Immediate relief of Mycoplasma pneumoniae encephalitis symptoms after intravenous immunoglobulin

Mycoplasma pneumoniae may cause acute encephalitis, resulting in severe neurologic complications despite antibiotic therapy. We report the case of a 12-year-old patient who presented with acute onset of orofacial tics, motor restlessness, compulsive behavior, and cerebellar symptoms. Cerebrospinal fluid examination demonstrated lymphocytic meningitis. Polymerase chain reaction for M. pneumoniae was strongly positive in the cerebrospinal fluid. Blood and cerebrospinal fluid were negative for M. pneumoniae antibodies (immunoglobulin M and immunoglobulin G). The child was administered intravenous gamma-globulin, which led to a dramatic improvement of her clinical condition and disappearance of the symptoms within 72 hours. This novel case points to the potential value of gamma-globulin in M. pneumoniae encephalitis confirmed with polymerase chain reaction and suggests that immediate administration of intravenous gamma-globulin in suspected mycoplasma encephalitis should be investigated in a larger patient cohort.