[Paresthesia and/or pain affecting the hand and/or wrist as a referral for electrodiagnostic studies].

To study the reasons for referral to electrodiagnostic evaluation, 490 patients referred for electrodiagnostic evaluation to two laboratories (UNIFESP and UNEF) answered the following question: "What was the reason that brought you to look for a physician and that led him to ask this examination?" Paresthesia and/or pain were answered as the main reason by 175 of them (26% UNIFESP and 40% UNEF). The electromyographical examinations were normal in 30.8% and 35.3% and involvement of the median nerve at the wrist was detected in 5 9% and 51.5% of them. Nocturnal symptoms and paresthesia were commonly noted in both groups of patients; they, however, were not able to separate the patients with and without median nerve compression at the wrist. The question asked seems to be a useful selection instrument, to select two similar symptomatic samples of patients from two laboratories serving with very different target populations.