Investigators at Tampere University Hospital, Finland measured C-reactive protein (CRP) serum concentrations in 31 patients (mean age 34, range 6-58 years) with refractory focal epilepsy while undergoing video-EEG monitoring and compared with 80 healthy controls. CRP concentrations were significantly higher in patients with refractory focal epilepsy than in controls (3.5 vs 0.7 mg/ml, p<0.001). All 5 patients with elevated CRP had temporal lobe epilepsy (TLE)(i.e. 33% of 15 with TLE). None of 16 patients with extra-temporal lobe epilepsy had elevated CRP concentrations. Increase in CRP from baseline to a maximum level after the index seizure was dependent on the type of seizure (p=0.005). Secondarily generalized tonic-clonic seizure (SGTCS) was the most important predictor of increase in CRP level (p=0.030), whereas simple and complex partial seizures were without effect on CRP. SGTCS stimulates CRP production. Patients taking enzyme-inducing AEDs (carbamazepine or phenytoin) had higher levels of CRP than those on noninducing drugs (p=0.084, NS). Higher CPR levels were associated with lower numbers of AEDs (p<0.001), and were found in patients of older age at diagnosis and in measurements during the 24 hour video EEG (p=0.003). Baseline CRP level was not significantly associated with sex, etiology, seizure frequency, or duration of index seizure. Elevated levels of CRP in patients with refractory epilepsy emphasize the association between inflammation and epilepsy. These results suggest that a more severe seizure type (SGTCS) shows a stronger inflammatory response after an acute seizure. 
COMMENT. C-reactive protein (CRP) is produced by the liver in response to an inflammatory signal, most prominently interleukin-6 (IL-6). Blood levels of CRP may be used as a biomarker for inflammation, cardiovascular disease, dementia, and some epilepsies. The more severe the seizure, the stronger the inflammatory response and the higher the CRP level after an acute seizure. Epileptic seizures provoke a production of cytokines such as IL-6 that may in turn cause an activation of the acute phase reaction and elevation of blood CRP.