Time dependency of CSF cell count, lactate and blood-CSF barrier dysfunction after epileptic seizures and status epilepticus.

BACKGROUND: This retrospective observational study was conducted to examine the temporal relationship between increased cell count, lactate concentration in cerebrospinal fluid (CSF) and blood-CSF barrier dysfunction and the onset of a seizure event. METHODS: Patients with a seizure event who underwent lumbar puncture for CSF analysis during diagnostic work-up (interindividual analysis) and those with at least one follow-up CSF analysis (intraindividual analysis) were studied. Pathologically altered parameters, such as cell count, lactate concentration, and blood-CSF barrier dysfunction as indicated by the albumin quotient (QAlb=CSF albumin/serum albumin), were examined with regard to the changes over time after seizure onset. RESULTS: An increased CSF cell count (>4/µl) was shown in 3% of our patients, whereas pathological lactate concentrations were found in 24% after single seizures and 28% after status epilepticus (SE)/recurring seizures. However, lactate levels showed a marked decrease with increasing time after an isolated seizure (p<0.0001) but not after SE/recurring seizures. Lactate levels were most frequently and significantly elevated within the first six hours after a single seizure (p<0.0001). Blood-CSF barrier dysfunction was detected in 34% after isolated seizures and in 47% after SE/recurrent seizures. Blood-CSF barrier dysfunction showed no association with latency between seizure onset and time of CSF collection. CONCLUSIONS: Changes in lactate and CSF protein concentrations are common after epileptic seizures. In contrast, CSF pleocytosis is uncommon and should prompt careful investigation for the presence of intrathecal infection or autoimmune CNS disease. Elevated lactate levels more than 6 h after the seizure event may indicate ongoing epileptic activity.

Cerebrospinal fluid changes following epileptic seizures unrelated to inflammation.

BACKGROUND AND PURPOSE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Kappa free light chains in cerebrospinal fluid to identify patients with oligoclonal bands.

BACKGROUND AND PURPOSE: The gold standard for detection of intrathecal immunoglobulin synthesis is the measurement of oligoclonal bands (OCB). In the diagnosis of multiple sclerosis, the kappa free light chains (KFLC) index has a similar sensitivity and specificity as OCB. This study investigated whether determination of the KFLC index could be used to predict the presence of OCB. METHODS: The KFLC index was determined prospectively from 295 paired serum and cerebrospinal fluid samples. KFLC were determined by nephelometry using the N Latex FLC kappa kit (Siemens Healthcare Diagnostics Products GmbH) on the BN Prospec analyzer (Siemens Healthcare Diagnostics Products GmbH) (cohort I). A cut-off value was determined using receiver operating characteristic analysis in relation to OCB positivity. These results were validated prospectively in 96 samples (cohort II) as well as retrospectively in samples of 46 patients known to be OCB positive (cohort III). We also compared the agreement of two commercially available nephelometric KFLC assays. RESULTS: In cohort I, a KFLC index of 3.61 yielded 100% sensitivity and 88% specificity. Prospective validation of this cut-off value in cohort II showed 92% sensitivity and 96% specificity. In cohort III, a sensitivity of 93% was achieved. Comparison of Siemens and Binding Site (Birmingham, UK) assays revealed good agreement (r2  = 0.86). CONCLUSIONS: The KFLC index with a cut-off value of 3.61 had high diagnostic accuracy to predict immunoglobulin G synthesis via OCB analysis. Determination of the KFLC index provided a quantitative parameter that could be used as an initial diagnostic step in inflammatory central nervous system disorders before measuring OCB.