The role of fever on cerebrospinal fluid glucose concentration of children with and without convulsions

In febrile convulsions glucose concentrations are known to increase both in the blood and cerebrospinal fluid (CSF). The reason behind this increase is, however, incompletely understood. We have studied the effects of convulsion and fever on the CSF and blood glucose concentrations in four different groups of children: febrile and non-febrile children, with and without convulsions. The concentration of glucose in the CSF was significantly higher in febrile children with (4.4 ± 0.1 mmol/1, mean ± SEM n = 35, p < 0.01, ANOVA, Duncan's test) and without convulsions (3.9 ± 0.2mmol/1, n = 22, p < 0.05) than in non-febrile, non-convulsive children (3.3 ±0.1 mmol/1, n = 21). In non-febrile convulsive children, the CSF glucose concentration was 3.7 ± 0.2mmol/l (n = 10). Both fever and seizures increased the CSF glucose levels (p < 0.0001 and p = 0.028, respectively, analysis of covariance). There was a linear correlation between the body temperature and concentration of glucose in the CSF (r = 0.454, p < 0.0001, n = 88, Pearson's correlation analysis). The changes in blood glucose concentrations between the groups parallelled those found in the CSF. Our results show that hyperglycaemia and an increase in the CSF glucose concentration in febrile convulsions is not explained just by a stress reaction, evoked by the seizure, as has been hypothesized earlier, but by the influence of increased body temperature as well.