The study was undertaken to examine nerve-immune processes and the specific visual and limbic-reticular-cortical systems by analysing visual evoked potentials (VEP), as well as nerve-immune relationships in 21 patients aged 62.2ë1.3 years who had Alzheimer's disease and in 15 healthy individuals of the same age. AD patients were found to have lower lymphocyte count, enhanced proliferative activity of T lymphocytes and to tend to have increased production of interleukin (IL-1) as compared to that in healthy individuals. In AD, latent periods of late EVP components are higher than normal age-specific ones. The relationship between VEP and immunity parameters differ in normal ageing and AD. In health, there is a negative correlation between the latencies of N1, P2, N2 VEP components and the lymphocyte count and between the amplitude of a N1 VEP component and the production of IL-1. There is a prevalent correlation of immune parameters with VEP parameters in the right hemisphere. In AD, the higher proliferative activity of T lymphocytes is associated with more prolonged latent periods of N3 VEP components, suggesting that there are abnormal changes in the limbic-reticular-cortical systems of the brain.