Aseptic meningoencephalitis in primary Sjögren's syndrome.

The clinical features and CSF characteristics of five patients with primary Sjögren's syndrome (SS) and associated aseptic meningoencephalitis (AME) are described. Episodes of AME were recurrent in four patients. Viral, fungal, and bacterial cultures were uniformly negative. Plasma cells were observed in the CSF but not in the blood of three patients. The CSF IgG:albumin index was elevated, suggesting intrathecal synthesis of IgG in each of the four patients tested; each patient had either one or two broad bands with the mobility of IgG on CSF agarose electrophoresis. These observations are consistent with current understanding of SS as a polyclonal gammopathy associated with the multifocal proliferation of B lymphocytes and plasma cells.