The Cortical Spinal Tract and Facial Weakness

The cortical bulbar tract begins with cells in the motor cortex. It travels via white matter through the corona radiata and then down again through the cerebral peduncles. The homunculus continues out into the lateral aspect of the cerebral cortex with the facial muscles or the muscles of voluntary facial movements. And there's a little bit more variable decosation here, but in general, these nerves will decosate at the level of the cranial nerve nucleus that they're going to innovate.