Study on the early-onset variant of benign childhood epilepsy with occipital paroxysms otherwise described as early-onset benign occipital seizure susceptibility syndrome.

PURPOSE

We studied the early-onset variant of benign childhood epilepsy with occipital paroxysms (EVBCEOP) proposed by Panayiotopoulos, to confirm whether his five criteria are sufficient to delineate EVBCEOP as a new epileptic syndrome, as well as to predict a good outcome prospectively at the time of the first examination.

SUBJECTS

The subjects were 649 children with localization-related epilepsies (LREs) observed in our hospital for >4 years.

METHODS

We applied the International Classification of Epilepsies and Epileptic Syndromes to the 649 patients and identified patients who had EVBCEOP from among those with nonspecific idiopathic LRE. The inclusion criteria were to satisfy all five criteria and all but one criterion (i.e., either ictal vomiting or occipital EEG paroxysms). We were blind as to the outcomes and selected patients who satisfied the following three of the five criteria at the time of the first examination, (a) normal development before the onset, (b) epilepsy onset age between 2 and 8 years, and (c) occipital EEG foci. We attempted to determine whether the outcome can be predicted prospectively, and whether the presence or absence of ictal vomiting affects the prognosis.

RESULTS

We identified 19 patients who satisfied all five criteria, 22 who exhibited all but occipital EEG foci, and 21 who exhibited all but ictal vomiting. The incidence of status convulsivus was higher in those with ictal vomiting than in those without ictal vomiting (p < 0.05). Interictal EEG performed every 6 months showed shifting and multiplication of EEG foci in 42 and 52% of all subjects, respectively. We identified 57 patients, 42 (74%) of whom were in remission by age 12 years. The number of patients who experienced remission did not differ significantly between those with (76%, n = 25) and without (72%, n = 32) ictal vomiting (p > 0.05).

CONCLUSIONS

Nosologically, EVBCEOP appears to constitute the earliest form of idiopathic epileptic syndrome different from classic BCEOP. However, its clinical spectrum, ranging from the absence of ictal vomiting to a combination of extraoccipital and multifocal EEG foci, is broad, such that further prospective study is expected to reveal the exact prerequisite criteria for determining the border of this epileptic syndrome and for clarifying the clinical spectrum within this syndrome.