I think it's mainstream vs alternative, for the most part. the mainstream tests are things like MRI, lumbar puncture, visual evoked potentials, nerve conductivity tests, etc etc.
alternative approaches use an assortment of tests for nutrient status, pathogens, etc.
READ ME key info on nutrient targets - www.thisisms.com/ftopict-2489.html
my approach: no meds so far - just nutrient-dense anti-inflammatory whole foods, and supplements where needed
info: www.whfoods.com, www.nutritiondata.com