The cause of neurologic (N) and psychiatric (P) syndromes in patients with systemic lupus erythematosus (SLE) is mutifactorial and includes primary immunopathogenic mechanisms, nonspecific sequelae of chronic disease, and concurrent illnesses. We compared the prevalence, diversity, and clinical significance of NP syndromes in patients with SLE and rheumatoid arthritis (RA).
Fifty-three patients with SLE were matched by age and sex to 53 patients with RA attending ambulatory clinics in a single academic medical center. All fulfilled the American College of Rheumatology (ACR) classification criteria for either SLE or RA. Cumulative NP manifestations were determined using the ACR nomenclature and case definitions for 19 NP syndromes. Depression and anxiety were measured by the Hospital Anxiety and Depression Scales (HADS) and symptoms of cognitive dysfunction were assessed by the Cognitive Symptoms Inventory (CSI). Health related quality of life (HRQOL) was evaluated by the SF-36 and fatigue by a 10 point Likert scale.
The patients were well matched with regard to age, sex, disease duration, and years of education. There were no significant differences in self-reported HRQOL, fatigue, anxiety, depression, and cognitive symptoms between the 2 groups. The proportion of patients with cumulative NP events was higher in RA than in SLE patients (47% vs 28%; p = 0.045), and of these the occurrence of multiple NP events in individual patients was comparable in both groups (SLE 53%; RA 48%; p = 0.75). Fifty-five percent and 66% of NP events occurred prior to the diagnosis of SLE and RA, respectively. NP events common to both SLE and RA patients were headaches, mood disorders, acute confusional states, anxiety, cerebrovascular disease, and cognitive dysfunction. Seizures and demyelinating syndrome occurred only in SLE patients, but were rare. Depression scores (HADS) were significantly higher in SLE patients with a history of cumulative NP events compared to RA patients with NP events (p = 0.02). Similarly, symptoms of cognitive dysfunction (CSI) were more common in SLE patients with a history of NP manifestations (p = 0.02). However, there were no significant differences in SF-36 subscale or fatigue scores between SLE and RA patients with cumulative NP events.
NP syndromes, regardless of etiology, are common in both SLE and RA patients. SLE patients with NP syndromes report more symptoms of depression and cognitive dysfunction compared to RA patients with NP syndromes, but do not report significantly poorer HRQOL. These results emphasize the presence of non-disease-specific causes of NP manifestations in SLE patients, which should be acknowledged in future studies of pathogenesis and treatment.