[Neuropsychiatric involvement in systemic lupus erythematosus. Part 1: clinical presentation and pathogenesis]

Central nervous system (CNS) involvement is a frequent complication of systemic lupus erythematosus (SLE) ranging from a subclinical to a severe disabling disease. Neuropsychiatric manifestations have been described in 18-67% of cases depending on the diagnostic criteria. The cerebral involvement may precede the full-blown picture of SLE or may develop in the course of disease, most frequently within the first 3 years.

Neuropsychiatric manifestations in SLE comprise diffuse psychiatric symptoms, focal neurologic symptoms, and the involvement of the peripheral nervous system. Numerous CNS syndroms have been described: migraine, seizure, stroke, chorea, transverse myelopathy, psychosis, mood disorders, acute confusional state, and cognitive dysfunction. The diagnosis of cerebral involvement can be difficult and has to be differentiated from neurologic complications which may be, for instance, due to uremia, hypertension, drug toxicity, and infection.

A large number of etiopathophysiologic processes are involved: antineuronal antibodies, antibodies against ribosimal P-protein, and cytokines have been implicated in the pathogenesis of diffuse neuropsychiatric symptoms. Focal neurologic symptoms are the consequence of vascular injury induced by circulating immune complex, occlusive vasculopathy as a result of endothelial cell activation induced by cytokines and complement activation, or macro- and microvascular thrombosis induced by antiphospholipid antibodies. In the later stages of disease, cerebrovascular manifestations are often related to accelerated atherosclerosis, which is entertained by increased intravascular complement turnover and antiphospholipid antibodies.