Purpose: We studied the electro-clinical evolution of the occipital EEG discharges characteristic of partial benign epilepsy of childhood with occipital paroxysms. The influence of age, sex, epilepsy course and treatment on the evolution of this electrical event were analyzed.
Methods: A longitudinal retrospective study that included 30 patients who fullfilled the diagnostic criteria of benign occipital epilepsy proposed by the ILAE. The onset, migration and disappearance of EEG foci were analyzed using the Pearson coefficient and non-parametric tests.
Results: Occipital spikes are found earlier when vomiting is an ictal symptom (p < 0.01) or longer seizures (p = 0.05). Patients with and antecedent of febrile seizures or with an visual aura show a later onset of occipital spikes (p < 0.05). Ictal vomiting is associated with a longer persistence of occipital spikes along the years. Migration of EEG foci to anterior regions is characteristic of early onset seizures and predicts a later remission (p < 0.05). Extraoccipital foci are associated with a high seizure and occipital spike recurrence rate.
Conclusions: Occipital spikes persist longer than seizures. Ictal vomiting is the only symptom related to specific EEG features: early onset, longer evolution and late remission of EEG discharges.