Schizophrenia and schizophrenia-like psychotic epilepsy: An electrophysiological-biochemical correlation

Abstract

In this study, 15 schizophrenic depressives (SD) with normal EEGs, 17 schizophrenia-like psychotic epilepsy (SLPE) cases with hypersynchronous EEG pathology, but with no epileptic seizures in their medical histories, and 24 healthy control subjects were included. The dexamethasone suppression test (DST) has been used to compare SD and SLPE. Out of 15 patients with SD, 13 (86.67%) had a plasma cortisol concentration higher than 5 μg/dl in the predexamethasone sample taken at 11:00 p.m. Regarding post dexamethasone samples, 8 (53.33%) in their 4:00 p.m. samples and 11 (73.33%) in their 11:00 p.m. samples showed early escape from suppression. Mean values of serum cortisol concentrations were as follows: predexamethasone, 12.63 ± 7.32 μg/dl; postdexamethasone 7.96 ± 7.79 μg/dl at 4:00 p.m. and 9.31 ± 8.97 μg/dl at 11:00 p.m. Out of the 17 SLPE cases, 12 (70.59%) had a plasma cortisol concentration higher than or equal to 5 μg/dl in their 11:00 p.m. predexamethasone blood samples. 2 (11.76%) in their 4:00 p.m. and 3 (17.60%) in their 11:00 p.m. postdexamethasone blood samples showed early escape from suppression. Mean values of serum cortisol concentration were as follows: predexamethasone, 7.15 ± 5.02 μg/dl; postdexamethasone 2.49 ± 2.09 μg/dl at 4:00 p.m. and 3.24 ± 3.44 μg/dl at 11:00 p.m. It was concluded through this research, that two groups of patients with the same clinical symptomatology had actually different aetiologies. SD is an endogenous psychosis, on the other hand SLPE an epileptic phenomenon.