Which sensory modalities are decreased by lower-extremity paralysis?

Which sensory modalities are decreased by lower-extremity paralysis?

• A. Visual, auditory, and olfactory
• B. Tactile, proprioceptive, and vestibular
• C. Gustatory, tactile, and auditory
• D. Vestibular only

Answer: (B)

Lower-extremity paralysis disrupts the sensory signals that come from the legs. Tactile sensation (touch, pressure, pain) and proprioception (awareness of where the limbs are and how they’re moving) travel from the legs through the spinal cord to the brain, so when motor function is lost at the lower levels, these sensations are decreased below the level of the lesion. Balance and orientation also depend on vestibular input from the inner ear, but accurate perception of body position relies on combining that vestibular information with proprioceptive feedback from the limbs. If the legs can’t provide proprioceptive signals due to paralysis, the overall sense of body orientation and balance is weakened, which effectively reduces vestibular-related perception for the lower body. In contrast, senses like vision, hearing, taste, and smell aren’t directly affected by paralysis of the lower extremities. So the modalities most affected are tactile, proprioceptive, and vestibular.

Lower-extremity paralysis disrupts the sensory signals that come from the legs. Tactile sensation (touch, pressure, pain) and proprioception (awareness of where the limbs are and how they’re moving) travel from the legs through the spinal cord to the brain, so when motor function is lost at the lower levels, these sensations are decreased below the level of the lesion.

Balance and orientation also depend on vestibular input from the inner ear, but accurate perception of body position relies on combining that vestibular information with proprioceptive feedback from the limbs. If the legs can’t provide proprioceptive signals due to paralysis, the overall sense of body orientation and balance is weakened, which effectively reduces vestibular-related perception for the lower body.

In contrast, senses like vision, hearing, taste, and smell aren’t directly affected by paralysis of the lower extremities. So the modalities most affected are tactile, proprioceptive, and vestibular.