A case of postmalaria neurological syndrome in Japan

Several neurological complications are associated with severe falciparum malaria. Indeed, some patients experience a neurological syndrome after complete recovery from Plasmodium falciparum infection. Particularly, postmalaria neurological syndrome (PMNS) is a self-limiting post-infective encephalopathy that occurs within 2 months after an episode of P. falciparum infection. We describe the case of a 54-year-old Japanese man who was readmitted to our hospital with incoherent speech and markedly disturbed and uncooperative behavior after a high-grade fever that occurred after an earlier adequately treated severe P. falciparum infection. Peripheral blood smears were repeatedly negative for malaria parasites, no organisms were detected in the cerebrospinal fluid, and no hallmark lesions of acute disseminated encephalomyelitis were depicted by brain magnetic resonance imaging. The neuropsychiatric symptoms were thought to be due to PMNS. The etiology of PMNS remains unclear, but it could be mediated by an immunological mechanism and could possibly be caused by mefloquine treatment. PMNS must be considered when characteristic neurological signs and symptoms such as psychotic or acute confusional episodes, general convulsions, and tremor occur after recovery from severe P. falciparum infection treated with oral mefloquine. This is the first reported case of suspected PMNS in Japan.