--you could have an acute onset small-fiber syndrome,and that would NOT be readily apprehensible through EMG and nerve conduction studies, as these tests only measure the function of larger, fully myelinated nerves. The smaller, lightly myelinated and unmyelinated fibers that subsume the sensations of pain and temperature (damage to which can produce all sorts of symptoms, including those you describe) cannot be tested in this way, they are just too small. Usually, these are tested through quantitative sensory testing, sudomotor axon reflex testing (a test of autonomic function), or through skin biopsy that quantifies the density of the smaller fibers.

A large number of acute neuropathies that aren't caused by injury have toxic or autoimmune components, but it often takes a while to find a nuero who is aware of the variety of tests that may need to be done. Many neuros are unaware of a lot of the serum tests for particular kinds of antibodies, for example. Some will even say if you have normal nerve conduction studies, you do not have neuropathy. (These neuros should be handed a number of the papers linked to in the Useful Websites section, and then lectured about not keeping current in the field. )

I wish you luck in finding a neuro who will take a comprehensive approach--but it wouldn't be a bad idea to take Liza Jane's spreadsheets with you anyway--not only are they good for tracking patterns over time, but they may suggest avenues of investigation that a doctor would not ordinarily think of.