Which pattern of sensory and motor loss describes Brown-Séquard syndrome from a hemicord lesion?

Which pattern of sensory and motor loss describes Brown-Séquard syndrome from a hemicord lesion?

• A. Contralateral spastic weakness with ataxia.
• B. Ipsilateral motor weakness and loss of position/vibration with contralateral loss of pain and temperature below the level.
• C. Ipsilateral facial numbness.
• D. Contralateral complete paralysis.

Answer: (B)

Brown-Séquard syndrome comes from a half-spinal cord injury and produces a distinct, side-specific pattern of deficits. Damage to the corticospinal tract on the same side as the lesion causes weakness and spasticity on that side below the level of injury. The dorsal columns on the same side are also affected, leading to loss of fine touch, vibration, and proprioception on that side below the lesion. The spinothalamic tract, which carries pain and temperature, crosses to the opposite side shortly after entering the cord, so pain and temperature sensation is lost on the opposite side below the level of the lesion. Together, this yields ipsilateral motor weakness and loss of position/vibration with contralateral loss of pain and temperature below the level, which is the described pattern.

Brown-Séquard syndrome comes from a half-spinal cord injury and produces a distinct, side-specific pattern of deficits. Damage to the corticospinal tract on the same side as the lesion causes weakness and spasticity on that side below the level of injury. The dorsal columns on the same side are also affected, leading to loss of fine touch, vibration, and proprioception on that side below the lesion. The spinothalamic tract, which carries pain and temperature, crosses to the opposite side shortly after entering the cord, so pain and temperature sensation is lost on the opposite side below the level of the lesion. Together, this yields ipsilateral motor weakness and loss of position/vibration with contralateral loss of pain and temperature below the level, which is the described pattern.