Spotlight on Impact of sleep on epileptic manifestations

The circadian, homeostatic, ultradian, and microstructural processes that regulate the sleep-wake cycle are endowed with modulatory properties on epileptic events. In particular, sleep is a powerful trigger of both ictal and interictal manifestations. Non-REM sleep and cyclic alternating pattern promote strong activating effects, although REM sleep tends to exert a more inhibitory action. These characteristics are highly expressed in nocturnal frontal lobe epilepsy.

In this article, Dr. Parrino of the University of Parma discusses the impact of sleep on epileptic manifestations.

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Spotlight on Tonic status epilepticus

Tonic status epilepticus is a serious, sometimes fatal, epileptic condition that may last for days or even months and occurs mainly in children with neurocognitive impairment and severe epilepsy, such as Lennox-Gastaut syndrome. Tonic status epilepticus in these children comprises repetitive, frequent tonic seizures. Characteristically, as the status progresses, motor symptoms tend to lessen whereas autonomic disturbances, including respiratory depression, become more prominent. At final stages, there may be only electrographic evidence of tonic seizures. Video-EEG monitoring is usually mandated for the recognition of autonomic status epilepticus, particularly when motor manifestations are minimal.

Treatment is demanding, and the intravenous administration of benzodiazepines may be of some concern because of a few reports that these may induce tonic status epilepticus; newer antiepileptic drugs such as lacosamide have been reported as effective. Unfortunately, the only systematic studies of tonic status epilepticus are dated 40 years ago.

Dr. C P Panayiotopoulos of St. Thomas’ Hospital in London reviews the limited information on clinical manifestations, investigative procedures, pathophysiology, and optimal but anecdotal management of patients with tonic status epilepticus.

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Spotlight on Schizencephaly

Schizencephalies are brain dysgeneses characterized by cerebral clefts lined by the polymicrogyric cortex extending from the pial surface to the lateral ventricles. The severity of the clinical picture, made up by motor deficits, intellectual disability, and epilepsy, is related to type, location, and size of the clefts and the presence of associated brain abnormalities. Epidemiologic and genetic studies suggest both acquired and genetic causes.

In this article, Dr. Peter Barth of the University of Amsterdam describes the various types of schizencephaly with an update on recent findings.

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Spotlight on Lennox-Gastaut syndrome

Lennox-Gastaut syndrome is diagnosed in individuals with intractable epilepsy characterized by multiple seizure types, slow spike-wave pattern on EEG, and cognitive deterioration typically after first seizure onset. Seizure types include tonic seizures that mainly occur in sleep, atonic seizures, atypical absences, and myoclonic seizures. The condition may follow West syndrome, but has also been associated with various genetic and neurocutaneous syndromes, metabolic diseases, and early infectious or ischemic insults, or may have an unknown etiology. Numerous interventions as well as medications have been studied in treating this condition. Clobazam has been studied in controlling drop attacks and cannabidiol is being researched as an adjunctive antiepileptic agent in patients with Lennox-Gastaut syndrome and other intractable epilepsy syndromes.

In this article, Dr. Mary Spiciarich of Albert Einstein College of Medicine and Montefiore Medical Center and Dr. Solomon Moshe of Albert Einstein College of Medicine discuss the clinical manifestations, diagnosis, and management of Lennox-Gastaut syndrome.

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Spotlight on Transient epileptic amnesia

Transient epileptic amnesia has been considered a syndrome of mesial temporal lobe epilepsy characterized by (1) recurrent episodes of isolated memory impairment of epileptic cause (ictal or postictal) while other cognitive functions remain intact; (2) interictal memory disturbances of accelerated long-term forgetting and autobiographical and topographical amnesia; and (3) late age of onset with a mean of 57 years. The duration of episodes of amnesia is usually less than an hour with usual recurrence of around 20 times each year in untreated patients. In addition, brief seizures typical of mesial temporal lobe epilepsy are detected in two thirds of patients. Interictal EEG, particularly when recorded in sleep, shows temporal lobe spikes whereas EEG during attacks of amnesia demonstrates either ictal discharges or postictal features. In most cases of transient epileptic amnesia, no clear cause for the epilepsy is identified though MRI may show hippocampal atrophy or focal structural lesions in the temporal lobes. Transient epileptic amnesia is considered rare though it is frequently underdiagnosed or misdiagnosed as transient global or psychogenic amnesia. Patients with transient epileptic amnesia usually have an excellent prognosis; seizures respond extremely well to monotherapy with small doses of lamotrigine or levetiracetam though interictal memory disturbances may persist.

In this article, Dr. C P Panayiotopoulos of St. Thomas’ Hospital  discusses the clinical manifestations, biological basis, and diagnosis of transient epileptic amnesia.

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Spotlight on Antibody-mediated epilepsies

In this article, Dr. Sarosh Irani and Angela Vincent of Oxford University Hospitals and Dr. Bethan Lang of John Radcliffe Hospital summarize the recent advances in the field of antibody-mediated epilepsies. This entity began to be defined with the frequent observation of seizures in encephalitides associated with autoantibodies directed against surface antigens. The seizures in the antibody-positive cases are often best controlled with immunotherapies, which simultaneously reduce the levels of autoantibodies.

