Postictal cerebrospinal fluid abnormalities in children.

OBJECTIVES To determine the frequency and characteristics of seizure-induced cerebrospinal fluid (CSF) abnormalities in children and to identify potential alternative causes of these findings. METHODS Consecutive patients (n = 80) who underwent lumbar puncture within 24 hours after a seizure were studied retrospectively. The presence of CSF abnormalities in total leukocytes, polymorphonuclear cells, and protein was determined by using age-specific reference values. Coexisting conditions that could affect CSF findings, such as traumatic lumbar puncture, concurrent neurologic disease, and undiagnosed meningitis, were identified. RESULTS Eighteen of the 80 patients were excluded from the final study group because of the presence of another condition that could alter the CSF. More than 50% of the excluded patients had an abnormal CSF leukocyte count or protein level, including 2 patients with initially undiagnosed meningitis, which was subsequently detected by post-hoc polymerase chain reaction testing. In the remaining 62 patients, postictal pleocytosis was detected in only 3 (5%), and increased protein was detected in only 6 (10%). The maximal postictal pleocytosis and protein level were 8 x 10(6) leukocytes/L (8 leukocytes/mm(3)) and 0.52 g/L (52 mg/dL), respectively. CONCLUSIONS Seizure-induced CSF abnormalities are rare in children, and alternative, often unidentified, disease processes may account for many observed postictal abnormalities. All patients with abnormal CSF after a seizure should be thoroughly evaluated for other causes of the abnormality.