[A case of encephalitis due to Mycoplasma pneumoniae: detection of specific DNA from cerebrospinal fluid and elevation of interleukin-6].

A 9-year-old female was admitted to our hospital due to a generalized seizure and consciousness disturbance. The patient had a fever and rash four days before admission, but she had no respiratory symptoms. The seizure and consciousness disturbance was prolonged and intractable. We diagnosed the patient as having encephalitis because of the increase in the cell count in the cerebrospinal fluid (CSF) and a diffuse slow EEG wave. The computed tomography of the head was normal. The causative agent was identified as Mycoplasma pneumoniae because of the increase of antibodies, and the detection of a specific DNA with a polymerase chain reaction. The interleukin (IL)-6 level of CSF was high (384 pg/ml). In spite of intensive treatment she had severe neurological sequelae. The invasion of Mycoplasma pneumoniae to the central nervous system appeared to have a role in the development of encephalitis in the patient. We speculated that there is a possible relationship between the IL-6 levels of CSF and clinical severity of encephalitis.