I had this same problem in the early nineties. The symptoms were a burning and tingling sensation in the little and ring finger, followed by numbness.
This ulnar paraesthesia came on without any history of trauma. There wasn't anything that I could think of that could have caused it.
I saw an upper limb surgeon and he told me that this was likely an impingement at the elbow, affecting the ulnar nerve. He said if this was the case, he could operate and release the nerve to bring it round to the front of the elbow. I wasn't too keen on that and wanted confirmation of the problem.
He sent me for elbow and ulnar groove and carpal tunnel X-rays and a set of cervical spine X-rays also.
Nothing significant was found on that imaging, so I was referred to a neurologist for an EMG. This is a nerve conduction study. I don't know if they still do those or if MRI is now the tool of choice, but I can tell you that it was a very uncomfortable study. I was given an electrode to hold in my left hand while the doc stuck a needle into various places in my forearm and neck. Attached to the needle was a wire through which a current was passed by means of a foot pedal. He basically delivers electric shocks near the nerve, and times the conduction velocity to the electrode. My arm was jumping involuntarily with each hit, and at one point I had a needle between my cervical spinous processes....not a nice sensation when the juice is turned on, I can tell you.
Well...conduction at the elbow was fine, this was not an ulnar groove problem, but he could not exclude a problem higher up. He recommended a CT scan of the neck, which turned out to be normal.
Next stop was physio to loosen up my neck: the theory at that point was that I had muscle tension and general stiffness of the neck made worse by wearing lead aprons as part of my job. I didn't notice an obvious improvement from physio: I suspect that it was good for me and helped me with a generic problem with my neck, but not THE problem with the tingling fingers.
In the end nothing was found, and I endured this problem for almost two years. It didn't compromise my work, the effect was more sensory than motor, although the physical assessment of L v R power indicated I had lost some on the left. I have my doubts about the significance of that, since I am right handed. In the end the problem went away by itself.
Anyway, have it investigated as thoroughly as you can...and if they still do EMGs then ask if you can have a few stiff whiskeys before you go in
