Neurobiology of sleeping sickness.

The advanced stages of sleeping sickness are correlated with a spread of trypanosomes into the central nervous system (CNS), producing a disseminated encephalitis. Inflammatory reactions extend along the blood vessels causing perivascular cuffing, which consists of in filtrations and proliferations of lymphocytes and also increased numbers of astrocytes and microglia. Progress in our understanding of the functions of astrocytes suggests that they are efficient antigen-presenting cells, initiating and regulating the intracerebral inflammatory response and limiting parasite spread to the perivascular spaces.