Cauda equina syndrome in a patient with high titer anti-RNP antibodies

Recently, several investigators have noted neurologic involvement in patients who have high titers of nuclear ribonucleoprotein (RNP) antibodies and who lack antibodies to the Sm antigen and dsDNA. Current evidence indicates the spectrum of neurologic disease in this group of patients differs from that seen in classic systemic lupus erythematosus (SLE). The most common neurologic problem in mixed connective tissue disease (MCTD) is a trigeminal neuropathy; this is seen only rarely in SLE, whereas convulsions, a common manifestation of 'cerebral lupus,' have only rarely been described in patients thought to have mixed connective tissue disease. This report describes a hitherto unreported association of cauda equina syndrome in a patient who had a high titer of autoantibodies exclusively reactive with RNP.