Functional Neurology usually refers to chiropractors who have been trained by the Carrick Institute. Some have found it to be helpful. Others have found it to be a big waste of money. It is difficult to get insurance to cover the costs.

It appears to be a "You gotta try it to see if it helps" situation.

btw, Not all Carrick trained chiros follow the Carrick protocols. Some pick and choose and integrate the concepts into their own ideas.