I present a case of neurosyphilis presenting as acute stroke in a 44-year-old male; I review the current literature, with a particular emphasis on diagnostics and the pitfalls of serological testing. Neurosyphilis is an imprecise term and subsumes meningitic, meningovascular, parenchymatous and gummatous syphilis. Of these, meningovascular syphilis is most commonly associated with large vessel arteritis and stroke, particularly of the middle cerebral artery. Although syphilis rates have increased since the latter part of the 20th century, neurosyphilis remains a rare disease and epidemiological estimates are marred by imprecise use of terminology and the complexity of interpreting common laboratory tests.
Neurosyphilis can present in myriad ways depending on the extent of meningeal and vascular involvement, earning it the moniker–‘the great imitator’. There are no characteristic imaging features; radiologically, syphilitic arteritis most frequently involves the middle cerebral artery, but may include any intracranial vessels. Testing uses highly sensitive, but non-specific treponemal tests, followed by highly specific, but insensitive non-treponemal tests. Investigation must be thoughtful if improper use and interpretation is to be avoided. The rising incidence of syphilis in recent decades warrants it's consideration in the differential diagnosis of atypical stroke, particularly as early treat-ment with penicillin is effective.