Atypical brain response to novelty in rural African children with a history of severe falciparum malaria

Abstract

Plasmodium falciparum is the most common parasitic infection of the central nervous system causing neuro-cognitive deficits in 5-26% of paediatric cases. The burden cannot be reliably estimated because of lack of sensitive, culture-fair and robust assessments in rural settings. Auditory and visual brain event related potentials (ERPs) are used to compare novelty processing in children exposed to severe malaria with community controls. Fifty children previously admitted and discharged from Kilifi District Hospital with severe falciparum malaria were selected and compared with 77 unexposed age matched children. The results showed that up to 14% of children exposed to severe malaria had significantly different responses to novelty compared to unexposed children. Children exposed to severe malaria had smaller P3a amplitudes to novelty in both auditory [F (3, 119)=4.545, p=0.005] and visual [F (3, 119)=6.708, p<0.001] paradigms compared to unexposed children. In the auditory domain the differences in processing of novelty were not related to early component processing. The percentage of children with severe malaria showing impaired performance using ERPs is within the range previously reported using neuropsychological tests. The overall pattern suggests that severe malaria affects prefrontal and temporal cortices normally activated by stimulus novelty.

Fig. 1

Grand averaged ERPs elicited by novel visual stimuli for each diagnostic group at each midline electrode.

Fig. 2

Grand averaged ERPs elicited by novel auditory stimuli for each diagnostic group at each midline electrode.

Fig. 3

Grand averaged waveforms for frequent, infrequent and novel visual stimuli at midline electrodes for diagnostic groups. CM represents children with cerebral malaria, MS are children with malaria with seizures and PM had malaria with prostration.

Fig. 4

Grand averaged waveforms for frequent, infrequent and novel auditory stimuli at midline electrodes for diagnostic groups. CM represents children with cerebral malaria, MS are children with malaria with seizures and PM had malaria with prostration.