Neurosyphilis can develop at any stage of syphilis despite of previously recieved treatment, and it can mimic any neuropschychiatric disorder. The psychopathology of neuroborreliosis is less described.

To describe the cases of schizophrenia - like psychosis in patients with these hronic neuroinfections.

Retrospective chart review study of five inmates (four with neurosyphilis and one with neuroborreliosis) was performed.

Psychiatric histories of two females (45 and 49 y.o.) and three males (31, 40, 45 y.o.) are achieved. In four cases they were initially misdiagnosed as paranoid schizophrenia and in one case - as a persistent alcoholic hallucinosis. The diagnosis of meningoencephalitis was verified by immunologic analysis of cerebrospinal fluid. Main psychiatric and neurologic features, radiologic findings and clinical outcomes of the desease are described.

Authors emphasize the significance of screening analises and neiroimaging data performed in psychiatric facilities and draw attention to a „new great masquerader” - neuroborreliosis.