A reappraisal of atypical absence seizures in children and adults: therapeutic implications

ABSTRACT

Introduction: Atypical absences are generalized epileptic seizures typically affecting children with severe epilepsies and learning difficulties along with other seizure types. Video-EEG is essential for their diagnosis. Recently, atypical absence seizures have been reported as a hallmark of some developmental and epileptic encephalopathies.

Areas covered: This is a narrative review of the literature which describes the electroclinical features of atypical seizures, the characteristics of developmental epileptic encephalopathies in which this seizure type can occur, and the evidence supporting the use of individual antiseizure drugs for the treatment of atypical absences.

Expert opinion: Treatment of absence seizures typically relies on ethosuximide (ineffective against tonic-clonic seizures), valproate (associated with larger proportion of adverse events), or lamotrigine (less effective than the other two). However, unlike typical absences, atypical absences are usually intractable, persist lifetime, and their prognosis depends on the underlying etiology or associated epilepsy syndrome. Besides efficacy, other relevant factors, such as drug formulation, ease of titration and dosing, and drug interactions, should be considered. Drugs that may worsen epilepsy, cognition and behavior should be avoided. In the vast majority of patients, a polytherapy is required, although usually with limited efficacy. Finally, epilepsy syndromes featuring atypical absences require a multidisciplinary approach.

KEYWORDS:

• Atypical absence seizures
• epileptic syndromes
• epilepsy
• lennox-gastaut syndromes

Article highlights

• Atypical absences are generalized epileptic seizures of mainly severe epilepsies in children with learning difficulties who also suffer from frequent seizures of another type.

• Atypical absence is defined by “slow onset or termination or significant changes in tone supported by atypical, slow, generalized spikes and waves on a patient’s EEG

• Atypical absence may be difficult to recognize due to their often-subtle onset and mild clinical manifestations. Accordingly, reliable diagnosis cannot be made on the basis of observation or history alone

• Prognosis and management depend on the underlying disease and electroclinical syndrome.

• Valproic acid and ethosuximide are commonly used for treating atypical absences, although the evidence supporting the use of individual drugs against this seizure type is sparse and of low-quality.

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Declaration of interest

F Brigo has received speakers’ honoraria from Eisai and PeerVoice, payment for consultancy from Eisai, and travel support from Eisai, Italfarmaco S.p.A., and UCB Pharma. Meanwhile, P Striano has received speaker’s honoraria from FB Health, Kolfarma s.r.l., UCB Pharma, and Eisai. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

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Funding

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