Improvement of <i>Mycoplasma pneumoniae</i> –Associated Acute Cerebellar Ataxia and Possible Encephalopathy After Intravenous Immunoglobulin

<i>Mycoplasma pneumoniae</i> (<i>M. pneumoniae</i>) can cause acute postinfectious cerebellar ataxia and encephalitis/encephalopathy. Although ataxia can be self-limited, prolonged duration of symptoms and long-term neurological sequelae that persist for months or more are associated with both conditions. Multiple mechanisms have been suggested in the pathogenesis, but it seems that immune-mediated damage plays a pivotal role. In this report, two children with community-acquired pneumonia developed acute cerebellar ataxia (one with possible encephalopathy) associated with serologically confirmed <i>M. pneumoniae,</i> after having received antibiotics effective against <i>M. pneumoniae</i>. They improved rapidly after the administration of intravenous immunoglobulin (IVIG), without any sequelae. The exact role of immunomodulatory treatment such as IVIG in decreasing the severity and duration of <i>M. pneumoniae</i> acute cerebellar ataxia and encephalitis/encephalopathy and the criteria for administration need to be further studied.