*discogenic pain is mainly central axial pain increase with flexion forward while facet pain exaggerated by extension0 and axial rotation (facet stress test ) , and is usually paraspinal
*discogenic pain is central over the spinous process ,
* applying vibration on the spinous process increases discogenic pain
many patient would experience both ( discogenic and facetogenic pain ) in the same time when they exhibit disc herniation
MRI is useful especially if you find disc with high intensity zone HIZ indicating disc degeneration
diagnostic facet medial branch block using small 0.25ml up to 0.5 ml L.A. could differentiate
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2764347/