Cerebrospinal fluid changes following epileptic seizures unrelated to inflammation

Analyzing cerebrospinal fluid (CSF) is crucial in the diagnostic workup of epileptic seizures to rule out autoimmunity or infections as the underlying cause. Therefore, the description of post-ictal changes in CSF is essential to differentiate between negligible and etiopathologically relevant changes in the CSF profile.

A retrospective analysis of 247 patients newly diagnosed with epileptic seizures and CSF analysis during diagnostic workup was conducted. Patients with possible or definitive autoimmune or infectious encephalitis were excluded. CSF results were evaluated for associations with seizure types, seizure etiology and electroencephalography (EEG) findings.

An increased cell count (>4/μL) was found in 4% (n = 10), increased lactate concentration (>2.5 mmol/L) in 28% (n = 70), increased total protein (>500 mg/L) in 51% (n = 125) and a dysfunction of the blood-brain barrier in 29% (n = 71) of patients. Intrathecal immunoglobulin G production was observed in 5% (n = 12) of patients. Higher lactate concentrations were found in seizures with motor onset (P = 0.02) compared with those with non-motor onset. Patients with generalized slow activity on EEG had significantly higher lactate values (P = 0.01) and albumin quotient (P = 0.05) than those with normal EEG.

Compared with mild pleocytosis and immunoglobulin synthesis, elevated lactate and total protein concentrations as well as blood-brain barrier dysfunction are frequently found following epileptic seizures. Our data suggest that seizure semiology might impact CSF profiles. The highest lactate concentrations were found following motor-onset seizures. Our findings may help clinicians to avoid over-interpretation of minor CSF changes; however, the exclusion of alternative causes should always be carefully considered, taking into account further clinical features.