Recognizing peripheral neuropathy. How to read the clues to an underlying cause.

Several systemic diseases, including some common ones (eg, diabetes, rheumatoid arthritis, thyroid disease) can cause symptoms of peripheral nerve dysfunction. Efficient identification and treatment of the underlying disorder can avoid costly and unnecessary testing. Patients' descriptions of symptoms and their onset, specific deficits found on physical examination, and family and medical history provide many clues to the cause of the neuropathy. Nerve-conduction studies, electromyography and, when necessary, nerve biopsy serve as complements to clinical evaluation.