Neopterin, a marker for activation of the cellular immune system, and interferon-gamma were measured in the cerebrospinal fluid of 40 infants and young children (ages 0.75 to 4.6 years) admitted with fever and/or convulsions to Nippon Medical School 2nd Hospital or Tama Nagayama Hospital, Japan.
CSF neopterin levels were significantly higher in 11 patients with febrile convulsions than in 22 with fever without convulsions or in 7 with convulsions without fever, 4 with status epilepticus. The CSF neopterin/serum neopterin ratio was also higher in patients with typical febrile convulsions, and those with prolonged febrile convulsions had higher CSF neopterin levels than patients with typical febrile convulsions. CSF interferon-gamma showed a tendency to higher levels in patients with febrile convulsions. 
COMMENT. Neopterin CSF levels are elevated in children with febrile convulsions, pointing to a mechanism involving an immune activation in the central nervous system. None had pleocytosis of the CSF, and the cause of the elevated neopterin levels is undetermined.