Brainstem and striatal encephalitis complicating Mycoplasma pneumoniae pneumonia: possible benefit of intravenous immunoglobulin.

Encephalitides of the brainstem and the striatum associated with Mycoplasma pneumoniae infection are believed to be mediated by an autoimmune process triggered by the organism, a toxin or direct invasion by the organism itself. Inability to identify M. pneumoniae from cerebrospinal fluid by culture or polymerase chain reaction suggested a possible immunologic process. A trial of intravenous immunoglobulin in a critically ill patient with encephalitis that developed in parallel to M. pneumoniae pneumonia was associated with neurologic improvement within 48 h of treatment.