The prevalence of neuropsychiatric syndromes in systemic lupus erythematosus.

OBJECTIVE: To describe the prevalence of neuropsychiatric (NP) syndromes in a Finnish population of patients with systemic lupus erythematosus (SLE) and to classify them according to the recently developed American College of Rheumatology (ACR) nomenclature and case definitions for NPSLE.

METHODS: Cross-sectional, population-based study covering an area with 440,000 people. A total of 58 patients with a definite diagnosis of SLE and aged 16 to 65 years were found in the computerized database of the area hospitals. Of these, 46 (79%) agreed to participate. The diagnosis of various NP syndromes was based on clinical impression (H.A.) following history, examination, review of medical records, and neuropsychologic testing.

RESULTS: At least one NP syndrome was identified in 42 patients (91%). The most frequent manifestation was cognitive dysfunction (n = 37; 81%), followed by headache (n = 25; 54%) and mood disorder (n = 20; 43%). When mild NP syndromes (mild cognitive deficit, headache, mild depression, anxiety, electroneuromyography-negative polyneuropathy) were excluded, the prevalence of NPSLE dropped to 46%.

CONCLUSIONS: According to the ACR nomenclature, there is a high prevalence of NP manifestations in a population-based sample of patients with SLE. Most NP syndromes were classified as minor; if they were excluded, the 46% prevalence of NPSLE would be slightly less than estimated in previous studies.