We report two cases of neurosyphilis with atypical clinical presentations that were compounded by atypical neuroimaging findings. In the first case, MRI brain scan findings were felt to be compatible with mesial temporal sclerosis or herpes simplex encephalitis. The second patient presented with a clinical picture compatible with normal pressure hydrocephalus as well as some degree of ventricular enlargement and prominent periventricular white matter changes by MRI brain scan. He actually underwent ventriculo-peritoneal shunting prior to determination that he had active syphilitic involvement of the central nervous system. Neurosyphilis, "the great imitator," is not only capable of mimicking various other neurological disease clinical presentations, it can also mimic neuroimaging features of various other disease processes as well.

Meningovascular syphilis is now quite uncommon, but there have been increasing reports in patients immunocompromised with human immunodeficiency virus. The response of syphilis affecting the central nervous system to antibiotic therapy remains a challenge. This is an even greater challenge in patients who have underlying compromise of the immune system. The authors present a 46-year-old male with recurrent stroke who was found to have cerebrospinal fluid compatible with syphilitic involvement of the central nervous system and a cerebral arteriogram, which revealed focal narrowing of the right middle cerebral artery. The baseline transcranial Doppler study demonstrated increased mean and peak flow velocity within the right middle cerebral artery. Despite a 10-day course of intravenous penicillin, with substantial improvement in the cerebrospinal fluid results, this flow velocity elevation persisted, in a remarkably consistent pattern, over a 4-month follow-up period. Thus, the involved vessel remained patent following treatment, but no clear resolution of the stenotic lesion was observed.

Meningovascular syphilis is now quite uncommon, but there have been increasing reports in patients immunocompromised with human immunodeficiency virus. The response of syphilis affecting the central nervous system to antibiotic therapy remains a challenge. This is an even greater challenge in patients who have underlying compromise of the immune system. The authors present a 46-year-old male with recurrent stroke who was found to have cerebrospinal fluid compatible with syphilitic involvement of the central nervous system and a cerebral arteriogram, which revealed focal narrowing of the right middle cerebral artery. The baseline transcranial Doppler study demonstrated increased mean and peak flow velocity within the right middle cerebral artery. Despite a 10-day course of intravenous penicillin, with substantial improvement in the cerebrospinal fluid results, this flow velocity elevation persisted, in a remarkably consistent pattern, over a 4-month follow-up period. Thus, the involved vessel remained patent following treatment, but no clear resolution of the stenotic lesion was observed.

It is important to distinguish the not unexpected neurological deficits associated with inadvertent trauma to normal brain tissue during procedures associated with epilepsy surgery from vascular insults. Postoperative neuroimaging can be useful in this endeavor.

It is important to distinguish the not unexpected neurological deficits associated with inadvertent trauma to normal brain tissue during procedures associated with epilepsy surgery from vascular insults. Postoperative neuroimaging can be useful in this endeavor.