Which cord syndrome yields bilateral loss of light touch and proprioception due to DCML disruption?

Which cord syndrome yields bilateral loss of light touch and proprioception due to DCML disruption?

• A. Anterior cord syndrome
• B. Posterior cord syndrome
• C. Central cord syndrome
• D. Conus medullaris syndrome

Answer: (B)

Disrupting the dorsal column-medial lemniscus pathway in the spinal cord stops the transmission of discriminative touch, vibration, and proprioception from the body. Those fibers travel up the dorsal columns on the same side, so when the posterior (dorsal) columns are damaged, light touch and position/vibration sense are lost on both sides below the level of injury. This pattern—bilateral loss of fine touch and proprioception with the motor and pain/temperature pathways spared early on—is characteristic of posterior cord syndrome, where the dorsal columns are affected. The other cord syndromes involve different tracts: anterior cord syndrome primarily hits motor pathways and the pain/temperature tract but spares the dorsal columns; central cord syndrome disrupts central structures and often presents with more upper-extremity weakness and a different sensory pattern; conus medullaris syndrome affects the sacral segments, causing early bowel/bladder changes and saddle anesthesia rather than a bilateral DCML sensory loss.

Disrupting the dorsal column-medial lemniscus pathway in the spinal cord stops the transmission of discriminative touch, vibration, and proprioception from the body. Those fibers travel up the dorsal columns on the same side, so when the posterior (dorsal) columns are damaged, light touch and position/vibration sense are lost on both sides below the level of injury. This pattern—bilateral loss of fine touch and proprioception with the motor and pain/temperature pathways spared early on—is characteristic of posterior cord syndrome, where the dorsal columns are affected.

The other cord syndromes involve different tracts: anterior cord syndrome primarily hits motor pathways and the pain/temperature tract but spares the dorsal columns; central cord syndrome disrupts central structures and often presents with more upper-extremity weakness and a different sensory pattern; conus medullaris syndrome affects the sacral segments, causing early bowel/bladder changes and saddle anesthesia rather than a bilateral DCML sensory loss.