= consequence of hematogenous dissemination

Risk of progression: 3% if treated with penicillin; accelerated in cell-mediated immunodeficiency (HIV, AIDS)

Types:

1. Meningeal neurosyphilis
   Latency period:<2 years
   • thick nodular meninges + gummas (similar to tuberculosis / sarcoidosis)
2. Vascular neurosyphilis
   Latency period: 5–7 years
   • alternating arterial stenoses + dilatations ← large-vessel arteritis
   • parenchymal edema ← perivascular extension of subarachnoid infection / from rare deposition of cerebral gummas
   
   Cx: large- / small-vessel infarctions
3. General paresis
   Latency period: 10–20 years
4. Tabes dorsalis
   Latency period: 15–20 years