What condition is characterized by the loss of motor or sensory function in the lower extremities?

The condition characterized by the loss of motor or sensory function in the lower extremities is paraplegia. Paraplegia specifically refers to paralysis that affects the legs and lower part of the body, resulting from damage to the spinal cord or nervous system below the level of the thoracic vertebrae. This loss can stem from various causes, such as trauma, accidents, or diseases affecting the spinal cord.

In contrast, hemiplegia involves paralysis on one side of the body, typically affecting an arm and a leg on the same side; thus, it does not solely impact the lower extremities. Multiple sclerosis is a chronic disease affecting the central nervous system, which can lead to various symptoms including weakness, numbness, and coordination problems, but it does not exclusively manifest as loss of function in the lower limbs. Neuralgia describes nerve pain that can occur in various parts of the body and does not refer to a loss of motor or sensory function. Therefore, understanding the scope of paraplegia clarifies why it is the correct answer to the question regarding loss of function specifically in the lower extremities.