Objectives To assess the prevalence of the 19 neuropsychiatric (NP) syndromes in systemic lupus erythematosus (SLE) patients, as defined by the American College of Rheumatology (ACR) in 1999, and ...better understand the reasons for interstudy variability of prevalence estimates, by performing a meta-analysis of relevant publications. Methods A literature search from April 1999 to May 2008 was performed to identify studies investigating NP syndromes in patients with definite SLE, applying the 1999 ACR case definitions and having a sample size of at least 30 patients. Excluded were studies that did not relate to all 19 NPSLE syndromes, presented duplicate data, or were irrelevant. Results Seventeen of 112 identified studies matched the inclusion criteria, reporting on a total of 5057 SLE patients, including 1439 NPSLE patients, with 2709 NPSLE syndromes. In a subanalysis of the 10 higher quality prospective and elicited studies (2049 patients) using the random-effects model, the prevalence of NP syndromes in SLE patients was estimated to be 56.3% (95% CI 42.5%-74.7%), and the most frequent NP syndromes were headache 28.3% (18.2%-44.1%), mood disorders 20.7% (11.5%-37.4%), cognitive dysfunction 19.7% (10.7%-36%), seizures 9.9% (4.8%-20.5%), and cerebrovascular disease 8.0% (4.5%-14.3%), although significant between-study heterogeneity was present ( P < 0.05). Autonomic disorder and Guillain-Barré syndrome carried a prevalence of less than 0.1%. No case of plexopathy was reported. Conclusions NP syndromes were estimated to exist in more than half of SLE patients. The most prevalent manifestations were headache, mood disorders, and cognitive dysfunction. A major limitation of the study was the significant heterogeneity of prevalence estimates between studies.
