[Visual evoked potentials and the P300 component in different courses of the posttraumatic vegetative state]

The late latency components of visual evoked potentials (VEP) and the component P300 AEP were analyzed to evaluate their informative value in the process of mental function restoration in patient after long-term traumatic coma. VEP components with latencies of 70 to 320 msec were studied in 24 patients. Topographical mapping of the power of the study VEP components and components P300 was made by the peak amplitude. Long-term VEP components and component P300 were examined by the method of three-dimensional localization of equivalent dipole sources. In 16 patients with positive tendencies in the condition there was a stable localization of the maximum VEP power in the parietal, sagittal, and occipital regions, component P300 showed its maximum amplitude in the central and parietal regions in the left hemisphere. Eight patients with negative tendencies in the status had the maximum VEP and component P300 in the frontal and temporal regions, predominantly in the right hemisphere. The paper shows it important to evaluate not only time-amplitude parameters and analyzes the tomographic features of its formation in dynamics.