Which pattern of deficits is most characteristic of Brown-Sequard syndrome after a unilateral spinal cord injury?

• A. Ipsilateral motor weakness with contralateral loss of pain and temperature
• B. Bilateral weakness with bilateral loss of sensation
• C. Ipsilateral loss of cranial nerve function with contralateral motor weakness
• D. Contralateral motor weakness with ipsilateral loss of vibration and proprioception

Answer: (A)

Brown-Sequard syndrome shows a distinct hemicord deficit pattern: motor control pathways (corticospinal tract) on the same side as the injury are interrupted, producing ipsilateral weakness below the lesion, while pain and temperature pathways (spinothalamic tract) cross early in the cord and carry contralateral pain and temperature sensation, which are lost on the opposite side below the injury. This combination—ipsilateral motor weakness with contralateral loss of pain and temperature—is the classic signature of a unilateral spinal cord injury. Vibration and proprioception would typically be lost on the same side due to dorsal column involvement, but the key characteristic described here is the ipsilateral motor deficit paired with contralateral pain/temperature loss.