Mycoplasma pneumoniae intrathecal antibody responses in Bickerstaff brain stem encephalitis.

The pathogenesis of Mycoplasma pneumoniae encephalitis is not established. We report, for the first time, the case of a patient with severe Bickerstaff brain stem encephalitis in whom we detected intrathecal production of M. pneumoniae-specific antibodies, contrasting the findings in another patient with less severe encephalitis in whom we detected intrathecal M. pneumoniae DNA but no specific antibodies. Our observations suggest that intrathecal M. pneumoniae-specific antibody responses may contribute to a more severe course of M. pneumoniae encephalitis.