A method of treating or improving neurological function in a human subject includes identifying a human subject diagnosed with at least one of post-CNS trauma, post-concussion syndrome, a chronic refractive epileptic encephalopathic condition, autism spectrum condition, cerebral palsy; or ischemic long term treatment for remote ischemic or traumatic brain injury; and administering to the human subject a composition comprising a pharmaceutically effective dose of filgrastim.