In tabes dorsalis demyelination occurs in all areas, EXCEPT:
Posterior column
Posterior root
Posterior root ganglion
Basal ganglia
Tabes dorsalis Late manifestation of syphilis Symptoms and signs of demyelination of the posterior columns, dorsal roots, and dorsal root ganglia. Symptoms are Ataxic wide-based gait Foot drop Paresthesia; Bladder disturbances; Impotence; Areflexia; and Loss of positional, Deep-pain, and Temperature sensations. Trophic joint degeneration (Charcot's joints) can result from loss of pain sensation. Optic atrophy occurs in tabes. Ref: Harrison, E-18, P-1383