Antineural antibodies occur in Guillain-Barré syndrome (GBS), but have not been studied in lymphocytic meningoradiculitis (Bannwarth’s syndrome), which has clinical features in common with GBS. Employing a sensitive complement-fixation assay with homogenates of nerve root and brain as antigens, we recorded positive serum reactions to either tissue in 14 of 18 samples from patients with GBS during the first three weeks of the
disease. Five of nine samples were positive during the fourth to eighth weeks, whereas all seven patients sampled thereafter had negative reactions. Four GBS serum samples reacted only with nerve root, seven reacted only with brain, and eight reacted with both antigen preparations. One of 12 patients with meningoradiculitis and one of 50 supposedly healthy blood donors had serum antibodies to brain. Our results support the concept of an autoimmune mechanism in GBS, while in Bannwarth’s syndrome an infectious cause related to that of
Lyme disease may be suspected.