Lateral corticospinal tract

The lateral corticospinal tract is formed at the level of the of the medullary pyramids when the majority (90%) of descending corticospinal tract fibers decussate. The remaining 10% do not decussate and form the much smaller anterior corticospinal tract. A few non-decussated fibers may enter the lateral corticospinal tract .

The lateral corticospinal tract descends along the lateral funicular and then lies anterolateral to the dorsal horn. As it descends it deviates to the dorsolateral surface of the spinal cord, with individual fibers leaving the tract to synapse with grey matter motor neurons within the ventral horns. As more fibers leave the corticospinal tract commensurately diminishes in size. At approximately the fourth sacral level, it terminates entirely.


The lateral corticospinal tract mostly mediates fine-motor movement of the upper and lower limbs .

Related pathology