headaches (about 85% in tertiary centers) ranges from 10% to 20% in schoolchildren, and increases with increasing age. No sex difference is apparent until age 11. Female preponderance begins about age 12; during adolescence the female-to-male ratio is about 2:1. A child is not a "little adult" and many developmental and individual factors affect headaches, pertaining to the clinical expression, diagnosis, and therapy of the primary headache. According to this view, several points have to be clarified, beginning by considering the child as a whole as regards his or her development, taking into account neurobiological and psychological maturational processes, familial, social, and environmental factors, and avoiding an adult-focused approach to the disease. It is necessary to find key points in the etiology, pathogenesis, diagnosis, treatment, and outcome of headache in childhood and adolescence.

Relationship between migraine and epilepsy in pediatric age

OBJECTIVE

Many studies have supported the hypothesis of alteration of cortical hyperexcitability as a possible pathological mechanism underlying the onset of migraine and epileptic attacks. Different biochemical pathways involving cellular structures may increase or decrease the excitability of neuronal membranes. The aim of this study was to identify a possible link between migraine and epilepsy from a clinical and neurophysiologic point of view.

METHODS

One-hundred thirty-seven children and adolescents consecutively diagnosed for tension-type headache and idiopathic migraine with and without aura were studied. Anamnestic, clinical, and instrumental data were collected by a neurological examination, a specific questionnaire, and awake electroencephalogram (EEG) registrations. EEG features of nonheadache and nonseizures control group were compared.

RESULTS

Fourteen cases (10.2%) had a positive history for seizures with fever, isolated seizures, or epilepsy. Distribution differed according to headache diagnosis; migraine with aura (MWA) was largely prevalent. Specific electroencephalographic abnormalities were present in 11.7% of the sample, with a significant different distribution across the groups of children with headache and the control group: specific interictal abnormalities were found in 10 of 23 (43.5%) children with MWA. Two factors, seizures and specific interictal electroencephalographic abnormalities, showed a different distribution in patients with MWA compared to other classes of headache and control group (P < or = .01).

CONCLUSION

The present study supports the hypothesis of a possible clinical continuum between some types of MWA and epileptic syndromes as entities due to altered neuronal excitability with similar genetic substrates.

Psychobiology of altered states of consciousness

The article reviews the current knowledge regarding altered states of consciousness (ASC) (a) occurring spontaneously, (b) evoked by physical and physiological stimulation, (c) induced by psychological means, and (d) caused by diseases. The emphasis is laid on psychological and neurobiological approaches. The phenomenological analysis of the multiple ASC resulted in 4 dimensions by which they can be characterized: activation, awareness span, self-awareness, and sensory dynamics. The neurophysiological approach revealed that the different states of consciousness are mainly brought about by a compromised brain structure, transient changes in brain dynamics (disconnectivity), and neurochemical and metabolic processes. Besides these severe alterations, environmental stimuli, mental practices, and techniques of self-control can also temporarily alter brain functioning and conscious experience.

Electroencephalography in migraine: a review with focus on quantitative electroencephalography and the migraine vs. epilepsy relationship

EEG-studies in migraine in the last decade has contributed modestly to the understanding of headache pathogenesis. Headache patient groups seem to have increased EEG responses to photic stimulation, but a useful biological marker for migraine in single patients has not been found. In future EEG and QEEG studies we recommend to use follow-up designs and record several EEGs across the migraine cycle. It is also important to use a blinded study design in order to avoid selection bias. A clinical EEG should be performed in patients with acute headache attacks when either epilepsy, basilar migraine, migraine with prolonged aura or alternating hemiplegia is suspected. Unequivocal epileptiform abnormalities usually suggest a diagnosis of epilepsy. In children with occipital spike-wave activity the probable diagnosis is childhood epilepsy with occipital paroxysms (CEOP). The final diagnosis of either an epilepsy syndrome or migraine must be mainly based on a clinical judgement [corrected].

Recent development in paediatric headache

Headache is one of the most common disorders that occurs during the early, developmental years of life. The present review critically discusses the most recently published reports concerning headache with onset in youngsters, delineating the current status of research in the various fields and outlining areas that require further investigation. Age-related characteristics need to be taken into account with considering the aetiology, diagnosis and treatment of juvenile headache.