The phrase "corticospinal tract" refers to a pathway in our body that transmits messages from our brain to our muscles. It helps us move and control different parts of our body. Full definition
A new approach for corticospinal tract reconstruction based on navigated transcranial stimulation and standardized fractional anisotropy values. (aetna.com)
This also occurs in babies under c. 1 year, because of low myelination of the corticospinal tracts. (en.wikipedia.org)