Admittedly, this is probably the toughest riddle to get. First you must know that the corticospinal tract is also called the pyramidal tract. Thus, it would have received its surname in Egypt. This is also hinted in the reference to something with walls that are tough to decrypt (hieroglyphics) being a key feature of pyramids. The pyramidal tract/corticospinal tract is a key descending pathway that decussates (switches sides) at the level of caudal medulla and descends toward the spinal cord (heads toward ground). Lesions affecting the corticospinal tract will produce clonus and spastic paralysis (clonia and hypertonia). Many of those with said lesions will sadly remain wheelchair-bound because of their injury.