Childhood occipital epilepsy of Gastaut is a purely occipital epileptic syndrome that manifests with frequent and brief visual seizures consisting of elementary visual hallucinations, blindness, or both. Postictal headache is common. Interictal EEG shows occipital spikes that may be activated by the elimination of fixation and central vision (fixation-off sensitivity); EEG may be normal. The syndrome is often misdiagnosed as basilar migraine or migraine with visual aura. Conversely, structural (symptomatic) epilepsies may imitate this syndrome. Prognosis is usually good, with remission of seizures and normalization of the EEG by the late teenage years. In this update, the author details developments in childhood occipital epilepsy of Gastaut and provides clues for its proper differential diagnosis in relation to migraine and other occipital epilepsies.
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• Childhood occipital epilepsy of Gastaut is purely occipital epilepsy with onset usually in late childhood and in the early teenage years.
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• It manifests mainly with typical visual seizures of elementary visual hallucinations or blindness that are usually of brief duration.
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• Seizures may be very frequent.
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• Postictal headache is common and it is often indistinguishable from migraine headache.
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• EEG often shows occipital spikes or occipital paroxysms that may demonstrate fixation-off sensitivity. However, some patients have consistently normal EEG.
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• Treatment with appropriate antiseizure medication is often needed.
Historical note and terminology
Gibbs and Gibbs documented that on EEG “. . . seizure foci in one or both occipital lobes are most commonly found in young children. Occipital foci tend to disappear in adult life, and the subsidence of the electroencephalographic abnormality is usually accompanied by a cessation of seizures” (27). Peak age at first discovery of occipital foci was 4 to 5 years, and they could occur in children without seizures. Gibbs and Gibbs also described an 8.5-year-old boy with “onset of attacks 2 months before the recording, consisting of blindness, followed by holding both hands to eyes, rolling up of eyes, and loss of consciousness. . . severe headache after attack. . . no convulsions at any time” (27). EEG showed independent bilateral occipital spikes. Although similar cases were later reported by other authors, the recognition of childhood occipital epilepsy of Gastaut was delayed. This was motivated in part by a report of several patients with occipital paroxysms on EEG with eye closure whose clinical features were interpreted as basilar migraine causing seizures (08).
Subsequently, Gastaut retrospectively identified 36 patients with occipital paroxysms and proposed them as “a new type of epilepsy: benign partial epilepsy of childhood with occipital spike-waves” (25; 26). The 1989 International League Against Epilepsy (ILAE) classification proposed this syndrome be called “childhood epilepsy with occipital paroxysms” (15). This was renamed as “late-onset childhood occipital epilepsy (Gastaut type)” in more recent ILAE proposals (18; 05). The ILAE 2017 operational classification of seizure types included this syndrome under “self-limited focal epilepsies,” meaning that it is an epilepsy syndrome that is likely to resolve over time.