The aim of the study was to examine the relationship between epilepsy etiology and localization of epileptogenic foci (according to EEG and neuroimaging studies), types of epileptic seizures associated with certain foci localization, and to determine the possibility of prognosis of epilepsy based on EEG data.

404 adult persons with epilepsy (average age 8,5±3,0 years) were under our prospective prolonged supervision (on the average 8,5±3,0 years). There were 236 patients with symptomatic epilepsy (58,4%), 130 – with cryptogenic (32,2%) and 38 – with idiopathic epilepsy (9,4%). All patients during the study period repeatedly underwent standard complex examination – somatic, neurological and psychopathologic ones, EEG and neuroimaging (CT/MRI). EEG was performed in all patients on the software and hardware complex DX-NT32 (Ukraine) during the observation period of at least 1–2 times a year. 19-channel recording was used with electrodes placement according to the international scheme “10–20” with the conventional functional tests and recording time of 20–30 min. In some patients sleep deprivation, or EEG tracing during the first 1–3 days after the seizure were performed to register paroxysmal activity. Also the level of coincidence of EEG results and CT/MRI data for localization of epileptogenic foci in symptomatic epilepsy was defined.

In patients with idiopathic epilepsy diagnosis was established through clinical features of these age-dependent forms of epilepsy in combination with characteristic patterns in EEG.

In majority of patients (76,4%) with focal forms of symptomatic or cryptogenic epilepsy the regional epileptiform discharges were identified: spikes, sharp waves, spike-wave complexes, sharp-slow wave complexes with or without secondary bilateral synchronization. According to the results of EEG there were no statistically significant differences in the localization of epileptiform activity between patients with symptomatic and cryptogenic epilepsy, which may indicate the symptomatic nature of the latter with unknown cause. Bilateral lesions, predominantly of frontal localization, occurred in diseases affecting the brain diffusely (multiple sclerosis, alcoholism, metabolic – hypoxic encephalopathy) with the prevalence in the clinical picture of secondarily generalized seizures. Temporal foci were determined by the presence of mesial temporal sclerosis with the development of complex partial seizures and secondarily generalized seizures. Occipital localization of lesions was associated with brain injuries, parietal – with space-occuping lesions and perinatal pathology, which correlated with the data of CT/MRI in these patients. Lesions in the posterior cortex correlated with simple and secondarily generalized seizures. EEG data with registration of epileptiform discharges in the temporal region (so called “temporal+” foci) at any, including extratemporal, localization of the main epileptogenic focus testified about poor prognosis of remission of epileptic seizures and negative clinical pathomorphosis of focal symptomatic or cryptogenic epilepsy. EEG patterns characteristic for idiopathic epilepsy allowed predicting a relatively favorable course of the disease in most patients.

Ключові слова: epilepsy, etiology of epilepsy, EEG, epileptogenic focus

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