Final answer:
A lesion to the spinal cord in the thoracic, lumbar, or sacral regions can lead to either complete paraplegia or incomplete loss of function in the form of hemiplegia, depending on the severity and nature of the injury.
Step-by-step explanation:
A lesion to the thoracic, lumbar, or sacral regions of the spinal cord can lead to paraplegia or hemiplegia depending on the extent and nature of the injury. A complete injury may result in paraplegia, or the loss of voluntary motor control of the lower body and sensation from that point downward. On the other hand, a hemisection of the spinal cord may cause hemiplegia, where one leg is paralyzed and sensory results can be complex, depending on which tracts are affected.
Physical injuries to the spinal cord such as from a motorcycle accident can damage the vertebrae, compressing or severing the spinal cord and leading to paralysis or loss of sensation in areas below the injury. Neurological disorders and spinal trauma can cause varying degrees of paralysis, with the outcome being complete or incomplete loss of function below the T, L, or S level of the lesion. Motor functions as well as sensory functions can be compromised, and in some cases, a person may experience paraplegia, affecting the trunk, legs, and pelvic organs, or a more localized hemiplegia, typically affecting one leg.