Posterior cord syndrome at level of injury results in bilateral loss of which modalities?

• A. Light touch and proprioception (DCML)
• B. Pain and temperature
• C. Motor function
• D. Vibration and temperature

Answer: (A)

Posterior (dorsal column) pathways carry discriminative touch, proprioception, and vibration. When these dorsal columns are damaged bilaterally at a given spinal level, the loss affects the modalities carried by the DCML system on both sides below that level. Pain and temperature travel in the spinothalamic tract, and motor function travels in the corticospinal tracts, which are not disrupted in pure posterior cord injury, so those modalities are preserved. So bilateral loss of light touch (a form of discriminative touch) and proprioception reflects damage to the DCML system, making that option the best answer.