Differential sequestration of parasitized erythrocytes in the cerebrum and cerebellum in human cerebral malaria.

Abstract

Sequestration of parasitized red blood cells (PRBC) in the microvessels results in impairment of microcirculation with organ dysfunction in complicated human Plasmodium falciparum malaria. In cerebral malaria patients, the percentage of small blood vessels with PRBC sequestration is higher in the brain than in other organs. The clinical severity of cerebral malaria depends on the level of PRBC sequestration in the brain. In our study, postmortem samples from cerebrum and cerebellum of 16 patients who died of P. falciparum malaria were examined and compared using light microscopy. In the cerebellum, the percentage of microvessels with PRBC sequestration was higher than that in the cerebrum. The difference in sequestration rates between cerebrum and cerebellum is statistically significant (P < 0.05). There is a higher degree of vascularity in the cerebellum (7 vessels/mm2) than in the cerebrum (5 vessels/mm2), and the difference is also statistically significant (P < 0.025). Perivascular hemorrhages also occur more frequently in the cerebellum than in the cerebrum. The results of this study, which show that differential sequestration of PRBC occurs in the microvessels of the cerebrum and cerebellum, explain the varied neurologic manifestations that result from cerebral and cerebellar dysfunction in human cerebral malaria. This study also reveals the necessity of postmortem histologic examination of the cerebellum in every suspected case of cerebral malaria.