CSF glucose levels in febrile infants.

Simultaneous blood and CSF glucose levels were investigated in 143 febrile children without cerebromeningeal illness, who were evaluated due to fever in the first 2 months of life or febrile convulsions. There was a significant decrease (P less than 0.001) in the mean CSF-blood glucose ratio from 0.67 +/- 0.13 in the first 2 weeks of life to 0.56 +/- 0.11, 0.57 +/- 0.8 and 0.58 +/- 0.11 at the ages 2-4, 5-6 and 6-8 weeks, respectively. The mean CSF and blood glucose levels did not change significantly in this period. After the 2nd month of life there was a significant rise P less than 0.01 in the mean CSF-blood glucose ratio to 0.72 +/- 0.11, the customary normal value in children. This was associated with a significant rise in CSF glucose levels as compared to the first 8 weeks as a whole. Our study suggests age-related changes in CSF blood-glucose ratios during the first weeks of life which are important when evaluating infants for the possibility of meningitis.