Neurophysiological Characteristics of Patients with Juvenile Schizophrenia at the Late Follow-Up Stage

Objective. To determine the neurophysiological features of schizophrenia at late (more than 20 years) follow- up and identify correlations between neurophysiological indicators and the clinical characteristics of the disease. Materials and methods. Patients of three groups were studied: those with a predominance of personality changes (group 1, 17 patients), those with negative disorders (group 2, 23 patients), and those with marked positive and negative disorders (group 3, 40 patients). The main study methods were psychopathological and neurophysiological, with assessment of event-linked potentials. Results and conclusions. A statistically significantly greater θ-rhythm frequency and a significantly lower α-rhythm frequency were found in group 3, the dominant frequency of the θ rhythm showing a correlation (positive) with the total score for positive disorders on the PANSS. No statistically significant between-group differences were seen in measures of the P300 wave of auditory event-related potential recorded in the oddball paradigm. These results are considered in the framework of views of the role of θ activity as a marker for hippocampal-prefrontal interactions.