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.
EMG: electromyography; ESR: erythrocyte sedimentation rate; SPEP: serum protein electrophoresis; TSH: thyroid stimulating hormone; ANA: antinuclear antibodies; UPEP: urine protein electrophoresis; HIV: human immunodeficiency virus; CIDP: chronic inflammatory demyelinating polyneuropathy; IVIG: intravenous immune globulin. * Including sympathetic skin response, tilt table, R-R interval testing, valsalva maneuver. ΒΆ In patients with borderline normal serum B12.
