I see you've seen Urologists, maybe you've also seen a specialist in colo-rectal surgery, but have any of them mentioned Spastic Pelvic Floor Disorder with Pudental Neuralgia? Your symptoms could certainly fit that condition; one that many doctors are still unfamiliar with, although awareness appears to be spreading.

Diagnosis consists of a MRI and EEG biofeedback, and with treatment varing from muscle relaxants through to surgery, treatment of choice seems to be physiotherapy by a therapist who specialises in pelvic floor conditions. A specialist physiotherapist would work your muscles and nerves from your abdomen to the thighs and buttocks external and internal. It's a bit invasive, but certainly worth a try.

I assume your doctor has ruled out chronic infection, both in your epididymis and your prostate gland because with pain in this area, most doctors would initially look for infection. With no infection present, and because tingling is nerve based, the muscle surrounding your prostate gland could be irritating the nerves around it. Again a physical therapist who specialises in pelvic floor therapy would be the person to see. They could determine if your muscles in the area are tight, and can treat it.

If you’ve had a vasectomy in the past, then one more thing to consider is Post Vasectomy Pain Syndrome, even though you describe tingling rather than pain. If you've not had the surgery then there's no need to read this site: http://www.vasectomy-information.com/moreinfo/pvps.htm

I daresay you’ve searched the internet for answers but here a few sites I found informative.

http://www.pudendalhelp.com/symptoms.html
http://www.theaword.org/index.php?op...d=90&Itemid=41
http://www.springerlink.com/content/m481856256l8r200/
http://www.london-urology.co.uk/scrotal%20problems.htm
http://www.netdoctor.co.uk/interacti...40458-f10.html

Good luck with getting a diagnosis; you'll need that before any effective treatment can begin.