Generalized 3-Hz spike-and-wave complexes emanating from focal epileptic activity in pediatric patients

Abstract

We present two pediatric patients with an uncommon electrophysiological seizure propagation pattern. Both had dialeptic seizure as the main or only symptom. Case 1 had a small mass in the left medial temporal structures; Case 2 had no lesion in MRI. In both, EEG showed not only left temporal spikes but also bilaterally synchronous 3Hz spike-and-wave complexes (SWC) from onset and unusual secondarily generalized 3 Hz SWC patterns arising from the left temporal region. Case 1 was seizure-free following mass resection; focal or generalized epileptiform EEG abnormalities were no longer present. In Case 2, magnetoencephalography localized the spikes to the left superior and mid-temporal gyrus, which ictal SPECT suggested was the origin of onset. These cases illustrate the close relationship between focal epileptic area and 3 Hz SWC and suggest that the focal area can trigger 3 Hz SWC. The therapeutic strategy may need to be altered in such patients.

Genetic generalized epilepsies with frontal lesions mimicking migratory disorders on the epilepsy monitoring unit

“…It has been suggested that one should not overinterpret “generalized” EEG abnormalities (such as hypsarrhythmia, slow spike‐wave complexes, (poly‐)spike‐wave complexes, polyspikes, and electrodecrement) as arguments against surgical epilepsy treatment in lesional patients . Classical 3/s spike waves, however, were not explicitly mentioned in this study. The hypothesis that even classical 3/s spike‐wave complexes may emanate from focal epileptogenic lesions and can be cured by epilepsy surgery was postulated by Kakisaka et al (2011) . However, evidence for that hypothesis was based on only one patient with a temporomesial ganglioglioma in whom 3/s spike waves disappeared after epilepsy surgery. Although there are clinical and EEG diagnostic criteria for the diagnosis of generalized genetic epilepsies by ILAE, in cases with more irregular findings, the diagnosis remains difficult.…”

Misleading Focal Clinical, Neurophysiologic, and Imaging Features in 2 Children With Generalized Epilepsy Who Underwent Invasive Electroencephalographic (EEG) Monitoring

“…Generalized discharges, resulting from secondary bilateral synchrony from a focal lesion, classically tend to be slower (<3 Hz) and have more irregular morphology. However, Kakisaka 8 reported one case with left mesial temporal lesion who had both temporal spikes and 3 Hz generalized spike-and-waves. The 3-Hz spike-and-waves disappeared after focal resection of the lesion.…”

Seizure Outcome and Its Prognostic Predictors After Hemispherotomy in Children With Refractory Epilepsy in a Chinese Pediatric Epileptic Center

“…As far as seizure semiology was concerned (3, 7), the presence of generalized seizures was related to unfavorable seizure outcomes ( OR = 1.84, 95% CI = 1.18–2.89, P = 0.008). It is reported that the immature structural and functional brains of younger children are more likely to experience generalized seizures than adult brains (12, 13). However, we did not determine any correlation between the presence of generalized seizures and unfavorable prognosis, although younger children constituted a large proportion of the cases in this study.…”