Clinical and electroencephalographic findings in early and late onset benign childhood epilepsy with occipital paroxysms.

Twenty-six patients were studied who had the clinical and electroencephalographic features of benign childhood epilepsy with occipital paroxysms (BCEOP) as defined by the Commission of the International League Against Epilepsy (ILAE). Twelve patients were characterized as having early-onset benign childhood occipital seizures (EBOS) susceptible syndrome, as described by Panayiotopoulos, and 14 patients had late onset childhood idiopathic occipital seizures (LOS). Patients with symptomatic epilepsy and whose EEGs exhibited occipital spikes were excluded. The age of onset of the EBOS group ranged from 2.6 to 9.4 years (mean: 4.9+/-1.7 years), which was significantly younger than the LOS group (range: 4-12 years, mean:8.4+/-2.5 years). Both sexes were equally affected. The patients in the EBOS group had less frequent and longer seizures, ictal vomiting, more frequent deviation of the eyes, adversive seizures and more frequent nocturnal and secondary generalized seizures (P<0.05). By comparison, patients in the LOS group had a higher incidence of seizures, shorter duration of seizures and more frequent diurnal onset (P<0.01); also, although not statistically significant, the LOS group had more frequent visual hallucinations and headaches. The EEG topography in both groups showed at either side of occipital area typical paroxysms that were unilateral or bilaterally synchronous. Neither group had dipoles according to scalp voltage mapping. The clinical prognoses were favorable for both groups. To distinguish EBOS from LOS, detailed description of the age of onset, motor symptoms, visual symptoms, presence of eye deviation and diurnal or nocturnal occurrence are essential.