The sequential changes in localization of EEG foci with age, and the relation between the clinical manifestations and EEG pattern in Panayiotopoulos syndrome (PS) were analyzed in a study of 76 children (37 boys and 39 girls) followed for>2 years at Tokyo Woman’s Medical University, Japan. PS syndrome (early-onset benign occipital seizure susceptibility syndrome) is characterized by the following: onset of epilepsy between ages 1 and 8 years; attacks of ictal vomiting and eye deviations, with or without secondary generalization; normal development before seizure onset; normal neuroimaging; occipital EEG foci, at times shifting to centrotemporal or frontal regions with age; and remission before age 12 years. In this study, the EEG findings were excluded from the criteria for inclusion. A history of febrile convulsions was recorded in 33 (43.4%) patients, and a family history of seizure disorder in 21 (27.6%). The age at onset of epilepsy ranged from 14 to 118 months (average 48 months). Seizures recurred from 0 to 139 months (median 70 months); the total number in each case was 1 to 27 (mean 4.8). Status epilepticus occurred in 45 (61.6%) cases.

The EEG occipital spike focus (12 cases) was seen most frequently at 2 to 5 years of age; independent and synchronous frontopolar and occipital spikes (Fp-0 spikes) (14 cases) at 4 to 7 years: and centroparietotemporal (CPT) spike foci (21 cases) at 6 to 10 years. EEG foci showed frequent shifting, multiplications, and generalization with age. The Fp-0 group showed the latest age at onset of epilepsy. The generalized EEG pattern (19 cases) had the highest frequency of seizures and status epilepticus, and the longest active seizure period. The prognosis was favorable regardless of the EEG pattern. [1]

COMMENT. EEG foci in Panayiotopoulos (PS) syndrome do not persistently localize to occipital regions but tend to shift location, multiply, and become generalized with age. The various EEG patterns tend to appear at different ages and to be associated with certain clinical characteristics. For example, the generalized EEG pattern group has the highest frequency of seizures, status epilepticus (SE), and longest active seizure period. In contrast, the CPT group has the shortest active seizure period, but often presents with SE. The most characteristic clinical manifestation, occurring in all patients, is the ictal vomiting. In PS a genetic predisposition to seizures is common. The outlook is generally good, with seizure remission before 12 years of age.

Abnormal neuroimaging in patients with BECTS is reported in 15% of 71 cases [2]. These included dilated lateral ventricles, neonatal intraventricular hemorrhage, and agenesis of corpus callosum.