Not Always an Infection: A Case Series of Immune-Mediated Encephalitis, Including the First Report of Hashimoto’s encephalopathy From Sub-Saharan Africa

Encephalitis is a global health problem particularly frequent in Sub-Saharan Africa (SSA), where aetiologies are most often thought to be infectious despite the low microbiological yield. Some evidence suggests that autoimmune encephalitis (AE) could, however, be more prevalent than reported. We report four (4) cases of immune-mediated systemic and non-systemic encephalitis, spanning across the large spectrum of this entity, presenting with a wide clinical and etiological heterogeneity. The first case is that of a 67-year-old lady with a three-month history of memory loss and abnormal behaviour. She was diagnosed with Hashimoto’s encephalopathy with a very good response on steroids. Case 2 is that of a 52-year-old man with an acute confusional syndrome with fever. He was diagnosed with encephalitis due to an undifferentiated connective tissue disorder responsive to immune therapy. The third case is that of a 14-year-old girl with a recurring history of motor deficits admitted for a rhomboencephalomyelitis due to neuromyelitis optica. Evolution was unfavourable in this case. The last case reports a 51-year-old male with an acute onset of behavioural abnormalities. MRI confirmed limbic encephalitis. Improvement was noted on steroids. The patient was lost to follow-up. We discuss the context-specific challenges of identifying AE, mainly due to diagnostic technologies' financial and geographical inaccessibility (cerebral imaging, serological tests, antibody panels). The goal of this case series is to raise awareness among clinicians managing patients with encephalitis in SSA to look beyond infectious causes and consider AE especially in the presence of subacute cognitive impairment, inflammatory cerebrospinal fluid (CSF), and limbic involvement on brain imaging.