Role of video-electroencephalography in the presurgical evaluation of patients with temporal lobe epilepsy due to mesial temporal sclerosis: A retrospective reliability study.

PURPOSE: To retrospectively examine whether prolonged video electroencephalography (vEEG) is a necessary diagnostic tool to help localize the seizure focus among patients who have evidence of mesial temporal sclerosis (MTS) on MRI and other clinical and ancillary findings of temporal lobe epilepsy.

METHODS

Seventy-nine patients with evidence of MTS on presurgical MRI testing were included in the study. Two independent epileptologists determined whether the provided workup information, including routine EEG, MRI, semiology, and neuropsychological assessment, was sufficient to localize and proceed with surgical resection or if the patient would need prolonged vEEG or potentially intracranial evaluation to localize the seizure focus. The reviewers then compared their decisions and came up with an agreed verdict for each patient. Final verdicts were then compared to the actual surgical decision.

RESULTS

There was "fair agreement" between the two epileptologists blinded to the prolonged vEEG results and actual surgical decision, with a Cohen's kappa of 0.245. After discussion, the epileptologists localized the seizure foci using the provided workup information for 40 of the 79 patients (50.6%) and required prolonged video-EEG to help localize the seizure focus for the remaining 39 patients.

CONCLUSIONS

Prolonged vEEG may be required to identify seizure foci localization in patients with evidence of mesial temporal sclerosis on MRI; however, substantial inter-rater variability (kappa = 0.245) suggests the need for standardized criteria and outcome validation before changing current practice. Further studies with surgical outcomes are warranted to develop a validated scoring system for requiring vEEG.