Clinical correlations of electroencephalographic occipital epileptiform paroxysms in children.

A longitudinal prospective approach was used to investigate clinical correlations of interictal occipital paroxysms with or without fixation-off sensitivity (FOS). Occipital paroxysms were recorded in the electroencephalograms (EEGs) of 76 children with heterogeneous clinical conditions including seizures in 39 patients. Occipital paroxysms with FOS (42 patients ) were only fractionally more frequent than non-FOS (34 patients ) and were not specific of any clinical condition. Although present and FOS-related in all 11 children with benign childhood epilepsies with occipital paroxysms (CEOP), they were also frequently encountered in symptomatic occipital epilepsy. The differentiation of CEOP from other syndromes established on clinical grounds could also be aided by the analysis of background EEG activity that was frequently significantly more abnormal in symptomatic than CEOP. Clinical characteristics and ictal seizure semiology as well as follow-up clearly distinguish two type of idiopathic CEOP syndromes: (1) early onset type or Panayiotopoulos syndrome characterized by excellent prognosis and rare, prolonged nocturnal seizures with tonic deviations of the eyes and vomiting, and (2) late onset or Gastaut type showing a common ictal visual symptomatology, co-occurrence of migraine, diurnal complex partial seizures and less favourable EEG-clinical prognosis.