Chronic polyneuropathies in Vest-Agder, Norway

Epidemiological data on chronic polyneuropathies, especially inflammatory t ypes, is limited. The purpose of this study was to examine the spectrum of causes and estimated prevalence of various polyneuropathy types in Vest-Agd er, and to examine the clinical features of the Vest-Agder population of ch ronic inflammatory demyelinating polyneuropathy (CIDP). In Vest-Agder county (population of 155 464). polyneuropathy patients are r egistered in a database and followed prospectively. We did a measure of the database on October 31 1999. A total of 192 patients were registered. The prevalence for chronic inflamm atory demyelinating polyneuropathy (CIDP) was 7.7 per 100 000 population. T he course was relapsing in five of fifteen patients, progressive in four pa tients and slowly progressive in six of fifteen patients. Two of the fiftee n patients had pure sensory symptoms. The mean Rankin disability score was 3.4 at maximal deficit and 2.1 at last follow-up. The prevalence of parapro teinemic polyneuropathy was 5.1 per 100 000 population. None of the patient s with paraproteinemic polyneuropathy were worse than slightly disabled (di sability score less than or equal to 2). The prevalences for other polyneur opathies were as follows: polyneuropathy and RA, 1.3; polyneuropathy and Sj ogren's syndrome or sicca complex, 4.5 (polyneuropathy was the presenting s ymptom in five of seven patients); sarcoidosis 1.9; polyneuropathy and chro nic Lyme, 0.6; paraneoplastic polyneuropathy, 1.9; diabetic polyneuropathy 23.2; vitamin deficiency, 5.1; alcoholic and toxic polyneuropathy, 19.9; he reditary polyneuropathy, 14.8. Cryptogenic polyneuropathies made up 26% of all polyneuropathies. The mean disability score was 2.0 (SD 1.1). In conclusion, prevalence of CIDP was significantly higher than previously reported, and the prognosis was good in the majority of patients. Patients with paraproteinemic polyneuropathy were not severely disabled. Polyneuropa thy was the presenting symptom in the majority of patients with Sjogren's s yndrome or sicca complex.