Infection or drug toxicity? Acute ataxia and encephalopathy after uncomplicated falciparum malaria and efavirenz dose adjustment

Acute ataxia in children is a rare clinical syndrome usually caused by an infectious, post-infectious, or toxin-related aetiology. Although infrequent, acute ataxia can be related to more common diseases and treatments in Southern African countries including side effects of efavirenz-based anti-retroviral therapy (ART) for HIV or the post-malaria neurologic syndrome (PMNS) after infection with falciparum malaria. We describe a case from Lilongwe, Malawi of a 16-year-old HIV-positive patient with viral load suppression who presented with acute ataxia, confusion, and diplopia. Although he was on efavirenz-based ART for many years, his dose was increased 6 weeks prior, and he was treated for uncomplicated falciparum malaria 5 weeks prior with resolution of symptoms. Studies including cerebrospinal fluid analyses were normal, and he had rapid improvement of symptoms following discontinuation of efavirenz-based ART. Several case series have described supratherapeutic levels of efavirenz leading to acute ataxia as well as the self-limiting PMNS after non-complicated falciparum malaria. Though rare, recognition of efavirenz and PMNS as causes of ataxia is important to inform prompt treatment for HIV patients with acute ataxia in Malawi and other similar settings.