Neuropsychiatric SLE: Lessons learned from MRI

OBJECTIVE:: The clinical manifestations of nervous system involvement in systemic lupus erythematosus (neuropsychiatric SLE or NPSLE) are highly diverse and their etiology is incompletely understood. The aim of this study was to provide an inventory of abnormalities on conventional brain MRI in NPSLE and to interpret the findings in relation to possible underlying pathogenetic mechanisms. METHODS:: MRI exams of the first episode of active NPSLE of 74 patients were retrospectively reviewed. All patients fulfilled the revised 1982 ACR criteria for SLE and were classified according to the 1999 ACR case definitions for NPSLE syndromes. Patients with a history of brain disease, and patients in whom other mechanisms unrelated to SLE caused the neuropsychiatric symptoms, were excluded. RESULTS:: The principal findings were: 1) focal hyperintensities in WM (49% of all patients) or both WM and GM (5%) suggestive of vasculopathy or vasculitis, 2) more widespread, confluent hyperintensities in the WM, suggestive of chronic hypoperfusion due to the same mechanisms, 3) diffuse cortical GM lesions (12%), compatible with an immune response to neuronal components or post-seizure changes, and 4) absence of MRI abnormalities, despite active signs and symptoms (42%). CONCLUSION:: Several distinct brain MRI patterns were observed in patients with active NPSLE, suggestive of different pathogenetic mechanisms. To advance our understanding of the various processes leading to NPSLE, the radiological manifestations may be a good starting point and useful for categorization of patients in further research