Clinical approach to peripheral neuropathy: anatomic localization and diagnostic testing.

PURPOSE OF REVIEW This article provides a clinical approach to peripheral neuropathy based on anatomic localization and diagnostic testing. RECENT FINDINGS Advances have been made in the evaluation of small fiber neuropathy and in the known genetic causes of neuropathy. SUMMARY History and physical examination remain the most useful tools for evaluating peripheral neuropathy. Characterization of a neuropathy aids in limiting the differential diagnosis and includes consideration of temporal profile (tempo of onset and duration), heredity, and anatomic classification. Anatomic classification involves (1) fiber type (motor versus sensory, large versus small, somatic versus autonomic), (2) portion of fiber affected (axon versus myelin), and (3) gross distribution of nerves affected (eg, length-dependent, length-independent, multifocal). Diagnostic testing may include serologic and CSF evaluation, electrodiagnosis, skin biopsy, quantitative sensory testing, autonomic testing, nerve biopsy, confocal corneal microscopy, and laser Doppler imager flare.