Recently, a new distinctive epileptic syndrome with frequent and brief dystonic episodes, typically involving the face and arm, has been recognized and found to be associated with VGKC-complex antibodies, almost always directed against LGI1. Patients with these “faciobrachial dystonic seizures” have a relatively poor response to antiepileptic drugs, but their seizures often respond better to immunotherapies. Emerging data suggest that patients who present with faciobrachial dystonic seizures progress to develop cognitive impairment, which may be prevented by treatment of the faciobrachial dystonic seizures. In addition, a few patients with status epilepticus and classical temporal lobe epilepsy have been described with these and other autoantibodies. Finally, although glutamic acid decarboxylase (GAD) is an intracellular enzyme, antibodies directed against GAD are found in patients with acute and chronic focal epilepsies and may be a marker of an autoimmune tendency. The antibody-mediated epilepsies are a growing field with important etiologic and therapeutic implications for both children and adults.

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MedLink Neurology authors are always at work to bring you broad and up-to-date coverage of neurology topics. We are pleased to highlight clinical summaries that have been recently added or updated and to introduce the authors who write these authoritative articles. We hope you enjoy these overviews and appreciate the contributions of our more than 450 authors who keep MedLink Neurology the premier information resource for neurologists.

Spotlight on Epileptic encephalopathy with continuous spike-and-wave during sleep

In this clinical summary, Dr. Natialio Fejerman of Hospital de Pediatria JP Garrahan in Buenos Aires, Argentina emphasizes the clinical and EEG features of epileptic encephalopathy with continuous spike-and-wave during sleep and the occurrence of secondary bilateral synchronies as a mechanism for the generalization of perviously focal epileptic discharges. In addition, the summary points out that this syndrome may appear in children, starting first with idiopathic focal epilepsies, and also in children with prenatal cerebral lesions. Language development and impairment in children and adolescents with the disorder is also discussed.

To view the complete clinical summary, click here.

MedLink Neurology authors are always at work to bring you broad and up-to-date coverage of neurology topics. We are pleased to highlight clinical summaries that have been recently added or updated and to introduce the authors who write these authoritative articles. We hope you enjoy these overviews and appreciate the contributions of our more than 450 authors who keep MedLink Neurology the premier information resource for neurologists.

Spotlight on Tonic status epilepticus

Tonic status epilepticus is a serious, sometimes fatal, condition that may last for days or even months and occurs mainly in children with neurocognitive impairment and severe epilepsy such as the Lennox-Gastaut syndrome. Tonic status epilepticus in these children comprises repetitive frequent tonic seizures. Characteristically, as the status progresses, motor symptoms tend to lessen while autonomic disturbances, including respiratory depression, become more prominent. At final stages, there may be only electrographic evidence of tonic seizures. Video-EEG monitoring is usually mandated for the recognition of autonomic status epilepticus, particularly when motor manifestations are minimal. Treatment is demanding, and there may be some concern about the intravenous administration of benzodiazepines because of a few reports that these may induce tonic status epilepticus; newer antiepileptic drugs such as lacosamide have been reported as effective. Unfortunately, the only systematic studies of tonic status epilepticus are dated 40 years ago. Dr. C P Panayiotopoulos, Consultant Emeritus in Clinical Neurophysiology and Epilepsy at St. Thomas’ Hospital in London, England, reviews the limited information on clinical manifestations, investigative procedures, pathophysiology, and optimal but anecdotal management of patients with tonic status epilepticus.

To view the complete clinical summary, click here.

MedLink Neurology authors are always at work to bring you broad and up-to-date coverage of neurology topics. We are pleased to highlight clinical summaries that have been recently added or updated and to introduce the authors who write these authoritative articles. We hope you enjoy these overviews and appreciate the contributions of our more than 450 authors who keep MedLink Neurology the premier information resource for neurologists.

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Spotlight on Ketogenic diet in the treatment of epilepsy

In this clinical summary, Dr. Marcio A Sotero de Menezes and Jennifer L Schoenfeld , both of the Swedish Medical Center in Seattle discuss the ketogenic diet, which is medical treatment for seizures that are refractory to antiepileptic drugs. It has been used as an earlier treatment option for infantile spasms, with some promising results. The ketogenic diet serves as an effective treatment option regardless of seizure type, seizure syndrome, and age. The authors discuss the scientific basis for the diet as well as the indications, contraindications, goals, and associated adverse effects.

To view the complete clinical summary, click here.

MedLink Neurology authors are always at work to bring you broad and up-to-date coverage of neurology topics. We are pleased to highlight clinical summaries that have been recently added or updated and to introduce the authors who write these authoritative articles. We hope you enjoy these overviews and appreciate the contributions of our more than 450 authors who keep MedLink Neurology the premier information resource for neurologists.

Spotlight on Genetic epilepsy with febrile seizures plus

In this clinical summary, Dr. Eleni Panagiotakaki of the University of Lyon and colleagues discuss genetic epilepsy with febrile seizures plus (GEFS+), an epileptic condition characterized by childhood febrile seizures and later development of epilepsy; the disorder is associated with dominant autosomal inheritance with incomplete penetrance. Therefore, the definition applies to families with multiple members that present febrile seizures or various types of (mostly) generalized epilepsies. The development of epilepsy typically presents as afebrile generalized tonic-clonic seizures that extend into later childhood. The predominant presence of this seizure type initially gave rise to the term “generalized epilepsy with febrile seizures plus”; however, the term “genetic epilepsy” is now preferred due to the presence of partial as well as generalized seizures in some patients. Other seizure types include myoclonic attacks, myoclonic-astatic seizures, absences, and episodes of status epilepticus.

To view the complete clinical summary, click here.

MedLink Neurology authors are always at work to bring you broad and up-to-date coverage of neurology topics. We are pleased to highlight clinical summaries that have been recently added or updated and to introduce the authors who write these authoritative articles. We hope you enjoy these overviews and appreciate the contributions of our more than 450 authors who keep MedLink Neurology the premier information resource for neurologists.