Burton Chair in Neurology
University of Glasgow, UK
THEME: VIRUSES AND THE NERVOUS SYSTEM
The virus enters the body, replicates extraneurally, enters the nervous system and infects the neural cells.
Enterovirus, measles and mumps viruses spread haematogenously, while the polio, rabies and herpes viruses
spread through neural pathways. Viral neurotropism refers to the affinity of the virus to bind to a particular
neural cell. This selective binding is seen, for example, in HIV, which binds to the CD 4 molecule on the
susceptible T4 helper lymphocyte. Neurovirulence refers to the ability of the virus to produce actual
neurological disease and the virus is parasitic on the host cell. To counter this state, the human body naturally
holds a systemic humoral immune response system which can prevent entry of the virus into the nervous
system, as well as a cell-mediated response.
About sixty to seventy percent of AIDS patients have neurological involvement at some stage of the disease,
either due to the primary virus infection or secondary to opportunistic infection, caused by HIV-induced
immunosupression. Azathioprine acts on HIV replication, while other antiretroviral drugs are being evaluated.