[Cognitive impairment? Don't forget neurolues].

Background: Cognitive disorders usually develop slowly over years and are mainly caused by untreatable neurodegenerative disorders. Rapidly progressive cognitive disorders should raise suspicion of an underlying and treatable psychiatric, internal or neurological condition. Timely recognition of these conditions is important.

Case: We present the case of a 68-year old man, presenting on the emergency department with a history of progressive cognitive impairment since several weeks. Cerebral MRI showed T2-hyperintensities in the left hippocampal, mesotemporal and insular regions; lesser so in the right mesotemporal region. After initial treatment for herpesencephalitis and autoimmune encephalitis, we diagnosed neurolues and started treatment with benzylpenicillin.

Conclusion: It may be difficult to diagnose neurolues because the vast variety of clinical symptoms and radiological signs. This case shows that neurolues should be considered in a patient with rapidly progressive cognitive disorders and that neurolues can mimic a herpesencephalitis or an autoimmune encephalitis. Timely recognition is important to prevent irreversible damage.