[Clinical and pathophysiologic aspects of viral infections of the CNS]

The available defensive mechanisms are generally sufficient to protect the central nervous system (CNS) against the penetration of infectious particles. The blood-brain-barrier plays a decisive role in this process. The present paper represents the most important circumstances realizing that: 1. The macrophage-lymphocyte-system, 2. the "oligoclonal-CSF-IgG-reaction", and 3. the influence of psychological and physiological burdens on clinical-chemical or immunological parameters. It seems to be important to overcome the instability of the immunosystem and to reestablish the base-line.