This patient likely has meningovascular syphilis, a condition in which low-grade infection in the subarachnoid space can affect the intracranial vessels and potentially result in stroke (due to vasculitis. Confusion, headache, and stiff neck are seen less frequently than in the more common meningitis form. RPR and VDRL testing should be performed to confirm the diagnosis of syphilis. Intravenous penicillin is the appropriate treatment.