Diagnostic approach to polyneuropathy

Extensive diagnostic testing is probably not necessary in a patient with mild symptoms who has a known underlying cause of neuropathy (eg, diabetes mellitus, alcohol abuse, or chemotherapy). However, a diagnostic evaluation is warranted in patients with no clear etiology or in whom symptoms are severe or rapidly progressive. In addition, a full diagnostic evaluation should be pursued in patients with atypical features, including asymmetry, non-length dependence, motor predominance, acute onset, or prominent autonomic involvement.