CNS involvement in primary Sjogren's syndrome - Prevalence, clinical aspects, diagnostic assessment and therapeutic approach

Among the systemic manifestations of primary Sjogren's syndrome, neurologic al involvement is still an intriguing and debated issue, Although periphera l nervous system abnormalities are a well documented occurrence with a repo rted prevalence ranging from 10 to 20%, opinions differ as to the prevalenc e of CNS disease, with suggestions from 'nonexistent' to 'very common'. The lack of agreement probably reflects the different populations selected, di fferent inclusion criteria and lack of rigorous epidemiological studies. In our experience, CNS involvement was detected in 7 of 87 (8%) unselected co nsecutive patients observed over a period of 5 years. The spectrum of CNS involvement is wide, including focal, diffuse, neuropsy chiatric and spinal cord symptoms, frequently characterised by insidious on set, remitting course and. sometimes, progressive evolution. The diagnostic approach enabling early recognition of this complication relies on careful clinical assessment using history and physical examination combined with n europsychological testing and instrumental, laboratory and imaging investig ations such as magnetic resonance imaging, single photon emission computed tomography, electrophysiological testing and CSF analysis. The clinical picture often shows spontaneous remission, but when overt neur ological symptoms occur or become progressive, therapeutic interventions wi th high dose corticosteroids and cytotoxic agents, such as intravenous cycl ophosphamide pulse therapy, may be indicated.