Objectives: The aim of this study was to determine the diagnostic yield and to describe the spectrum of diagnosis encountered by evaluation of patients with symptoms suggestive of chronic polyneuropathy.
Methods: We prospectively evaluated 198 patients referred to a department of neurology with symptoms suggestive of polyneuropathy. The evaluation included nerve conduction studies with near-nerve technique, quantitative examination of temperature sensation, blood tests, chest x-rays, and skin biopsies as well as diagnostic tests for differential diagnoses.
Results: Polyneuropathy was found in 147 patients, alternative diagnoses in 25, and 26 remained undiagnosed. The etiology of polyneuropathy could not be identified in 25% of the patients with polyneuropathy. In the remaining 75%, the cause of neuropathy was diabetes and/or alcohol abuse (41%), monoclonal gammopathy of undetermined significance (5%), drugs (5%), connective tissue disease (3%), and a number of less frequent conditions. A previously undiagnosed condition was found in 30% of the patients with polyneuropathy.
Conclusion: Evaluation of patients with symptoms suggestive of polyneuropathy reveals a high fraction of patients with previously undiagnosed conditions both in patients ending up with a polyneuropathy diagnosis and those without this diagnosis.