Objective: To study the clinical features and natural course of idiopathic polyneuropathy.
Design: Prognostic and descriptive cohort study.
Setting: University Hospital, Utrecht, the Netherlands.
Method: 75 patients (46 men, 29 women) with a mean age of 56.5 years at onset of symptoms were clinically investigated during two years.
Results: The features of chronic idiopathic polyneuropathy were heterogeneous. Clinically, 44 patients had a sensorimotor, 29 patients a sensory and 2 patients a motor polyneuropathy. Electrophysiological and nerve biopsy studies were compatible with an axonal polyneuropathy. The overall clinical course was slowly progressive. None of the patients became severely disabled. After one year of follow up one patient proved to have a hereditary neuropathy. In the other 74 patients no cause for the polyneuropathy was found even after 2 years of follow-up.
Conclusion: Chronic idiopathic polyneuropathy is a heterogeneous entity, leading to only slight disability. The neuropathy is due to axonal degeneration.