RESUMO
Neuralgic amyotrophy (NA), also known as acute brachial plexitis, is postulated as an autoimmune pathogenesis. In a well-defined cohort of patients with NA, we analyzed the cerebrospinal fluid (CSF) profile and the prevalence of antiganglioside antibodies. Patients with Varicella zoster-associated radiculitis and healthy blood donors served as controls. An abnormal routine laboratory CSF profile was found in 29% of those with NA, mostly showing a disruption of the blood-brain barrier. Antibodies predominantly from the immunoglobulin M (IgM) isotype against at least one human ganglioside were detected in 36% of sera from patients with NA but in only 2% of controls. An NA-specific reactivity pattern was not detected, and there was no significant association with clinical or CSF parameters. This suggests that the seroprevalence of antiganglioside autoantibodies in patients with NA is nonspecific.