VI. Central nervous system syphilis
C. Tabes Dorsalis:
1. Pathology: Inflammatory lesions involving meninges and vessels in subarachnoid space of dorsal nerve roots. Loss of axons and myelin in dorsal roots with Wallerian degeneration of dorsal columns. (T. pallidum absent in cord parenchyma.)
2. Clinical symptoms: lightning pains; sensory deficits, including loss of pain sensation and loss of position sense (leading to ataxia); Argyll-Robertson pupils (react to accommodation but not to light).