In anterior cord syndrome, which pattern of motor and sensory findings is most characteristic?

• A. UMN signs at the level of the lesion, LMN signs below the level of the lesion, and decreased pain and temperature below the lesion.
• B. Pure sensory loss with no motor involvement.
• C. LMN symptoms below the level of the lesion with preserved pain and temperature.
• D. LMN symptoms at the level of the lesion, UMN symptoms below the level of the lesion, decreased pain and temperature below the lesion.

Answer: (D)

Anterior cord syndrome damages the front two-thirds of the spinal cord, where the corticospinal and spinothalamic tracts reside. This causes motor signals to be disrupted below the lesion (producing upper motor neuron signs under the level of injury) while the anterior horn cells at the level can produce lower motor neuron signs right at the lesion. Pain and temperature pathways are also lost below the lesion due to spinothalamic tract disruption. Proprioception and vibration (carried in the dorsal columns) are spared because those pathways are preserved. So the typical pattern is LMN signs at the level, UMN signs below the level, and decreased pain and temperature below the lesion.