Brown-Séquard syndrome is caused by partial cutting of one side of the spinal cord, resulting in sensory and motor loss on which side?

Brown-Séquard syndrome is caused by partial cutting of one side of the spinal cord, resulting in sensory and motor loss on which side?

• A. Contralateral motor and sensory loss
• B. Ipsilateral motor and sensory loss
• C. Bilateral motor loss
• D. Ipsilateral motor loss only

Answer: (B)

A hemisection of a spinal cord disrupts pathways differently on the same side versus the opposite side. The corticospinal tract and the dorsal columns carry motor and fine touch/proprioception on the same side as the injury, so you get motor and sensory loss on that side. In contrast, the spinothalamic tract (pain and temperature) crosses to the opposite side early in the cord, so those sensations are lost contralaterally below the lesion. So the pattern is ipsilateral motor and sensory loss, with contralateral loss of pain and temperature. This makes the description of ipsilateral motor and sensory loss the best fit.

A hemisection of a spinal cord disrupts pathways differently on the same side versus the opposite side. The corticospinal tract and the dorsal columns carry motor and fine touch/proprioception on the same side as the injury, so you get motor and sensory loss on that side. In contrast, the spinothalamic tract (pain and temperature) crosses to the opposite side early in the cord, so those sensations are lost contralaterally below the lesion. So the pattern is ipsilateral motor and sensory loss, with contralateral loss of pain and temperature. This makes the description of ipsilateral motor and sensory loss the best fit.