All - I'm just wondering if anyone out there has determined that their PN is being caused, at least in part, due to nerve impingement or damage in soft tissue. I had an injury (backed into an industrial fan) around the same time my PN started...can't remember if it was before or after the PN began (the PN started 16 years ago so my memory is cloudy). It turned my rear-end totally black and blue but it did not break the skin. I am toying with a theory that some of my neuromuscular tissue may have been damaged then and could be contributing to my PN. I have no idea whether I'm right or not. But a Physical Therapist told me that it feels like I could have nerve entrapment in my Gluteus Medius (sits just below the hip bone in the back) or in my piriformis muscles. My Glut Medius muscle actually feel lumpy, like I have nodules or something there. It also always feels so GOOD for someone to do deep tissue massage on the Glut Medius and piriformis, but even more at the Glut Medius. It does not eliminate the PN, but feels like something kind of temporarily releases.

In addition to the MRIs I'm supposed to have of my brain, cervical spine, and LS spine. I requested my neurologist to order an MRI of my pelvis with emphasis on soft tissue to investigate whether there is some sort of soft tissue damage or entrapment in my butt. Also, because of the vulvar pain and skin problems I have, I think the pelvic MRI might offer some clues. I specifically requested a 3-Tesla MRI because I understand they are the highest resolution and can detect soft tissue issues better than conventional MRI.

Any thoughts are appreciated.

--to have compressive neuro symptoms caused by malpositioned or overdeveloped muscle.

As you mentioned, piriformis syndrome is the most well-know example of this, but it has also been reported in some over-developed athletes in the area of the quadriceps and/or lower leg muscles. It is mentioned in the following:

http://emedicine.medscape.com/article/1234809-overview

I wonder if some steroid-using bodybuilders might have experienced this.

Also, particularly in the pelvic area, it is possible for tight or malpositioned ligaments to produce neuropathic symptoms. The track of the pudendal nerve (which serves the pubic area) takes it through some rather narrow spaces and sharp bends and compression is possible at several spots--particularly behind the sacrospinal ligament:

http://pudendal.com/

http://www.pudendalhope.org/node/13#...Pudendal_Nerve

I seem to have a recurrent case of pudendal neuralgia that I try to keep at bay with very hands-on physical therapy. An MRI of my pelvis also showed some evidence of varicose veins traversing the path of the S2 nerve pathway down to the pudendal nerve (the vein and nerve paths are parallel and close together anatomically)--it's unclear if this is contributing. (My radiologist said it's the first time she'd ever seen this in a male.)

I do know in other parts of my body I am prone to compressive neural symptoms when my muscles are engorged, such as after weightlifting. In my case I suspect it may have to do with regenerated nerve pathways that traverse the anantomy differently than my origianl ones did--my original acute-onset body-wide small fiber syndrome killed off or damaged a large proportion of my unmyelinated nerves that subsume pain and temperature sensations, and ongoing skin biopsies seem to show that I am slowly regenerating nerves, but these have to fight around and through other body tissue and likely end up traversing differently than they once did. It has certainly altered my fitness regimen--I go much more for high reps with light weights, trying not to build any bulk.

I believe that there is an anatomical variant in people concerning the piraformis muscle and the path of the sciatic nerve in the buttock area. Let me see if I can find that %...

yes, 10-30% is a figure often quoted:

http://en.wikipedia.org/wiki/Piriformis_syndrome

I personally think that sitting on stools, which are common in some large kitchens with islands in them, may also cause sciatica. I had a stool at my midnight job, and I'd perch on it doing paperwork (those were long painful 11 hr shifts), and I had a terrible sciatica after a year there. It took quite a while to heal up... and did so when I left that job (I quite midnights all together). Certainly an injury would do it too...but look around your life and see if you are sitting on something that is aggravating it, as well.