Transient lesion in the splenium of the corpus callosum in acute uncomplicated falciparum malaria

Abstract

Patients with acute uncomplicated Plasmodium falciparum malaria have no evident neurologic disorder, vital organ dysfunction, or other severe manifestations of infection. Nonetheless, parasitized erythrocytes cytoadhere to the endothelium throughout their microvasculature, especially within the brain. We aimed to determine if 3 Tesla magnetic resonance imaging studies could detect evidence of cerebral abnormalities in these patients. Within 24 hours of admission, initial magnetic resonance imaging examinations found a lesion with restricted water diffusion in the mid-portion of the splenium of the corpus callosum of 4 (40%) of 10 male patients. The four patients who had a splenial lesion initially had evidence of more severe hemolysis and thrombocytopenia than the six patients who had no apparent abnormality. Repeat studies four weeks later found no residua of the lesions and resolution of the hematologic differences. These observations provide evidence for acute cerebral injury in the absence of severe or cerebral malaria.

Figure 1.

Magnetic resonance imaging studies of two patients with acute malaria who had no neurologic symptoms or signs. A–D, A 30 year-old man with uncomplicated malaria and a mixed infection (Plasmodium falciparum: 9,200 parasites/μL; P. vivax: 128 parasites/μL). E–H, A 22 year-old man with hyperparasitemia (P. falciparum: 588,000 parasites/μL). T2-weighted fluid-attenuated inversion recovery sequences (A and E) obtained shortly after admission show hyperintense, symmetrical oval lesions in the midline of the splenium of the corpus callosum (black arrows). Repeat examinations four weeks later (B and F), show resolution of the lesions. Diffusion-weighted imaging echo-planar imaging studies (C and G) shortly after admission showed relative decreases in the apparent diffusion coefficient within the lesions (white arrows) that had also resolved on the repeat studies (D and H) four weeks later.

Figure 2.

Change in apparent diffusion coefficient (ADC) (%) from day 1 (the first day after admission) to day 28 for four patients with a splenial lesion (left panel) and six patients without a splenial lesion (right panel). Gray circles and lines show the individual values; gray squares and lines show medians for each group of patients. Upper and lower 95% confidence intervals for the median are shown by the vertical gray lines.

Figure 3.

A, Change in hematocrit (%) from day 0 (admission) to day 3 for 4 patients with a splenial lesion (left panel) and six patients without a splenial lesion (right panel). Gray circles and lines show individual values; gray squares and lines show medians for each group of patients. Upper and lower 95% confidence intervals for the median are shown by the vertical gray lines. B, Change in indirect bilirubin concentration (mg/dL) from day 0 (admission) to day 3 for 4 patients with a splenial lesion (left panel) and 6 patients without a splenial lesion (right panel). Gray circles and lines show individual values; gray squares and lines shows medians for each group of patients. Upper and lower 95% confidence intervals for the median are shown by the vertical gray lines. C, Change in platelet count (×10³/μL) from day 0 (admission) to day 28 for four patients with a splenial lesion (left panel) and six patients without a splenial lesion (right panel). Gray circles and lines show individual values; gray squares and lines show medians for each group of patients. Upper and lower 95% confidence intervals for the median are shown by the vertical gray lines. Shaded areas in the figure indicate the laboratory reference range for each measurement.