The effect of artesunate on short-term memory in Lyme borreliosis.

Lyme borreliosis is associated with memory deficits. While this may be related to cerebral infection by Borrelia bacteria, it may also be caused by concomitant co-infection by Babesia protozoa. The anti-malarial artemisinin-derivative artesunate has been shown to be effective against a number of Babesia species and to have efficacy against human cerebral malaria. We hypothesised that concomitant administration of artesunate in Lyme borreliosis patients would help alleviate the severity of self-reported short-term memory impairment. This hypothesis was tested in a small pilot study in which patients were treated with both an intravenous antibiotic and oral artesunate (20mg four times per day); treatment was associated with a reduction in the severity of short-term memory difficulties (P≃0.08). In light of these findings, we recommend that a formal randomised, placebo-controlled study be carried out.