Absence seizures in children: Clinical and electroencephalographic features

Abstract

The clinical and electroencephalographic (EEG) features of absence seizures in children were evaluated using EEG frequency modulation radiotelemetry and videotape monitoring. The only seizures evaluated were those with a spike-and-wave or multiple spike-and-wave duration lasting at least 3 seconds. A total of 926 absence seizures (426 typical, 500 atypical) were reviewed in 54 patients. Abnormal interictal EEGs, multiple seizure types, mental retardation, or developmental delay were more likely in patients with atypical absence seizures than in patients with typical absence seizures. Both types of absence seizures usually had a clear onset and cessation. Atypical absence seizures lasted significantly longer than did typical absence seizures. Automatisms occurred more frequently in typical absence seizures than in atypical ones, while decreases in postural tone or tonic activity occurred more frequently in atypical absence seizures. Receptive and expressive speech were retained in some patients during both types of seizures. This study demonstrates that typical and atypical absence seizures are not discrete entities but rather form a continuum. No single clinical feature can adequately distinguish the two seizure types.

The EEG in Selected Generalized Seizures

“…The background activity is usually normal, although some degree of slowing of the background rhythms may be seen in up to one third of patients (Sato et al, 1983;Holmes et al, 1987). Paroxysms of rhythmic slow wave activity with a frequency of 2.5 to 3.5 Hz may occur in a generalized fashion or may be restricted to the occipital derivations ( Fig.…”

“…The interictal EEG in patients with absence seizures typically demonstrates brief bursts of 3 Hz spike-and-wave activity that are bilaterally synchronous and symmetric (Penry et al, 1975;Holmes et al, 1987). These bursts are usually frontocentral dominant; however, in some patients the bursts are restricted to, or maximally expressed in, the occipital regions.…”

“…This rhythmic slow activity is generally symmetric and usually blocks with eye opening. It may occur in isolated runs or may be coupled with the bursts of generalized spike and wave activity described below (Dalby, 1969;Holmes et al, 1987).…”

Idiopathic generalized epilepsy

“…The distinction between typical and atypical absence seizures has been recognized for decades [4]. Atypical absence seizures often have tonic or atonic components and occur in neurologically abnormal children [5]. Typical absence seizures are seen with CAE, but the official diagnostic criteria for CAE are surprisingly vague [1].…”

Systematischer Zugang zur EEG-Befundung bei Epilepsie

“…Repetiti sence genannt, obwohl nachweislich kei ne Bewusstseinsstörung, sondern die Un fähigkeit, eine Bewegung zu initiieren, vorliegt [33]. Während Slowspikewave Komplexen findet sich keine gute Korre lation zur klinischen Anfallssymptomatik ("atypische Absencen"; [12]; . Abb.…”