A rational diagnostic approach to peripheral neuropathy.

Peripheral neuropathies are among the most common disorders encountered by neuromuscular specialists and their evaluation can be challenging. The first part of this review outlined an algorithm based on anatomy, pathology, electrodiagnosis, and clinical localization that leads to a full characterization of the peripheral neuropathy. In the second part, we apply this approach, emphasizing recognition of atypical features and formulation of a focused differential diagnosis, thus reducing the number of uninformative tests. We review evidence supporting the routine use of commonly ordered laboratory tests and recommend a panel of tests that should be performed in patients with symmetric, distal, sensory-predominant peripheral neuropathy. Using this diagnostic approach, a diagnosis could be made in two thirds of patients.