THE VALUE OF SPECT FOR DIFFERENTIAL DIAGNOSIS OF PSYCHOGENIC PSEUDOEPILEPTIC AND EPILEPTIC SEIZURES. PRELIMINARY RESULTS

Summary Introduction.Neuroimaging techniques using radioisotope methods may be useful in the differen- tial diagnosis of epileptic and psychogenic pseudoepileptic seizures (PPS), especially when there is no ictal activity during video-EEG monitoring. Single-photon emission tomography (SPECT) con- ducted during an epileptic seizure reveals hyperperfusion in the part of the brain in which the seizure is taking place whereas there is suggestion of hypoperfusion during PPS. Objective.The purpose of this study was to assess the value of ictal and interictal SPECT in patients with PPS. Material and method. Material and method. Material and method. Material and method. Material and method. Twelve patients with PPS confirmed by video-EEG monitoring with ictal and interictal SPECT images were studied. Semi-quantitative analysis of the tomographic images was performed. Discussion and conclusions. Discussion and conclusions. Discussion and conclusions. Discussion and conclusions. Discussion and conclusions. Interictal SPECT was analysed in 12 patients and both ictal and inte- rictal images were analysed in 5 of them. Six patients showed regional decrease of perfusion with dominant deficit in the frontal region (5/6) and one patient showed frontal-temporal-parietal hyper- perfusion. In one patient the SECT images were the same in the ictal and interictal phases and regional decrease in perfusion in the ictal phase compared with the interictal phase was found in 4 patients. Interictal SPECT image cannot be a differential factor in diagnosis of PPS and epileptic seizures. Ictal SPECT with decreasing perfusion can be a useful tool in differential diagnosis. Addi- tionally, the correlation of regional hypoperfusion and interictal EEG changes in the group of pa- tients with PPS suggests that PPS may be biologically determined.